A method of manufacturing a composite article may include attaching a polymer element to a tool. The polymer element may be pre-stretched prior to attachment to the tool. The method may further include annealing the polymer element at a predetermined temperature while constraining a length of the polymer element using the tool. In addition, the method may include curing or solidifying resin associated with the polymer element. The annealing step may be performed prior to the curing or solidifying step. Alternatively, the annealing step may be performed concurrently with the curing or solidifying step.