Optimal Design and Experimental Study of a Layer Counting Sensor for High-Speed Penetration Through Multilayer Hard Targets

Explosion point control must be achieved for a projectile striking a multi-layer hard target via layer detonation. However, multiple oscillating signals are superimposed on the penetration deceleration when a high-speed warhead penetrates through multiple layers of a hard target. Signal overlap occurs when an acceleration sensor is used to measure the penetration deceleration, causing the projectile to be unable to identify layer penetration characteristics and thus seriously affecting the layer detonation accuracy. A special layer counting identification sensor is designed in this paper to resolve the acceleration signal overlap phenomenon caused during the projectile penetration event for multi-layer hard targets. When the vibration frequency of the measured system is far higher than the natural frequency of the sensor, the relative vibration displacement amplitude of the sensing mass block inside the sensor is related linearly to the displacement amplitude of the measured system. Based on this principle, this work investigates the mechanisms and the structural design of the layer counting sensor, and optimizes the main sensor parameters that affect its output characteristics. The sensor output characteristics were tested using a multi-impact simulated test device developed by the authors. The test results show that the layer counting sensor’s output signal has a single waveform with easily identifiable characteristics that can effectively avoid the influence of structural response and vibration interferences on the sensor output signal, which means that layer detonation can be controlled accurately for high-speed penetration through multi-layer hard targets. Index Terms-high-speed penetration, layer counting sensor, natural frequency, optimal design.