Design And Implementation Of Continuous Explosive Shock Wave Automatic Storage Testing System

With the continuous advancement of China’s national defense and military modernization in the new era,the development of various new weapons requires more precise assessment of destructive power to guide them.Shock wave overpressure testing is an important means of weapon power assessment.Considering the simple function of the conventional storage testing system and its shortcomings in real explosion testing,an automatic storage testing system for continuous explosion shock wave was designed.The hardware circuit and functional programme of the testing system have been designed according to the technical index,with core functions including multi-trigger,adaptive negative delay,and multi-channel and multi-trigger data storage.Pressure sensors are a critical component of shock wave testing,PVDF thin film polymer materials have excellent piezoelectric properties,making them suitable as sensitive materials for sensors.In this study,the design of an integrated piezoelectric film sensor for explosion shock wave overpressure testing was completed,including the fabrication of the piezoelectric film sensor,structural design,and charge amplification circuit design.The installation of the piezoelectric film and circuit structure were integrated,and the interwire capacitance and wire resistance can be reduced,which is beneficial for controlling the frequency characteristics and solves the problems of insufficient bandwidth and large interference caused by the long lead in the testing.During the process of shock wave pressure testing,fragments generated by weapon and ammunition explosions can damage the shock wave measurement equipment.Therefore,protective structures are needed to reduce damage to the testing system.In this paper,the design of the protective structure was optimised with respect to the influence of the protective structure on the shock wave characteristics.Using ANSYS AUTODYN software and adopting 2D-Euler Multi-material algorithm,the propagation of shock wave signals under protective structure conditions was numerically simulated.The shock wave pressure curves and characteristic parameters were compared with those in an open environment to analyze the effect of the distance between the protective structure and the measurement point,as well as the angle αbetween the protective structure and the direction of shock wave propagation on shock wave testing.The numerical simulation provides a basis for the layout of protective structures and the optimization of model in shock wave testing experiments,thereby reducing the impact of protective structures on shock wave testing in lethal weapon explosion tests and improving testing accuracy.The measured performance of the sensor and testing system was validated through relevant experiments.To investigate the dynamic characteristics of the integrated piezoelectric film sensor,shock tube calibration and small-scale explosion simulation tests were performed,and the sensitivity and rise time of the sensor charge amplification output were determined to be5.56 m V/k Pa and 8μs,respectively.The testing system was used in actual explosion shock wave testing on a test field,and the test results showed that the designed shock wave testing system can accurately and reliably record explosion shock wave overpressure data,achieving automatic triggering and storage of multiple consecutive shock wave signals.