Figure 8.12

Figure 8.28

A single-edge-cracked plate is made of material with Kc = 30 MPa m and o = 600 MPa. The plate has dimensions, as defined in Fig. 8.12(c) (p. 290), of b = 30 mm, t = 6 mm, large h, and crack a = 6 mm. Under tension load, failure by sudden fracture occurred at a load of Pmax = 37 kN. There was a small amount of stable crack growth, with the P-v curve being similar to Fig. 8.28, Type II, and crossing the 5% slope deviation at P5 = 33 kN. Prior to this, the local peak load was 33.6 kN. (a) Calculate KQ corresponding to PQ and determine whether or not KQ qualifies as a valid Kic. (b) Estimate the plastic zone size at Kousing 2roo or 2ros, whichever applies. (c) Also calculate Ke corresponding to Po when the plastic zone adjustment is used.