AN ANISOTROPIC ELASTOPLASTIC-DAMAGE MODEL FOR PLAIN CONCRETE

A material model for plain concrete formulated within the framework of multisurface elastoplasticity-damage theory is proposed in this paper . Anisotropic stiffness degradation as well as inelastic deformations are taken into account. The applicability of the model encompasses cra cking as well as the non-linear response of concrete in compression. T he effect of different softening laws on the stress-strain relationshi p and on the dissipation is investigated in the context of a 1D model problem. The integration of the evolution laws is based on the standar d return map scheme. Further computational issues include the stabilit y of the local iteration procedure and the treatment of the apex regio n of the damage surface. The model is employed for re-analyses of a cy linder splitting test and of a notched concrete beam. Results from the composite elastoplastic-damage model are compared with test results a nd results from other material models for concrete, respectively. (C) 1998 John Wiley & Sons, Ltd.