Creep life prediction under stepwise constant uniaxial stress and temperature conditions

In this paper the problem of cumulative creep damage is considered. A general non-linear creep damage accumulation model, suitable for variable step uniaxial loading and/or temperature, is presented. The proposed damage accumulation function takes into account the previous damage history as well as the loading order effect. This damage function is specified with respect to damage parameters derived by the stress versus Larson–Miller parameter curve. It is shown that some of the existing models can be obtained as a particular case of the model developed here in. Theoretical results are correlated well with experimental data for austenitic steel X-8-CrNiMoNb-16-16 at 700°C and Al-99.98 at 225°C subjected to a square block loading.