A rosette composed of three strain gages measures strain at a point on the surface of a flat sheet of annealed stainless steel loaded in plane stress. The strains measured (numbers correspond to strain gages in the figure) are
ε1 = +280 μstrain, ε2 = +720 μstrain, ε3 = -120 μstrain.
a. Find the in-plane strains at this point using the xy-axes shown.
b. Find the in-plane stresses at this point.
c. What is the percent change in thickness of the plate if this stress state is uniform over it?