Effect of extension-twisting and extension-bending coupling on a compressed plate with a cut-out

This paper investigates the behaviour of thin-walled composite plates with a cut-out under compression. The effects of lamina ply orientation on the critical state and the behaviour of the plates in the post-critical range were examined. The scope of the research involved numerical modelling of linear and non-linear stability problems by the finite element method, using the simulation software ABAQUS®. The created numerical models were then verified experimentally. The study was performed on a plate with an unsymmetric stacking sequence of plies. To force buckling into a higher mode, an unsymmetric laminate with extension-twisting and extension-bending coupling was used. This approach led to obtaining the natural, lowest mode of buckling (flexural-torsional), one that ensures stable performance of the structure in the post-critical range (no transition to flexural mode).