KOITER'S POST-BUCKLING ANALYSIS OF GENERAL SHELL STRUCTURES USING THE FINITE ELEMENT METHOD

摘要

We present in this paper a simple finite element implementation of Koiter's perturbation analysis for initial post-buckling of general shell structures. The calculation of post-buckling curvature coefficients shows converge problems when careless finite element implementation of Koiter's analysis is carried out. Instead of using special formulations, we show that reasonably accurate results can be obtained by extending an existing linear triangular shell element with a nonlinear strain contribution derived from simple linear displacement shape functions. The resulting constant strains alleviate locking phenomena in the calculation of the post-buckling coefficients. Numerical results are shown to validate the proposed approach.