Determine amount of fibers by burn-out test

Question

Response to the following:

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 WF and matrix weight fraction W_M.

2. Compute E₁, E₂, G₁₂, and ν₁₂ given E_f = 230 GPa, E_m = Ef /50, G_f = E_f /2.5, G_m = E_m/2.6, ν_f = 0.25, ν_m = 0.3, and V_f = 40%. The fibers have a circular cross-section. Assume there are no voids.