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(1) Answer the following short answer questions to the best…

(1) Answer the following short answer questions to the best of your ability. (a) (3 points) Explain the difference between the micromechanical analysis of a lamina and the macromechanical analysis of a lamina. (b) (3 points) Describe the steps for developing a semi-empirical model for the elastic properties of a composite lamina. (c) (4 points) Consider a graphite/epoxy composite lamina with 40% fiber volume fraction. Draw the tensile stress-strain diagram for the fiber material, the matrix material, and the composite lamina if both fiber and matrix materials are linear elastic. State any assumptions that you make in your stress-strain diagrams.   (2) (10 points) A unidirectional composite lamina has fibers with an elastic modulus of 220 GPa and a Poisson’s ratio of 0.375 while its matrix material has an elastic modulus of 15 GPa and a Poisson’s ratio of 0.25. Determine the fiber volume fraction (or fractions) which produces an axial to shear modulus ratio (E1 / G12) equal to 10 for the composite. Assume that the strength of materials approach is sufficiently accurate and that both the fiber and matrix materials are isotropic.   (3) (20 points) Suppose that you have an angle composite lamina with 50% volume fraction glass fibers in an epoxy matrix. The fibers are oriented at 60o relative to the global x-axis. An engineer measures the following state of stress acting on the lamina, Determine the strain in the global coordinate system for the given state of stress. Use the Halpin-Tsai equations to model the elastic properties of the composite lamina. Assume the glass fibers are circular and arranged in a square array within the matrix so that