Optimized cure cycle to minimize fiber stresses in polymer matrix composites

摘要

A technique for the cure cycle optimization for a thermoset polymer matrix composites is developed. In this technique, a given polymer is cured around a pretensioned fiber. As the curing continues, the volume of polymer changes due to its thermal expansion and polymerization shrinues, the volume of polymer changes due to its thermal expansion and polymerization shrinkage. The matrix volume change occurring after the point in the cure cycle when fiber-matrix interface has developed enough shear strength affects the fiber tension. An automated feedback system is developed to change the heating rate proportional to the change in fiber tension so as to produce the minimum fiber tension change. Such a cure cycle is defined as the optimum. The volumetric dilatometer is also used to independently monitor the matrix volume change during the standard and the optimum cure cycles. The comparison between the two techniques show that the cure cycle that produces minimum change in fiber tension also produces minimum change in polymer volume.