severe mechanical loading brittle material like concrete can be described favourably using damage models. J. Mazars (1984), S. Ramtani (1990) C. Laborderie (1991) propose such models established within the framework of thennodynamics. Internal state variables are used to describe cracking…
severe mechanical loading brittle material like concrete can be described favourably using damage models. J. Mazars (1984), S. Ramtani (1990) C. Laborderie (1991) propose such models established within the framework of thennodynamics. Internal state variables are used to describe cracking or micro cracking process. The number of internal state variables depends on the level of sophistication. Crack closure effect, inelastic strains and induced anisotropic damage can be introduced in the constitutive equations. order to solve a more efficient way dynamic engineering problems involving complex two or three dimensional structures, damage model with explicit fonnulation are recommended. Computation time can be therefore reduced drastically. Here we present two explicit damage models. The first one uses two scalar variables and takes into account pennanent strains. This model is introduced a finite element program and gives interesting results. The second damage model uses a scalar damage variable for micro cracking effects and a second order tensor variable to model anisotropic tensile damage. Inelastic strains are also introduced. respective principal axes inelastic strains and tensile damage variables can be represented with an ellipsoid shape. This model is still under development. Thennodynamic aspects are presented and the first evolution laws damage variable are discussed and the model response is presented with fixed axes. 1001 1 rnlnAt""Jlh11l1h.r of buried or half buried reinforced concrete shock loading, ril<111'n