Publications Details

Elastic-plastic constitutive relations at large strain

Herrmann, W.

Present practice in most computer codes intended for the solution of dynamic mechanics problems is to use the classical infinitesimal plasticity relations together with the Jaumann stress rate to account for finite rotations. Use of the Jaumann stress rate is known to lead to oscillating stress-strain response in simple shear at large deformations for elastic and some plastic relations, and is limited to isotropic material descriptions. Formulations of finite deformation plasticity based on the Lagrangian reference configuration and an unrotated configuration have been proposed which, in principle, should overcome these limitations. The latter has been implemented in a finite element computer code. In this paper, it is shown how a Lagrangian description based on the reference configuration may be implemented in computer codes, and how it may be translated into a corresponding Eulerian description based on the current configuration and a description based on the unrotated configuration for comparison with currently used descriptions. 11 refs.