Analysis of ductile-brittle competitive fracture criteria for tension process of 7050 aluminum alloy based on elastic strain energy density

摘要

To predict the damage and fracture of material accurately in the process of large elastic-plastic deformation, this paper proposed ductile-brittle competitive fracture criteria based on elastic strain energy density (ESED), which have been proved to competitively affect fracture behavior in the analysis of metal forming process. Additionally, the ductile fracture criterion is based on continuous damage mechanics (CDM) and the brittle fracture criterion is based on fracture mechanics (FM). The analyses of deformation damage and fracture for notched and unnotched tension specimens in complex stress states have been carried out by experiment and finite element method (FEM) using the ductile-brittle competitive fracture criteria. The results from analyses on damage evolution and fracture of FEM are in good agreement with the experimental ones. The law of ductile-brittle competitive fracture has been quantitatively proved to be effective in the process of metal deformation.