A NONLOCAL DAMAGE MECHANICS APPROACH TO HIGH-TEMPERATURE FATIGUE-CRACK GROWTH

A nonlocal damage constitutive model is developed for elasto/visco-pla stic materials and is used to analyze fatigue crack growth at high tem perature. In this model, no kinematic hardening rule is needed to acco unt for the subsequent yielding and strain hardening behavior of the m aterials. A calculation method for nonlocal damage is introduced. The fatigue crack growth tests at high temperature for pure titanium (99.5 %) are carried out. By means of FEM, the mechanical fields (sigma(ij), epsilon(ij), D) and their redistribution due to damage effect near th e crack tip are investigated. The numerical simulation results of the fatigue crack growth are shown. The validity of the presented damage m odel is verified by comparing the FEM numerical simulation with experi mental results.