EQUIVALENT CRACK FORMATION BY PROPAGATING CRACKS UNDER TENSION

A hybridized displacement discontinuity element and indirect boundary element (or fictitious stress) procedure is being used to model crack propagation in cases involving one, two and three cracks in a two-dimensional linear elastic medium under tension or partial tension/ compression. By comparing with published results, the simulation results are found to be satisfactory and the hybridized procedure (called FROCK) is verified. It is interesting to discover that in each of the cases involving one, two and three cracks, an equivalent crack perpendicular to the direction of maximum tension is formed through propagation of the outer and inner crack tips. An important capability of FROCK is shown in a complicated case with applied compression and tension in which parts of the crack and crack extensions open up while the rest remain closed with shear resistance acting on the closed crack surfaces.