Research On Stress Simulation And Testing Technology Of Multilayer Penetrating Explosive Charge

The research on the stress of explosive charge penetrating multi-layer concrete target is of great significance to the safety of explosive charge in the process of penetration.Because of the harsh environment,heavy overload and interference,it is difficult to measure the charge stress in the penetration process.In this paper,the stress testing technology of multi-layer penetrating explosive charge was studied in the following aspects:(1)The stress of explosive charge was simulated by LS-DYNA software in the process of single impact and multi-layer target penetration.From the simulation of the explosive stress of the projectile impacting on the target plate in a single time,the change of the internal stress of the projectile impacting on the plain concrete target from different altitudes can be analyzed.It has certain guiding significance for the simulation experiment of stress measurement in single impact charge of projectile.The stress state and amplitude change of the internal charge of the projectile during penetration and flight are calculated by the simulation of the explosive stress of the projectile penetrating the four-layer concrete target.It not only provides a reference for the design of the multi-layer penetrating charge stress test system,but also lays a foundation for the in-charge stress test of the projectile penetrating multi-layer concrete.(2)According to the simulation results of the internal stress of the projectile in two cases,a suitable multi-layer penetrating explosive stress testing system is designed.According to the characteristics,working principle and equivalent circuit of PVDF piezoelectric thin film sensor,a measuring circuit suitable for measuring the charge stress in the process of penetrating multi-layer targets is selected.In addition,the analog circuit and the digital circuit are designed according to the simulation stress signal results.(3)In this paper,various calibration methods of PVDF piezoelectric thin film were analyzed.Finally,drop hammer test device was used to calibrate the secondary packaging PVDF piezoelectric thin film sensor.In this paper,the change of explosive stress of projectile penetrating multi-layered target is analyzed by numerical simulation.According to the characteristics of the stress signal,the hardware circuit of the stress measurement system was designed.The sensitivity of PVDF piezoelectric films after secondary packaging was calibrated.These work provide support for the test of explosive stress during the process of projectile penetrating multi-layered target.