Accession Number : ADP004922

Title :   Finite Increment Formulation of the Prandtl-Reuss Constitutive Equations,

Corporate Author : RENSSELAER POLYTECHNIC INST TROY NY DEPT OF MECHANICAL ENGINEERING AERONAUTICAL ENGINEERING AND MECHANICS

Personal Author(s) : Mallett,R. L.

Report Date : FEB 1985

Pagination or Media Count : 17

Abstract : The early finite increment formulations of elastic-plastic constitutive laws for use in large deformation finite-element codes placed severe limits on step size in order to avoid significant error accumulation. In this paper finite increment forms of the constitutive equations for Prandtl-Reuss materials are investigated, two primary sources of finite increment error are identified, and procedures for elimination of these errors are developed. By adopting a geometric description in nine-dimensional stress space, the relevant stress and strain increments are shown to all lie in a two-dimensional subspace. This allows the nature of the errors and the description of procedures which overcome them to be easily and precisely visualized with the aid of planar vector diagrams. (Author)

Descriptors :   *FORMULATIONS, *FINITE ELEMENT ANALYSIS, *NONLINEAR ALGEBRAIC EQUATIONS, PLASTIC DEFORMATION, STRAIN HARDENING, CARTESIAN COORDINATES, STRESSES, TENSORS

Distribution Statement : APPROVED FOR PUBLIC RELEASE