• Given a graphite/epoxy lamina with fiber orientation angle = 60 with the strength properties listed belowand subjected to a state of stress {ox, Oy, Txy} = {2B, -3B, 4B}

where B is some variable to be determined. а.Draw a complete and correct FBD for this lamina. b. Using Tsai-Wu Failure criterion, find the value of B that causes failure of this lamina. X_{t}=1500 \mathrm{MPa}, X_{c}=1500 \mathrm{MPa}, Y_{t}=40 \mathrm{MPa}, Y_{c}=246 \mathrm{MPa}, S=68 \mathrm{MPa} Approximate answer: B = 21 +/- 10% (units you figure out)