Effect of Higher-Order Terms in the Thermal Transient Stress Intensity Factor for a Cracked Semi-Infinite Medium Under Thermal Shock

This paper studies the transient thermal fracture problem of a semi-infinite medium containing an edge crack using the non-Fourier heat conduction theory. Dual-phase-lag (DPL) model, which takes into account the effect of higher-order terms, (named x-DPL model) is proposed to predict the temperature gradient of the medium, which experiences a heat shock on its edge. The temperature gradient and the corresponding thermal stresses are obtained by applying the Laplace transform method and neglecting the thermo-elastic coupling and inertial effects in the absence of crack for the semi-infinite medium. Thereafter, mode I crack problem is formulated in the Laplace domain using the superposition method. Numerical results of the thermal stress and mode I stress intensity factor (SIF) are calculated by implementing Durbin’s method in the time domain. The effects of higher-order terms on the axial thermal stress and the mode I SIF are investigated and discussed. The DPL model that considers higher-order terms is more conservative than this model neglecting these terms.