Numerical study of compressive behavior of concrete at high strain rates

High strain rate unconfined compressional tests on concrete are simulated b y a 3D discrete-element method. The laboratory data set was provided by thr ee unconfined experiments on a split Hopkinson pressure bar apparatus at ve ry high strain rates (350-700 s(-1)). This numerical method was chosen beca use it is well adapted to problems involving the characterization of fractu ring and fragmentation in geomaterials. The simulations input data are the recorded experimental velocities, whereas the simulations output data are t he computed forces that are compared with the experimental ones. The fit be tween the experimental and the numerical data is quite good. Based on this fit, it is shown that the strain rate dependency of the material strength c an be explained by inertial effects.