Accession Number:

ADA270307

Title:

The Flow Stress of a Mild Steel for Dynamic Calculations Involving Large Plastic Deformations,

Descriptive Note:

Corporate Author:

MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)

Personal Author(s):

Report Date:

1993-01-01

Pagination or Media Count:

9.0

Abstract:

The flow stress of steel is a function of strain rate and is generally observed to increase with increasing strain rate. Experiments were conducted in compression over a wide strain rate range from 10exp-3s to 2 x 10exp-4s to determine the flow stress of a 0.21 C mild steel. While, a high strain rate was found to strongly influence the flow stress in the vicinity of the yield stress, this was not observed to be the case beyond yield. Thermal softening from the adiabatic temperature rise associated with the rapid plastic flow at high strain rates may have masked part of the strain rate effect at high strains. Furthermore, the strain rate effect that is evident at low strains appears to depend on the effectiveness of the lubrication between the specimen and the compression patterns. An empirical relation that is a function of true strain between 0.05 to 0.4 was fitted to the experimental data from strain rates of 10exp-3s to 10exp-3s. This relation can be used in dynamic calculations involving gross plastic deformation, as are typically performed for vehicle crash, projectile impact and explosive air-blast loading simulations. Author

Subject Categories:

  • Properties of Metals and Alloys
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE