Accession Number : AD0732196

Title :   An Analytical Study of the Split Hopkinson Bar Technique for Strain-Rate Dependent Material Behavior.

Descriptive Note : Summary rept. Sep 70-Jun 71,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Nicholas,Theodore

Report Date : AUG 1971

Pagination or Media Count : 32

Abstract : The validity of the split Hopkinson bar technique for determining dynamic material behavior is examined for speciment materials which exhibit strain-rate dependent mechanical behavior. The torsional mode of deformation is chosen as more closely representing a one-dimensional state of stress. The details of the propagation and reflection of stress waves within the specimen are studied using a numerical procedure based on the method of characteristics. Reconsitituted stress- strain curves calculated from the conventional analysis of the split Hopkinson bar experiment are compared with actual material behavior for a number of simulated experiments involving variations in input stress, gage length, material behavior, and static stress-strain curves including statically prestressed materials. The validity of the experimental technique is discussed and limitations on its use are delinaeated. (Author-PL)

Descriptors :   (*STRAIN(MECHANICS), *TEST METHODS), DEFORMATION, NUMERICAL ANALYSIS, STRESSES, DYNAMICS, ALUMINUM

Subject Categories : Metallurgy and Metallography
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE