1994 Fiscal Year Final Research Report Summary
A STUDY ON THE DEVELOPMENT OF STABILITY DESIGN METHODS FOR STEEL FRAMES
| Project/Area Number |
05650451
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
構造工学・地震工学
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| Research Institution | NAGOYA UNIVERSITY |
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Principal Investigator |
USAMI Tsutomu NAGOYA UNIVERSITY,DEPARTMENT OF CIVIL ENGINEERING,PROFESSOR, 工学部, 教授 (50021796)
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| Co-Investigator(Kenkyū-buntansha) |
GE Hanbin NAGOYA UNIVERSITY,DEPARTMENT OF CIVIL ENGINEERING,RESEARCH ASSOCIATE, 工学部, 助手 (90262873)
MIZUNO Eiji NAGOYA UNIVERSITY,DEPARTMENT OF CIVIL ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (80144129)
ITOH Yoshito NAGOYA UNIVERSITY,DEPARTMENT OF CIVIL ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (30111826)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Buckling / Coupled instability / Elastic second-order analysis / Frame structure / Stability design / Equivalent initial deflection / Stepped section / Strength |
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| Research Abstract |
The purpose of this study is to develop a design method for stability of steel frames. At the beginning, a critical review of stability design methods for steel frames is performed. Next, a new stability design method for frames is presented. Contray to the effective buckling length concept, the proposed method is based on the elastic second-order analysis. In this method, the introduction of equivalent initial deflections corresponding to the imperfections is of utmost importance. Therefore, a new equivalent deflection formula using curvature is suggested. Moreover, a methodology is proposed to explain the systematic application of this formula to a frame with stepped cross section. The validity of the method is demonstrated by some examples. Finally, a simplified analysis of steel frame strength by the second-order analysis, consideringthe local buckling of component plates, is shown. In the analysis, the initial equivalent deflection and local buckling criterion of stub column are introduced. On the other hand, although several elaborate analyzes have been performed to make clear the interactive behavior, there is little agreement with each other. Therefore, a detailed comparison of those results has shown that the analysis using moment-thrust-curvature relations are in best agreement with Q-factor method, accuracy of which was confirmed by experiments. Accordingly, the validity of the proposed simplified analysis was examined by comparison with the analysis using moment-thrust-curvature relations.
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