ANALYSIS ON ENERGY ABSORPTION CAPACITY OF MIXED LIGHT WEIGHT CONCRETE (MLWC) UNDER ELECTROMAGNETIC DRIVING SPLIT HOPKINSON PRESSURE BAR (SHPB) CONDITION

Abstract

To investigate the energy absorption capacity of the mixed lightweight aggregate concrete (MLWC), a new device of electromagnetic driving split Hopkinson pressure bar (SHPB) was self-developed, and the numerical model of electromagnetic driving SHPB and the mesoscale model of MLWC were established. Some simulations of electromagnetic driving SHPB impact for MLWC with different gravel replacement rates under different initial voltages were carried out, which were verified by the indoor experiments. Results show that the peak velocity of the bullet is exponentially related to the initial voltage, and the peak velocity has a power function relationship with the power-off time when the bullet reaches the peak velocity. With the increase of gravel replacement rate, the peak value of specific energy absorption for MLWC and the dynamic compressive strength increase gradually, while the absorbed energy density decreases. When the gravel replacement rate is 25-35%, the strength of MLWC is effectively improved on the premise of ensuring its energy absorption capacity. The obtained conclusions can provide a reference for the application of MLWC. Keywords: Electromagnetic drive, Mixed aggregate concrete, Simulation modelling, Split Hopkinson pressure bar (SHPB), Energy absorption