Buckling and post-buckling of delaminated Reissner–Mindlin panels subjected to hygro-thermal-mechanical multi-field loading

Abstract

This paper proposed a theoretical study on buckling and post-buckling responses for delaminated Reissner–Mindlin composite panels under hygrothermal environment based on the first order shear deformation theory. Constitutive equations of the laminated panel which takes into consideration of the transverse shear and the hydrothermal effects were conducted. Using the von-Kaman nonlinear displacement–strain relationship governing equations in terms of displacements and the slope functions were derived in which the nonlinear contact effect at the interface of delamination was included. Asymptotic solutions of the delaminated composite panel were obtained using perturbation approach and the post-buckling equilibrium paths of the panel characterized by the in-plane load vs deflection amplitude curves were determined via Galerkin approach. By developing Matlab programs, theoretical solutions were computed and parametric studies were carried out to examine the effect of the temperature, the hygroscopic concentration and the delamination conditions on the buckling and post-buckling behaviors of the delaminated panel. It is found that increasing the environmental temperature and hygroscopic concentration will significantly reduce the load carrying capacity of the delaminated composite panels in buckling and post-bucking stage. Solutions from the analysis were validated against finite element results from ABAQUS analysis and were found in good agreement with the latter.