Accession Number : AD0780733

Title :   Measurement of Strain Rate Effects in Metals.

Descriptive Note : Final rept.,

Corporate Author : LEHIGH UNIV BETHLEHEM PA

Personal Author(s) : Smith,Wesley R.

Report Date : APR 1974

Pagination or Media Count : 38

Abstract : A new shock tube technique has demonstrated the existence of strain rate effects in the plastic deformation of metals. A transient deformation is produced in a thin-walled cylindrical metal tube loaded by a plane air shock wave propagating inside it. Surface strain gauges allow a direct measurement of the shock-produced transient strain. Preliminary experiments with annealed aluminum tubes have demonstrated the existence of strain relaxation when the shock-applied normal surface stress exceeds the static elastic limit. Strain relaxation data from these experiments was used with the quasi-static model developed to describe the deformation of the tube. The experimental and model strain-time profiles compared favorably. (Modified author abstract)

Descriptors :   *Strain rate, *Impact tests, Shock tubes, Wave propagation, Plastic deformation, Aluminum, Strain gages, Mathematical models, Measurement

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE