1999 Fiscal Year Final Research Report Summary
Analysis of the fracture process of wooden frame structure under seismic loading by modified distinct-element method.
| Project/Area Number |
09460072
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林産学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
OHTA Masamitsu Graduate School of Agricultural and Life Sciences, The University of Tokyo, Professor, 大学院・農学生命科学研究科, 教授 (20126006)
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| Co-Investigator(Kenkyū-buntansha) |
TSUCHIMOTO Takahiro Graduate School of Agricultural and Life Sciences, The University of Tokyo, Assistant Professor, 大学院・農学生命科学研究科, 助手 (00261959)
YOSHIHARA Hiroshi Fac. of Science & Technology, Shimane University, Associate Professor, 総合理工学部, 助教授 (30210751)
ARIMA Takanori Graduate School of Agricultural and Life Sciences, The University of Tokyo, Professor, 大学院・農学生命科学研究科, 教授 (10144057)
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| Project Period (FY) |
1997 – 1999
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| Keywords | dynamic loading / wooden frame structure / metal-fastened joint / fracture aspect / Modified Distinct Element Method / Three-dimensional simulation / collapsing process / model used experiment |
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| Research Abstract |
This study was aimed to develop a new method, that enables to simulate the collapsing processes of wooden frame structure.
Firstly, the mechanical and fractographical behaviors of the joint parts under the dynamic loading were examined by experimental studies. Tensile and shearing tests of metal-fastened joints, which are made between the column and sill / beam, were made under various loading rate from 0.2 mm/sec to 2000 mm/sec. It was found that the fracturing aspects of the joint parts were different between the slow loading case and the high speed one.
Secondly, we tried to simulated the collapsing process of the frame structure in two dimensional frame models by a modified distinct element method, and we could make a program that can show the changing process of the frame from a rectangle to a parallelogram. In the next step, we developed a three dimensional program. In this program, each bar element was represented by four lows of distinct element. Composing these elements, we could arrive to analyze the collapsing process of two- story frame buildings under dynamic loading to the basement. For examples, a structure that have non-symmetric brace arrangement showed a rotating collapsing pattern, which can be observed in actual wooden house.
We also made a dynamic loading experiment using a reduced scale model structure. The order that joints destroy and the process of the buildings fall down agreed well between the simulation and the experiment.
We believe that our research can provide a powerful mean for the analysis of the wooden frame structure's behavior under a large scale earthquake.
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