Time-domain BEM for dynamic crack analysis Original Research Article

Time-domain boundary element method (BEM) for elastodynamic crack analysis is presented in this paper. Special attention is devoted to BEM based on traction boundary integral equations (BIEs) in time-domain. Both the hypersingular and the non-hypersingular traction BIEs are dealt with. A time-stepping scheme in conjunction with a collocation method is applied for solving the time-domain BIEs numerically. This scheme uses a linear shape-function in time which allows an analytic time-integration of the system matrix. Two different spatial shape-functions are used in the numerical solution procedure, namely, “crack-tip elements” behind crack-tips while constant elements away from crack-tips. The use of “crack-tip elements” takes the proper local behavior of the crack opening displacements (COD) at crack-tips into account, and it makes an accurate calculation of the dynamic stress intensity factors feasible. The hypersingular integrals arising in the hypersingular time-domain traction BEM can be easily evaluated numerically and analytically by a direct method. Numerical examples for the dynamic stress intensity factors are given to show that the time-domain traction BEM is very accurate and efficient for elastodynamic crack analysis.