Analysis for fracture characteristic of pre-cracked directionally solidified turbine blades

Based on the numerical simulation of fracture toughness of the compact tensile (CT) specimen, a numerical model for the stress intensity factor of turbine blades was established by use of MSC. MARC software. The stress intensity factor of pre-cracked turbine blades was evaluated for the fracture state of blades. The fracture toughness of blades shows great scatter, and some of them are remarkably lower than that obtained in material testing. The simulation results of failure blade under operating condition show that the characteristic in fracture section, i.e. the area of fatigue zone is small while that of the instantaneous fracture zone is large.