AN ANISOTROPIC MATERIAL MODEL FOR CRACKED CONCRETE BASED ON PLASTICITY-THEORY AND DAMAGE THEORY

Tensile loading of plain concrete induces a growth and coalescence of microcracks which results in the formation of macroscopic cracks and p rogressive degradation of the elastic moduli. This deterioration proce ss prevents a complete closure of microcracks in unloading processes. As a consequence, permanent strains develop. The proposed material mod el for plain concrete [1] is based on an anisotropic damage evolution law [2] and formulated within the framework of multisurface damage-ela stoplasticity allowing for stiffness degradation as well as for the mo delling of inelastic deformations. Cracking under tension as well as t he nonlinear response of concrete in compression is taken into account .