Problem 1 (25 points) A sheet of epoxy matrix is reinforced with unidirectional carbon fibers. The fiber volume fraction is 65% (V = 0.65). Er The elastic constants of the fiber reinforcement are: E =200 GPa, V = 0.20, Gr= 2(1+v+) The elastic constants of the matrix material are: Em = 5 GPa, vm = 0.33, Gm = Em 2(1+vm) In a lab test, this composite sheet is simultaneously subjected to 3 stresses: x, y and Txy where X is the fiber direction and Y is the transverse direction. Using Digital Image Correlation (DIC) techniques, the strains on the surface of the composite sheet can be measured. The measured strains of the composite are: x = 0.0035, y = -0.0025, and Yxy = 0.0030 (a) Determine the moduli and Poisson's ratio of the composite: Ex, Ey, Gxy, and VXY (b) Determine the stresses of the composite: x, y and Txy.