We aim to model the static-dynamic fracture, often propagates in mixed-mode in lightly rein- forced concrete beams. When a beam does not have enough shear reinforcement, fracture can initiate and propagate unstably and lead to failure through diagonal tension. In…
We aim to model the static-dynamic fracture, often propagates in mixed-mode in lightly rein- forced concrete beams. When a beam does not have enough shear reinforcement, fracture can initiate and propagate unstably and lead to failure through diagonal tension. In order to study this phenomenon numeri- cally, a model capable of dealing with both static and dynamic crack propagation as well as the natural transi- tion of these two regimes is necessary. A cohesive model for concrete fracture and an interface model for the deterioration between concrete and steel re-bar, both combined with an insertion algorithm, are chosen for this task. The static process is solved by dynamic relaxation (DR) method together with a modified tech- nique to enhance the convergence rate. This same DR method is used to detect a dynamic process and switch to a dynamic calculation. The numerically obtained load-displacement curves, load-CMOD curves and crack patterns fit very well with their experimental counterparts, having in mind that we fed the calculations only with parameters measured experimentally.