A material was tested under the proportionally increasing state of stress:
2̃́1 = -3̃́2 = ̃́3.
Yielding was observed at ̃́3 = 400 MPa.
a) What would be the yield stress of this material under simple tensile loading?
b) If the same material is used under the conditions such that ̃́1 = -̃́2 = 2̃́3, at what value of ̃́1 will yielding occur?
Solve the problem completely using:
i. Von Mises yield criterion
ii. Tresca yield criterion.