Material Modeling of Elasto-Plastic Creep Behavior for Gray Cast Iron Based on Damage Mechanics and Its Applications to Creep Fatigue Life Prediction

Abstract

The elasto-plastic constitutive equation based on the concept of continuum damage mechanics is extended to cover the creep behavior for the gray cast iron as used in diesel engine parts. It employs the creep strain given by Perrin and Hayhurst and the creep damage given by Dunne and Hayhurst. Lots of material parameters in the constitutive equation are determined by using the uniaxial tensile/compressive, the creep, the relaxation, and the fatigue test results at 400°C. The identified model is used to predict the creep fatigue life with 600 sec hold-time at the maximum compressive strain. The validity of the proposed model is illustrated by comparing the calculated results with the experimental results. It is expected that the developed computational modeling can be used effectively to predict the creep fatigue life of gray cast iron machine parts.