A FINITE-ELEMENT TECHNIQUE TO SIMULATE THE STABLE SHAPE EVOLUTION OF PLANAR CRACKS WITH AN APPLICATION TO A SEMIELLIPTIC SURFACE CRACK IN ABIMATERIAL FINITE SOLID

This paper describes a numerical procedure to model the crack front ev olution of initially arbitrary shaped planar cracks in a three-dimensi onal solid. The influence of a bimaterial interface on the fracture pa th of a semi-elliptical surface crack in a three-dimensional structure is examined. The analysis is based on the assumption that fracture is controlled by small-scale yielding and linear elastic fracture mechan ics. The finite element method and the crack-tip contour J-integral in a volume domain representation are utilized to calculate the crack fr ont energy release rate. The computed values of the energy release rat e are used with a crack-tip velocity growth law to model crack growth increment. The progress of the crack growth evolution is brought forwa rd by successive iterations. Examples of computed crack evolution are given for an embedded circular crack, a semi-elliptical surface crack in a finite plate, and a configuration that defines an isotropic homog eneous material layer with a surface crack located between two materia l layers.