1. The amount of fibers in a composite sample can be determined by a burn-out test. The burn-out eliminates all the resin and only the fibers remain. A composite sample plus its container weights 50.182 grams before burn-out and 49.448 grams after burn-out. The container weighs 47.650 grams. Compute the fiber weight fraction WFand matrix weight fraction WM.
2. Compute E1, E2, G12, and ν12 given Ef = 230 GPa, Em = Ef /50, Gf = Ef /2.5, Gm = Em/2.6, νf = 0.25, νm = 0.3, and Vf = 40%. The fibers have a circular cross-section. Assume there are no voids.