Crack Paths 2012

temperatures are provided). Whenthe temperature distribution has been found, the

determination of the resulting stress distribution comes from the non linear uncoupled

quasi-static theory of thermoelasticity. Temperature-dependent stress/strain curves are

used in nonlinear solutions to allow for yielding (Figure 3).

Table 1. Youngmodulus (MPa) and Poisson ratio against temperature (°K)

Table 2. Yield stress (MPa) and plastic modulus (MPa) against temperature (K)

Table 3. Thermal expansion coefficient (K-1) against temperature (K)

Table 4. Thermal conductivity (W/(mK)) against temperature (K)

The 3D-20 node tetrahedral thermal solid element Quadratic Solid90 is used for the

thermal analysis, with a transition to the Solid186 element type for the subsequent

structural analysis, where mechanical boundary conditions are added in terms of elastic

reaction pressures p1, p2,p3 (corresponding to resultant forces F1=410 N, F2=1205 N and

F 3 = 5 4 0 N) and a fluid pressure ('p=0.26 MPa) is applied on the pressure side, as shown

in Fig. 4. The N G VF E Mmesh adopted is based on 83000 elements with a localised

refinement in the area of crack insertion (Fig. 5).

Numerical fracture mechanics analysis

The D B E Msubmodel, extracted form the blade trailing edge, after crack insertion, has a

mesh with 2192 reduced quadratic elements (the central node is missing). The D B E M

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