Impact splitting tensile experiments of concrete and numerical modeling by meso-scale discrete elements

In this work,an impact splitting tensile experiment of concrete using Hopkinson pressure bar was performed.Strain-rate effects of concrete were reflected by the observed dynamic fracture patterns,and strength enhancement was observed in the experiment.A meso-scale discrete element model(DEM) of concrete was developed by pre-processing approach based on a background-grid search method.Using this model,numerical simulations of the test conditions in meso-scale were conducted.The simulated dynamic strength and fracture patterns agree well with the measurements,and hence the model is validated experimentally.The simulations show that higher strain rates cause more disperse patterns of fracture and more energy demand by structure failure,and this could be a major mechanism for the strain-rate effects.Thus,the numerical and experimental results in this study would shed light on understanding of the dynamic failure behavior of concrete.