1997 Fiscal Year Final Research Report Summary
Analysis of Local Stress and Collapse of Steel One-sided Angle Bracings subjected to Seismic Force
| Project/Area Number |
08650662
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMADA Motohiko Tohoku University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (90005471)
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| Co-Investigator(Kenkyū-buntansha) |
HUJIMOTO Katushige Tohoku University, Graduate School of Engineering, Research Assistant, 大学院・工学研究科, 助手 (50271888)
UEMATSU Yasushi Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (60151833)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Braced bay / an angle section bracing / friction connection / stress distribution / 3D elastic-plastic problem / contact problem / FEM analysis |
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| Research Abstract |
It has been clarified by the investigations of recent seismic disasters that huge number of the one-sided angle bracings of steel structures broke near the first bolt of one of friction connections in advance of the angle's full plastic force in spite of the application of the new anti-seismic design codes enacted in 1981.
In this project, the three dimensional elastic-plastic contact problem of both the tensile test models of friction connections by the use of high-strength bolts and the braced bay models with an one-sided angle section bracing were analyzed by the use of the finite element method to investigate the cause of the above mentioned phenomena.
The rational and simple finite element modeling of the bolt and the plate near the bolt was studied first, and the change in deformation and stress distribution of the friction connection was minutely clarified.
The elastic-plastic deflection process inclusive the slip phenomenon at the friction connection of one-sided angle bracing was calculated, and it was clarified that the relation of bracing's force versus the story drift is expressed by a tri-linear curve and its first critical point corresponds to the slip around the first bolt and/or the yield of the angle's fastened flange. it was also clarified that the effect of number of bolts on this process is negligilbly small.
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