The SG of fiber-reinforced composites can be represented as shown below. Let the material properties of the fiber and matrix be: Fiber: E,,11,, =230 GPa, E,,22,, =15 GPa, G,,12,,=G,,13,, =15GPa, G,,23,, =7GPa Matrix: E =4.0GP, ν=0.35 Fiber volume of fraction is assumed to be 60% The material properties are obtained from: “Soden, P. D., Hinton M. J. and Kaddour, A. S., Lamina properties, lay-up configurations and loading conditions for a range of fibre reinforced composite laminates. Compos. Sci. Technol., 1998, 58(7), 1011”