A uniaxial off-axis tensile test is conducted as shown in Figure 4.5. Using the Tsai-Hill criterion and assuming that the lamina strengths are the same in tension and compression, develop an equation relating the applied stress, \(\sigma_{x^{\prime}}\) to the lamina strengths \(s_{\mathrm{L}}, s_{\mathrm{T}}\), and \(s_{\mathrm{LT}}\), and the lamina orientation, \(\theta\), and

(b) using the result from part (a), for a unidirectional composite having strengths \(s_{\mathrm{L}}=1500 \mathrm{MPa}, s_{\mathrm{T}}=100 \mathrm{MPa}, s_{\mathrm{LT}}=70 \mathrm{MPa}\), and fiber orientation \(\theta=60^{\circ}\), determine whether or not an applied stress \(\sigma_{x}=200 \mathrm{MPa}\) would cause failure according to the Tsai-Hill criterion.

Transcribed Image Text:

2 A FIGURE 4.5 Off-axis uniaxial test of a unidirectional lamina specimen. x 0x