Process-induced stress analysis of composite laminates using semi-analytical Hamiltonian method

Abstract

A study of process-induced stress in composite laminates is presented. A methodology is proposed for predicting the evolution of the process-induced stress field during the curing process. An analysis of the process-induced stress is conducted on the basis of a systematic Hamiltonian thermo-elasticity theory in conjunction with a semi-analytical finite element method. The formulation of the numerical method is briefly introduced in this paper and some numerical examples are presented to illustrate it. From numerical results for a typical example of process-induced stress analysis for laminates, it is clear that the process-induced thermo-stress fields involve complex variations of gradient and multipeak values at different stages during the curing process. This is the reason for prefailure damage to such laminates, which results in a reduction of their load carrying capacity. The method and numerical conclusions provided in this paper should be of great value to engineers dealing with composite structures.