Page 105 - T. Anderson-Fracture Mechanics - Fundamentals and Applns.-CRC (2005)
P. 105
1656_C02.fm Page 85 Thursday, April 14, 2005 6:28 PM
Linear Elastic Fracture Mechanics 85
FIGURE 2.55 Cracked plane subject to a biaxial stress state.
The maximum local stress intensity factor and energy release rate occurs at the optimum propagation
*
angle α , which depends on the biaxiality ratio. Figure 2.56 illustrates the effect of B and β on the
propagation angle. Note that when B > 0 and β = 90°, propagation occurs in the crack plane (α* = 0),
since the crack lies on a principal plane and is subject to pure Mode I loading.
FIGURE 2.56 Optimum propagation angle as a function of β and biaxialty.
