Analysis And Modeling Of Dynamic Response Characteristics Of Fuze Under High Speed Penetration

The precise and efficient knockdown on high-value hard targets such as command posts,ammunition depots and large warships hidden deep underground or in caves under multi-storey buildings plays an increasingly important role in the modern war.Accurately hitting these high-value hard targets depends mainly on the precise guidance of the kinetic energy penetrating projectile.The high-level damage to the targets not only needs the penetrating projectile is equipped with ammunition that are sufficiently powerful,but also rely on whether the hard targets penetrating fuze can identify the penetrating information(namely the depth of penetration and the number of layers)precisely and accurately,and whether it can launch the warhead at ideal positon.Therefore,the reliability of the penetrating fuze directly influences the damage effect of the targets.With the continuous enhancement of the high-value hard targets protection capability,the penetration speed of the penetration bomb is also on the rise.At present,under high-speed penetration conditions,fuzes are prone to fail with system destruction and abnormal performance.Especially in the case of high-speed penetration of multi-layer targets,the fuze overload signal tends to cause adhesion and cannot effectively identify the problems such as strata penetration situation.One of the reasons for these problems is that under the condition of high-speed penetration,the understanding of the dynamic response characteristics of the fuze system is not sufficiently,and thus specific protection measures cannot be taken.In order to solve the problems above,based on the analysis of the projectile-fuse structure,an equivalent structural model of the projectile-fuse system is established.By using the methods of dimension analysis,numerical simulation and signal time-frequency analysis,the dynamic response characteristics of the fuze in the process of high-speed penetration are analyzed in this paper,and the factors that affect the fuze overload characteristics,the signal adhesion and their influence rules are analyzed and studied in the case of high-speed penetration of multi-layer target plate.The main contents and achievements of this paper are listed as follows:(1)Based on the characteristics of projectile-fuse system structure,an equivalent model of projectile-fuze-sensor projectile-fuse system is established in this paper,as well as its dynamical equation.Numerical calculation method is used to solve and analyze the fuze response.Compared with the penetration overload signal by actual measurement,the model can well reflect the response effect of projectile-fuse system.(2)This paper defines five dimensionless factors which influence the dynamic response characteristics,the overload signal adhesion structure as well as the environment of the projectile-fuze system through dimension analysis,which are equivalent stiffness factor,equivalent damping factor,target plate thickness factor,target plate spacing factor and radial length ratio.(3)For structural factors represented by equivalent stiffness factor and equivalent damping factor,this paper adopting the MATLAB / Simulink which is a numerical simulation method to simulate the projectile penetration at different penetration velocities by imposing exciting force with different pulse widths and intervals to the system.Then the influence of equivalent stiffness and equivalent damping on the dynamic response characteristics and signal adhesion of fuze is given after the analysis.(4)For environmental factors influenced the penetration like target thickness and target spacing,dynamic simulation method by ANSYS / LSDYNA is used to analyze the effects of the dynamic response characteristics and the overload signal adhesion situation when the initial penetration velocity are set at 500 m / s,800 m / s and 1000 m / s,and the influence law is given.(5)Through the analysis of different influence factors,the necessity of modeling the integrality of the projectile structure is reflected in the dynamics simulation of the projectile-fuze structure.For the special problems like trans-dimension structure of the projectile and fuze,a dynamic substructure method is proposed to numerically model and simulate the projectile-fuze structure.In addition,in this paper,the projectile penetrating semi-infinite thick target plate is also modeled and simulated,and feasibility of this method is verified,which provides a basis and reference for further modeling and simulation of complex projectile-fuze structure.The research in this paper not only provides a theoretical basis and simulation support for further in-depth analysis of dynamic response characteristics of projectile-fuze system during high-speed penetration,but also provides basis and reference for research on penetration fuze reliability design and penetration information identification method.