Influence of Pressed Connection on Accelerometer Signal Adhesion between Target Layers

Fuze control is one of the key technologies in developing warhead. The signal adhesion of deceleration may lead to wrong response of layer-counting fuze. Based on numerical simulation, the dynamic response of a projectile connected with an accelerometer equipment by pressed fitting is obtained during the projectile perforating multi-layer target. It is indicated that the maximum dynamic gap between the accelerometer equipment and the projectile can reach to 25 μm, which may induce gap collision and increase the signal adhesion of the accelerometer between target layers. The pressed fitting with a proper preload could suppress the gap collision, and then the pressed fitting connection between warhead and accelerometer could be approximated as the ideal rigid connection. With the proper preload, the frequency response of the overload signal obtained by the accelerometer shows a single peak, and the corresponding frequency of the peak is close to the eigen frequency of the stretching out and drawing back in the first order of the projectile. There is a critical minimum preload that makes the pressed fitting connection approximate to the ideal rigid connection. The minimum preload increases with the impact velocity and the target layers quantity. This may be due to the fact that a higher impact velocity and a larger target layers quantity enhance the maximum stress of wave generated in the projectile. This work provides a foundation for the mechanism identification and the control of the deceleration signal adhesion in interlayers. Moreover, it can give a guidance to projectile and accelerometer equipment assembly with pressed connection in engineering applications.