Accession Number : ADP003113

Title :   Dynamic Kinking and Bifurcation of Cracks in Plane Strain,

Corporate Author : HIBBITT KARLSSON AND SORENSEN INC PROVIDENCE RI

Personal Author(s) : Burgers,P.

Report Date : OCT 1983

Pagination or Media Count : 9

Abstract : The bifurcation event in dynamic crack propagation is an extremely complicated process. Typically, experiments show that the process is inherently three-dimensional in that the crack front is not straight. Also there is no single instant of bifurcation but in the process zone multiple bifurcation attempts are made by the propagating crack. Only a few of these attempts are successful on a macorscopic scale. For these successful bifurcation attempts, usually there is not a sharp point at which the crack kinks, but a short distance over which the crack direction changes rapidly. It is only recently that experimental results have been obtained for which the experiments are sufficiently simple that there is any hope of modelling them analytically. The detailed three dimensional situation existing at bifurcation is far too complex to be treated at present. It is true however that providing the microscopic details are not considered, the approximation to planar deformation is not unreasonable. The details of deformation in the process zone can then presumably be lumped into a fracture criterion as is typically done in fracture mechanics. The determination of fracture criterion is the purpose of this work together with much of the other work presented at this workshop.

Descriptors :   *Glass, *Polymers, *Cracks, *Crack propagation, *Strain(Mechanics), *Numerical analysis, Bifurcation(Mathematics), Dynamic loads, Orientation(Direction), Deformation, Planar structures, Caustics, Three dimensional, Microstructure, Shear stresses, Fracture(Mechanics), Dislocations, Stress concentration, Mathematical prediction, Rayleigh waves, Stress waves, Graphs, Symposia

Distribution Statement : APPROVED FOR PUBLIC RELEASE