Strain accumulation and rupture during creep under variable uniaxial tensile loading

Abstract

The results of uniaxial creep tests performed on a structural aluminum alloy at 180°C are presented for steady and variable loading. Continuous measurement of strain throughout the tests has enabled a meaningful comparison of commonly used creep theories for strain accumulation and ruptue to be made. For the material investigated it appears that creep strains are accurately predicated by time-hardening theory and the total-strain theory is likely to be a useful approximation for predicting component behaviour at large strains. Stress relaxation has no effect on rupture times and there is some evidence for strain as a criterion for rupture.