Modal coupled instabilities of thin-walled composite plate and shell structures

The problem of buckling and initial post-buckling equilibrium paths of thin-walled structures built of plate and/or shell elements subjected to compression and bending has been solved. Plate and shell elements can be made of multi-layer orthotropic materials. A method of the modal solution to the coupled buckling problem within the first-order approximation of Koiter’s asymptotic theory, using the transition matrix method, has been presented. In the solution obtained, the effect of cross-sectional distortions and a shear lag phenomenon is included. The calculations are carried out for a few thin-walled structures.