A Comprehensive Constitutive Model Solver

Abstract

The object-oriented software concept is applied to material mechanics calculations. The result is a comprehensive predictor-corrector which has been employed to solve virtually all of the constitutive exercises in a mature, general-purpose, finite element program. In addition to updating internal variables consistent with global inputs (corrector), the software also produces consistent material tangents (corrector), without resort to formulae. Coupled mechanical-thermal-porous flow problems are addressed as well as compound mechanical responses: creep-plasticity, creep-damage, etc. Material and spatial coordinate transformations are incorporated as well as transformation to and from local material axes. Internal calculations may be undertaken in either spatial or material coordinates, depending upon the native definition. Even viscoelasticity and hyper-viscoelasticity, via Prony series, are efficiently handled by the sparse solver. A tool to exercise any material model, simulating global inputs, is incorporated. Historical plots may be produced and inputs may be cyclical or otherwise simulate complex histories. This is accomplished by using PostScript operators.