PERFORMANCE OF QUARTER-POINT BOUNDARY ELEMENTS IN ANALYZING THERMALLYSTRESSED KINKED AND CURVED CRACKS

The performance of quarter-point and traction-singular quarter-point b oundary elements, dealing with kinked and curved thermal cracks, is in vestigated. These special crack-tip elements simulate correctly the r( 1/2) and r(-1/2) near-tip behavior of temperature/displacement and hea t flux/thermal stress fields, respectively. The well-known displacemen t and traction-based formulas are generalized for any crack configurat ion and used for the evaluation of heat flux and mixed-mode thermal st ress intensity factors. The two-dimensional stationary thermoelasticit y problem is solved via the boundary-only element method, through whic h volume discretization is completely eliminated. It is demonstrated b y the conducted numerical experiments that present results converge to the exact ones, obtained from the literature, when the crack-tip elem ent size tends to zero. The accuracy of the proposed method is maintai ned at high levels for all crack configurations considered, without th e need for a dense mesh. This conclusion stands even for cracks nearly zero in size, thus rendering the method a potent tool for thermal cra ck initiation and extension analysis.