Continuum damage mechanics analysis of high temperature creep and creep fracture for titanium alloy IMI834

A nonlinear continuum damage model was employed to study the creep and creep rupture behaviour of an aeroengine material, a high temperature titanium alloy (IMI834), at 650°C. The results predicted by the model utilized were found to be in good agreement with the experimental results. The distribution of the stress triaxiality factor in an axisymmetric semicircular notched specimen was achieved by the stress analysis using the finite element method (FEM), then the influence of the multi-axial stress state was considered in the creep damage analysis. It was found that the multi-axial stress state remarkably reduces the creep fracture life of the structures. The results prove that the multi-axial creep damage model can describe the cumulation and development of damage and predict the creep rupture life more accurately.