Thermoelastic postbuckling response of strip delamination models

Abstract

Postbuckling solutions are obtained for multilayered strip delamination models subjected to in-plane compression, bidirectional bending, twisting, and a temperature load that may vary arbitrarily in the thickness direction. The differential equations of equilibrium, the end conditions and the continuity conditions at the junction of the sublaminates are reduced to a system of algebraic equations governing the deformation parameters. Besides providing closed-form postbuckling solutions, these equations also reveal explicitly the effects on buckling due to various factors including delamination geometry, anisotropic elastic and thermal expansion coefficients, in-plane force and strain loads, bending and twisting curvatures, and the temperature field. A simple expression is given for the energy release rate in terms of the mid-plane strains and the curvatures of the sublaminates at the delamination front. A moderate temperature gradient in the thickness direction may severely aggravate the postbuckling deformation and increase the energy release rate.