Composite Reliability Enhancement Via Reloading

摘要

Composite strength is an inverse function of the size of the composite. As the use of composites expands into larger applications, such as airplane wings, missile components and ship superstructures the ability to accurately predict composite performance for large applications has become more important. The composite failure process is sequential and initiates with early breaking of the weak fibers. Concentration of breakage sites accumulate and lead to ultimately catastrophic failure. Prestressing fibers prior to solidification of the matrix has been demonstrated to increase the reliability of the composite by minimizing the spatial concentration of the breakage sights. This study concentrates on quantifying the level of preload and gauge length to optimize the prestress effect. Computer simulations of graphite bundle tests were used to validate actual AS-4 graphite bundle tests. The simulations were then extended to predict prestress performance. Keywords: Tensile failure; Theses; Weibull strength distribution. (KR)