Cracking Behaviours of Thermal Components

Abstract

The cracking initiation and trajectory of structure components under mechanical and thermal load is discussed in this work. Based on the uncoupled thermoelastic theory, the analytic solution of temperature field of a cracked body can be obtained associated with the complex potential and the formulation of Hilbert problem by assuming the crack surface is insulated. And the temperature field of a finite cracked domain is solved by using the numerical technique of the boundary collocation method in conjunction with the least square method. Then the stress field can be found in the same way by substituting the temperature field into the elastic potentials. According to the strain energy density theory, fracture initiation can be examined from the strain energy density field around the crack tip, while the fracture trajectories will be predicted from the global view of the strain energy density field affected by the finite boundary conditions. Moreover, some numerical examples of finite cracked plate with various oblique cracks under both mechanical and thermal load are discussed: The results show that the crack growth always appears to advance toward the region in tension experienced by the presence of lower temperature.