An isotropic damage model for concrete is presented. The main features of t
he model are: limited number of constitutive parameters required; independe
nt modelling of tension and compression behaviour by means of two damage va
riables and two separate activation criteria (bi-dissipative model); indepe
ndent definition of tension and compression fracture energies by means of c
onstitutive parameters which do not affect the pre-peak behaviour; consiste
nt modelling of the unilateral effect upon transition from tension to compr
ession. To overcome the problem of mesh dependence in the softening regime,
the effectiveness of a fracture energy based regularisation strategy is sh
own and the conditions for its correct application are defined. Comparisons
of numerical simulations with experimental tests reveal the good accuracy
and the robustness of the proposed model. (C) 2001 Elsevier Science Ltd. Af
t rights reserved.