Performance of quarter-point boundary elements in analysing thermally stressed kinked and curved cracks Original Research Article

The performance of quarter-point and traction-singular quarter-point boundary elements, dealing with kinked and curved thermal cracks, is investigated. These special crack-tip elements simulate correctly the r12 and r−12 near-tip behavior of temperature/displacement and heat flux/thermal stress fields, respectively. The well-known displacement and traction-based formulas are generalized for any crack configuration and used for the evaluation of heat flux and mixed-mode thermal stress intensity factors. The two-dimensional stationary thermoelasticity problem is solved via the boundary-only element method, through which volume discretization is completely eliminated. It is demonstrated by the conducted numerical experiments that present results converge to the exact ones, obtained from the literature, when the crack-tip element size tends to zero. The accuracy of the proposed method is maintained at high levels for all crack configurations considered, without the need for a dense mesh. This conclusion stands even for cracks nearly zero in size, thus rendering the method a potent tool for thermal crack initiation and extension analysis.