On quadratic isoparametric transition elements for a crack normal to a bimaterial interface

The quadratic isoparametric crack-tip elements proposed by R. E. Abdi and G. Valentin (Computers and Structures 33, 241}248) are reconsidered and a simpler method for calculating the optimal position of the side nodes proposed. Quadratic isoparametric transition elements for an rj!1 (0(j(1) strain singularity are formulated. The e!ects of these transition elements on the accuracy of the calculated stress intensity factors are shown numerically for a crack normal to and terminating at a bimaterial interface. Finally, layered transition elements are formulated for this case and their e!ects studied numerically. Copyright ( 1999 John Wiley & Sons, Ltd.