ABSTRACT
For concrete, the dependence of the creep strain rate on the acting stress under high stress levels is nonlinear. Furthermore, very high stress levels may lead to a growth of microcracks resulting in material failure. For the realistic life time assessment of creep sensitive concrete structures by means of numerical simulations, the appropriate description of nonlinear creep is crucial. However, many material models developed for concrete focus on either time-dependent behavior, restricted to linear creep, or nonlinear short-term material behavior. This is the motivation for an extended damage-plasticity model, aiming at a unified and computational efficient approach for representing the highly nonlinear time-dependent behavior in large-scale finite element simulations. Well established approaches for modeling the evolution of material properties, inelastic deformation, damage, creep and shrinkage serve as basis for considering nonlinear creep and material failure due to creep.
