Shear band spacing in gradient-dependent thermoviscoplastic materials |
| |
Authors: | R C Batra L Chen |
| |
Affiliation: | (1) Virginia Polytechnic Institute and State University, Department of Engineering Science and Mechanics, MC-0219, Blacksburg, VA 24061, USA, US |
| |
Abstract: | We study thermomechanical deformations of a viscoplastic body deformed in simple shear. The strain gradients are taken as
independent kinematic variables and the corresponding higher order stresses are included in the balance laws, and the equation
for the yield surface. Three different functional relationships, the power law, and those proposed by Wright and Batra, and
Johnson and Cook are used to relate the effective strain rate to the effective stress and temperature. Effects of strain hardening
of the material and elastic deformations are neglected. The homogeneous solution of the problem is perturbed and the stability
of the problem linear in the perturbation variables is studied. Following Wright and Ockendon's postulate that the wavelength
whose initial growth rate is maximum determines the minimum spacing between adjacent shear bands, the shear band spacing is
computed. It is found that the minimum shear band spacing is very sensitive to the thermal softening coefficient/exponent,
the material characteristic length and the nominal strain-rate. Approximate analytical expressions for the critical wave length
for heat conducting nonpolar materials and locally adiabatic deformations of gradient dependent materials are also derived. |
| |
Keywords: | : Material characteristic length strain-rate gradient dominant growth rate viscoplastic material stability |
本文献已被 SpringerLink 等数据库收录! |
|