1998 Volume 41 Issue 1 Pages 79-95
A new rigid plastic constitutive model for ductile materials with void evolution processes, which was developed on the base of the modified Gurson's yield function in previous research, is carefully investigated in this paper. In order to check the reasonability, reliability and accuracy of this model, detailed numerical calculations on the response of porous materials under uniaxial stress condition, biaxial equal stress condition and uniaxial strain condition are carried out respectively. The influence of triaxiality on the deformation behaviours and void evolution characteristics are revealed through such kind of calculations. Systematic comparisons of the calculation results based on both the present model and the conventional models show the correctness of the new constitutive theory. The advantages of the present model over other conventional models are discussed. This research displays the possibility of estabilishing the constitutive model for porous materials, such as sintered metals, on a solid theoretical basis.