PROCESS-INDUCED STRESS-ANALYSIS OF COMPOSITE LAMINATES USING SEMIANALYTICAL HAMILTONIAN METHOD

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 pr ocess-induced stress is conducted on the basis of a systematic Hamilto nian thermo-elasticity theory in conjunction with a semi-analytical fi nite element method. The formulation of the numerical method is briefl y introduced in this paper and some numerical examples are presented t o illustrate it. From numerical results for a typical example of proce ss-induced stress analysis for laminates, it is clear that the process -induced thermo-stress fields involve complex variations of gradient a nd multipeak values at different stages during the curing process. Thi s is the reason for prefailure damage to such laminates, which results in a reduction of their load carrying capacity. The method and numeri cal conclusions provided in this paper should be of great value to eng ineers dealing with composite structures. (C) 1998 Published by Elsevi er Science Ltd. All rights reserved.