Answer:153.76 MPa
Explanation:
[tex]Initial Area\left ( A_0\right )=12.56 mm^2[/tex]
[tex]Final Area\left ( A_f\right )=0.7\times 12.56 mm^2=8.792 mm^2[/tex]
[tex]Die angle=30^{\circ}[/tex]
[tex]\alpha =\frac{30}{2}=15^{\circ}[/tex]
[tex]\mu =0.08[/tex]
[tex]Yield stress\left ( \sigma _y \right )=350 MPa[/tex]
[tex]B=\mu cot\left ( \aplha\right )=0.2985[/tex]
[tex]\sigma _{pressure}=\sigma _y\left [\frac{1+B}{B}\right ]\left [ 1-\frac{A_f}{A_0}\right ]^B[/tex]
[tex]\sigma _{pressure}=350\left [\frac{1+0.2985}{0.2985}\right ]\left [ 1-\frac{8.792}{12.56}\right ]^{0.2985}[/tex]
[tex]\sigma _{pressure}=153.76 MPa[/tex]
