Abstract
The aim of this project is to evaluate the static strength and fatigue lives of Graphite/PEEK thermoplastic composite materials after pretorsion、repair and thermal effects. Composite shows different mechanical properties in different environmental conditions, especially under pretorsional and thermal effects. For example,pretorsional effect will result in the delamination of specimens, and its mechanical property will be degraded. On the other hand, thermal loading has an effect on the matrix of polymer resin. Due to the different coefficient of thermal expansion between reinforced fiber and matrix, static and fatigue strengths will be decreased. And specimens will be repaired after various environmental loadings, the effect of repair will be examinated. In the project, the residual strength, toughness, fatigue lives on the composites after pretorsional and thermal effects are tested for comparison with the original composites. Furthermore, a predicted model will be proposed to evaluate the fatigue lives under different conditions.