Problem A:  Consider a plane stress element.  Let the magn…

  Problem A:  Consider a plane stress element.  Let the magnitudes of the stresses be σxx = 200 N/m2; σyy = – 100 N/m2; and σxy = 50 N/m2.   Find the maximum shear stress (σxy max) generated in this material and the surface orientation (in terms of an angle) where the maximum shear stress appears.   Find the principal stresses, σ1 and σ2 , and the principal axes   Draw the original diagram with stresses; and then draw a superimposed figure with the principal stresses, the maximum shear stress, and the angle they appear.