numerical implementation of a nonlocal damage model for a stress regime-dependent creep constitutive model

Several components of aeronautical motors and power plant stations are subjected to high temperatures, leading to creep deformation. it’s common practice to predict crack development in such components by using continuum damage mechanics (cdm). nevertheless, mesh dependency is a well-known issue in the classical cdm approach. the mesh sensitivity problem can be solved by using a nonlocal continuum approach. in the present study, in order to improve the numerical efficiency, a stress regime dependent creep model has been extended to a nonlocal model using a nonlocal theory from the literature. the nonlocal creep model was applied to a commercial finite element code, such as abaqus, with the help of user-defined routines (creep+usdfld) to predict the load point displacement (lpd) and creep crack growth (ccg) for a compact tension (ct) specimen made of high creep strength 1crmov steel. a comparison between the results of the new nonlocal model and experimental data was made for verification. the mesh dependency of the new nonlocal model was investigated. the results indicate that the proposed nonlocal creep model demonstrates good mesh objectivity that was not feasible when considering the traditional local creep model.