The application of combined kinematic-isotropic hardening and the mechanical sublayer model to small strain inelastic structural analysis by the finite element method

Abstract

First, the continuum equations of motion are referred to the initial structural configuration and then linearized with respect to the displacement increments to obtain a form of the so-called total Lagrangian formulation whose kinematics are valid for large strains. These equations are then converted to a set of nonlinear differential equations via the finite element method. The formulation and computational procedures of two incremental plasticity theory hardening rules, namely combined kinematic-isotropic hardening and the mechanical sublayer model, are then presented with the limitation of small strains. Of particular interest is a new method of determining sublayer parameters of the mechanical sublayer model applicable to multiaxial loading. Finally, three simple structures subjected to loading into the plastic range are analyzed using the finite element code AGGIE I.