Measurement and analysis of stress waves in concrete targets under ultra-high velocity impact conditions

To investigate the stress wave characteristics within concrete targets under ultra-high velocity impact conditions, a stress wave testing system based on PVDF piezoelectric stress gauges was established, and research on the calibration method for PVDF piezoelectric stress gauges was conducted. The stress waveforms within concrete targets impacted by kilogram-scale cylindrical 93W tungsten alloy projectiles at ultra-high velocity were measured, and the generation and propagation mechanisms of stress waves were analyzed using numerical simulation methods. The following conclusions were drawn: (1) The dynamic characteristic parameters of the PVDF piezoelectric stress gauge were calibrated, yielding a dynamic sensitivity coefficient of 17.5±0.5 pC/N for the PVDF piezoelectric stress gauge; (2) High signal-to-noise ratio stress waveforms within the concrete target under ultra-high velocity impact conditions were obtained using the PVDF piezoelectric stress gauge; (3) The stress waveforms obtained from numerical simulation were in good agreement with the experimentally measured waveforms, with the maximum deviation of the stress wave peak values between simulation and experimental results not exceeding 20%, providing a useful tool for mechanism exploration; (4) The characteristics of stress waves within the target and the mechanisms of generation and attenuation were further understood using numerical simulation methods.