when the maximum shear stress in a bi-axial stress system reaches the shear stress at elastic limit in a simple tension test
when the maximum principal stress in a bi-axial stress system reaches the elastic limit of the material in a simple tension test
when the strain energy per unit volume in a bi-axial stress system reaches the strain energy at the elastic limit per unit volume as determined from a simple tension test
when the maximum princ
✅ The correct answer is option B.