Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
HIROKI TAMAI Last modified date:2024.04.23

Associate Professor / Civil design and materials / Faculty of Engineering


Papers
1. Souphavanh Senesavath, Hiroki Tamai, Chi Lu, Yoshimi Sonoda, Strengthening of RC Beams with CFC Panels for Improving Impact Resistance, Applied Sciences, https://doi.org/10.3390/app131910625, 13, 19, 論文番号10625, 2023.10.
2. Yoshimi Sonoda, Hiroki Tamai, Tatsuya Ifuku, Masami Koshiishi, Reinforcing effect of polyurea resin coating on RC members subject to low-speed and medium-speed impact, Advances in Structural Engineering, https://doi.org/10.1177/13694332221088945, Volume: 25 issue: 7, page(s): 1609-1621, 2023.05.
3. Yoshimi Sonoda, Hiroki Tamai, Hirotsugu Ikeda, Seismic Performance of Dam Piers Retrofitted with Reinforced Polymer Cement Mortar, Applied Sciences, https://doi.org/10.3390/app11167255, Volume 11, Issue 16, 7255, 2021.08.
4. Tadaaki Nozawa, Yuki Kobayashi, Yoshimi Sonoda, Hiroki Tamai, A basic study on characteristics of RC beam using ESCON, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 10.1201/9780429279119-166, pp.1225-1231, 2021.04.
5. Hiroki Tamai, Chi Lu, Yoichi Yuki, New Design Concept for Bridge Restrainers with Rubber Cushion Considering Dynamic Action: A Preliminary Study, Applied Sciences, https://doi.org/10.3390/app10196847, Volume 10, Issue 19, 6847, 2020.09.
6. 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..
7. Hagere Alemayehu Gibe, Hiroki Tamai, Yoshimi Sonoda, Numerical Study on Failure Process and Ultimate State of Steel Bearing Under Combined Load, Heliyon, https://doi.org/10.1016/j.heliyon.2020.e03764, 6, 4, Heliyon 6 (2020) e03764, 2020.04.
8. Hiroki Tamai, Sota Jinkawa, Yoshimi Snoda, Damage evaluation and protection method of resin pipe for gas conduit subjected to impact load, International Journal of Protective Structures, https://doi.org/10.1177/2041419620902791, Volume 11, Issue 4, page 423-447, 2020.12.
9. 中山歩,玉井宏樹,園田佳巨,神川創太, 材種の異なるガス用樹脂管の耐衝撃性能に関する研究, 第12回構造物の衝撃問題に関するシンポジウム論文集, 2019.12.
10. 曾健恒,園田佳巨,玉井宏樹, CFパネル補強したRC 梁の耐衝撃性能に関する数値研究, 第12回構造物の衝撃問題に関するシンポジウム論文集, 2019.12.
11. Yamazaki Kazuki, Yoshimi Sonoda, Hiroki Tamai, Hiroyuki Yamada, Masahiro Haruguchi, Analytical Study on Dynamic Behavior of Reinforced Dam Pier under Seismic Load, Modern Developments in Performance of Structures under Extreme Loading ~Proceedings of PROTECT 2019~, 944-955, ISBN 978-0-88865-341-3, 2019.09.
12. Hiroki Tamai, Yoshimi Sonoda, A Study on Impact Resistance Performance of RC Member Deteriorated by Reinforcement Corrosion, Modern Developments in Performance of Structures under Extreme Loading ~Proceedings of PROTECT 2019~, 352-363, ISBN 978-0-88865-341-3, 2019.09.
13. Hiroki Tamai, Sota Jinkawa, Yoshimi Sonoda, Ayumi Nakayama, A Comparative Study on Impact Resistance of Plastic Gas Pipes with Different Materials, Modern Developments in Performance of Structures under Extreme Loading ~Proceedings of PROTECT 2019~, 364-374, ISBN 978-0-88865-341-3, 2019.09.
14. Lu Chi, Hiroki Tamai, Yoshimi Sonoda, An Evaluation Method for the Impact Load Carrying Capacity of RC Beam Members under the Influence of ASR, Modern Developments in Performance of Structures under Extreme Loading ~Proceedings of PROTECT 2019~, 277-287, ISBN 978-0-88865-341-3, 2019.09.
15. 山崎航希, 玉井宏樹, 園田佳巨, 鉄筋とポリマーセメントモルタルにより補強された扁平状RC 梁の曲げ耐荷性状に関する研究, コンクリート工学年次論文集, 第41巻, 第2号, 1267-1272, 2019.07.
16. 曾健恒, 玉井宏樹, 園田佳巨, 小尾 博俊, NUMERICAL STUDY ON FAILURE BEHAVIOR OF RC BEAM RETROFITTED BY CFC PANEL UNDER IMPACT LOAD, コンクリート工学年次論文集, 第41巻, 第2号, 703-708, 2019.07.
17. Hiroki Tamai, Yoshimi Sonoda, Impact resistant capacity and failure behaviour of RC slab with corroded reinforcement, Proceedings of the 5th International Conference on Protective Structures, 551-556, ISBN: 978-83-89333-71-1 (e-version), 2018.08.
18. Yoshimi Sonoda, Kazuki Fukunaga, Hiroki Tamai , Impact resistance performance assessment of wire ring net guard fence using full scale test and numerical analysis, Proceedings of the 5th International Conference on Protective Structures, 502-505, ISBN: 978-83-89333-71-1 (e-version), 2018.08.
19. Hiroki Tamai, Chi Lu, Yoshimi Sonoda, An Experimental Study on the Impact Resistance of RC Members with Reinforcement Corrosion, Proceedings of 6th Annual International Conference on Architecture and Civil Engineering, 10.5176/2301-394X_ACE18.128, 336-340, 2018.05.
20. Yoshimi Sonoda, Mari Okamura, Hiroki Tamai, A Fundamental Study on Hammering Sound Test of Deteriorated Concrete Structures, Proceedings of 6th Annual International Conference on Architecture and Civil Engineering, 10.5176/2301-394X_ACE18.118, 89-94, 2018.05.
21. 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..
22. Chi Lu, Hiroki Tamai, Yoshimi Sonoda, A Numerical Study on the Impact Resistant Capacity of RC Beams with Corroded Reinforcement, Procedia Engineering, https://doi.org/10.1016/j.proeng.2017.11.086, 341-348, Volume 210, 2017, Pages 341-348, 2017.12, 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..
23. Hiroki Tamai, Yoshimi Sonoda, A Study on Impact Resistant Capacity of RC Slab with Corroded Reinforcement and its retrofitting method, Proceedings of 6th International Conference on Design and Analysis of Protective Structures, 559-564, 2017.11, The reinforcement corrosion of RC structures due to chloride attack or neutralization is a serious problem to shorten the service life of them. In order to properly maintain and manage the RC structure with corroded reinforcement, it is necessary to clarify the relationship between the degree of deterioration and the remaining loading capacity. However the existing studies mainly focused on the evaluation of the load bearing capacity of RC beams subjected to static load, and there are few studies on the impact loads involved in natural disasters. Considering the fact that the large-scale natural disasters happened more frequently in recent years, it is important to quantitatively evaluate the impact behavior and resistance of the RC structures with corroded reinforcement for disaster-prone countries like Japan. In this study, to clarify the impact resistance of the RC slabs with corroded reinforcement under medium velocity impact by a rigid projectile, a horizontal impact test was conducted on the RC slab specimen with corroded reinforcement made by electrolytic corrosion method. In a series of impact tests, an air-acceleration type horizontal impact test machine like a launcher was used, and a flat nose projectile of a mass of 3kg and a RC slab with 600 mm x 600 mm in length and width, 80 mm in depth were used. Impact velocity was set to 15m/s. Through the impact tests, the difference of impact response and fracture pattern between the RC slabs without and with corroded reinforcement was clarified as a fundamental information. The relationship between the degree of corrosion and impact resistance of the slabs was also clarified. In addition, we tried to clarify the impact resistance improvement effect of RC slab retrofitted by continuous fiber composite panel (CFC panel) which has already been applied to repair and reinforcement such as renewal of tunnel lining and seismic reinforcement of pillar parts..
24. Yang Sun, Hiroki Tamai, Yoshimi Sonoda and Hirotoshi Obi, Experimental study on impact resistance of corroded rc beams reinforced by CFC plate, Proceedings of the 12th International Conference on Shock & Impact Loads on Structures, 978-981-11-2850-9, 409-418, 2017.06, In recent years, as the aging of existing reinforced concrete (RC) structures is progressing, research on reinforcement and repair methods has become a concern. However, most of these researches mainly focus on the study of static behaviour for RC structures. Therefore, it is necessary to clarify the decrement of the impact resistance of the protective structure that is expected to be subjected to impact loads due to deterioration damage. It is important to provide an appropriate repairing and reinforcing method. From these backgrounds, in this research, we first attempted to corrode the rebar by electrolytic corrosion and to do the drop weight impact test to clarify the decrement of the impact resistance of the RC beam due to deterioration. Furthermore, by doing the same test, we tried to clarify the impact improvement effect of RC beam reinforced by continuous fiber composite panel (CFC panel) which has already been applied to repair and reinforcement such as renewal of tunnel lining and seismic reinforcement of pillar parts. As a result, we could get some findings. Firstly, reinforcement with CFC panel can greatly improve the
impact resistance of the RC beam by reinforcing the bottom surface or three surfaces of the RC beam, and it was confirmed that this tendency does not depend on the deterioration degree before reinforcement. Second, although the upper surface reinforcement does not exert much effects on the deformation of the RC beam, it was found that it is effective for preventing the compressive failure of the collision surface..
25. Chi Lu, HIROKI TAMAI, YOSHIMI SONODA, A STUDY ON IMPACT COMPRESSIVE PROPERTIES OF CUSHION RUBBER FOR CABLE BRIDGE RESTRAINERS, 4th International Conference on Protective Structures, 476-485, 2016.10.
26. Yoichi Yuki, HIROKI TAMAI, Hironori Ishii, YOSHIMI SONODA, Toshihiro Kasugai, Weight-drop tests of bridge restrainers under large weights, 11th German Japanese Bridge Symposium, 2016.08.
27. HIROKI TAMAI, ISAO KUWAHARA, YOSHIMI SONODA, A STUDY ON THE EFFECT OF CORROSION RATE OF REINFORCING STEEL ON ITS EXPANSION PRESSURE AND LOAD BEARING CAPACITY OF RC BEAM, 41st Conference on OUR WORLD IN CONCRETE & STRUCTURES, 275-284, 2016.08.
28. ISAO KUWAHARA, HIROKI TAMAI, YOSHIMI SONODA, Experimental Study on Impact Load Resistance of RC Beam with Corroded Reinforcement, MATEC Web of Conferences, 47, 02004-p1-02004-p7, 2016.04.
29. Hariyadi, HIROKI TAMAI, Enhancing the performance of porous concrete by utilizing the pumice aggregate, Elsevier: Procedia Engineering, 125, 732-738, 2015.11.
30. HIROKI TAMAI, ISAO KUWAHARA, YOSHIMI SONODA, An experimental study on static and impact load resistance of RC beam with corroded reinforcement, Proceedings of 40th Conference on OUR WORLD IN CONCRETE & STRUCTURES, 467-474, 2015.08.
31. HIROKI TAMAI, YOSHIMI SONODA, Evaluation of cumulative damage of RC members under repeated impact loading, Applied Mechanics and Materials, 784, 500-507, 2015.07.
32. HIROKI TAMAI, YOICHI YUKI, YOSHIMI SONODA, TOSHIHIRO KASUGAI, A study on shock absorbing properties of rubber pieces for bridge seismic restrainers, Proceedings of the Fifth International Workshop on Performance, Protection & Strengthening of Structures Under Extreme Loading (PROTECT 2015), 27-35, 2015.06.
33. Kozo Onoue, HIROKI TAMAI, Hendro Suseno, Shock-absorbing capability of lightweight concrete utilizing volcanic pumice aggregate, Elsevier: Construction and Building Materials, 83, 261-274, 2015.05.
34. HIROKI TAMAI, LU CHI, YOSHIMI SONODA, FUNDAMENTAL STUDY ON EVALUATION OF IMPACT LOAD OF COLLAPSED SOIL BY EXTENDED DISTINCT ELEMENT METHOD, Proceedings of 11th International Conference on Shock & Impact Loads on Structures, 27-35, 2015.05.
35. YOSHIMI SONODA, HIROKI TAMAI, Damage evaluation of the existing PC bridge by vehicle collision using numerical analysis, Proceedings of the 3rd International Conference on Protective Structures ICPS3, 550-560, 2015.02.
36. Shinobu Sano, HIROKI TAMAI, Yoshihiko Murata, YOSHIMI SONODA, Numerical study on a thermal crack control effect of concrete structures using delayed-setting mortar, Proceedings of 39th conference on Our World in Concrete & Structures, XXXⅢ, 425-434, 2014.08.
37. 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, 5, 2, 219-237, 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..
38. Yoichi Yuki, HIROKI TAMAI, Naoki Wada, YOSHIMI SONODA, Toshihiro Kasugai, A Fundamental Study on the Shock Cushioning Characteristics of a Novel pin-Fixed Aseismatic Connector for Bridges, Applied Mechanics and Materials, 566, 637-642, 2014.06, This paper presents a novel pin-fixed aseismatic connector for bridges. A feature of this device is that the anchorage areas of both ends are connected with hinges; thus, there are no restrictions with respect to their mounting angles. Additionally, the PC cable of this device is given an appropriate amount of sag; thus, within the range of the sag the structure is capable of absorbing the amount of displacement because of temperature changes and live loads. In addition, this device has a certain shock-cushioning effect because of the rubber material surrounding the hinge pins. However, there is no quantitative evaluation method on the shock-cushioning effect of this device. Therefore, in this study, the shock-cushioning effect of the novel pin-fixed aseismatic connector for bridges is investigated using impact load tests and numerical analysis. It is found that the shock-cushioning effect of this device is almost equal to similar aseismatic connectors. Furthermore, it is also confirmed that their effects can be quantitatively evaluated using impact response analysis..
39. Mariko Uno, HIROKI TAMAI, Yoichi Yuki, YOSHIMI SONODA, Toshihiro Kasugai, A study on the impact resistance of pin fixed cable restrainers for bridges, Proceedings of 10th International conference on Shock and Impact Loads on Structures, 471-480, 2013.11, 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 hyper-elastic behaviour of three-parameter Mooney-Rivlin model. The analyses could nearly demonstrate the impact response trend obtained from the conducted experiments..
40. HIROKI TAMAI, Seongbong Cheon, Satoshi Goya, YOSHIMI SONODA, Case study of damage of PC bridge by vehicle collision and its numerical analysis, Proceedings of 10th International conference on Shock and Impact Loads on Structures, 451-460, 2013.11, 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..
41. YOICHI YUKI, HIROKI TAMAI, NAOKI WADA, YOSHIMI SONODA, TOSHIHIRO KASUGAI, A fundamental study on the shock cushioning characteristic of a new pin fixed aseismatic connector for bridges, Proceedings of the 8th International Symposium on Impact Engineering, 2013.08.
42. HIROKI TAMAI, YOSHIMI SONODA, A fundamental study on the impact resistance of damaged RC slab under single and repeated low-velocity impact, Proceedings of 4th International Workshop on Performance, Protection, and Strengthening of Structures under Extreme Loading-PROTECT2013, 2013.08.
43. Satoshi Gouya, HIROKI TAMAI, YOSHIMI SONODA, A Fundamental Study on the Repeated Impact Analysis of RC Slab with Consideration of Local Damage, Proceedings of 5th International Conference on Protection of Structures against Hazards, 2012.11.
44. NAOKI WADA, HIROKI TAMAI, YOSHIMI SONODA, SATORU MUNEMOTO, Experimental Study on Dynamic Response Characteristic of the Bridge Restrainer Plate System with Shock Absorber Device, Proceedings of 9th German-Japanese Bridge Symposium, 2012.09.
45. 玉井 宏樹, 園田 佳巨, 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, Volume 3, Number 2, 147-160, 2012.06.
46. 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..
47. Hiroki Tamai and Yoshimi Sonoda, A numerical approach for damage evaluation of RC slab under single and repeated impact loading, Proceedings of 9th International conference on Shock and Impact Loads on Structures, pp.643-652, 2011.11.
48. 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..
49. 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..
50. 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..