A thin solid plate that has a Young's modulus of 100 GPa, Poisson's ratio of 0.30 and a yield

stress in uniaxial tension of 220 MPa. Consider a mode I crack in this thin plate (o= 0) with an

applied stress intensity factor Kr= 10 MPa m¹/2. At an angle 0 = 30°, determine the value of r

for which the solid no longer experiences yielding. Use the von Mises yield criteria.