ON THE COMPUTATION OF MODE-I AND MODE-II THERMAL-SHOCK STRESS INTENSITY FACTORS USING A BOUNDARY-ONLY ELEMENT METHOD

A time domain boundary-only element method is used for the analysis of fractured planar bodies, subjected to thermal shock type loads. The u ncoupled quasistatic thermoelasticity equations are solved without the need for domain discretization. The singular behaviour of the tempera ture and displacement fields, in the vicinity of the crack tip, is mod elled by quarter-point elements. Transient thermal stress and heat flu x intensity factors are evaluated from computed nodal values, using th e well-known displacement and traction formulas. The accuracy of the m ethod, the stability of the solution and the dependence on space-time discretization is investigated through comparison of present results w ith analytical and computational ones, taken from the literature. For mode I and mixed mode two-dimensional problems examined, the method pr oved to be a potent tool for fracture analysis in presence of severe t hermal shock loads, even in the microcrack size range. Potent in the s ense that, it is very stable and cost effective from the space-time di scretization point of view.