A [0/+60/-60]s laminate with the ply properties listed in the table below is to be subjected to a temperature change from its initial temperature of 75°F. This temperature change can be

expressed as a linear temperature change through the thickness of the laminate, with the temperature at the top of the six-ply laminate set at 225°F and the temperature at the bottom of the six-ply laminate set to -75°F. Therefore, for the temperature distribution defined by the equation AT(2) = AT+T'z, with ATh2=225°F - 75°F = 150°F and AT-2=-75°F-75°F=-150°F, AT. =(AT1/2+AT-1/2)/2= [150+(-150)]/2=0°F and T'=(AT12-AT-1/2)/h=(150-(-150))/6(0.0052) = 9,615.4°F/inch we obtain the distribution expression a) Determine the stresses in the lamina coordinate system at both the top and bottom in each of the 0°, +60° and -60° plies. b) Given the lamina strengths in the table below, determine if the laminate subjected to this temperature change distribution could be expected to survive with no excessive lamina stresses and therefore with no damage to the laminate. c) Assuming the same initial stress-free temperature of 75°F and by subjecting this same [0/+60/-60]s laminate separately to (i) a uniform temperature of 225°F and (ii) a uniform temperature of -75°F, answer the question "Is the through thickness temperature gradient more stressing on the laminate than either the uniform through thickness temperature of 225°F or the uniform through thickness temperature of -75°F?" Property E₁ E₂ G12 V12 α₁ (-200°F to 200°F) α₂ (-200°F to 200°F) 01 0 AT(2) AT+T'z = 9,615.4°F/inch*z TL cu OL σχετι Ply thickness Lamina Value 25 x 10º psi 1.7 x 106 psi 1.3 x 10º psi 0.3 -0.3 x 10 in/in/°F 19.5 x 10 in/in/°F 110 x 10³ psi 4.0 x 10³ psi 9.0 x 10³ psi 110 x 10³ psi 20 x 10³ psi 0.0052 inch