Accession Number : ADA338750

Title :   Stress Concentrators and Rate Effects in Formation of Adiabatic Shear Bands

Descriptive Note : Final rept. 7 Nov 96-6 Jan 98

Corporate Author : METZ UNIV (FRANCE) LAB OF PHYSICS AND MECHANICS OF MATERIALS

Personal Author(s) : Klepaczko, Janusz R.

PDF Url : ADA338750

Report Date : JAN 1998

Pagination or Media Count : 42

Abstract : This Final Technical Report covers the contract period from 7 Nov 96 to 6 Jan 98. A more detailed information on the progress of this Contract can be found in the previous Interim Reports. During the period under consideration the research has been continued on analyses of experimental results obtained via the Modified Double Shear experimental technique (MDS). This technique has been applied for VAR 4340 steel with the heat treatment to -50 HRC. In order to study the effect of stress concentrators in shear at different rates of loading four MDS geometries have been tested with different stress concentrators, from "standard" geometry to a very sharp notch. A wide loading rate spectrum has been covered, from quasi-static to impact (up to impact velocity ^ 100 m/s). Experiments confirmed that the adiabatic stress concentrators accelerate failure in shear. This mechanism leads to a decrease of the fragmentation energy when the impact velocity is increased. In parallel, the numerical studies for all four geometries have been performed using the FE code ABAQUS. Details of the numerical studies are given in the appendix to this Report. The numerical analyses have confirmed all observations from experiments.

Descriptors :   *HIGH STRENGTH ALLOYS, NUMERICAL ANALYSIS, HEAT TREATMENT, FRANCE, PLASTIC PROPERTIES, FAILURE(MECHANICS), ADIABATIC CONDITIONS, STRESS CONCENTRATION, SHEAR TESTS.

Subject Categories : Properties of Metals and Alloys
      Test Facilities, Equipment and Methods
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE