Mechanism Of Terminal Guidance Projectile With Cannon Gun Tube Mutual Coupling And Fitment Technology

Under the background of an Advance National Defense Research Project, this thesis is concerned with the terminal guided projectile’s overload in bore, dynamic strength, plastic belt and terminal guided projectile decreasing spin problems. The main contents are as below.Firstly, the structure, working principle and main performance parameters of the terminal guided projectile are presented in this thesis. Specifically, for the structure of the terminal guided projectile, we primarily introduce guided part, combat and control parts. The working principle of active and semi active guidance systems are mainly introduced. Meanwhile, we briefly describe the guidance system in the form of laser, millimeter wave, infrared, composite guide.Secondly, the terminal guided projectile in bore by gunpowder gas pressure, inertial force, band pressure, nonhomogeneity force, driving side force and friction are analyzed and calculated. The terminal guided projectile in bore stress situation is extremely complex, mainly depends on the terminal guided projectile relative to the bore and ground location, artillery and terminal guided projectile motion and powder characteristics. Then, based on the nonlinear finite element theory, this paper established a terminal guided projectile entity model and finite element model, discussed the terminal guided projectile meshing principle and quality control, as well as the different types of connections between the elements. The reduced integration, isoparametric hexahedron element, shell element, beam, bar and other types of elements are proposed. The terminal guided projectile and barrel coupling dynamics simulation models are established. Analysis of the terminal guided projectile overall dynamic strength is introduced, and we gives the printed circuit board and package bubble dynamic strength and stress cloud chart at the time of maximum bore pressure.Then the problem addressed here is the movement characteristics and influencing factors of the terminal guided projectile in different periods. And a detailed analysis of the definition of the contact interface between the terminal guided projectile with the bore, cartridge belt and bore, the contact interface of normal behavior and tangential behavior are presented. The application of the penalty function method is gived. The analysis of the the display integration scheme solving characteristics is introduced. The combination of the above theoretical analysis, this paper gives the high-precision modeling methods and steps of the rifled barrel. Considering the initial gap between the projectile and artillery, structure length of the terminal guided projectile, the different structures of the bore and the projectile and artillery between different coefficient of friction and other factors, the numerical calculation of terminal guided projectile overload is presented, and based on the calculation results we obtained the law of the terminal guided projectile’s overload in bore.Finally, according to the domestic and foreign scholars on the belt, the research into stress calculation and the theory formula, this paper analyses the the terminal guided projectile muzzle speed influence factors, and the terminal guided projectile in different width of the belt, elastic belt and the belt groove between different coefficient of friction, elastic belt and the rifling different friction coefficient and elastic belt radial force quantity under the condition of rotating speed and speed ratio of muzzle are calculated. In this paper, nylon belt uses Johnson-Cook material model. Considering its plastic deformation, through finite element simulation of band engraving process, the procedure of the belt at different time engraving process is described. Baed on the above theory, this part gives the dynamic stress curve and related plastic results.