Accession Number : ADA193460

Title :   Results on the Influence of Crack Tip Plasticity During Dynamic Crack Growth.

Descriptive Note : Final rept.,

Corporate Author : BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING

Personal Author(s) : Freund, L B

PDF Url : ADA193460

Report Date : Aug 1987

Pagination or Media Count : 32

Abstract : Dynamic fracture processes in structural materials are often described in terms of the relationship between a measure of the crack driving force and the crack tip speed. In this article, ongoing research directed toward establishing a basis for such a relationship in terms of crack tip plastic fields is described. In particular, the role of material inertia on a small scale as it influences the perceived fracture resistance of a rate independent material is discussed. Also, the influence of material strain rate sensitivity on the development of crack tip plastic deformations, and the implications for cleavage propagation and arrest in a material that can undergo a fracture mechanism transition, is considered. The discussion is concluded with mention of a few outstanding problems in the study of dynamic fracture, including some recent experimental evidence that the traditional crack tip characterization viewpoint of fracture mechanics may be inadequate under very high rate loading conditions. Keywords: Dynamic fracture, Dynamic crack propagation, Elastic-plastic fracture, High strain rate fracture, Crack arrest.

Descriptors :   *CRACK PROPAGATION, *PLASTIC DEFORMATION, ARRESTING(PROCESS), CLEAVAGE, CONSTRUCTION MATERIALS, CRACKS, DYNAMICS, ELASTIC PROPERTIES, FORCE(MECHANICS), FRACTURE(MECHANICS), HIGH RATE, INERTIA, MATERIALS, PLASTIC PROPERTIES, RATES, RESISTANCE, SENSITIVITY, STRAIN RATE, TRANSITIONS, VELOCITY

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE