Finite Strip Elements in Thin Plate Buckling Analysis

摘要

An important design limit on thin walled plate structures under compressiveloading is the buckling stress. The main goals is to have a tool for thin plate structures under compressive loading and to have a good basis for further development. The subroutines used for calculating the stiffness matrices involved are printed as direct listings of the computer program so that the text of this report can be checked with the computer listings. In order to find the critical buckling stress for a chosen half wave length, two methods were used. First a determinant search is used which gives only the buckling stress. The second method used is the inverse iteration method which gives besides the lowest eigenvalue also the eigenvector (buckling mode). The combination of eigenvalue and eigenvector can be used to calculate the derivative of the eigenvalue with respect to any design variable very efficiently. The first derivative of the eigenvalue with respect to the half wave length is considered only, but derivatives with respect to plate thicknesses could be included without much effort. Further work is done to extend the method to anisotropic material and to include an optimization process.