Thermal shock fracture mechanics analysis of a semi-infinite medium based on the dual-phase-lag heat conduction model

摘要

The generalized lagging behaviour in solids is very important in understanding heat conduction in small-scale and high-rate heating. In this paper, an edge crack in a semi-infinite medium subjected to a heat shock on its surface is studied under the framework of the dual-phase-lag (DPL) heat conduction model. The transient thermal stress in the medium without crack is obtained first. This stress is used as the crack surface traction with an opposite sign to formulate the crack problem. Numerical results of thermal stress intensity factor are obtained as the functions of crack length and thermal shock time. Crack propagation predictions are conducted and results based on the DPL model and those based on the classical Fourier heat conduction model are compared. The thermal shock strength that the medium can sustain without catastrophic failure is established according to the maximum local stress criterion and the stress intensity factor criterion.