Accession Number : AD0762610

Title :   The Effect of Strain Rate on the Cyclic Stress-Strain Response of Metals.

Corporate Author : MIDWEST RESEARCH INST KANSAS CITY MO

Personal Author(s) : Benson,David K. ; Hancock,James R.

Report Date : 31 JAN 1973

Pagination or Media Count : 35

Abstract : Monotonic and cyclic strain hardening parameters were measured for five alloys: 7075-T6 aluminum; 6061-T651 aluminum; an alpha/beta brass (alloy 365); copper-1.9% beryllium (alloy 172); and martensitic 4340E steel. Cyclic measurements were made under fully reversed strain control at constant strain rate by the incremental step test. A maximum strain range of plus or minus 0.015 and strain rates of 0.003, 0.03, 0.10 and 0.30/sec were used. The cyclic softening/hardening behavior of the alloys was predictable on the basis of established empirical rules. The cyclic stress-strain coefficients K' and exponents n' were independent of strain rate and had the values: 7075-T6 (105Ksi, 0.06); 6061-T651 (60 Ksi, 0.06); brass (132 Ksi, 0.21); copper-beryllium (165 Ksi, 0.13); 4340E steel (300 Ksi, 0.19). Adiabatic heating in high-strength materials appears to impose an upper limit (<0.3/sec) on the strain rate at which isothermal cyclic strain hardening tests can be performed. (Author)

Descriptors :   (*ALUMINUM ALLOYS, FATIGUE(MECHANICS)), (*COPPER ALLOYS, FATIGUE(MECHANICS)), (*STEEL, FATIGUE(MECHANICS)), STRAIN HARDENING, STRAIN(MECHANICS)

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE