NUMERICAL-SIMULATION OF MODE-1 DYNAMIC FRACTURE OF CONCRETE

Nonsingular and singular fracture process zones (FPZ) are used to replicate numerically, dynamic fracture of displacement-controlled and drop-weight three-point bend, concrete specimens and crack-line wedge-loaded, double-canti-lever beam (CLWL-DCB) concrete specimens. An inverse procedure, which is based on dynamic finite element analysis, is used to match the measured load, load-line displacement and three stain histories of the fracturing specimen. This numerical analysis shows that the singular-FPZ model provides the most realistic simulation of dynamic fracture of concrete. The resulting constitutive relation between the crack closure stress and crack opening displacement for the sigular FPZ model is geometry and strain rate-independent. The dynamic stress intensity factor, however, is strain rate-dependent.