On artificial geometry errors in the adaptive analysis of eigenvalues and eigenmodes of curved shell structures using the finite element method

The standard procedure to compute design loads for shell structures as also proposed in design rules is based on the computation of the limit load taking into account the modification of the so-called stability loads due to geometrical imperfections. The imperfections are mostly chosen affine to the buckling patterns, which are solutions of the eigenvalue-problem for the geometrically perfect structure. Thus, the eigenvalue-problems for stability points have to be solved very accurately. In the present contribution an adaptive h -refinement procedure is taken for the solution using low order shell elements. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)