Buckling And Post Buckling Behavior For Unsymmetrical Laminates Part II: Stability Characteristics

This is the second of two companion papers that examine the elastic buckling and post buckling behavior of unsymmetric cross-ply laminates. The existence of geometric imperfection and thermal mismatch between plies result in these panels to retain two equilibrium configurations despite being cured in a flat mold. These equilibrium configurations conform to cylindrical shapes of orthogonal and opposite curvatures. Under externally applied load a panel undergoes snap-through behavior from one equilibrium shape to the other. The unified finite element methodology based on Koiter’s theory and presented in the first companion paper is extended to predict the required force responsible for snap-through behavior. Accordingly, ABAQUS, ANSYS and LS-DYNA finite element codes are used to predict the critical snap-through forces and their predictions are compared.