This work is concerned with the numerical study of dynamic mode I and mixed- modefractureinfiberreinforcedconcrete(FRC).Arecentlydevelopedeigensofteningalgorithm to deal with the fracture of quasi-brittle materials is employed in a meshfree framework. Three- point bending tests on notched beams reinforced with steel fibers…
This work is concerned with the numerical study of dynamic mode I and mixed- modefractureinfiberreinforcedconcrete(FRC).Arecentlydevelopedeigensofteningalgorithm to deal with the fracture of quasi-brittle materials is employed in a meshfree framework. Three- point bending tests on notched beams reinforced with steel fibers carried out through a drop weight device at two loading velocities are modelled herein. Since the notch was placed with an offset from the middle section, mixed-mode crack formation was facilitated. Three types of concrete with the same matrix reinforced with different amounts of steel fibers were used for these beams. All mechanical and fracture properties were measured through independent tests. Assumingalinearsofteningstress-equivalentcrackopeningrelation, thenumericalmethodology is first validated against experimental results on plain concrete. Subsequently, it is applied to study the dynamic fracture of fiber reinforced concrete with a bilinear softening relation. The numerical simulations reproduced remarkably well the experimental results such as load-line displacements, crack patterns and reaction forces. The parametric studies show that the total energy dissipation plays an important role on the peak reaction load, whereas the transitional point between the two branches has a significant influence on the crack patterns. 1 R. C. Yu, P. Navas and G.