A cohesive damage–friction interface model accounting for water pressure on crack propagation.pdf

/locate/cma Comput. Methods Appl. Mech. Engrg. 196 (2006) 192–209A cohesive damage–friction interface model accounting for water pressure on crack propagation G. Alfano a, S. Marfia b, E. Sacco b,* a Dipartimento di Scienza delle Costruzioni, Universita? di Napoli, Via Claudio, 21-80125 Napoli, Italy b Dipartimento di Meccanica, Strutture, Ambiente e Territorio, Universita? di Cassino, Via G. di Biasio 43, 03043 Cassino, Italy Received 16 May 2005; received in revised form 2 December 2005; accepted 13 March 2006Abstract Aim of the work is the study of crack propagation in concrete constructions, such as dams, taking into account the water pressure effects and the damage–friction evolution with unilateral contact. With this aim, an interface model, based on the cohesive fracture, is developed. In particular, a damage–friction model based on a new multiscale approach is proposed for the interface, which is able to simulate crack propagation in mode I, mode II, and mixed mode. The criteria for crack initiation and propagation and the closure and reopening of the crack are considered for the interface. The friction and the dilatancy are characterized by a decreasing rate of fric- tion and dilatancy angles, respectively, with the possibility of the dilatancy recovering during cyclic loading. The water pressure effect is taken into account by considering a further static pressure acting on the real crack and in the process zone. The value of this pressure is set as a function of the crack opening displacement and it varies from a prescribed initial pressure to the external water pressure. A numerical procedure is developed in order to integrate the evolutive laws governing the interface model. The interface model is imple- mented in finite element codes; some numerical simulations and a comparison with experimental data are performed in order to validate the proposed model and to investigate the influence of the water pressure effects on the crack propagation. Finally, th