ENDOCHRONIC SIMULATION FOR FINITE VISCOPLASTIC DEFORMATION

The rate-sensitivity function of the endochronic theory proposed by Ba n and Chern (1997) is modified herein to incorporate with the finite e ndochronic constitutive equations obtained by Pan et al. (1996) for si mulating the material responses subjected to finite viscoplastic defor mation. Explicit constitutive equations subjected to finite torsion wi th an axial pre-stress are derived in this study. Experimental data of iron (alpha-Fe) in simple torsion and commercial nickle (Ni-200) in t orsion with an axial pre-stress for different shear strain-rates found in previous literature are used for comparison. It is shown that the simulated shear stress-strain responses and the axial effects caused b y finite torsion correlate well with the experimental data. (C) 1997 E lsevier Science Ltd.