Dynamic modeling and simulation of impact loading during short concrete columns testing

The determination of the intrinsic strength of concrete at high strain-rates has been a matter of dispute among researchers; some claim that it increases with strain-rate, while others support that it remains the same as in quasistatic tests. In order to clarify this issue a 2-DOF dynamic model employing spring and mass clamped elements was constructed in order to simulate the concrete column & load-cell pair, which undergoes dynamic or impact loading. The analysis reveals that the existence of the load cell plays an important role on the measured force magnitude, thus yielding false results of higher yield and ultimate strength of the tested material. Also a non-linear filter was developed for calculating the real compressive force acting on the specimen from the force readings from the load-cell. The simulation results are in good accordance with stroboscopic high-speed reflective photoelasticity findings.