A strain rosette consisting of three strain gages was used to measure the strains at a point in a thin-walled plate. The measured strains in the three gages are εA = 0.001, εB = -0.0006, and εC = 0.0007. Note that gage C is at 45° with respect to the x-axis.
(a) Determine the complete state of strains and stresses (all six components) at that point. Assume that E = 70 GPa, and ν = 0.3.
(b) What are the principal strains and their directions?
(c) What are the principal stresses and their directions?
(d) Show that the principal strains and stresses satisfy the stress-strain relations
