(30p) Consider a plane stress problem of a material whose yielding is described by the von Mises criterion (1/2)[(01-02)2 + 0 +03] = 03. Assume this material strain hardens kinematically, i.e. plastic deformation entails a shift of the center of the yield surface by some values, a and B, in both the o, and oz directions. The magnitude of this shift depends on the amount of plastic strain occurring in the two principal stress directions, 1 and 2, and should be considered here as a parameter. Suppose one performs a biaxial tensile test (plane stress in the third direction), then unloads, and reloads in shear. At what shear stress do you expect yielding (to be computed in terms of Oy, a and )? Note: you will have to first modify the Mises criterion by including a and B to account for the shift of the origin of the coordinate system; then you consider the shear deformation, compute principal stresses in terms of the applied shear stress, plug in the updated yield criterion and compute the shear stress at yielding. (30p) Consider a plane stress problem of a material whose yielding is described by the von Mises criterion (1/2)[(01-02)2 + 0 +03] = 03. Assume this material strain hardens kinematically, i.e. plastic deformation entails a shift of the center of the yield surface by some values, a and B, in both the o, and oz directions. The magnitude of this shift depends on the amount of plastic strain occurring in the two principal stress directions, 1 and 2, and should be considered here as a parameter. Suppose one performs a biaxial tensile test (plane stress in the third direction), then unloads, and reloads in shear. At what shear stress do you expect yielding (to be computed in terms of Oy, a and )? Note: you will have to first modify the Mises criterion by including a and B to account for the shift of the origin of the coordinate system; then you consider the shear deformation, compute principal stresses in terms of the applied shear stress, plug in the updated yield criterion and compute the shear stress at yielding