Probabilistic analysis of buckling loads of structures via extended Koiter law

Kiyohiro Ikeda, Makoto Ohsaki, Kentaro Sudo and Toshiyuki Kitada

Abstract

Initial imperfections, such as initial deflection or remaining stress, cause deterioration of buckling strength of structures. The Koiter imperfection sensitivity law has been extended to describe the mechanism of reduction for structures. The extension is twofold: (1) a number of imperfections are considered, and (2) the second order (minor) imperfections are implemented, in addition to the first order (major) imperfections considered in the Koiter law. Yet, in reality, the variation of external loads is dominant over that of imperfection. In this research, probabilistic evaluation of buckling loads against external loads subjected to probabilistic variation is conducted by extending the concept of imperfection sensitivity. A truss arch subjected to dead and live loads is considered as a numerical example. The mechanism of probabilistic variation of buckling strength of this arch is described by the proposed method, and its reliability is evaluated.

Key Words

buckling loads; imperfection sensitivity law; probabilistic analysis.

Address

Kiyohiro Ikeda: Dept. of Civil & Environmental Engineering, Tohoku University, Sendai 980-8579, Japan Makoto Ohsaki: Dept. of Architecture & Architectural Engineering, Kyoto University, Kyoto 615-8540, Japan Kentaro Sudo: Dept. of Civil & Environmental Engineering, Tohoku University, Sendai 980-8579, Japan Toshiyuki Kitada: Dept. of Civil Engineering, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan

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