6. (a) Write a function to predict the first ply failure in a laminate. The inputs should be the global applied stress g, the ply layup angles, thicknesses and stiffness tensor C and the composite strengths (1*, 02* and T12+). It should use a Tsai-Hill criterion to predict failure. The function should output which if any ply has failed and the corresponding stresses in that ply. (b) Now take a CFRP composite with fiber properties Ef = 410 GPa, v = 0.19, matrix properties of Em = 3.2, vm = 0.39 and a volume fraction V = 65%. This is made into lamina and stacked in a [0/30/45/60/90], layup. The thickness of the 0, 45 and 90 plies is 1.0mm and the thickness of the 30 and 60 plies is 0.75mm. The failure strengths of the plies are = 1.9 GPa, = 60 MPa and T12* = 140 MPa. If a global stress is applied with a ratio of = [3, 2, 1]o, find the at which the laminate will fail to the nearest MPa and indicate which ply has failed and at what ply stress. Hint: To check your code, take a [0%45/90]; laminate with ply thicknesses of 0.5mm for the 0 and 90 plies and 1.0mm for the 45 plies. The first ply to fail will be the -45, which will fail at = 114.6 MPa with a ply stress of -45 = [-207.5, 73.8, 22.6] MPa.