NUMERICAL MODELLING OF DAMAGE AND FRACTURE IN CONCRETE.

Abstract

An attempt is made to combine Damage Theory and Fracture Mechanics. The strain softening at the crack tip is realized by decreasing the elastic modulus in relation to the strain energy density locally absorbed, whereas both stable and unstable crack propagation are independently simulated. It appears clear that the two extreme situations of ultimate strength collapse at the ligament (small size) and brittle fracture (large size) are connected by a transition. The ability of describing such a transition shown by the Fictitious Crack Model and by the Strain Energy Density Theory are eventually discussed.