? E (GPa) Tensile Strength (MPa) Compressive Strength (MPa) Shear Strength (MPa) AS4 Carbon 0.20 235 3700 Epoxy 3501-6 0.35 4.3 69 200 100 1. A continuous fiber-reinforced composite is constructed from epoxy 3501-6 matrix and AS4 Carbon fibers. The volume fraction of fibers is 50%. The fibers are arranged in a triangular array resulting in d/s = 0.7425. Estimate the following composite properties: a) E1 b) E2 c) F1t d) F2t State all necessary assumptions to support your calculations.
F1t (MPa) F2t (MPa) F6 (MPa) F1c (MPa) F2c (MPa) Aramid 49/Epoxy 1400 30 49 335 158 2. Aramid 49/Epoxy is loaded according to ?x = 2?y. Calculate the value of ?x (assume ?x is tensile) at failure according to a) the Maximum Stress Failure Criterion and b) the Tsai-Wu Failure Criterion assuming ? = 45?. Repeat the calculation for the case where ?x is compressive.
3. The elastic modulus of polyimide is measured to be 0.5 X 106 psi at 65?F. The glass transition temperature for this material in the dry state is 600?F. Predict the modulus of this material at 200?F if it has absorbed 2% moisture (by weight).
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