Modeling of residually stressed materials
Professor Luis Dorfmann, Department of Civil Engineering , Tufts University
Stress that is present in a material body in the absence of any applied loads is referred to as residual stress. To effectively model the elastic response, relative to a residually stressed configuration, the residual stress needs to be incorporated into the constitutive equations. In this talk we provide an overview of the basic equations required to present a general elastic, invariant-based anisotropic constitutive formulation that includes residual stress. We summarize a three-dimensional incremental formulation appropriate for the implementation of the theory in a nonlinear finite element code. To validate the theory and its implementation the wall stress distribution in an abdominal aortic aneurysm (AAA) using patient specific geometry and material model parameters is evaluated. The method presented in this talk is general and can be used, by specifying appropriate energy functions, to investigate other residually stressed biological systems.