Accession Number : ADP003105

Title :   Short Pulse Fracture Mechanics,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Shockey,D. A. ; Kalthoff,J. F. ; Homma,H. ; Erlich,D. C.

Report Date : OCT 1983

Pagination or Media Count : 15

Abstract : A research effort was begun eight years ago at SRI International to analyze the response of a crack struck by a short-lived tensile pulse and to modify static fracture mechanics concepts to allow predictions of dynamic crack instability. The results of this work, which have been presented in a series of papers over the past six years, comprise a unified extension of classical fracture mechanics and are summarized here. We first review considerations of the stress intensity history experienced by a dynamically loaded crack tip and deduce the instability criterion. Then we describe the experiments that were performed to test the 'minimum time' criterion, present the results, and compare them with predictions of the criterion. The agreement between predictions and experimental results suggests that certain key aspects of crack instability under short pulse loads are understood and that this understanding can be applied to solve dynamic fracture problems. The current research effort is aimed at developing equipment and procedures for valid dynamic fracture testing, measuring for selected materials, and establishing minimum times for crack instability.

Descriptors :   *Materials, *Fracture(Mechanics), *Dynamic tests, Pulses, Short range(Time), Cracks, Crack propagation, Tensile properties, Aluminum, alloys, Epoxy compounds, Steel, Mechanical properties, Stress concentration, Stability, Front ends and surfaces, Stress waves, Mathematical prediction, Geometry, Time dependence, Mechanical properties, Loads(Forces), Structural response, Graphs, Configurations, Symposia

Distribution Statement : APPROVED FOR PUBLIC RELEASE