ABSTRACT
Fiber composites have excellent properties which make them widely used. However, they are not as tough as many structural metals and also can warp and microcrack during manufacture. Expressions governing composite mechanical properties can be very simple and straight-forward. The simplest is that for the Young’s modulus in the fiber direction of an aligned fiber laminate. In composites, the water absorption was reduced approximately in proportion to the amount of fibers present. The volume change of the resin during the manufacture of a composite affects such things as the surface finish of reinforced polymer moldings. In high performance composites, the resin shrinkage is less because epoxies are used, and the surface finish of the composite is determined by the surfaces used in the molding process. Experiments using expanding monomers are reviewed here and it is shown that, when shrinkage stresses are reduced, the benefits and more are obtained.
