| 1. |
Mitsuteru Asai, Shujiro Fujioka, Kumpei Tsuji, Daniel Morikawa, New 2nd order particle simulation model ISPH(2) and its application to complex disaster simulation, ACM 2023, Advanced in Computational Mechanics, 2023.10. |
| 2. |
Yifang Qin, Mitsuteru Asai, Shunhua Chen, Crack propagation simulation using cohesive zone approach based on nodal Lagrange multiplier, ACM 2023, Advanced in Computational Mechanics, 2023.10. |
| 3. |
Hiroyuki Omura, Naoto Mitsume, Mitsuteru Asai, Daigoro Isobe, Tsunami-building interaction simulations using coupled ISPH/ASI-Gauss method, ACM 2023, Advanced in Computational Mechanics, 2023.10. |
| 4. |
Shota Deguchi, Mitsuteru Asai , Adaptive loss weighting of physics informed neural network for fast and accurate inverse analysis, ACM 2023, Advanced in Computational Mechanics , 2023.10. |
| 5. |
Daniel Morikawa, Mitsuteru Asai, Finite strain elastoplastic and solid-solid contact problems with the Smoothed Particle Hydrodynamics, PARTICLES 2023, 2023.10. |
| 6. |
Kumpei Tsuji, Mitsuteru Asai, Kiyonobu Kasama, Particle-based Semi-resolved Coupling Model for the Simulation of Internal Erosion in soil structures, PARTICLES 2023, 2023.10. |
| 7. |
Yangfan Ma, Mitsuteru Asai, Zheng Han, Guangqi Chen, Physical Process-Based Entrainment Behaviour Modelling of Diluted Debris Flow Using SPH Incorporated with HBP-DP Approach, PARTICLES 2023, 2023.10. |
| 8. |
Haruki Osaki, Daniel Morikawa, Mitsuteru Asai, ISPH with a Geometric Multigrid Preconditioning Solver using Background cells in GPU environment, PARTICLES 2023, 2023.10. |
| 9. |
Yusuke Saeki, Shujiro Fujioka, Kumpei Tsuji, Mitsuteru Asai, Improvement of ISPH-DEM Coupling Simulator Using SPH(2), PARTICLES 2023, 2023.10. |
| 10. |
Daniel Morikawa, Kumpei Tsuji, Mitsuteru Asai, Corrected ALE-ISPH with novel Neumann boundary condition and density-based particle shifting technique, 第28回計算工学講演会, 2023.06. |
| 11. |
辻勲平，浅井光輝，笠間清伸, 粒子法による半解像型連成モデルの開発および地盤の内部侵食解析への適用, 第28回計算工学講演会, 2023.06. |
| 12. |
Yifang Qin, Mitsuteru Asai, Shunhua Chen, A nodal-based Lagrange Multiplier / Cohesive Zone (LM / CZ) Method for Crack Simulations, 第28回計算工学講演会, 2023.06. |
| 13. |
Haruki Osaki, Daniel Morikawa, Mitsuteru Asai, Boosting a large-scale SPH particle methods using many GPUs, including inter-node communications, ICCCI2022, The 7th International Conference on the Characterization and Control of Interface for high Quality Advanced Materials, 2022.11. |
| 14. |
Yusuke Saeki, Kumpei Tsuji, Mitsuteru Asai, Modified gradient and Laplacian models in the SPH method to improve accuracy including negative pressure regions, ICCCI2022, The 7th International Conference on the Characterization and Control of Interface for high Quality Advanced Materials, 2022.11. |
| 15. |
Shujiro Fujioka, Kumpei Tsuji, Mitsuteru Asai, High-order SPH method with spatial second-order accuracy for derivative operator, ICCCI2022, The 7th International Conference on the Characterization and Control of Interface for high Quality Advanced Materials, 2022.11. |
| 16. |
Mitsuteru Asai, Kumpei Tsuji, ISPH-DEM coupling simulation for estimating internal erosion in soil, ICCCI2022, The 7th International Conference on the Characterization and Control of Interface for high Quality Advanced Materials, 2022.11. |
| 17. |
Daniel Morikawa, Mitsuteru Asai, Haruki Osaki, A phase-change approach to landslide simulations: coupling finite strain elastoplastic TLSPH with non-Newtonian IISPH, ICCCI2022, The 7th International Conference on the Characterization and Control of Interface for high Quality Advanced Materials, 2022.11. |
| 18. |
Mitsuteru Asai, Multi -scale and -physics particle simulations for natural hazard, The 41st JSST Annual International Conference on Simulation Technology, 2022.09. |
| 19. |
Kumpei Tsuji, Yusuke Saeki, Shujiro Fujioka, Mitsuteru Asai, A Hybrid ISPH-DEM Coupling Simulation for Estimating Internal Erosion in Soil, MFEM2022, 2022.09. |
| 20. |
Yusuke Saeki, Shujiro Fujioka, Kumpei Tsuji, Mitsuteru Asai, A class of Laplacian and mixed derivative models in the SPH framework, MFEM2022, 2022.09. |
| 21. |
Mitsuteru Asai, Shujiro Fujioka, A class of Laplacian and mixed derivative models in the SPH framework, WCCM-APCOM2022, 2022.08. |
| 22. |
Kumpei Tsuji, Yusuke Saeki, Mitsuteru Asai, A Hybrid seepage failure analysis between two-phase mixture flow techniques using an ISPH-DEM coupling method, WCCM-APCOM2022, 2022.08. |
| 23. |
Shota Deguchi, Yousuke Shibata, Mitsuteru Asai, Unknown parameter identification from noisy training data using physics-informed neural networks, WCCM-APCOM2022, 2022.08. |
| 24. |
Munkhzaya Myagmarjav, Mitsuteru Asai, Hideyuki Otani, Daigoro Isobe, City-scale simulation of wooden house collapse prediction using the ASI-Gauss Code, 第27回計算工学講演会, 2022.06. |
| 25. |
Morikawa Daniel Shigueo, 浅井光輝, 大崎春輝, 一色正晴, A phase-change approach to landslide simulations: coupling finite strain elastoplastic TLSPH with nonNewtonian IISPH, 第27回計算工学講演会, 2022.06. |
| 26. |
Kumpei Tsuji, Mitsuteru Asai, Hemanta Hazarika, ISPH-DEM Coupled Simulation for Designing Resilient Breakwater with Gabion Reinforcements, PARTICLES 2021, 2021.10. |
| 27. |
Daniel S. Morikawa, Mitsuteru Asai, Incompressible smoothed particle hydrodynamics (ISPH) for Geomechanics problems, PARTICLES 2021, 2021.10. |
| 28. |
Kumpei Tsuji, Mitsuteru Asai, Kiyonobu Kasama, SPH-DEM simulation for estimating seepage failure of breakwaters, ICADD15, 2021.09. |
| 29. |
Mitsuteru Asai, Daniel S. Morikawa, Kumpei Tsuji, Fluid-Soil-Structure interaction simulation for natural disaster damage estimation using a particle method, ICADD15, 2021.09. |
| 30. |
Daniel S. Morikawa, Mitsuteru Asai, Smoothed particle hydrodynamics method for landslide problems based on Biot’s formulation and elastoplastic constitutive models, COUPELED PROBLEMS 2021, 2021.06. |
| 31. |
Kumpei Tsuji, Mitsuteru Asai, Kiyonobu Kasama, Simulation of Breakwater Failure induced by Tsunami Using an ISPH-DEM Coupled Method, COUPELED PROBLEMS 2021, 2021.06. |
| 32. |
Mitsuteru Asai, Daniel S. Morikawa, Non-Newtonian fluid simulation using a particle method for landslide simulations, 14th World Congress in Computational Mechanics and ECCOMAS, 2021.01. |
| 33. |
Mitsuteru Asai, Yi Li, Simulations of free-surface flow interacting with multiple rigid bodies using coupled ISPH-DEM incorporated with an energy-tracking impulse method, 14th World Congress in Computational Mechanics and ECCOMAS, 2021.01. |
| 34. |
Shota Deguchi, Mitsuteru Asai, Hiroto Ueki, Yuki Takeuchi, Koji Kawasaki, Probabilistic disaster risk evaluation with surrogate-modelled numerical simulations, COMPSAFE 2020, 2020.12. |
| 35. |
Hidetaka Ishii, Mitsuteru Asai, Daigoro Isobe, Hideyuki O-tani, Seismic response analysis for the whole city with the ASI-Gauss code to estimate a city level damage, COMPSAFE 2020, 2020.12. |
| 36. |
Kumpei Tsuji, Mitsuteru Asai, Comparison of Spherical and Non-Spherical DEM in Reproducing Arch-Effect Characteristic of Ground Collapse Phenomenon, COMPSAFE 2020, 2020.12. |
| 37. |
Takehiro Fujii, Mitsuteru Asai, Yusuke Imoto, Fluid-solid multiphase analysis using a selective dual velocity ISPH method dividing into physical and transport velocity, COMPSAFE 2020, 2020.12. |
| 38. |
Kunpei Tsuji, Mitsuteru Asai, Fluid-Solid Multiphase Disaster Simulator using SPH-DEM coupled Method, 7th Asian Pacific Congress on Computational Mechanics, 2019.12. |
| 39. |
Hiroto Ueki, Mitsuteru Asai, Koji Kawasaki, Shigetoshi Kawasaki, Drainage simulation using highly detailed unstructured grid for urban flood damage prediction, 7th Asian Pacific Congress on Computational Mechanics, 2019.12. |
| 40. |
Kohei Hara, Mitsuteru Asai, Daigoro Isobe, Seizo Tanaka, Wooden houses collapse simulation during earthquake and tsunami at a city level base on the ASI-Gauss finite element method, 7th Asian Pacific Congress on Computational Mechanics, 2019.12. |
| 41. |
Takehiro Fujii, Mitsuteru Asai, A validation for soil scouring analysis based on a SPH-DEM coupled method, 7th Asian Pacific Congress on Computational Mechanics, 2019.12. |
| 42. |
Taiga Makino, Mituteru Asai, Multi scale tsunami simulation from earthquake initiation tsunami run-up into the coastal area, 7th Asian Pacific Congress on Computational Mechanics, 2019.12. |
| 43. |
Mitsuteru Asai, Mikito Furuichi, Daisuke Nishiura, Dynamic Load Balanced Expanding Slice Grid Method for Large-scaled High Fidelity Tsunami Run-up Simulation suing an Explicit SPH, VI International Conference on Particle-based Method - Fundamentals and Applications PARTICLES 2019, 2019.10. |
| 44. |
Li Yi, Mitsuteru Asai, Bodhinanda Chandra, Simulation of Free-surface Flow Interacting with Multiple Rigid Bodies using Coupled ISPH－DEM incorporated with Energy Tracking Impulse Contact, VI International Conference on Particle-based Method - Fundamentals and Applications PARTICLES 2019, 2019.10. |
| 45. |
Kunpei Tsuji, Mitsuteru Asai, Fluid-Solid multi-phase flow simulator using a SPH-DEM coupling method in consideration of liquid bridge force related to water content, VI International Conference on Particle-based Method - Fundamentals and Applications PARTICLES 2019, 2019.10. |
| 46. |
Daniel Morikawa, Mitsuteru Asai, Masaharu Isshiki, Verification and Validation in Highly Viscous Fluid Simulation using a Fully Implicit SPH Method, VI International Conference on Particle-based Method - Fundamentals and Applications PARTICLES 2019, 2019.10. |
| 47. |
Kohei Hara, Mitsuteru Asai, Daigoro Isobe, Seizo Tanaka, Collapse Simulation of Aso Bridge During The 2016 Kumamoto Earthquakes By Asi-Gauss Code, 7th International Colloquium on Performace, Protections & Strengthening of Structure Under Extreme Loading & Events, 2019.10. |
| 48. |
Mitsuteru Asai, Li Yi, Fluid-rigid body interaction simulation based on a stabilized ISPH incorporated with an Energy Tracking Impulse method, 20th Internatinal Conference on Fluild Flow Problem, 2019.04. |
| 49. |
Daniel Shigueo Morikawa, Mitsuteru Asai, Improvements on Highly Viscous Fluid Simulation Using the SPH Method, 7th International Conference on Protection of Structures against Hazards, 2018.10. |
| 50. |
Kohei Hara, Mitsuteru Asai, Daigoro Isobe, Verification on collapse process of Aso bridge during the 2016 Kumamoto earthquakes by ASI-Gauss method, 7th International Conference on Protection of Structures against Hazards, 2018.10. |
| 51. |
Kumpei Tsuji, Mitsuteru Asai, Yasuhiko Konishi, Shuichi Oomine, 3-Dimensinal SPH-DEM coupled simulation for elucidating road caving collapse processes involving water-soil coupling phenomenon, 7th International Conference on Protection of Structures against Hazards, 2018.10. |
| 52. |
Naoki Nakaya, Mitsuteru Asai, Ryoichiro Agata, Takane Hori, Toshitaka Baba, Tsunami Run-up Simulation Based on Crustal Deformation Simulation by FEM, 7th International Conference on Protection of Structures against Hazards, 2018.10. |
| 53. |
Mitsuteru Asai, Naoki Nakaya, Ryoichiro Agata, Takane Hori, Toshitaka Baba, A physical simulation based earthquake scenario and a multi-scale Tsunami simulation, 13th World Congress on Computational Mechanics, 2018.07. |
| 54. |
Li Yi, Mitsuteru Asai, Fluid-rigid body interaction simulation based on ISPH incorporated with impulse-based method, 13th World Congress on Computational Mechanics, 2018.07. |
| 55. |
Daniel Shigueo Morikawa, Mitsuteru Asai, Improvements on Highly Viscous Fluid Simulation using a Particle Method and Its Application to Landslide Problems, 13th World Congress on Computational Mechanics, 2018.07. |
| 56. |
Verification on Collapse Process of Aso Bridge during the 2016 Kumamoto Earthquake by ASI-Gauss Method. |
| 57. |
Tsunami Run-up Simulation Based on Crustal Deformation Simulation by BEM. |
| 58. |
Performance evaluation and Implementation of subcycle method on SPH-FEM coupled analysis system. |
| 59. |
Development of a SPH-DEM coupled analysis for elucidation of ground collapse phenomenon caused by sewer pipe defect. |
| 60. |
Mitsuteru Asai, Natural disaster simulation by as multiphysics particle simulation, 4th Computational Desing in Engineering, 2018.04, 独自に開発を進めている粒子法によるマルチフィジックス解析ツールによる災害被害予測シミュレーションに関する招待講演（セミプレナリー）を実施した。. |
| 61. |
Daniel Shigueo Morikawa, Mitsuteru Asai, Improvements on Highly Viscous Fluid Simulation using a Particle Method, 4th Computational Desing in Engineering, 2018.04. |
| 62. |
Li Yi, Mitsuteru ASAI, A bridge wash-out simulation using a stabilized ISPH incorporated with multi-body dynamivs based on the impulse-based contact force method, Compsafe 2017, 2017.10. |
| 63. |
Masao Ogino, Mitsuteru ASAI, Takuya Iwama, A study on parallel fluid-structure interaction simulations using a SPH code and the adventure through REVOCAP_coupler, Compsafe 2017, 2017.10. |
| 64. |
Masao Ogino, Mitsuteru Asai, Takuya Iwama, A study on parallel fluid-structure interaction simulations using a SPH code and the adventure through REVOCAP coupler, Compsafe 2017, 2017.10. |
| 65. |
Yi Li, Mitsuteru Asai, A bridge wash-out simulation using a stabilized ISPH incorporated with multi-body dynamivs based on the impulse-based contact force method, Compsafe 2017, 2017.10. |
| 66. |
Mitsuteru Asai, Multi-scale and –physics tsunami disaster simulation for disaster prevention and mitigation, Compsafe 2017, 2017.10. |
| 67. |
Kensuke Harasaki, Mitsuteru ASAI, Development of a fluid-solid multiphase flow simulation by a SPH-DEM coupled method for simulating a seawall destruction due to soil foundation scour, Particle 2017, 2017.09. |
| 68. |
Mitsuteru ASAI, Multi-scale and –physics tsunami disaster simulation for disaster prevention and mitigation, Particle 2017, 2017.09. |
| 69. |
Keita Ogasawara, Mitsuteru Asai, Mikito Furuichi, Daisuke Nishiura, Peformance of large scaled tsunami run-up analysis using Explicit ISPH method, Particle 2017, 2017.09. |
| 70. |
津波による防波堤崩壊解析に向けた水‐土粒子連成解析手法の開発. |
| 71. |
粒子法コードとADVENTUREによるREVOCAP_Couplerを用いた並列FSI解析に関する検討. |
| 72. |
2次元差分法と3次元粒子法による津波遡上解析の比較とその特徴~高知県高知市を対象とした数値実験~. |
| 73. |
防波堤の洗掘解析に向けたSPH‐DEM法による流体‐土粒子の混相流解析手法の開発. |
| 74. |
2次元差分法と3次元粒子法による津波遡上解析の比較とその特徴. |
| 75. |
SPH粒子法コードとADVENTUREによる並列流体構造連成解析システムに関する検討. |
| 76. |
Tetsuro Goda, Mitsuteru Asai, Seepage flow analysis on caisson-type breakwater reinforced with sheet piles by using the SPH method, 16th Techno-Ocean, Techno-Ocean 2016, 2017.03, the understanding of the collapse mechanism of a caisson-type breakwater has been an urgent task to reduce the projected damages caused by next millennium tsunamis. A variety of research has been done to understand this phenomenon further. From the current observations, the seepage-induced piping phenomenon, which is caused by the bearing capacity degradation inside a mound, is determined as one of the main causes. With the aim of moderating the bearing capacity degradation, a design to reinforce a mound by utilizing sheet piles has been proposed. Although the effectiveness of sheet piles installation has been confirmed through some experimental tests, the optimized design to determine the dimension and position of the sheet piles has not been established yet. Numerical simulation, which can evaluate the effect of the installed sheet piles accurately, is desired to design durable and economical breakwaters. In this study, a 3D numerical simulation based on a particle method is implemented by considering sheet piles inside a mound, and its accuracy is discussed by comparing it with experimental tests.. |
| 77. |
Seepage flow analysis on caisson-type breakwater reinforced with sheet piles by using the SPH method
© 2016 IEEE. the understanding of the collapse mechanism of a caisson-type breakwater has been an urgent task to reduce the projected damages caused by next millennium tsunamis. A variety of research has been done to understand this phenomenon further. From the current observations, the seepage-induced piping phenomenon, which is caused by the bearing capacity degradation inside a mound, is determined as one of the main causes. With the aim of moderating the bearing capacity degradation, a design to reinforce a mound by utilizing sheet piles has been proposed. Although the effectiveness of sheet piles installation has been confirmed through some experimental tests, the optimized design to determine the dimension and position of the sheet piles has not been established yet. Numerical simulation, which can evaluate the effect of the installed sheet piles accurately, is desired to design durable and economical breakwaters. In this study, a 3D numerical simulation based on a particle method is implemented by considering sheet piles inside a mound, and its accuracy is discussed by comparing it with experimental tests.. |
| 78. |
浅井 光輝, Multi-scale and –physics tsunami disaster simulation for disaster prevention and mitigation, Compsafe 2017, 2017.02. |
| 79. |
Kensuke Harasaki, Mitsuteru Asai, Development of a fluid-solid multiphase flow simulator by a sph-dem coupled method for simulating a seawall destruction due to soil foundation scour, 5th International Conference on Particle-Based Methods - Fundamentals and Applications, PARTICLES 2017, 2017.01, In 2011, Tohoku-Kanto earthquake tsunami caused serious damage to the port and coastal structures such as breakwaters and seawalls. The damage mechanism of these structures has been studied in the past, and it is found that there are some causes. In this study, a new simulation tool taking account of the soil scouring and seepage flow phenomena is developed to represent and predict the collapse of the breakwater with SPH-DEM coupled method.. |
| 80. |
Keita Ogasawara, Mitsuteru Asai, Mikito Furuichi, Daisuke Nishiura, Performance of large scaled tsunami run-up analysis using explicit isph method, 5th International Conference on Particle-Based Methods - Fundamentals and Applications, PARTICLES 2017, 2017.01, The tsunami run-up simulation by the particle method at city level needs to huge number of particle at least 1 billion particles. The conventional particle simulation method is not easy to solve these huge problem even on the premise of using supercomputer. Then, a new particle method 'fully explicit Incompressible SPH' is developed that takes into consideration both calculation efficiency and accuracy. Finally, we demonstrate the future plan how to use our simulation resultes for a practical 'Soft' disaster mitigation method through the evacuation education with the Virtual Reality(VR) system.. |
| 81. |
Development of a fluid-solid multiphase flow simulator by a sph-dem coupled method for simulating a seawall destruction due to soil foundation scour
In 2011, Tohoku-Kanto earthquake tsunami caused serious damage to the port and coastal structures such as breakwaters and seawalls. The damage mechanism of these structures has been studied in the past, and it is found that there are some causes. In this study, a new simulation tool taking account of the soil scouring and seepage flow phenomena is developed to represent and predict the collapse of the breakwater with SPH-DEM coupled method.. |
| 82. |
Performance of large scaled tsunami run-up analysis using explicit isph method
The tsunami run-up simulation by the particle method at city level needs to huge number of particle at least 1 billion particles. The conventional particle simulation method is not easy to solve these huge problem even on the premise of using supercomputer. Then, a new particle method 'fully explicit Incompressible SPH' is developed that takes into consideration both calculation efficiency and accuracy. Finally, we demonstrate the future plan how to use our simulation resultes for a practical 'Soft' disaster mitigation method through the evacuation education with the Virtual Reality(VR) system.. |
| 83. |
浅井 光輝, Multi-scale -physics tsunami simulation using a particle method, Internatnional Workshop on Priority Issue 3 to Tackled by Using Post K Computer, Development of integrated simulation system for earthquakes and tsunami hazards and disasters, 2016.12. |
| 84. |
合田哲郎, 浅井 光輝, A coupled simulation of seepage and surface flow using a stabilized ISPH for caisson-type breakwaters collapse problems, Internatnional Workshop on Priority Issue 3 to Tackled by Using Post K Computer, Development of integrated simulation system for earthquakes and tsunami hazards and disasters, 2016.12. |
| 85. |
原崎健輔, 浅井 光輝, SPH-DEM coupled particle simulator for fluid-soil multiphase flow, Internatnional Workshop on Priority Issue 3 to Tackled by Using Post K Computer, Development of integrated simulation system for earthquakes and tsunami hazards and disasters, 2016.12. |
| 86. |
小笠原 圭太, 浅井 光輝, 江口史門, Large scaled tsunami run-up analysis using explicit ISPH method, Internatnional Workshop on Priority Issue 3 to Tackled by Using Post K Computer, Development of integrated simulation system for earthquakes and tsunami hazards and disasters, 2016.12. |
| 87. |
浅井 光輝, 江口史門, Bodhinanda Chandora, Multi-scale tsunami simulation for simulating bridge washout disaster by using a particle method, The 12the World Congres on Computational Mechanics, 2016.07. |
| 88. |
Nur Ain Binti Idris, 浅井 光輝, 宮川欣也, Multi-level tsunami disaster simulation with a matrix array shaped vittual wave makng plate by using the particle method, The 12the World Congres on Computational Mechanics, 2016.07. |
| 89. |
Nur Ain Binti Idris, 浅井 光輝, 宮川欣也, Multi-level tsunami disaster simulation by the particle method with a matrix array shaped virtual wave making plate, The 16th International Conference on Computiong in Civil and Building Engineering, 2016.07. |
| 90. |
Bodhinanda Chandora, 浅井 光輝, 大屋朋子, A study of bridge wash0out simulation during tsunami using a paticle method considering frictional contact, The 16th International Conference on Computiong in Civil and Building Engineering, 2016.07. |
| 91. |
Tomotaka Nogami, Mitsuteru Asai, Kiyonobu Kasama, Taro Arikawa, A coupling simulation between soil scour and seepage flow by using a stabilized ISPH method, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015, 2016.04, In 2011, the example that breakwaters collapsed because of the basic ground's destabilization was reported by Tohoku-Kanto earthquake tsunami. Fluid-Structure-Soil coupling simulation is desired for a systematic comprehension of the breakwater collapse mechanism, and it may help to develop next disaster prevention method. In this study, A particle simulation tool based on the SPH has been modified and improved to analyze seepage flow and soil scouring. In seepage flow analysis, as a first step, this simulation treat the surface flow and seepage flow interactions by using governing equation. In the scouring analysis, soil scour is judged by an empirical criteria based on quicksand quantity formula.. |
| 92. |
Yoshiya Miyagawa, Mitsuteru Asai, Multi-scale bridge wash out simulation during tsunami by using a particle method, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015, 2016.04, In 2011, the huge tsunami caused by the great east Japan earthquake devastated many infrastructures in pacific coast of north eastern Japan. Particularly, collapse of bridges caused a traffic disorder and these collapse behaviors led to delay of recovery after the disaster. In this study, the bridge wash away accident is selected as a target issue, and it is represented by a numerical simulation. For this purpose, Smoothed Particle Hydrodynamics (SPH) Method, which is one of the pure mesh free methods, is utilized for the rigid body motion simulation. In this study, rigid body motion is introduced for the fluid-rigid interaction behavior during bridge wash away simulation. In the numerical analysis, the upper bridge structure is washed away by receiving an impact fluid force. The wash away simulation of two types of the bridge girder showed good agreement with the real accident on the great east Japan earthquake tsunami.. |
| 93. |
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, 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.. |
| 94. |
A coupling simulation between soil scour and seepage flow by using a stabilized ISPH method
© Owned by the authors, published by EDP Sciences, 2016. In 2011, the example that breakwaters collapsed because of the basic ground's destabilization was reported by Tohoku-Kanto earthquake tsunami. Fluid-Structure-Soil coupling simulation is desired for a systematic comprehension of the breakwater collapse mechanism, and it may help to develop next disaster prevention method. In this study, A particle simulation tool based on the SPH has been modified and improved to analyze seepage flow and soil scouring. In seepage flow analysis, as a first step, this simulation treat the surface flow and seepage flow interactions by using governing equation. In the scouring analysis, soil scour is judged by an empirical criteria based on quicksand quantity formula.. |
| 95. |
Multi-scale bridge wash out simulation during tsunami by using a particle method
© Owned by the authors, published by EDP Sciences, 2016. In 2011, the huge tsunami caused by the great east Japan earthquake devastated many infrastructures in pacific coast of north eastern Japan. Particularly, collapse of bridges caused a traffic disorder and these collapse behaviors led to delay of recovery after the disaster. In this study, the bridge wash away accident is selected as a target issue, and it is represented by a numerical simulation. For this purpose, Smoothed Particle Hydrodynamics (SPH) Method, which is one of the pure mesh free methods, is utilized for the rigid body motion simulation. In this study, rigid body motion is introduced for the fluid-rigid interaction behavior during bridge wash away simulation. In the numerical analysis, the upper bridge structure is washed away by receiving an impact fluid force. The wash away simulation of two types of the bridge girder showed good agreement with the real accident on the great east Japan earthquake tsunami.. |
| 96. |
The modification of boundary treatment in the incompressible sph for pressure calculation accuracy on the solid boundary
© Owned by the authors, published by EDP Sciences, 2016. 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.. |
| 97. |
浅井 光輝, 江口史門, Nur Ain Binti Idris, Multi-Scale and –physics tsunami simulation from earthquake center to infractructures, 3rd International Conference on Violent Flows2016, 2016.03. |
| 98. |
宮川欣也, 浅井 光輝, Multi-scale bridge wash out simulation during tsunami by a stabilized ISPH method, The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES2015), 2015.12. |
| 99. |
野上智隆, 浅井 光輝, Kiyonobu KASAMA, A coupling simulation between soil scour and seepage flow by using a stabilized ISPH method, The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES2015), 2015.12. |
| 100. |
浅井 光輝, 宮川欣也, Multi-scale and -physics particle simulation for tsunami disaster mitigation, Analysis of Continuum Mechanism and Industrial Applications (CoMFoS15), 2015.12. |
| 101. |
浅井 光輝, 野上智隆, 宮川欣也, Multi-level tsunami disaster simulation by a particle method, 2nd Japan-Spain Workship on Computational Mechanics, 2015.10. |
| 102. |
浅井 光輝, 宮川欣也, 野上智隆, Multi-scale and -physics tsunami disaster simulation for disaster mitigation, The 3rd International Workshops on Advances in Computational Mechanics, 2015.10. |
| 103. |
Abdelraheem M. Aly Abd Allah, 浅井 光輝, Application of ISPH method in fluid-structure interactions, The 3rd International Workshops on Advances in Computational Mechanics, 2015.10. |
| 104. |
野上智隆, 浅井 光輝, Abdelraheem M. Aly Abd Allah, Clarification of soil scour and seepage flow by using a particle method, IV International Conference on Particle-based Methods(Particle2015),, 2015.09. |
| 105. |
宮川欣也, 浅井 光輝, Nur Ain Binti Ideis, Bridge washout simulation during Tsunami by a stabilized ISPH method, IV International Conference on Particle-based Methods(Particle2015),, 2015.09. |
| 106. |
浅井 光輝, 宮川欣也, Multi-scale and –physics tsunami disaster simulation, International Symposium on Disaster Simulation, 2015.05. |
| 107. |
Yoshiya Miyagawa, Mitsuteru Asai, Nur Ain Binti Idris, Bridges wash out simulation during tsunami by a stabilized ISPH method, 4th International Conference on Particle-Based Methods, PARTICLES 2015, 2015.01, In 2011, the huge tsunami caused by the great east Japan earthquake devastated many infrastructures in pacific coast of north eastern Japan. Particularly, collapse of bridges caused a traffic disorder and these collapse behaviors led to delay of recovery after the disaster. In this study, the bridge wash away accident is selected as a target issue, and it is represented in order to investigate the criteria and its mechanism by a numerical simulation. For this purpose, Incompressible Smoothed Particle Hydrodynamics (ISPH) Method, which is one of the pure mesh free methods, is utilized for the rigid body motion simulation. In this study, rigid body motion is introduced for the fluid-rigid interaction behavior during bridge wash away simulation. In the numerical analysis, the upper bridge structure is washed out by receiving an impact fluid force. The validation tests in two scales showed good agreement with experimental test and the real accident on the great east Japan earthquake tsunami.. |
| 108. |
Tomotaka Nogami, Mitsuteru Asai, Aly Abdelraheem, Clarification of soil scour and seepage flow by using a particle method, 4th International Conference on Particle-Based Methods, PARTICLES 2015, 2015.01, In 2011, Tohoku-Kanto earthquake tsunami caused serious damage to the port structures such as a breakwater and seawalls. Damage mechanisms of these structures have been studied in the past, and there are some causes. In this study, Soil scour and seepage flow are focused on. A particle simulation tool based on a stabilized ISPH method [1] has been extended to solve the different soil damage mechanisms; soil sour and seepage flow problem at the same time.. |
| 109. |
Bridges wash out simulation during tsunami by a stabilized ISPH method
In 2011, the huge tsunami caused by the great east Japan earthquake devastated many infrastructures in pacific coast of north eastern Japan. Particularly, collapse of bridges caused a traffic disorder and these collapse behaviors led to delay of recovery after the disaster. In this study, the bridge wash away accident is selected as a target issue, and it is represented in order to investigate the criteria and its mechanism by a numerical simulation. For this purpose, Incompressible Smoothed Particle Hydrodynamics (ISPH) Method, which is one of the pure mesh free methods, is utilized for the rigid body motion simulation. In this study, rigid body motion is introduced for the fluid-rigid interaction behavior during bridge wash away simulation. In the numerical analysis, the upper bridge structure is washed out by receiving an impact fluid force. The validation tests in two scales showed good agreement with experimental test and the real accident on the great east Japan earthquake tsunami.. |
| 110. |
Clarification of soil scour and seepage flow by using a particle method
In 2011, Tohoku-Kanto earthquake tsunami caused serious damage to the port structures such as a breakwater and seawalls. Damage mechanisms of these structures have been studied in the past, and there are some causes. In this study, Soil scour and seepage flow are focused on. A particle simulation tool based on a stabilized ISPH method [1] has been extended to solve the different soil damage mechanisms; soil sour and seepage flow problem at the same time.. |
| 111. |
Yoshiya Miyagawa, Mitsuteru Asai, Abdelrageem M. Aly, Fundamental study for wash out simulation of bridge girders by using a particle method, 2014 World Congress on Advances in Civil, Environmental and Materials Research (ACEM14), 2014.08. |
| 112. |
Abdelrageem M. Aly, Mitsuteru Asai, Simulation of fluid-structure interaction using an incompressible smoothed particle hydrodynamics, 2014 World Congress on Advances in Civil, Environmental and Materials Research (ACEM14), 2014.08. |
| 113. |
Tetsuro Goda, Mitsuteru Asai, Abdelraheem M. Aly, Nur’Ain Idris, Numerical evaluation of tsunami force acting on tsunami refuge building by using a particle method, 2014 World Congress on Advances in Civil, Environmental and Materials Research (ACEM14), 2014.08. |
| 114. |
Toshihiro Morimoto, Mitsuteru Asai, Kiyonobu Kasama, Fundamental study of Fluid-Soil-Seepage flow coupled analysis by a particle method based on the mixed flow theory, 11th World Congress on Computational Mechanics (WCCM XI), 2014.07. |
| 115. |
Abdelraheem M. Aly, Mitsuteru Asai, Large scale simulation of fluid-structure interaction using an incompressible Smoothed Particle Hydrodynamics, 11th World Congress on Computational Mechanics (WCCM XI), 2014.07. |
| 116. |
Mitsuteru Asai, Kazuo Kashiyama, Kenjiro Terada, Shuji Moriguchi, Mao Kurumatani, Large scale tsunami simulation by a particle method and its 3D visualization, 11th World Congress on Computational Mechanics (WCCM XI), 2014.07. |
| 117. |
Shoiji Tanabe, Mitsuteru Asai, Kazuo Kashiyama, Kenjiro Terada, Shuji Moriguchi, Mao Kurumatani, Numerical evaluation of tsunami impact force acted on a bridge girder druing tsunami by using a particle method, 11th World Congress on Computational Mechanics (WCCM XI), 2014.07. |
| 118. |
Toshihiro Morimoto, Mitsuteru Asai, Kiyonobu Kasama, Fundamental study of fluid-soil-seepage flow coupled analysis by a particle method based on the mixed flow theory, Joint 11th World Congress on Computational Mechanics, WCCM 2014, the 5th European Conference on Computational Mechanics, ECCM 2014 and the 6th European Conference on Computational Fluid Dynamics, ECFD 2014, 2014.07, Damage mechanisms of port structures such as breakwater and seawall have been studied in the past, and there are mainly three causes; I. horizontal force due to the water level difference between the front and rear breakwater, II. soil scour and erosion behind the seawall during overflow and III. piping destruction associated with the decline of the bearing capacity by seepage flow. In this study, a particle simulation tool based on the SPH has been developed to solve the different soil damage mechanisms; soil sour and seepage flow problem. These simulations should treat the Fluid-Soil and Fluid-Seepage flow interactions, and the particle simulation tool has been modified and improved to solve each interaction problem. For the Fluid-Soil interactions in the soil scour problem, soil is modeled by a Bingham flow model which is one of the non-Newtonian fluids, and the Mohr-Coulomb criterion is applied in the plastic yield judgment. On the other hand, in the seepage flow analysis, surface flow and seepage flow are described by the same government equation "Darcy-Brinkman equation", and simultaneous analysis is carried out. These different simulations have been implemented by modifying the standard SPH method.. |
| 119. |
Shoichi Tanabe, Mitsuteru Asai, Kenjiro Terada, Kazuo Kashiyama, Shuji Moriguchi, Mao Kurumatani, Numerical Evaluation of Impact Tsunami Force Acted on Bridge Girders by Using a Particle Method, Computational Engineering and Science for Safety and Environmental Problems (COMPSAFE2014), 2014.04. |
| 120. |
Abdelraheem M. Aly, Mitsuteru Asai, Simulation of Fluid-Structure Interaction in Flood Disasters Using ISPH Method, Computational Engineering and Science for Safety and Environmental Problems (COMPSAFE2014), 2014.04. |
| 121. |
Toshihiro Morimoto, Mitsuteru Asai, Kiyonobu KASAMA, Fundamental Study for Seawall Collapse Simulation during Tsunami by Using a Particle Method, Computational Engineering and Science for Safety and Environmental Problems (COMPSAFE2014), 2014.04. |
| 122. |
Abdelraheem M. Aly, Mitsuteru Asai, Large scale simulation of fluid-structure interaction using an incompressible smoothed particle hydrodynamics, Joint 11th World Congress on Computational Mechanics, WCCM 2014, the 5th European Conference on Computational Mechanics, ECCM 2014 and the 6th European Conference on Computational Fluid Dynamics, ECFD 2014, 2014.01, Numerical simulations for free surface flow models, which are water entry of several rigid bodies, fluid tank sloshing and flood disaster over several rigid bodies were conducted by using an Incompressible smoothed particle hydrodynamics (ISPH) method. The governing equations are discretized and solved with respect to Lagrangian moving particles filled within the mesh-free computational domain and the pressure was evaluated by solving pressure Poisson equation using a semi-implicit algorithm based on the projection scheme to ensure divergence free velocity field and density invariance condition. In this study, we modeled the structure as a rigid body motion by two different techniques. In the first technique, we modelled the rigid body corresponding to Koshizuka et Al. [1]. They proposed a passively moving-solid model to describe the motion of rigid body in a fluid. Firstly, both of fluid and solid particles are solved with the same calculation procedures. Secondly, an additional procedure is applied to solid particles. In the second technique, we compute the motions of a rigid body by direct integration of fluid pressure at the position of each particle on the body surface and the equations of translational and rotational motions were integrated in time to update the position of the rigid body at each time step. The performance of these two techniques was validated through the comparison with experimental results.. |
| 123. |
Shoichi Tanabe, Mitsuteru Asai, Kenjiro Terada, Kazuo Kashiyama, Shuji Moriguchi, Mao Kurumatani, Numerical evaluation of tsunami impact force acted on a bridge girder during tsunami by using a particle method, Joint 11th World Congress on Computational Mechanics, WCCM 2014, the 5th European Conference on Computational Mechanics, ECCM 2014 and the 6th European Conference on Computational Fluid Dynamics, ECFD 2014, 2014.01, On March 11, 2011, the huge Tsunami caused by the great east Japan earthquake devastated the Pacific coast of north-eastern Japan. Many infrastructures including bridges were collapsed by the Tsunami. New generation of Tsunami disaster prevention and mitigation method should be reconsidered toward the next millennium Tsunami. In this study, a stabilized Smoothed Particle Hydrodynamics (SPH) has been utilized for an evaluation of fluid force acted on bridge girders. In addition, a new boundary treatment using a virtual marker and fixed boundary particle is developed to satisfy the slip and no-slip boundary condition for the velocity field and to satisfy the pressure Neumann condition at the same time. The accuracy and efficiencies of our proposed method are validated by comparison between a numerical solution and experimental results. Finally, a simple treatment for the particle method has been introduced to our developed SPH tool to simulate wash out of the bridge girder.. |
| 124. |
N. M. Amin, Mitsuteru Asai, Yoshimi 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, 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.. |
| 125. |
Application of a model order reduction method based on the Krylov subspace to finite element transient analysis imposing several kinds of boundary condition
© 2010 IOP Publishing Ltd. 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.. |
| 126. |
Fundamental study of fluid-soil-seepage flow coupled analysis by a particle method based on the mixed flow theory
Damage mechanisms of port structures such as breakwater and seawall have been studied in the past, and there are mainly three causes; I. horizontal force due to the water level difference between the front and rear breakwater, II. soil scour and erosion behind the seawall during overflow and III. piping destruction associated with the decline of the bearing capacity by seepage flow. In this study, a particle simulation tool based on the SPH has been developed to solve the different soil damage mechanisms; soil sour and seepage flow problem. These simulations should treat the Fluid-Soil and Fluid-Seepage flow interactions, and the particle simulation tool has been modified and improved to solve each interaction problem. For the Fluid-Soil interactions in the soil scour problem, soil is modeled by a Bingham flow model which is one of the non-Newtonian fluids, and the Mohr-Coulomb criterion is applied in the plastic yield judgment. On the other hand, in the seepage flow analysis, surface flow and seepage flow are described by the same government equation "Darcy-Brinkman equation", and simultaneous analysis is carried out. These different simulations have been implemented by modifying the standard SPH method.. |
| 127. |
Large scale simulation of fluid-structure interaction using an incompressible smoothed particle hydrodynamics
Numerical simulations for free surface flow models, which are water entry of several rigid bodies, fluid tank sloshing and flood disaster over several rigid bodies were conducted by using an Incompressible smoothed particle hydrodynamics (ISPH) method. The governing equations are discretized and solved with respect to Lagrangian moving particles filled within the mesh-free computational domain and the pressure was evaluated by solving pressure Poisson equation using a semi-implicit algorithm based on the projection scheme to ensure divergence free velocity field and density invariance condition. In this study, we modeled the structure as a rigid body motion by two different techniques. In the first technique, we modelled the rigid body corresponding to Koshizuka et Al. [1]. They proposed a passively moving-solid model to describe the motion of rigid body in a fluid. Firstly, both of fluid and solid particles are solved with the same calculation procedures. Secondly, an additional procedure is applied to solid particles. In the second technique, we compute the motions of a rigid body by direct integration of fluid pressure at the position of each particle on the body surface and the equations of translational and rotational motions were integrated in time to update the position of the rigid body at each time step. The performance of these two techniques was validated through the comparison with experimental results.. |
| 128. |
Numerical evaluation of tsunami impact force acted on a bridge girder during tsunami by using a particle method
On March 11, 2011, the huge Tsunami caused by the great east Japan earthquake devastated the Pacific coast of north-eastern Japan. Many infrastructures including bridges were collapsed by the Tsunami. New generation of Tsunami disaster prevention and mitigation method should be reconsidered toward the next millennium Tsunami. In this study, a stabilized Smoothed Particle Hydrodynamics (SPH) has been utilized for an evaluation of fluid force acted on bridge girders. In addition, a new boundary treatment using a virtual marker and fixed boundary particle is developed to satisfy the slip and no-slip boundary condition for the velocity field and to satisfy the pressure Neumann condition at the same time. The accuracy and efficiencies of our proposed method are validated by comparison between a numerical solution and experimental results. Finally, a simple treatment for the particle method has been introduced to our developed SPH tool to simulate wash out of the bridge girder.. |
| 129. |
Syoichi Tanabe, Mitsuteru Asai, YOSHIMI SONODA, Numerical evaluation of fluid force acted on bridge girders during tsunami by using a particle method, 5th Asia Pasific Congress on Computational Mechanics & 4th International Symposium on Computational Mechanics, 2013.12. |
| 130. |
Toshihiro Morimoto, Mitsuteru Asai, YOSHIMI SONODA, Fundamental study for seawall collapse simulation during Tsunami by using a particle method, 5th Asia Pasific Congress on Computational Mechanics & 4th International Symposium on Computational Mechanics, 2013.12. |
| 131. |
Mitsuteru Asai, Masaharu Isshiki, Syoichi Tanabe, Large scale tsunami simulation by the incompressible SPH with real geography generated from aero-survery data, International Conference on Particle-Based Method (Particle2013), 2013.09. |
| 132. |
浅井 光輝, 田邊将一, 一色正晴, A large scale tsunamiu run-up simulation and numarical evaluation of fluid force during tsunami by using a partilce method, The 2013 World Congress on Advances in Structural Engineering and Mechanics (ASEM13), 2013.09. |
| 133. |
浅井 光輝, 森本敏弘, 一色正晴, A large scale tsunamiu run-up simulation by a partilce method with a real geography, 11th International Conference on Analysis of Discontinuous Deformation, 2013.08. |
| 134. |
浅井 光輝, Large scale tsunami simulation by a particle method and its application to disaster prediction, 12th U.S. Natinal Congress on Computational Mechanics (USNCCM12), 2013.07. |
| 135. |
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, 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.. |
| 136. |
N. Ishikawa, M. Beppu, T. Mikami, H. Tatesawa, Mitsuteru Asai, Collapse mechanism of seawalls by impulsive load due to the March 11 tsunami, 9th International Conference on Shock and Impact Loads on Structures, 2011.12, On March 11, 2011 the huge tsunami caused by the magnitude 9.0 earthquake devastated the Tohoku Pacific Ocean coastal regions of Japan. The impulsive fluid load of the tsunami caused devastating damage to the seawalls in the Tohoku region of Japan. On April 13-15, we investigated one of the disaster area, the town of Taro which had been very famous for having a 10m high seawall. This special lecture focuses on the collapse mechanism of the seawall by the impulsive fluid load due to the March 11 tsunami.. |
| 137. |
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, 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.. |
| 138. |
A study of violent water induced impact problems using ISPH method
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.. |
| 139. |
Collapse mechanism of seawalls by impulsive load due to the March 11 tsunami
On March 11, 2011 the huge tsunami caused by the magnitude 9.0 earthquake devastated the Tohoku Pacific Ocean coastal regions of Japan. The impulsive fluid load of the tsunami caused devastating damage to the seawalls in the Tohoku region of Japan. On April 13-15, we investigated one of the disaster area, the town of Taro which had been very famous for having a 10m high seawall. This special lecture focuses on the collapse mechanism of the seawall by the impulsive fluid load due to the March 11 tsunami.. |
| 140. |
Fast dynamic solver for the design of bridge using a model order reduction
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.. |
| 141. |
Study on fast dynamic analysis using mesh superposition method and model order reduction. |
| 142. |
MULTI-SCALE EVALUATION METHOD FOR STRENGTH OF BRITTLE MATERIALS. |
| 143. |
THE IMAGE-BASED FCM USING A MULTI-COVER SYSTEM. |
| 144. |
A STUDY ON THE BOUNDARY CONDITION OF MULTI-PHASE MATERIALS FOR A FCM. |
| 145. |
ANALYSIS OF SHARE FRACTURE OF RAINFORCED CONCRETE BEAMS BY LATTICE MODEL. |
| 146. |
REDUCTION TECHNIQE IN SYMMETRY BREAKING BIFURCATION PROBLEMS USING EIGENVECTORS. |
| 147. |
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, 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.. |
| 148. |
N. Ishikawa, M. Beppu, T. Mikami, H. Tatesawa, Mitsuteru Asai, Collapse mechanism of seawalls by impulsive load due to the March 11 tsunami, 9th International Conference on Shock and Impact Loads on Structures, On March 11, 2011 the huge tsunami caused by the magnitude 9.0 earthquake devastated the Tohoku Pacific Ocean coastal regions of Japan. The impulsive fluid load of the tsunami caused devastating damage to the seawalls in the Tohoku region of Japan. On April 13-15, we investigated one of the disaster area, the town of Taro which had been very famous for having a 10m high seawall. This special lecture focuses on the collapse mechanism of the seawall by the impulsive fluid load due to the March 11 tsunami.. |
| 149. |
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, 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.. |
| 150. |
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, 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.. |
