Process-Induced Residual Thermal Stresses in Advanced Fiber-Reinforced Composite Laminates

Abstract

A study of process-induced stresses in advanced fiber-reinforced composite laminates is presented. An analysis of the residual thermal stresses is conducted on the basis of laminate thermoelasticity theory in conjunction with a quasi-three-dimensional finite element method. Formulation of the numerical method is briefly outlined in the paper. To illustrate the fundamental nature of the problem, numerical examples for a quasi-isotropic [0 deg/90 deg/ ± 45 deg]s graphite-epoxy composite system are presented. Complex three-dimensional stress states of significant magnitude are reported. Emphasis is placed on the interlaminar stress distributions along ply interfaces. Effects of laminate stacking sequence on the residual thermal stresses are examined in detail. Implications of the results on deformation and failure of composite laminates are discussed.