Examination of selected failure criteria with asymmetric shear stresses in the collapse analysis of laminated shells

Abstract

The paper is concerned with failure analysis of composite shells performed with the usage of the nonlinear 6-parameter shell theory with drilling rotation degree of freedom. This special theory embodies naturally unlimited translations and rotations and is suitable for analysis of irregular shells for instance with various, particularly orthogonal, intersections. The presence of the drilling rotation is inherently accompanied with asymmetry of in-plane shear stresses and strains which must be taken into account in the composite failure criteria. In the paper in general two failure measures are applied: Hashin criterion and Tsai-Wu criterion which are appropriately modified to accommodate the stress asymmetry. It is shown, that depending on the used failure criterion, it is possible to obtain slightly different damage zones and values of the first ply failure and ultimate load. These values are compared with those obtained experimentally.