PERFORMANCE OF TRACTION-SINGULAR BOUNDARY ELEMENTS IN ANALYZING FRACTURE PROCESS IN TRANSIENT QUASI-STATIC ENVIRONMENTS

The performance of singular crack elements including the behavior of a ssociated field derivatives dealing with multiple cracking in composit e thick walled cylinders subjected to blasting is investigated. Transi ent opening mode thermal stress intensity factors of multiple radial c racks emanating from the bore of autofrettaged, internally plated, thi ck-walled cylinders, subjected to thermal shock and internal pressuriz ation, are evaluated. Quasistatic thermoelasticity problem is solved u sing the well-known boundary-only element method, in conjunction with the subregion technique, whereas the singular behavior of temperature/ displacement and flux/stress fields in the vicinity of the crack-tip i s modeled through the traction-singular quarter-point element. Results obtained during thermomechanical shocks in chromium-plated composite tubes, illustrate the considerable influence of the plating thickness as well as the autofrettage process on thermal stress intensity factor s. (C) 1998 Elsevier Science S.A. All rights reserved.