| 1. |
Chi Lu, Yoshimi Sonoda, Application of light-weighted CNN for diagnosis of internal concrete defects using hammering sound, Nondestructive Testing and Evaluation, https://doi.org/10.1080/10589759.2023.2301032, 2024.01, In the past, diagnoses of the internal defects of ageing concrete members by sound tests have relied on the ability and experience of the inspector. However, with the development of deep neural networks, building diagnosis tools without the subjective judgements of humans is feasible. In this study, sound samples are collected from a tapping sound test on concrete slab specimens with internally embedded artificial defects. Spectrograms are generated from the sound samples and used to train a light-weighted convolutional neural network (CNN). Thereafter, the performance of
the proposed CNN models at diagnosing the defects of the concrete slabs are examined and compared with convolutional autoencoder (CAE) and support vector regression (SVR). All the models performed well at distinguishing between healthy and defective concrete. Whereas noise can impair the performance of CAE and SVR, CNN is less affected, particularly when classifying sound samples with distinctive features. CNN also has other advantages: the physical area of the artificial defect can be output directly from CNN, and CNN performance is also less affected by the depth of the
artificial defect and the rebar embedded in the concrete. At increased depths, the CNN is still able to identify the defect area.. |
| 2. |
Souphavanh Senesavath, Hiroki Tamai, Chi Lu and Yoshimi Sonoda, Strengthening of RC Beams with CFC Panels for Improving Impact Resistance, Applied Sciences, https://doi.org/10.3390/app131910625, 2023.09. |
| 3. |
Yoshimi Sonoda, Chi Lu, Yifan Yin, Basic research on usefulness of convolutional autoencoders in detecting defects in concrete using hammering sound, Structural Health Monitoring, 10.1177/14759217221122296, 2022.09, Because hammering sound tests are inexpensive and can be performed easily, they are commonly used as an inspection method for examining the presence of defect areas (voids or peelings) in aged concrete structures. However, the evaluation of the health of concrete using hammering sounds depends on the subjective experience of the inspector. Therefore, there is a demand to develop a highly reliable and objective diagnostic method that is accurate and efficient. In this study, we used a convolutional autoencoder (CAE) to develop a diagnostic method that could assist the inspectors with quantitative diagnostic results of tapping sound when detecting defect areas in concrete. In particular, we verified the anomaly detection accuracy of hammering sound data of actual bridges that have deteriorated over time using the proposed CAE model.. |
| 4. |
Yoshimi Sonoda, Hiroki Tamai, Tatsuya Ifuku, Masami Koshiishi, Reinforcing effect of polyurea resin coating on RC members subjected to low-speed and medium-speed impact, Advances in Structural Engineering, 10.1117/13694332221088945, 2022.03.  |
| 5. |
Lu Chi, Yoshimi Sonoda, An Analytical Study on the Pull-Out Strength of Anchor Bolts Embedded in Concrete Members by SPH Method, Special Issue Seismic Assessment and Design of Structures, Applied Sciences MDPI, https://doi.org/10.3390/app11188526, 2021.09. |
| 6. |
Yoshimi Sonoda, Hiroki Tamai, Hirotsugu Ikeda, Seismic Performance of Dam Piers Retrofitted with Reinforced Polymer Cement Mortar, Special Issue Seismic Assessment and Design of Structures, Applied Sciences MDPI, 10.3390/app11167255, 2021.08. |
| 7. |
Hiroshi Kokuryo, Toshiyuki Horiguchi, Nobutaka Ishikawa, Kengo Hori, Yoshimi Sonoda , A Study of the Load Performance of a Steel Pipe Beam supported by Sleeve Pipes, International Journal of Erosion Control Engineering, Vol.13, No.3, 2021.02. |
| 8. |
Hiroki Tamai, Yoshimi Sonoda, John E. Bolander, Impact resistance of RC beams with reinforcement corrosion
Experimental observations, Construction and Building Materials, 10.1016/j.conbuildmat.2020.120638, 263, 2020.12, Reinforcing steel corrosion is a serious problem that may negatively impact the safety and serviceability of reinforced concrete (RC) structures. To properly maintain and manage RC structures with corroded reinforcement, it is necessary to clarify the relationship between the degree of deterioration and the remaining load capacity. Most previous studies have focused on evaluating the load-bearing capacity of RC beams with corroded reinforcement subjected to quasi-static loads. In contrast, there are relatively few studies on the behavior of corroded RC beams subjected to impact loads, as might occur during natural disasters. In this study, RC beam specimens with varying degrees of reinforcement corrosion are subjected to quasi-static and falling-weight impact load tests. Electrolytical means are employed to induce corrosion. The test results are used to evaluate: 1) the impact resistance of RC beams deteriorated by reinforcement corrosion, including the effects of repetitive impact; and 2) the differing effects of corrosion on static load-carrying performance and impact resistance. The results indicate that, for corrosion degrees higher than 10%, the impact resistance is significantly reduced and the failure mode becomes more brittle. The brittleness can be attributed to, at least in part, interactions between flexural cracking caused by the loading and preexisting damage associated with the corrosion process. Furthermore, the results reveal that reinforcement corrosion has a greater influence on impact resistance than on quasi-static load capacity.. |
| 9. |
Sittisak Jamnam, Buchit Maho, Apisit Techaphatthanakon, Yoshimi Sonoda, Doo Yeol Yoo, Piti Sukontasukkul, Steel fiber reinforced concrete panels subjected to impact projectiles with different caliber sizes and muzzle energies, Case Studies in Construction Materials, 10.1016/j.cscm.2020.e00360, 13, 2020.12, In special situations like terrorist attacks, concrete structures are occasionally subjected to impact loads such as firearms. Since concrete is brittle, it often shatters into several pieces under impact loadings. In order to alleviate this brittleness, fibers are generally incorporated into concrete. In this study, steel fiber reinforced concrete panels subjected to projectile impact loads with different geometries was investigated. The impactors in the form of bullets came in three different caliber sizes 9, 11, and 7.62 mm, providing muzzle energies of 468, 1972, and 3259 J, respectively. Hooked end type steel fibers were used at 3 vol fractions of 1–3%. The specimens were cast in square panels with dimensions of 400 × 400 mm and varying thickness from 10 to 100 mm. Each panel was subjected to a single impact at the center. Data in the form of velocity (prior to and after impact event), failure modes, and spalling diameters were collected. Results showed that four typical failure modes were commonly found in panels: perforation, scabbing, spalling, and cracking. For piercing type bullets, the thickness played an important role on the impact resistance of the panels. However, for large and blunt tip bullets, both thickness and fiber volume fraction must be considered together to provide sufficient impact resistance.. |
| 10. |
Ryuhei Tateishi, Toshiyuki Horiguchi, Yoshimi Sonoda, Nobutaka Ishikawa, Experimental study of the woody debris trapping efficiency of a steel pipe, open sabo dam, International Journal of Sediment Research, 10.1016/j.ijsrc.2020.03.011, 35, 5, 431-443, 2020.10, In recent years, the damage caused to human settlements in Japan by large woody debris (LWD) has been increasing. For example, the 2013 Izu Oshima typhoon resulted in a large number of fatalities and missing persons, and the Kagoshima Typhoon Disaster and Northern Kyusyu torrential downpour caused vast infrastructure damage due to the associated LWD. Current countermeasures for preventing LWD are insufficient to maintain the safety of residential areas. One type of protective barrier, the open sabo dam, has been constructed in Japan during the past 30 years. The primary function of open sabo dams is to block the flow of boulders, thereby also reducing sediment flow by reducing the gap size. However, because Japanese open sabo dams are designed specifically for boulder-trapping, the ability of these dams to trap LWD remains uncertain. In particular, many problems have been reported with respect to sediment trapping by driftwood with roots in an open sabo dam setting. The objective of this study was to examine the trapping efficiency of open sabo dams for LWD and sediment. The experimental approach clarified the influence of driftwood, without and with roots, on sediment trapping for a straight-channel flume. The flexible roots of the driftwood were shown to have a significant effect on the sediment trapping efficiency of the dam.. |
| 11. |
Sittisak Jamnam, Buchit Maho, Apisit Techaphatthanakon,
Yoshimi Sonoda, Doo-Yeol Yoo, Piti Sukontasukkul, Steel fiber reinforced concrete panels subjected to impact
projectiles with different caliber sizes and muzzle energies, Case Studies in Construction Materials, 13, e00360, 2020.04. |
| 12. |
Hagere Alemayehu Gibe, Hiroki Tamai, Yoshimi Sonoda, Numerical study on failure process and ultimate state of steel bearing under combined load, Heliyon, 10.1016/j.heliyon.2020.e03764, 6, 4, 2020.04, Civil engineering; Structural engineering; Earthquake engineering; Structural analysis; Structural mechanics; Pin bearing; Pin-roller bearing; Failure process; Ultimate load capacity; Bridge axis; Perpendicular bridge axis; Dead load; Uplift load; FEM. |
| 13. |
Lu Chi, Yoshimi Sonoda, An analytical approach on the perforation limit of concrete slab by a high-velocity flying object using SPH method, 構造工学論文集, https://doi.org/10.11532/structcivil.66A.996, 996-1003, Vol.66A,pp.996-1003, 2020.03. |
| 14. |
Hiroki Tamai, Sota Jinkawa, Yoshimi Sonoda, Damage evaluation and protection method of resin pipe for gas conduit subjected to impact load, International Journal of Protective Structures, 10.1177/2041419620902791, 2020.01, Medium-density polyethylene pipe has been widely introduced to low-pressure gas pipes because of its high flexibility and corrosion resistance. However, many third-party damages due to the impact of heavy equipment have been reported during the construction every year, thus, to prevent the third-party damage, materials such as high-density polyethylene and polyamide have been considered as the new gas pipe candidates. However, their impact resistance capacity under the third-party attack has not been clarified. In this study, static and impact loading experiments were conducted to compare load resistance capacities. As a result, it was revealed that the high-density polyethylene pipe and the polyamide pipe had higher static load capacity and impact resistance than the medium-density polyethylene pipe. By comparing the absorbed energy of the static test and the impact test and calculating the pseudo absorbed energy of the impact test, the evaluation formula judging the safer side of whether the penetration occurred was proposed. Furthermore, as one of the methods to protect the gas pipe, the protective effect of winding a sheet made of reinforced fiber and non-woven fabric was clarified.. |
| 15. |
LU CHI, YOSHIMI SONODA, IMPACT RESPONSE ANALYSIS OF RC SLAB WITH POLYUREA RESIN BY SPH METHOD, 13th International Conference on Shock & Impact Loads on Structures, 353-360, 2019.12. |
| 16. |
Yamazaki Kazuki, Yoshimi Sonoda, Hiroki Tamai, Hiroyuki Yamada, Masahiro Haruguchi
, Analytical Study on Dynamic Behavior of Reinforced Dam Pier under Seismic Load, Proceedings of PROTECT 2019 Structures under Extreme Loading, 2019.09. |
| 17. |
Hiroki Tamai, Yoshimi Sonoda, A Study on Impact Resistance Performance of RC Member Deteriorated by Reinforcement Corrosion, Proceedings of PROTECT 2019 Structures under Extreme Loading, 2019.09. |
| 18. |
Hiroki Tamai, Sota Jinkawa, Yoshimi Sonoda, Ayumi Nakayama, A Comparative Study on Impact Resistance of Plastic Gas Pipes with Different Materials, Proceedings of PROTECT 2019 Structures under Extreme Loading, 2019.09. |
| 19. |
Lu Chi, Yoshimi Sonoda, Hiroki Tamai, An Evaluation Method for the Impact Load Carrying Capacity of RC Beam Members under the Influence of ASR, Proceedings of PROTECT 2019 Structures under Extreme Loading, 2019.09. |
| 20. |
S. N. Mokhatar, S. S.M. Zuki, H. J. Tan, Y. Sonoda, K. Inoue, A. F. Kamarudin, M. S. Md Noh, A Fundamental Hammering Sound Test to assess the Degree of Deterioration in Reinforced Concrete Structure, 14th International Conference on Concrete Engineering and Technology, CONCET 2018
IOP Conference Series: Materials Science and Engineering, 10.1088/1757-899X/431/12/122013, 431, 12, 2018.11, Conventional hammering method is the most common used inspection tools in the industry. This method requires skilled inspector to inspect. However, it is cheap and easy to use. This research is to associate spectral analyzer together with conventional analyzer to gather quantitative data. Research was conducted on both laboratory and site testing. Laboratory specimens were created with polystyrene replicating the defects. The depths and thickness were determined to vary the degree of defects. The sound pressure produced from the impact of the hammer is then evaluated with the degree of defect. From laboratory testing, healthy mortar specimen produced higher sound pressure than defective mortar specimens. The void affected the results on the defective mortar specimen. Finishing surface (plastering) also affected the sound pressure produced. Plastering on reinforced concrete (RC) structure plays huge role in inspecting as the bonding of the plastering can affect the sound pressure produced. Conventional hammering can be associated with spectral analyzer to inspect existing RC structures. Conventional hammering can replace other expensive NDT method such as infrared thermography, GPR, and etc.. |
| 21. |
S. N. Mokhatar, Y. Sonoda, S. S.M. Zuki, A. F. Kamarudin, M. S. Md Noh, Simulation of Shear and Bending Cracking in RC Beam
Material Model and its Application to Impact, 4th International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2017
IOP Conference Series: Earth and Environmental Science, 10.1088/1755-1315/140/1/012130, 140, 1, 2018.04, This paper presents a simple and reliable non-linear numerical analysis incorporated with fully Lagrangian method namely Smoothed Particle Hydrodynamics (SPH) to predict the impact response of the reinforced concrete (RC) beam under impact loading. The analysis includes the simulation of the effects of high mass low-velocity impact load falling on beam structures. Three basic ideas to present the localized failure of structural elements are: (1) the accurate strength of concrete and steel reinforcement during the short period (dynamic), Dynamic Increase Factor (DIF) has been employed for the effect of strain rate on the compression and tensile strength (2) linear pressure-sensitive yield criteria (Drucker-Prager type) with a new volume dependent Plane-Cap (PC) hardening in the pre-peak regime is assumed for the concrete, meanwhile, shear-strain energy criterion (Von-Mises) is applied to steel reinforcement (3) two kinds of constitutive equation are introduced to simulate the crushing and bending cracking of the beam elements. Then, these numerical analysis results were compared with the experimental test results.. |
| 22. |
S. N. Mokhatar, Y. Sonoda, A. F. Kamarudin, M. S. Md Noh, S. Tokumaru, The effects of pressure dependent constitutive model to simulate concrete structures failure under impact loads, International Seminar on Mathematics and Physics in Sciences and Technology 2017, ISMAP 2017
Journal of Physics: Conference Series, 10.1088/1742-6596/995/1/012029, 995, 1, 2018.04, The main objective of this paper is to explore the effect of confining pressure in the compression and tension zone by simulating the behaviour of reinforced concrete/mortar structures subjected to the impact load. The analysis comprises the numerical simulation of the influences of high mass low speed impact weight dropping on concrete structures, where the analyses are incorporated with meshless method namely as Smoothed Particle Hydrodynamics (SPH) method. The derivation of the plastic stiffness matrix of Drucker-Prager (DP) that extended from Von-Mises (VM) yield criteria to simulate the concrete behaviour were presented in this paper. In which, the displacements for concrete/mortar structures are assumed to be infinitesimal. Furthermore, the influence of the different material model of DP and VM that used numerically for concrete and mortar structures are also discussed. Validation upon existing experimental test results is carried out to investigate the effect of confining pressure, it is found that VM criterion causes unreal impact failure (flexural cracking) of concrete structures.. |
| 23. |
Yoshimi Sonoda, Mari Okamura, Hiroki Tamai, A fundamental study on hammering sound test of deteriorated concrete structures, 6th Annual International Conference on Architecture and Civil Engineering, ACE 2018
Proceedings of the Annual International Conference on Architecture and Civil Engineering, 10.5176/2301-394X_ACE18.118, 216379, 2018.01, There are many methods available to diagnosis structural deterioration of concrete structures, the most commonly used is the hammering sound test. Though this method is inexpensive, simple and easy to use, the accuracy of it depends on the subjective sense of the inspector to distinguish defective spots from healthy spots. Thus, to construct diagnostic method of hammering sound test is very promising. In this study, not only hammering sound inspection but also specimen experiment and analysis were conducted. As a result, several feature quantities of hammering sound test are presented and their efficiency are confirmed by comparison between defective spots and healthy spot.. |
| 24. |
Hamidun Mohd Noh, Yoshimi Sonoda, Hiroki Tamai, Isao Kuwahara, An analysis of chemical-mechanical damage in reinforced concrete beam, International Journal of Integrated Engineering, 10, 4, 156-164, 2018.01, Nowadays, a major issue in the field of construction is the deterioration of reinforced concrete structures due to chemical and mechanical attacks. This deterioration directly impacts construction safety and serviceability, as well as the cost of maintenance. For the purpose of maintaining safety and serviceability, it is necessary to evaluate the durability of existing structures accurately, in order to predict the structure's deterioration and its future strength. In this study, an experiment was conducted in which the electrolytic process was carried out for several levels of corrosion. Next, a static loading test was adopted to assess the structural performance and obtain the ultimate strength of the beam. In addition, continuum damage mechanics were utilized in the analysis of damage caused by chemical and mechanical effects. Within the framework of this method, chemical damage caused by the corrosion of steel bars was considered. Then the coupling effects of chemical and mechanical damage were calculated by introducing two independent scalar damage variables into the constitutive equation. To calculate the chemical damage evolution, we carried out a diffusion process of chloride ions that impact the corrosion of steel bars in concrete, and an evaluation was conducted on an affected cross-sectional area of a steel bar. The proposed method was found to validate the experiment's results and could predict the ultimate strength under various exposure conditions. Moreover, the proposed orthotropic conditions may be carried out as an alternative to isotropic analysis in order to identify the worst-case scenario of the structure.. |
| 25. |
Hiroki Tamai, Chi Lu, Yoshimi Sonoda, An experiment study on the impact resistance of RC members with reinforcement corrosion, 6th Annual International Conference on Architecture and Civil Engineering, ACE 2018
Proceedings of the Annual International Conference on Architecture and Civil Engineering, 10.5176/2301-394X_ACE18.128, 216379, 2018.01, To evaluate the remaining service life and determine the appropriate timing and method for repair and reinforcement for the reinforced concrete (RC) structures, it is important to quantitatively evaluate the residual load capacity of RC structures deteriorated by rebar corrosion due to chloride attack or neutralization. There have been many studies on the load capacity during static loadings. However, for disaster-prone areas, the evaluation of the residual load should be conducted also against the dynamic and impact loads. In this study, RC slab specimens and RC beam specimens with reinforcement corrosion is prepared with electrolytic corrosion. To clarify the impact resistance of the RC members with rebar corrosion, a falling weight impact experiment is conducted on the RC beam specimens and a medium velocity impact test is conducted on the RC slab specimens. Based on the experimental results, the relationship between the degree of deterioration and impact resistance is clarified.. |
| 26. |
Yoshimi Sonoda, Mikihiro Kageyama, Masami Koshiishi, Kazunao Ide, Impact analysis of rc cantilever beam with polyurea resin using SPH method, 6th Annual International Conference on Architecture and Civil Engineering, ACE 2018
Proceedings of the Annual International Conference on Architecture and Civil Engineering, 10.5176/2301-394X_ACE18.113, 216379, 2018.01, Polyurea resin is one of the possible material that can absorb impact energy by their large deformability. In order to confirm the efficiency of polyurea resin for impact load, low speed weight drop test on RC cantilever beams with and without polyurea resin were performed. After that, impact behavior of them were simulated by improved SPH method and discussed with respect to shock absorbing effect of polyurea resin. Furthermore, middle speed impact test for RC slab with and without polyurea resin were also conducted. From these two kinds of experiments, it is confirmed that shock absorbing effect of polyurea resin is relatively small under low speed impact test however it becomes large under middle speed impact test. In addition, proposed analysis method was verified under low speed impact case and adequate dynamic model of polyurea resin is needed for middle speed impact problem.. |
| 27. |
Hamidun Mohd Noh, Yoshimi Sonoda, Impact of cover/bar diameter ratio to the structural performance of reinforced concrete member due to corrosion, Malaysian Construction Research Journal, 5, 3 Special issue, 145-152, 2018.01, Corrosion of steel in reinforced concrete is one of the main issues among construction stakeholders. The main consequences of steel corrosion include loss of cross section of steel area, generation of expansive pressure which caused cracking of concrete, spalling and delaminating of the concrete cover. Thus, it reduces the bond strength between the steel reinforcing bar and concrete, and deteriorating the strength of the structure. The objective of this study is to investigate the impact of c/d ratio to the structural performance of reinforced concrete member due to corrosion. A series of reinforced concrete cylinder of .100mm x 200mm, .150mm x 300mm and .200mm x 400mm with c/d ratio of 2.13, 3.45 and 4.76 was modelled consisting of 19mm diameter of reinforcement bar at the center of the cylinder. Corrosion rate of 0%, 5% and 10% of rebar corrosion is used in parametric study to assess the influence of different level of corrosion rate to the structural performance. As a result, a positive linear relationship was sketched between the increase of expansive pressure and the corrosion rate for each c/d ratio. Meanwhile, the expansive pressure is inversely proportional to the c/d ratio due to the deflection effect in the larger concrete cover is smaller compared to the lower c/d ratio which is more severe. Furthermore, the analysis shows that there is a significant effect on the failure pressure for each c/d ratio as the failure pressure of lower c/d ratio increase proportionally with the increase of c/d ratio. This study could predict the structural deterioration by numerical analysis using the c/d ratio. Hence, the findings provide a good input in designing a structure which takes into account the c/d ratio and also the corrosion level of the structure.. |
| 28. |
Tadashi Deshimaru, Shingo Tamagawa, Hiroo Kataoka, Yoshimi Sonoda, A Study on Fatigue Test Conditions for Certification of Rail Fastening Systems, International Heavy Haul Association Conference 2017, 2017.09. |
| 29. |
Yang Sun, HIROKI TAMAI, YOSHIMI SONODA, HIROTOSHI OBI, EXPERIMENTAL STUDY ON IMPACT RESISTANCE OF CORRODED RC BEAMS REINFORCED BY CFC PLATE, 12th International Conference on Shock & Impact Loads on Structures, 409-418, 2017.06. |
| 30. |
YOSHIMI SONODA, kO GOTO, AN ANALYTICAL STUDY ON THE IMPACT PENETRATION FAILURE OF A CONCRETE SLAB USING SPH METHOD, 12th International Conference on Shock & Impact Loads on Structures, 399-407, 2017.06. |
| 31. |
Tadashi Deshimaru, Shingo Tamagawa, Hiroo Kataoka, Yoshimi Sonoda, A Study on Verification Test Method for Rail Fastening Systems, Railway Engineering, 2017.06. |
| 32. |
Chi Lu, Hiroki Tamai, Yoshimi Sonoda, A Numerical Study on the Impact Resistant Capacity of RC Beams with Corroded Reinforcement, 6th International Workshop on Performance, Protection & Strengthening of Structures under Extreme Loading, PROTECT 2017
Procedia Engineering, 10.1016/j.proeng.2017.11.086, 210, 341-348, 2017.01, To evaluate the remaining service life and determine the appropriate timing and method for repair and reinforcement for the reinforced concrete (RC) structures, it is important to quantitatively evaluate the residual load capacity of RC structures deteriorated by rebar corrosion due to chloride attack or neutralization. There have been many studies on the load capacity during static loadings. However, for disaster-prone areas, the evaluation of the residual load should be conducted also against the dynamic and impact loads. In this study, to clarify the impact resistance of the RC beam members with rebar corrosion, a falling weight impact experiment is conducted on the RC beam specimen with accelerated deterioration. Based on the experimental results, the relationship between the degree of deterioration and impact resistance is clarified. To numerically simulate the rebar corrosion by FEM, FE modelling of RC beam with corroded rebar is proposed focusing on the following 3 factors related to the mass loss ratio of the rebar: the reduction of the cross-sectional area of the reinforcement is reproduced by adjusting the parameters of the rebar material; an interface element is defined to describe the reduction of the bond strength; the cracks are generated by subjecting expansion pressure to the concrete. Uneven corrosion model is introduced to simulate the actual corrosion result. By comparing the analytical result with the experimental result, it can be found that the experimental result is accurately reproduced.. |
| 33. |
Hariyadi, Satoru Munemoto, Yoshimi Sonoda, Experimental Analysis of Anchor Bolt in Concrete under the Pull-Out Loading, 3rd International Conference on Sustainable Civil Engineering Structures and Construction Materials, SCESCM 2016
Procedia Engineering, 10.1016/j.proeng.2017.01.391, 171, 926-933, 2017.01, The design of pull-out strength of anchor bolt in concrete is generally based on standards which are assumed to have a single crack failure and the uniform stress. However, in real phenomenon these assumptions are not reliable and a combination of failure modes between the cone and bond failure is commonly found. This research was conducted to analyze the failure mechanism and the strength of the anchor bolt under static pull-out load. Normal strength of concrete-mortar block and the shallow depth of anchor bolt was used in this research. The failure mode, reaction force, and concrete cone stress will be discussed and compared to the design standards. The experimental results clearly show that a combination failure mode between the cone and bond failure of anchor bolt was found, consequently the depth of the cone failure part reduced and the angle of cone slope narrowed. The cone stress and loading capacity of the experimental result is extremely lower than the design standards, which is around a half. Therefore a certain safety factor is required to guarantee the safety of anchor bolt structures.. |
| 34. |
Isao Kuwahara, Hiroki Tamai, Yoshimi Sonoda, Experimental study on impact load resistance of RC beam with corroded reinforcement, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164702004, 47, 2016.04, In Japan, many concrete bridges along the coastline have suffered corrosion due to the chloride attack from seawater and airborne salt. Therefore, now, several researches on corroded RC structures have been ongoing around the world. Especially, as a basic research, many researchers have studied on the numerical and experimental method to evaluate static load resistant capacity of RC beams with corroded reinforcements. However, there has been almost no research to evaluate impact load resistant capacity. Of course, it is important that impact load resistant capacity is clarified, if the possibility of acting of impact load including in natural disaster on corroded RC structures is dealt with. With a background like this, this paper describes an experimental investigation of the structural behavior of corroded RC beams. To be precise, in this study, RC beams with corroded reinforcement by using electrolytic corrosion method were made, and both of static loading test and repeated impact test for those RC beams were conducted in order to clarify the static and impact load resistant capacity of them. As a result, we could get some findings. At first, through repeated impact tests (which has 1.0m/s impact velocity and a 100kg steel weight), the number of impacts to the failure of corroded RC beams were less than half of healthy RC beams. It was also found that fracture pattern was completely different due to some axial cracks by corrosion. In addition, even though the corrosion rate is same level, the impact load resistant capacity reduce greatly compared to the static load resistant capacity because of the existence and pattern of cracks due to corrosion.. |
| 35. |
Hamidun Mohd Noh, Yoshimi Sonoda, Potential effects of corrosion damage on the performance of reinforced concrete member, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164702007, 47, 2016.04, Corrosion of steel in reinforced concrete is one of the most serious issues for the owners. The main consequences of this phenomenon include loss of cross section of steel area, induced the expansive pressure which caused cracking of concrete, spalling and delaminating of the concrete cover. Thus, it reduces the bond strength between steel reinforcing bar and concrete, and deteriorates the strength of whole structure. In this study, a non-linear finite element analysis was conducted to investigate the potential effects of corrosion damage. A series of corroded reinforced concrete cylinder is used in the parametric study to assess the influence of different level of corrosion to the structural performance. As a result, a clear picture of corrosive expansion was investigated and the relationship between the expansive pressure and the degree of corrosion was identified to be the important factors of the structural deterioration.. |
| 36. |
Nuràin Idris, Mitsuteru Asai, Yoshimi Sonoda, The modification of boundary treatment in the incompressible sph for pressure calculation accuracy on the solid boundary, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164702018, 47, 2016.04, The Incompressible Smoothed Particle Hydrodynamic (ISPH) is one of the particle methods and commonly used to solve some complicated physical problems including free surface flow problems. The study regarding the boundary treatment has become an active research area in the mesh-free or particle method recently for measuring the accurate and robust pressure near the boundary. The penetrations of fluid particles may be happened if the adequate pressure boundary condition on the solid boundary cannot be satisfied. In this paper, a simple boundary treatment, which can be satisfied the non-homogenous Neumann boundary condition on the solid boundary and Dirichlet condition on the water surface, is proposed. The key point of our proposed treatment is that these boundary conditions are automatically satisfied by solving a modified pressure Poisson equation. Lastly, the effectiveness and accuracy of boundary treatment proposed are then authenticated with couples of numerical analysis and compared with the experimental tests.. |
| 37. |
Yoshimi Sonoda, A numerical study on the pull-out strengths of anchor bolts embedded in concrete using the smoothed particle hydrodynamics method, 8th International Conference on Concrete under Severe Conditions - Environment and Loading, CONSEC 2016
Concrete under Severe Conditions - Environment and Loading, 10.4028/www.scientific.net/KEM.711.1111, 1111-1117, 2016.01, The strength of an anchor bolt in concrete structure under pull-out load is usually designed by three possible failure modes such as fracture of anchor bolt, cone failure of concrete and bond failure between anchor bolt and concrete. In general, the design load is considered the smallest load corresponding to the aforementioned failure mechanisms. However, unexpected failure often occurs in the anchorage zone due to the complex failure or the change of failure condition. Therefore, it is important to develop the accurate analysis method of ultimate load bearing capacity of the anchor bolt. In this study, we conducted an analytical study using Adaptive Smoothed Particle Hydrodynamics (ASPH) in order to simulate the failure process of anchorage zone and discussed the effect of embedment depth of anchor bolts on their ultimate strength.. |
| 38. |
Shahrul Niza Mokhatar, Yoshimi Sonoda, Jin Fukazawa, Application of orthotropic constitutive model incorporated with SPH to simulate tensile failure of RC beam, ARPN Journal of Engineering and Applied Sciences, 11, 4, 2614-2621, 2016.01, The responses of reinforced concrete beams subject to low velocity impact loading are simulated using orthotropic constitutive model incorporated with Smoothed Particle Hydrodynamics (SPH) method. The tensile failure of the beam is using the orthotropic constitutive equation during the softening phase on tension region, where the three principle strain components for tension (positive value) and compression (negative value) are used independently. In order to validate the proposed model, two impact cases were analyzed. The first case is simulation of simply supported beam without shear rebar using SPH and FEM. The second case is involving the comparisons of impact case of RC beam using proposed model with existing experimental tests. By adopting orthotropic constitutive equation and tensile softening algorithm defined by damage parameter, flexural cracks and shear failure can be analyzed by tracing the local stress condition.. |
| 39. |
S. N. Mokhatar, Yoshimi Sonoda, A. B.H. Kueh, Z. M. Jaini, Quantitative impact response analysis of reinforced concrete beam using the Smoothed Particle Hydrodynamics (SPH) method, Structural Engineering and Mechanics, 10.12989/sem.2015.56.6.917, 56, 6, 917-938, 2015.12, The nonlinear numerical analysis of the impact response of reinforced concrete/mortar beam incorporated with the updated Lagrangian method, namely the Smoothed Particle Hydrodynamics (SPH) is carried out in this study. The analysis includes the simulation of the effects of high mass low velocity impact load falling on beam structures. Three material models to describe the localized failure of structural elements are: (1) linear pressure-sensitive yield criteria (Drucker-Prager type) in the pre-peak regime for the concrete/mortar meanwhile, the shear strain energy criterion (Von Mises) is applied for the steel reinforcement (2) nonlinear hardening law by means of modified linear Drucker-Prager envelope by employing the plane cap surface to simulate the irreversible plastic behavior of concrete/mortar (3) implementation of linear and nonlinear softening in tension and compression regions, respectively, to express the complex behavior of concrete material during short time loading condition. Validation upon existing experimental test results is conducted, from which the impact behavior of concrete beams are best described using the SPH model adopting an average velocity and erosion algorithm, where instability in terms of numerical fragmentation is reduced considerably.. |
| 40. |
YOSHIMI SONODA, Kenta Innoue, Defect assessment of concrete structure using the self-organizing map by hammering test data, The 39th Conference on OUR WORLD IN CONCRETE & STRUCTURES
Singapore, 20-22 August 2014, 2014.08. |
| 41. |
Shinobu Sano, HIROKI TAMAI, Yoshihiko Murata, YOSHIMI SONODA, Numerical study on a thermal crack control effect of concrete structures using delayed-setting mortar, The 39th Conference on OUR WORLD IN CONCRETE & STRUCTURES
Singapore, 20-22 August 2014, 2014.08. |
| 42. |
Hariyadi, Kohei Kiyonari, Satoru Munemoto, YOSHIMI SONODA, Tensile failure mechanism of anchor bolts in concrete structures under the pull-out loading using SPH method, The 39th Conference on OUR WORLD IN CONCRETE & STRUCTURES
Singapore, 20-22 August 2014, 2014.08. |
| 43. |
Hiroki Tamai, Mariko Uno, Yoichi Yuki, Yoshimi Sonoda, Toshihiro Kasugai, A study on the effectiveness of energy absorbing rubber in pin-fixed cable restrainer of a bridge, International Journal of Protective Structures, 10.1260/2041-4196.5.2.219, 5, 2, 219-238, 2014.06, The Japanese specifications for highway bridges require unseating prevention devices to be installed on bridges as necessary. Recently, a new type of cable restrainer was developed where the assembly allows the cable to rotate without restriction on the brackets' mounting angle. Cylindrical rubber pieces are inserted around pins to absorb impact forces. However, no standard design method has been established for the shock absorbers so far. This paper presents the impact-resisting characteristics of a pin-fixed cable device; design indications for shock absorbers were acquired based on the results of impact tests on bracket models of actual restrainers. The results showed that the pin-fixed restrainers had sufficient impact resistance for all tested sizes and that the maximum impact load showed consistent trends. Finite element analysis was also performed on the device assuming hyper-elastic bodies for rubber pieces. The numerical results sufficiently represented the impact response trend obtained from the experimental results.. |
| 44. |
N. Ishikawa, N. Chouw, Y. Sonoda, Preface
A special issue on performance based design of protective structures, International Journal of Protective Structures, 10.1260/2041-4196.5.2.i, 5, 2, i, 2014.06. |
| 45. |
Satoru Munemoto, Yoshimi Sonoda, An analytical study on dynamic strength evaluation of perfobond strip shear connectors, 8th International Symposium on Impact Engineering, ISIE 2013
Proceedings of the 8th International Symposium on Impact Engineering, 10.4028/www.scientific.net/AMM.566.179, 179-184, 2014.01, In this paper, we conducted static push-out simulations of perfobond shear connectors (PBL) using SPH (Smoothed Particle Hydrodynamics), and validated their static strength and failure mechanism. In order to express hydrostatic pressure dependency of concrete in the analysis, The Drucker-Prager criteria with plane cap model and damage concept caused by compression fracture were applied. Appropriateness of constitutive model for concrete was confirmed on their static behaviors comparing with triaxial compression tests. Secondly, dynamic push-out test simulations were conducted using this model. The influence of input load velocity on strength and failure mechanism of perfobond shear connectors was examined.. |
| 46. |
N. M. Amin, M. Asai, Y. Sonoda, Application of a model order reduction method based on the Krylov subspace to finite element transient analysis imposing several kinds of boundary condition, 9th World Congress on Computational Mechanics, WCCM 2010, Held in Conjuction with the 4th Asian Pacific Congress on Computational Mechanics, APCOM 2010
IOP Conference Series: Materials Science and Engineering, 10.1088/1757-899X/10/1/012118, 10, 1, 2014.01, Model order reduction (MOR) via Krylov subspace (KS-MOR) is one of projection-based reduction method for spatially discretized time differential equation. This paper presents a treatment of KS-MOR incorporating with finite element method for structure dynamics. KS-MOR needs basis vectors for the projection into Krylov subspace. In this context, Arnoldi and/or Lanczos method are typical techniques to generate basis vectors, and these techniques requires the information of right hand side (RHS) vector, which is the loading pattern vector in structure dynamics. In this study, we propose a treatment of Dirichlet boundary problem by generating an equivalent blocked system equation including three RHS vectors. In order to solve the multiple RHS vector problem, Block Second Order Arnoldi (BSOAR) is utilized in this paper. After projection, time integration of the projected small system equations was performed by the conventional Newmark-β method. In order to show the performance of KS-MOR, several numerical simulations are conducted. The numerical results show less than 1% of the original degrees of freedoms (DOFs) are necessary to get the accurate results for all of our numerical examples, and the CPU time is less than 2% of the conventional FE calculation.. |
| 47. |
Seong Bong Cheon, Masuhiro Beppu, Yoshimi Sonoda, Masaharu Itoh, Failure behavior and numerical simulation of the local damage of ultra high strength fiber reinforced concrete subjected to high velocity impact, 8th International Symposium on Impact Engineering, ISIE 2013
Proceedings of the 8th International Symposium on Impact Engineering, 10.4028/www.scientific.net/AMM.566.205, 205-210, 2014.01, This study presents the local damage of ultra high strength fiber reinforced concrete plates. Impact test of the reinforced concrete plates using two different short fibers are conducted to examine the failure behavior and impact resistant performance. Material models are discussed and proposed by simulating the high speed tri-compressive and uni-tensile tests. Numerical simulations of the impact tests are carried out. Numerical results show good agreements with the test results.. |
| 48. |
Yoshimi Sonoda, Present status and future problems on the impact resistance performance design of civil engineering protective structures, 8th International Symposium on Impact Engineering, ISIE 2013
Proceedings of the 8th International Symposium on Impact Engineering, 10.4028/www.scientific.net/AMM.566.10, 10-25, 2014.01, There are many civil engineering structures that have different systems and required functions. Their design methods do not have consistent design concepts. Thus, it has been pointed out the necessity of universal concepts on assumed external actions and risk for various structures and on the required level of safety. In order to meet those demands, a research committee as part of Japan Society of Civil Engineers summarizing the basic concepts of impact resistance design. This paper introduces several design methods of structures subjected to impact loads, and presents the current status and remaining issues of establishing new performance-based design methods.. |
| 49. |
Mariko Uno, Hiroki Tamai, Yoichi Yuki, Yoshimi Sonoda, Toshihiro Kasugai, A study on the impact resistance of pin fixed cable restrainers for bridges, 10th International Conference on Shock and Impact Loads on Structures
10th International Conference on Shock and Impact Loads on Structures 2013, 471-480, 2013.01, The Japanese Specification for Highway Bridges requires the installation of unseating prevention device on bridges identified as necessary. Recently, a new type of cable restrainer was developed, whose assembly allows the cable to rotate and creates no restriction to their brackets' mounting angle. Cylindrical rubbers are inserted around pins to absorb impact forces. However, no standard design method of the shock absorber has been established yet. This paper presents the study of the impact resisting characteristics of the pin-fixed cable device with a goal of developing the appropriate design method of the shock absorbing rubbers by conducting impact load tests on bracket models of the actual restrainers. As a result, it was observed that pin fixed restrainer has sufficient impact resistance and that there are some trends with maximum impact load. We have also conducted FE analyses on the device assuming the hyperelastic behaviour of three-parameter Mooney-Rivlin model. The analyses could nearly demonstrate the impact response trend obtained from the conducted experiments.. |
| 50. |
Satoru Munemoto, Yoshimi Sonoda, An analytical study on the dynamic strength of perforrated steel plate shear connectors, 10th International Conference on Shock and Impact Loads on Structures
10th International Conference on Shock and Impact Loads on Structures 2013, 433-440, 2013.01, The perforated steel plate shear connectors (PBL) are one of the best joint part for composite structure because they have excellent ultimate shear strength and durability performance. In fact, many experimental studies have been already carried out on the static push-out and pullout strength of PBL with transverse reinforcement and several design formula for static load have already been proposed. However, all of them are valid only for the same concrete failure type in their experiment. So there is no design formula for arbitrary failure type. Moreover it is pointed out that failure behaviour of concrete subjected to dynamic load is generally different from the behaviour under the static load. Therefore we need to grasp the influence of loading speed on the strength of PBL. In this paper, to establish a general evaluation method of their ultimate strength for an arbitrary condition, the analyses of PBL using SPH method are conducted and we investigate their load bearing capacity and failure mechanism. At first, both effects of tensile failure and compression failure in the load bearing capacity of PBL are considered using simple model. Secondly, static push-out test are simulated by SPH analysis and the applicability of SPH is confirmed. Finally, the load bearing capacity of PBL under dynamic load are simulated and the influence of loading speed can be predicted.. |
| 51. |
Hiroki Tamai, Seongbong Cheon, Satoshi Goya, Yoshimi Sonoda, Case study of damage of pc bridge by vehicle collision and its numerical analysis, 10th International Conference on Shock and Impact Loads on Structures
10th International Conference on Shock and Impact Loads on Structures 2013, 451-460, 2013.01, Accidental collisions occur frequently between bridge superstructures and over-height vehicles passing under the bridges. In order to keep the damaged bridge in a serviceable state, it is important to conduct quantitative evaluation of its damage level and residual performance. In this study, we performed FE simulation of an actual collision accident between PC girder and container truck, and confirmed that the simulation reproduced the condition of damage from the actual incident such as cracks and deformation. In addition, we conducted the collision analyses assuming various collision cases and also static vertical loading analyses of PC girder received collision. The analyses elucidate the effect of collision speed, collision angle, gross vehicle weight on the damage of PC girder. Based on results of each analysis, the correlation of damage and residual performance is assessed.. |
| 52. |
Yoshimi Sonoda, Hiroki Tamai, First draft of performance-based design code for Japanese protective structures, IAPS Forum on Recent Research Advances on Protective Structures
Advances in Protective Structures Research
IAPS Special Publication 1 - Proceedings of the IAPS Forum on Recent Research Advances on Protective Structures, 305-330, 2012.11, This chapter introduces a commission report on the performance-based design concept for protective structures under an impact load by subcommittee activities of the Japan Society of Civil Engineers. Although definite prescription and procedure of design are not involved, fundamental philosophy on the performance design for structures under an impact load is discussed. In addition, several important points to notice on the evaluation of structural performance by numerical analysis or impact experiment are indicated. From these initial trials, JSCE committee will continue to revise them and improve their degree of completion.. |
| 53. |
Yoshimi Sonoda，Shahrul Niza Bin Mokhtar，Shoichiro Tokumaru, ELASTIC PLASTIC IMPACT RESPONSE OF BEAM ELEMENT SUBJECTED TO LOW VELOCITY IMPACT LOAD USING SPH METHOD, 土木学会論文集A2（Vol.68), 応用力学論文集 （Vol.15）, 373-381, 2012.08. |
| 54. |
Hiroki Tamai and Yoshimi Sonoda, A Numerical Study on Impact Damage Assessment and Dynamic Behaviour of Concrete Bridges by Pounding Effect, International Journal of Protective Structures, Volume 3, Number 2, pp.147-160, 2012.06. |
| 55. |
Hiroki Tamai, Yoshimi Sonoda, A numerical study on impact damage assessment and dynamic behaviour of concrete bridges by pounding effect, International Journal of Protective Structures, 10.1260/2041-4196.3.2.147, 3, 2, 147-160, 2012.06, The South Hyogo prefecture earthquake indicated that various kind of damage was incurred under severe ground motion. Some of the reported damage cases are caused by pounding between bridge girders and between a superstructure and an abutment. To establish the reasonable and safe seismic design for bridges, it is necessary to evaluate the damage level of bridge abutment under impact of bridge girder and to clarify dynamic behaviour of whole bridge under pounding. So the main objective of this study is to evaluate the damage level of an abutment by pounding. To achieve this, impact response analyses of pounding effect were conducted by using 3-dimensional FEM. Furthermore, to clarify dynamic behavior of whole bridge under pounding, frame analyses were conducted.. |
| 56. |
Mitsuteru Asai, Abdelraheem M. Aly, Yoshimi Sonoda, Yuzuru Sakai, A stabilized incompressible SPH method by relaxing the density invariance condition, Journal of Applied Mathematics, 10.1155/2012/139583, 2012, 2012.06, A stabilized Incompressible Smoothed Particle Hydrodynamics (ISPH) is proposed to simulate free surface flow problems. In the ISPH, pressure is evaluated by solving pressure Poisson equation using a semi-implicit algorithm based on the projection method. Even if the pressure is evaluated implicitly, the unrealistic pressure fluctuations cannot be eliminated. In order to overcome this problem, there are several improvements. One is small compressibility approach, and the other is introduction of two kinds of pressure Poisson equation related to velocity divergence-free and density invariance conditions, respectively. In this paper, a stabilized formulation, which was originally proposed in the framework of Moving Particle Semi-implicit (MPS) method, is applied to ISPH in order to relax the density invariance condition. This formulation leads to a new pressure Poisson equation with a relaxation coefficient, which can be estimated by a preanalysis calculation. The efficiency of the proposed formulation is tested by a couple of numerical examples of dam-breaking problem, and its effects are discussed by using several resolution models with different particle initial distances. Also, the effect of eddy viscosity is briefly discussed in this paper.. |
| 57. |
S. Munemoto, Yoshimi Sonoda, An analytical study about dynamic failure mechanism of anchor bolts embedded in concrete, 10th International Conference on Advances in Discontinuous Numerical Methods and Applications in Geomechanics and Geoengineering, ICADD 10
Proceedings of the 10th International Conference on Advances in Discontinuous Numerical Methods and Applications in Geomechanics and Geoengineering, ICADD 10, 387-392, 2012, Many bridges were seriously damaged by the Higashi Nihon Earthquake Disaster on March 11, 2011. Especially, bridge restrainer systems on the concrete pier were failed due to the anchorage zone's fracture. In general, dynamic failure of concrete is quite different from static failure thus we have to consider of it and evaluate the possibility of brittle failure. In this paper, we conducted impact failure patterns such as corn failure and bond failure of anchor bolt embedded in concrete using the bond failure criteria and the strain rate effect of concrete. Consequently, proposed method could simulate dynamic failure of anchor bolt in the bridge restrainer system.. |
| 58. |
Hiroki Tamai, Yoshimi Sonoda, Yuichirou Kawabata, Makoto Shinozaki, A numerical approach for damage evaluation of RC slab under single and repeated impact loading, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 643-651, 2011.12, Dynamic behavior of RC beam under single impact loading has been studied by many researchers in recent years. However some RC protective structures such as RC caisson breakwater wall are subjected to not only single impact but also repeated impact loading in in-service period. So, it is important to clarify the damage condition of RC member under repeated impact loading. We have studied cumulative damage of RC beam under repeated impact loading by using numerical technique. In that previous study, to evaluate the damage condition and residual performance of RC beam under repeated impact loading, we have proposed the evaluation method of residual performance based on cumulative damage models. As a result, it is found that the cumulative damage and residual displacement of RC beam could be properly evaluated by using our proposed method. Although our proposed method has been verified for RC beam under repeated impact loading, the validity and accuracy for RC slab have not been thoroughly studied. The main objective of this study is to quantitatively evaluate the dynamic behavior, the impact failure mechanism and the residual performance of RC slab subjected to repeated impact loading. From the viewpoint of the impact-resisting design of RC caisson breakwater wall covered with wave-dissipating blocks, at first, structural behavior and damage distribution of the RC slabs subjected to repeated impact loads were investigated through falling weight impact loading tests. Second, numerical approaches for damage evaluation of RC slab under single and repeated impact loading (low velocity impact) were conducted by using proposed method.. |
| 59. |
Abdelraheem M. Aly, Mitsuteru Asai, Yoshimi Sonoda, A study of violent water induced impact problems using ISPH method, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 217-224, 2011.12, In this study, violent water induced impact problems are simulated by using incompressible SPH (ISPH) method. In the framework of ISPH method, there are several models, which have different source term in their pressure Poisson equation. The conventional source terms are velocity divergence free formulation called by "Truly incompressible SPH model" and density invariance formulation. In addition, we have proposed a relaxed density invariance formulation incorporated with divergence free term. This formulation is called 'stabilized ISPH' in this paper. Boundary condition using dummy particles with slip condition is introduced to prevent penetration and adjust wave velocity and profile compare to experimental results. The same formulation of the stabilized ISPH including the turbulence model is applied into the impact pressure evaluation for inclined dam break in two and three dimensions. Comparison between the proposed model and experimental results is performed and it has a reasonable agreement.. |
| 60. |
Yoshimi Sonoda, Yoshihiro Hata, Kazuki Fukunaga, Analytical study on impact response characteristic of wire ring net system by using the concept of particle method, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 605-613, 2011.12, In Japan, there are a numerous steep mountainous areas and severe seasonal heavy rainfall is common. Thus, rock-fall accidents occur in mountain regions annually. In order to protect an arterial road, the urban areas and human life from rock-fall accidents, various protective structures had been constructed. Previously, most of them have been made of reinforced concrete such as the Rock Sheds. However, they require huge construction costs and impair the surrounding landscape. Hence, new economical protective structures have been considered for a long time. From these needs, several high-energy absorption rock-fall nets have been developed. Some of them have specialized shock absorbing devices or specialized columns with plastic rotation capacity. Wire frame structures (called the wire ring net system) are composed of several interconnected wire rings of about 30 cm in diameter and are predominantly used in Europe. Because these structures can absorb large kinetic energy of a falling rock due to their deformation capacity, they are introduced from Europe as highly-effective structures. The wire ring net system is composed of many parts (wire ring, wire rope, supporting post, brake system, etc), and does not require large bases due to its light-weight. However, there is no analysis method that can calculate their impact response (dynamic behaviour and energy absorbing capacity), and has been only confirmed by full-scale falling weight tests. Although, there are several cases that evaluate the performance by similar testing in Japan, the test condition is limited by restriction of test station and costs. Therefore, this study aims at simulating the impact response of wire ring net system by using the concept of particle method.. |
| 61. |
Mitsuteru Asai, Hiroki Iida, Norliyati M. Amin, Yoshimi Sonoda, Fast dynamic solver for the design of bridge using a model order reduction, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 225-234, 2011.12, A model order reduction via Krylov subspace has been utilized as a booster of the finite element analysis in this paper. In the seismic design of structures, low frequency responses up to about 20Hz should be accurately predicted. A stepwise iterative frequency response analysis is utilized to evaluate an effective reduced order to maintain the accuracy at the target frequency range. In the frequency analysis, simple error estimation is performed to check the comparison is supported by the Moment Matching (MM), which is one of the important approximation properties of the KS-MOR. In the numerical example, a 3D bridge model with different bearing system was solved to show performance of KS-MOR. One of the bearing system is classical steel hinge, the other is steel laminated rubber bearing. The KS-MOR can apply to the general dynamic structure analysis including the damping matri. The efficiency in the CPU time is about 20-30 times faster than the conventional FEM calculation.. |
| 62. |
Shahrul Niza Mokhatar, Yoshimi Sonoda, Shoichiro Tokumaru, Impact response simulation of mortar beam using ASPH method, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 481-490, 2011.12, In this paper, an Adaptive Smoothed Particle Hydrodynamics has been utilized in order to simulate the impact response of reinforced mortar beam subjected to low velocity impact loading. Drucker-Prager (DP) with Plane-Cap (PC) yield surface is assumed for the mortar, and shear strain energy criterion (Von-Mises) is applied for steel reinforcement. Dynamic Increase Factor (DIF) has been employed for the effect of strain rate (SR) on the mortar and steel reinforcement. The constitutive equation of PC model is employed on compression, while, orthotropic constitutive equation due to the damage effect is considered on tension. Shear cracking, bending cracking and compressive behavior of the beam were evaluated by using displacement-time histories as well as overall failure mode. The investigations enabled a better understanding of the behavior of beam elements under low velocity impact loads and it is confirmed that this numerical methods give good agreement with experimental results.. |
| 63. |
Yoshimi Sonoda, Tat Seng Lok, Preface, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, iv, 2011.12. |
| 64. |
Yoshimi Sonoda, Yoshihiro Hata, Kazuki Fukunaga, Impact Response Analysis of Wire Ring Net System using the Concept of Particle Method, Proceedings of PROTECT 2011 Structures under Extreme Loading , 2011.08. |
| 65. |
Yoshimi Sonoda, Shoichirou Tokumaru, Jin Fukazawa, A Study on the Estimation of Failure Mode in Impact Analysis using SPH Method, Proceedings of PROTECT 2011 Structures under Extreme Loading , 2011.08. |
| 66. |
Hiroki Tamai, Yoshimi Sonoda, Numerical Studies on Cumulative Damage of RC members under Repeated Impact Loading, Proceedings of PROTECT 2011 Structures under Extreme Loading , 2011.08. |
| 67. |
Yoshimi Sonoda, Shoichirou Tokumaru, Jin Fukazawa, A study on the estimation of failure mode in impact analysis using SPH method, 3rd International Workshop on Performance, Protection and Strengthening of Structures under Extreme Loading, PROTECT2011
Performance, Protection and Strengthening of Structures under Extreme Loading, 10.4028/www.scientific.net/AMM.82.332, 332-337, 2011.08, This paper proposes an analysis algorithm that can appropriately distinguish shear failure from bending failure of an RC beam under impact load, by using the SPH method. As structural members, beams generally fail by one of two modes: bending failure caused by excessive bending deformation of the member, and shear failure caused by shear crack growth, leading to rapid destruction at an angle in the web. In this study, to calculate the failure behavior accurately in the local stress field in which shear stress prevails such as when a shear crack occurs, an orthotropic constitutive equation is used. This equation is derived by applying the integrity tensor proposed by Ignacio Carol, Egidio Rizzi and Kasper William, to the usual SPH method. This operation is also extended to the tensile softening characteristic of concrete material. The results confirm that the failure behavior of RC beams under a wide range of conditions can be analyzed accurately by using the proposed algorithm.. |
| 68. |
Y. Sonoda, Y. Hata, K. Fukunaga, Impact response analysis of wire ring net system using the concept of particle method, 3rd International Workshop on Performance, Protection and Strengthening of Structures under Extreme Loading, PROTECT2011
Performance, Protection and Strengthening of Structures under Extreme Loading, 10.4028/www.scientific.net/AMM.82.446, 446-451, 2011.08, In Japan, there are many steep mountainous areas and we have local severe rain in the season, thus rock-fall accidents occur in mountain regions year after year. In order to protect an arterial road and the urban areas from the rock-fall accidents, various protective structures had been already constructed. However most of them are made of reinforced concrete and they require huge construction cost. Hence a new economical protective structure has been expected for a long time. From these needs, several high-energy absorption rock-fall nets have been developed. Some of them have specialized shock absorbing device or specialized column which has plastic rotation capacity. On the one hand, wire frame structure (called the wire ring net system) that is composed of interconnected many wire rings of about 30 cm in diameter are predominant in Europe. Because these structures can absorb large kinetic energy of a falling rock due to their deformation capacity, they are introduced from Europe as the highly-effective structures. The wire ring net system is composed of many parts (wire ring, wire rope, supporting post, etc), and it does not require large bases due to its light weight. However, there is no analysis method that can calculate their impact response (dynamic behaviour and energy absorbing capacity), and it has been only confirmed by the full-scale falling weight tests. Although, there are several cases that evaluate the performance by same tests in Japan, the test condition is limited by restriction of test station and its cost. Therefore, this study aims at simulating the impact response of wire ring net system by using the concept of particle method. The following conclusions are obtained from this study. 1) The proposed method can simulate the impact response of the wire ring net system. 2) Fracture of the wire ring net is predicted applying critical strain limit for the material.. |
| 69. |
Hiroki Tamai, Yoshimi Sonoda, Numerical studies on cumulative damage of RC members under repeated impact loading, 3rd International Workshop on Performance, Protection and Strengthening of Structures under Extreme Loading, PROTECT2011
Performance, Protection and Strengthening of Structures under Extreme Loading, 10.4028/www.scientific.net/AMM.82.320, 320-325, 2011.08, We have tried to develop the simple FE analysis method based on continuum damage mechanics to quantitatively evaluate the impact behaviour and the cumulative damage of RC beam under repeated impact loading. As a result, it has been found that the cumulative damage and residual displacement of RC beam under repeated impact load can be properly evaluated, but the crack propagation cannot be evaluated by using the proposed method. This paper presents the following matters: (1) Numerical investigation on the impact behaviour and cumulative damage of RC beam under repeated impact loading by using the proposed method. (2) Numerical investigation of the relationship between cumulative kinetic energy of repeated impact loading and cumulative damage of RC members. (3) Investigation on improved points of our existing proposed method to evaluate the crack path of RC member under repeated impact.. |
| 70. |
Satoru Munemoto, Yoshimi Sonoda, An analytical study about dynamic failure mechanism of anchorage zone of cocrete embedded anchor bolt, 9th International Conference on Shock and Impact Loads on Structures
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures, 501-506, 2011, Many bridges were seriously damaged by the Higashi Nihon Earthquake Disaster on March 11, 2011. Especially, bridge restrainer systems on the concrete pier were failed due to the anchorage zone's fracture. In general, dynamic failure of concrete under impact force loading is quite different from static failure. However, number of studies about damage mechanism caused by impact force between concrete and anchor bolts is few. Therefore, for the purpose of prevention a bridge restrainer system from collapsing by unexpected impact force, it is very important to consider of dynamic failure of concrete and evaluate the possibility of brittle failure. In this paper, in order to grasp impact failure condition such as corn failure and bond failure of anchor bolt embedded in concrete, we conducted dynamic pullout test with 3D FE analysis. In particular, to confirm the validity of FE analysis, at first we checked failure mechanism of anchor bolt embedded in concrete and compared the strength of them with experimental result in the static pullout test. Next, dynamic pullout simulations using the bond failure criteria and the strain rate effect of concrete are examined. Consequently, proposed method could simulate dynamic failure of anchor bolt in the previous experiments.. |
| 71. |
Mitsuteru Asai, Yoshiyuki Kimura, Yoshimi Sonoda, Yasushi Nishimoto, Yoshio Nishino, Constitutive modeling for texture reinforced rubber by using an anisotropic visco-hyperelastic model, Doboku Gakkai Ronbunshuu A, 10.2208/jsceja.66.194, 66, 2, 194-205, 2010.12, Fabric reinforced rubber shows an anisotropy and viscosity in wide strain range. In this paper, an anisotropic visco-elastic model based on Mooney-Rivlin model is developed for fabric reinforced rubber. Anisotropy is introduced, in this constitutive model, by using a structure tensor that shows direction of reinforced fiber. A new strain energy density function for anisotropic elasticity is proposed to improve accuracy associated with shear behaviors. After developing an elastic model, an anisotropic viscosity is modeled by a kind of Maxwell viscosity model at large strains. In addition to the development of constitutive model, a simple fracture prediction method, which refers to the finite element solution incorpolated with our proposed constitutive model, is proposed. Finally, our proposed constitutive model and fracture prediction method are validated with comparisons of uni-axial tension tests with fabric reinforced rubber.. |
| 72. |
J. Fukazawa, Y. Sonoda, A fundamental study on the SPH method application for impact response of RC structural members, 9th International Conference on Analysis of Discontinuous Deformation, ICADD
Analysis of Discontinuous Deformation
New Developments and Applications, 10.3850/9789810844554-0138, 495-504, 2010.11. |
| 73. |
Yoshimi SONODA, Yoshihiro HATA and Kazuki FUKUNAGA, Impact Response Analysis of Flexible Rock-fall Fence using the improved SPH Method, Proceedings of the first international conference of protective structures, 2010.10. |
| 74. |
Yoshimi SONODA, Satoru MUNEMOTO, 3-DIMENSIONAL IMPACT FAILURE SIMULATION OF RC BEAM UNDER THE FALLING WEIGHT COLLISION, 7th International Symposium on Impact Engineering, 2010.07. |
| 75. |
Yoshimi Sonoda, Masashi Suezaki and Kazuki Fukunaga, An analytical simulation on the impact behavior of flexible rock-fall fence using the SPH method
, Proceedings of the First Makassar International Conference on Civil Engineering, 2010.03. |
| 76. |
Yoshimi Sonoda, ANALYTICAL STUDIES ON THE CRASHWORTHINESS
OF STEEL DERAILMENT STOPPER, 8th International Conference on Shock & Impact Loads on Structures, 2009.12. |
| 77. |
Yoshimi Sonoda, Ayumi Nakayama, Akane Miyoshi, Naotsugu Yoshida, A fundamental study on diagnostic characteristics of the rotary hammering test, Doboku Gakkai Ronbunshuu A, 10.2208/jsceja.65.514, 65, 2, 514-522, 2009.12, The rotary hammering test is a way that could improve inspection accuracy and efficiency of conventional hammering test. This study is to examine diagnostic capability by means of the experiment with concrete specimens and the acoustic analysis based on finite element method. From experimental and analytical results of the rotary hammering test for concrete specimens, the influences of defect condition on sound pressure characteristics are figured out. In addition, it is confirmed that acoustic analysis simulates the experiment well.. |
| 78. |
Jin FUKAZAWA, Yoshimi SONODA
, A fundamental study on the SPH method application for impact response of RC structural members, Proceedings of the 9th International Conference On Analysis Of Discontinuous Deformation, 2009.11. |
| 79. |
Yoshimi Sonoda, Jin Fukazawa, A fundamental study on SPH method accuracy for elastic plastic impact response of RC beam, INTERNATIONAL WORKSHOP ON STRUCTURES RESPONSE TO IMPACT AND BLAST, CD-ROM, 2009.11. |
| 80. |
Yoshimi SONODA, Satoshi MUNEMOTO, Shota FUCHIGAMI, Analytical Studies on the Crashworthiness Evaluation of Train Derailment Stopper
, Proceedings of PROTECT 2009 Structures under Extreme Loading , 2009.08. |
| 81. |
Hiroki TAMAI, Yoshimi SONODA
, A Numerical Study on Evaluation of Residual Performance of RC Beam under Repeated Impact Load
, Proceedings of PROTECT 2009 Structures under Extreme Loading , 2009.08. |
| 82. |
Yoshimi SONODA, Masashi SUEZAKi, Jin FUKAZAWA, A Fundamental Study on SPH Method Applicability for Impact Analysis of RC Beam
, Proceedings of PROTECT 2009 Structures under Extreme Loading , 2009.08. |
| 83. |
Yoshimi Sonoda, Analytical studies on the crashworthiness of steel derailment stopper, 8th International Conference on Shock and Impact Loads on Structures
Proceedings of the 8th International Conference on Shock and Impact Loads on Structures, 99-111, 2009, Recently, the risk of derailment accident caused by great earthquake is pointed out in Japan. If bullet trains derail and collide against structures at high-speed, unimaginable catastrophic accident would occur. From these circumstances, the steel derailment stopper is proposed as one of the effective measures. However, collision between a rotating wheel and steel derailment stopper become extremely complex phenomenon. Therefore, there is no design concept for the preventive device against derailment accident. This study aims at evaluating crashworthiness of the steel derailment stopper using 3-D elasto-plastic FE analysis. In FE analysis, both target train and steel derailment stopper are modeled assumed as elasto-plastic body and to evaluate precise impact responses of collision wheel and derailment stopper, dynamic contact condition is employed. As each parts of derailment stopper is connected by steel bolt and overall structure is installed on the concrete roadbed, fundamental load capability of steel stopper is investigated by impact analysis that considered fracture possibility of steel bolt and concrete roadbed. After that, influences of impact velocity and incident angle on the crashworthiness of steel derailment stopper are examined by numerical analyses. It is found that critical damage such as cone fracture of concrete roadbed could not be occurred. Furthermore, according to vehicular crash simulations, it is confirmed that steel derailment stopper could withstand a crash of train and alter their trajectory appropriately.. |
| 84. |
Hiroki Tamai, Yoshimi Sonoda, A numerical study on evaluation of residual strength of rc member under repeated impact load, Doboku Gakkai Ronbunshuu A, 10.2208/jsceja.64.915, 64, 4, 915-925, 2008.12, To evaluate the impact behavior and the residual strength of RC protective structure under repeated impact load is essential for building of performance based design method of protective structure.In this study, damage condition of RC beam under single impact load was clarified by using Lemaitre's damage model, which can evaluate stiffness degradation of damaged materials for unloading/reloading. Further, a new cumulative damage model was proposed. By using the model, the residual strength and allowable impact condition were evaluated based on cumulative damage level of RC beam under repeated impact load.. |
| 85. |
Hiroki Tamai, Yoshimi Sonoda, A study on impact response analysis of RC beam using damage model, Doboku Gakkai Ronbunshuu A, 10.2208/jsceja.63.411, 63, 3, 411-422, 2007.12, The impact responses of steel and reinforced concrete (RC) beams were previously analyzed. It was found that the decrease in the stiffness of concrete is a key feature to analyse RC beam. Consequently, introducing the damage model, analytical solutions are improved, and the applicability is demonstrated. Further, a new model is developed, estimating the residual impact resistance. Thus, the impact response of RC beam under cyclic loading is clarified.. |
| 86. |
Jin FUKAZAWA, Yoshimi SONODA, Masamichi SOGABE, Numerical Simulation On The Impact Response Characteristics of Derailment Stopper Using 3D FE Analysis
, Proceedings of PROTECT 2007 Structures under Extreme Loading , 2007.08. |
| 87. |
Masafumi SHIMOZONO,Yoshimi SONODA, Hiroki TAMAI
, A Fundamental Study on the Impact Response of Rubber Fender Considered Strain Rate Effect
, Proceedings of PROTECT 2007 Structures under Extreme Loading , 2007.08. |
| 88. |
Hiroki TAMAI, Yoshimi SONODA, Keiichi GOTOU, Yukihide KAJITA, A Numerical Study On Impact Damage Assessment Of PC Box Girder Bridge By Pounding Effect, Proceedings of PROTECT 2007 Structures under Extreme Loading , 2007.08. |
| 89. |
Eiki Yamaguchi, Shozo Nakamura, Koji Hirokado, Chihiro Morita, Yoshimi Sonoda, Toshihiko Aso, Hiroshi Watanabe, Kohei Yamaguchi, Kaname Iwatsubo, Performance of weathering steel in bridges in kyushu-yamaguchi region, Doboku Gakkai Ronbunshuu A, 10.2208/jsceja.62.243, 62, 2, 243-254, 2006.12, Many weathering steel bridges have been constructed in recent years. However, the performance of the steel in those bridges is not well traced and so little known. Against this background, "Committee on the Performance of Weathering Steel Bridges in Kyushu-Yamaguchi Region" in Kyushu Association for Bridge and Structural Engineering (KABSE) , conducted the filed study of performance of weathering steel in bridges in the region. This paper describes the result of this study, based on which the factors that may influence the rust development are also discussed.. |
| 90. |
TAMAI Hiroki, SONODA Yoshimi, HAMAMOTO Tomohisa, A Numerical Study on the Damage Evaluation of Abutment by Pounding of Bridge Girder, Proceedings of International Conference on Bridge Engineering, Abstract:pp.217
Full Paper: in CD-ROM, 2006.11. |
| 91. |
KUDO Natsuko, SONODA Yoshimi, HINO Shinichi, TESHIMA Yasuhiro, An Analytical Study on the Mechanical Characteristic of Joint System in Prestressed Composite Truss Bridge, Proceedings of International Conference on Bridge Engineering, Abstract:pp.203
Full Paper: in CD-ROM, 2006.11. |
| 92. |
Masuhiro Beppu，Yoshimi Sonoda，Hiroki Tamai, Dynamic behavior of simple beam member under impulsive load using particle method, 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, Proceedings of the 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, pp.165-173, 2005.12. |
| 93. |
Yoshimi Sonoda, Hiroki Tamai, T.Kato, H.Ohsumi, A Study on the impact resistance of steel frame dam by discrete element method, 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, Proceedings of the 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, pp.517-522, 2005.12. |
| 94. |
Hiroki Tamai, Yoshimi Sonoda, A Fundamental Study on the Impact Response Analysis of RC Beam using Damage Mechanics, 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, Proceedings of the 6th Asia-Pacific Conference on Shock & Impact Loads on Structures, pp.539-544, 2005.12. |
| 95. |
S. Berton, T. Takahashi, Yoshimi Sonoda, Fluid viscous damper optimal design for seismic protection of bridges, 10th International Conference on Civil, Structural and Environmental Engineering Computing, Civil-Comp 2005
Proceedings of the 10th International Conference on Civil, Structural and Environmental Engineering Computing, Civil-Comp 2005, 2005.12, In bridge structures during strong earthquakes impact as well as intermediate joint unseating can occur when the induced deformations exceed the joint gaps or the joint seat lengths, respectively. Passive dissipation devices such as fluid viscous dampers (FVDs) have been recently used for seismic protection of bridges. These devices are usually installed at the expansion joint or abutment locations and activated by the relative movements of the structural components induced by earthquakes. In this paper the benefits of using FVDs to prevent seismic induced damage in bridges is investigated through a series of finite element time history analyses. The example model used in this study represents a reinforced/prestressed concrete box-girder bridge having five spans and only one expansion joint at one of the infiection points of the intermediate span. The effect of the nonlinear FVDs is taken into account by using a modified Maxwell type element that connects the two independent frames at the structural joint. From the numerical simulation results, an optimal damper degree of non-linearity and damper size are selected so that the structural response is optimized. Analysis results confirm that FVDs can be effective in improving the overall dynamic behavior of bridge structures and emphasize the better performance of nonlinear devices. Additional benefits include significant reductions in base-shear forces and longitudinal pier moments.. |
| 96. |
Yoshimi Sonoda, N. Murato, H. Hikosaka, A fundamental study on deterioration of the existing RC beam by chemical and mechanical damage, First International Conference on Fatigue Damage of Materials Experiment and Analysis, Fatigue Damage of Materials
Fatigue Damage of Materials
Experiment and Analysis, 295-306, 2003.12, Recently, the maintenance problem of existing RC structures has increased in Japan, and it is important to estimate the total life cycle cost of structure, which includes not only construction cost but also maintenance cost. In order to accomplish this purpose, it is necessary to evaluate the durability and predict the deterioration of the existing structures accurately. In this study, the damage evolution processes caused by chemical and mechanical effects are considered by using continuum damage mechanics. Within the framework of this method, chemical damage due to the corrosion of the steel bar is considered, and the coupling effect between chemical damage and mechanical damage is calculated by introducing two independent scalar damage variables into the constitutive equation. To calculate the chemical damage evolution, diffusion process of the chloride ions that strongly affect the corrosion of the steel bar in the concrete beam is solved, and evaluate the effective cross-sectional area of the steel bar. It is found that the proposed method could evaluate the deterioration of the existing RC beam, and the change of its ultimate strength under the various exposition conditions.. |
| 97. |
K. Thepvongsa, Yoshimi Sonoda, H. Hikosaka, Fatigue damage analysis of welded structures based on continuum damage mechanics, First International Conference on Fatigue Damage of Materials Experiment and Analysis, Fatigue Damage of Materials
Fatigue Damage of Materials: Experiment and Analysis, 309-319, 2003, In this study, the fatigue damage analysis and life prediction of welded structures are carried out by using continuum damage mechanics. For high cycle fatigue, it is considered that plastic deformation and damage occurs at a microscopic scale. Therefore, a two-scale model presented by Lemaitre is introduced to evaluate the high cycle fatigue damage evolution. As it is difficult to identify the parameters directly at the micro scale, the identification method is proposed to obtain the reliable material parameters for weldment. In order to consider the effect of residual stress on fatigue behavior of welded joints, the inherent strain method is applied to determine the residual stress. The analytical results by the proposed method are compared to experimental results and it is confirmed that the proposed method could give the reliable fatigue lifetime of welded structures.. |
| 98. |
N. Ishikawa, Yoshimi Sonoda, H. Hikosaka, Development of new bridge restrainer with rubber-rolled pin for the great earthquake, Unknown Journal, 23, 661-670, 1996, A new bridge restrainer system with rubber-rolled pin is proposed for the great earthquake. First, the static and high-speed loading tests are performed for the bridge restrainer system with and without rubber, respectively. Second, it is found that the rubber-rolled pin can absorb the large strain energy by cutting the fiber involved in the rubber and, as such, it has the large ultimate displacement until failure. Therefore, it is confirmed that this new bridge restrainer with rubber-rolled pin will be useful for the great earthquake.. |
| 99. |
N. Ishikawa, Y. Sonoda, H. Hikosaka, Development of new bridge restrainer with rubber-rolled pin for the great earthquake, Proceedings of the 1996 1st International Conference on Earthquake Resistant Engineering Structures, ERES 96
Earthquake Resistant Engineering Structures, 2, 661-670, 1995.12, A new bridge restrainer system with rubber-rolled pin is proposed for the great earthquake. First, the static and high-speed loading tests are performed for the bridge restrainer system with and without rubber, respectively. Second, it is found that the rubber-rolled pin can absorb the large strain energy by cutting the fiber involved in the rubber and, as such, it has the large ultimate displacement until failure. Therefore, it is confirmed that this new bridge restrainer with rubber-rolled pin will be useful for the great earthquake.. |
| 100. |
Yoshimi Sonoda, Nobutaka Ishikawa, Keiichiro Sonoda, Toshiaki Ohta, Load carrying capacity and safety check of prestressed concrete rock-shed, Doboku Gakkai Rombun-Hokokushu/Proceedings of the Japan Society of Civil Engineers, 495 pt 1-2, 83-92, 1994.12, This paper presents a computational approach for the evaluation of the load carrying capacity and the safety check of the prestressed concrete (PC) rock-shed structures under falling rocks. At first, the impact response analysis is performed by connecting the distinct element method with the rigid body spring model in order to consider the interaction of PC rock-shed and sand cushion. Secondly, the load carrying capacity of PC rock-shed is evaluated by performing the impact failure analysis of PC rock-shed. It is confirmed that this analytical method can evaluate the load carrying capacity of PC rock-shed by considering the effect of lateral prestressing. Finally, the safety check of PC rock-shed is performed by using the energy criterion in which the limit absorbed energy is found by the incremental elastic-plastic analysis and the transmitted kinematic energy is obtained by the conservative law of momentum.. |
| 101. |
Yoshimi Sonoda, Hiroshi Satoh, Nobutaka Ishikawa, Toshiaki Ohta, Fundamental study on impact response of sand cushion by distinct element method, Doboku Gakkai Rombun-Hokokushu/Proceedings of the Japan Society of Civil Engineers, 483 pt 1-26, 51-60, 1994.01, This paper presents a computational approach for the impact response of the sand cushion under a falling rock by using distinct element method (DEM). At first, the static loading test and falling weight test for the sand cushion are performed by using a small size model. It is found that the impact load of a sand cushion can be estimated by using the spring constant of sand obtained in the static loading test. Secondly, the relation between the spring constant of sand and the fictitious elastic modulus of a sand element in DEM is found and the impact response analysis is performed by combining the DEM with Rigid Body Spring Model (RBSM). It has been confirmed that this computational approach can estimate the impact response of a sand cushion by comparing with the experimental results. Finally, the actual size impact tests have been simulated by this approach. It has been found the weight impact load is about 2 times smaller than the transmission impact load and the transmission energy factor is about 6approx.13% in the case of the span length of H type beam 8 approx.12 m and sand cushion 90cm.. |
| 102. |
Hisanori Otsuka, Yoshimi Sonoda, NON-LINEAR BEHAVIOR OF LONG SPAN CABLE-STAYED BRIDGES WITH FULL, SELF AND PARTIAL ANCHORAGES., Memoirs of the Faculty of Engineering, Kyushu University, 47, 2, 145-155, 1987.06, The object of this paper was to clarify the effect of non-linear characteristics of each structural member on the structural behaviors in the long span cable-stayed bridges with full, self and partial anchorages. Numerical results by the non-linear analysis of varying span length, span sag ratio and cable system are presented to investigate the static characteristics in long span cable-stayed bridges with various types of anchorages.. |
