f Moayyedian - Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
m Kadkhodayan - Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

In this study, a non-associated viscoplastic flow rule (NAVFR) with combining von Mises and Tresca loci in place of yield and plastic potential functions and vice verse is presented. It is shown that theproposed NAVFR can be adopted to forecast the experimental events more accurate than theconventional associated viscoplastic flow rules (AVFR). This outcome obtained with the aid of fully implicit time stepping scheme and discussing the other studies on plastic potential flow rules and also experimental results.

Viscoplastic,Thick Walled Cylinder,Time Stepping Scheme,Internally Pressurized,