Models in Nonlinear Thermomechanics. Finite Element Models and Constitutive Models for Large Deformation Elastoplasticity

摘要

Finite element models for the discrete description of the thermomechanical behavior of continua are discussed. The approach constitutes an alternative to commonly adopted Galerkin methods in conjunction with numerical integration. Application to problems of large deformation elastoplasticity according to a material and a spatial approach is discussed. Two-dimensional problems of incompressible viscous fluid flow and heat flow illustrate the theory. The so-called redundant pressure method is presented as a solution method for handling the incompressibility constraints. Constitutive models for large deformation elasto-plasticity are derived from the general constitutive theory for materials possessing a natural reference state. Based upon the concept of a plastically induced orientational structure, a relatively simple and reasonably specific constitutive theory which accounts explicitly for the progressive development of anisotropy during plastic deformation processes is presented.