A Constitutive Model for Creep Rupture

Abstract

The paper presents a viscoplastic formulation including damage for creep and creep rupture. Themodel incorporates a damage evolution law which includes both the viscoplastic strain rate as well as stress rate. Primary, secondary and tertiary creep are incorporated in this formulation. Model parameters are obtained for polycarbonate using both creep test and the constant strain rate test data. It is found that the model can give a reasonable predictions for creep and creep rupture. However the model will need to be modified for the constant strain rate case. The paper also presents a multi-axial formulation for the model. The formulation is general enough so we will be able to apply it to a complex problem of landslides in soil masses which is stated in the paper as our plan for future research.