5. A unidirectional composite failed during operation, and you are trying to find its strength to determine if the failure was due to a design error or due to poor material quality. Three different uniaxial tension tests are done at angles of 30, 45 and 60 relative to the fiber axis. The failure stress for these parts is 89 MPa, 54 MPa and 39 MPa respectively. a. Find the strengths in each direction (*, 2, and T12+) assuming the composite failure is governed by a Tsai-Hill model. Hint: you can use your stress rotation functions from previous assignment. (20 points) b. If the anticipated strengths were 0 = 400 MPa, 2* = property (if any) was overestimated? (5 points) = 50 MPa and T12* = 60 MPa, which 30 45 60