Ballistic Initial Segment. Outside The Fuze Mechanical Environment Analysis

The dynamics environment for fuze in the initial phase of the exterior ballistic is of great significance to analyze ballistic safety, design ballistic safety device, and to provide the second environment for the redundancy safety and the environment for the delay arming. By dynamics analysis, establishment of mathematical models, calculation of examples, numerical simulation and range test, the dynamics environment for fuze in the initial phase are studied.First, the force of fuze components of spinning projectile in exterior ballistic is analyzed and calculated. The concept of the "nutation-precession force" is proposed. The axial inertial force created by angular motion is the axial projection of resultant force of nutation and precession of spinning projectile, rather than the traditional nutation force.Secondly, the ballistic safety device in the fuze of a small caliber projectile is analyzed. The environment force in exterior ballistic of impact mechanism in the fuze is analyzed and calculated, then the appropriate resistance of ballistic safety device is determined, and a solution to resolve the contradiction of ballistic safety and impact sensitivity is given.Thirdly, the force for fuze components of fin stabilized projectile in exterior ballistic is analyzed and calculated. Unlike the spinning projectile, the inertia force of pendular movement of fin stabilized projectile is far smaller than the creep force, and its effect to the axial movement components can be ignored.Fourthly, the roll damping of spinning projectile in the exterior ballistic is researched. The general program that calculates the roll damping of spinning projectile is compiled in MATLAB. And the errors of roll frequency of spinning projectile are simulated by this program. It is found that the caning groove has great influence on the roll damping of spinning projectile and the aerodynamic coefficient of cross section of carving groove is general 0.45.Lastly, the spin eccentricity of impact mechanism of fuze is researched. The vector dimension chain with random which including its spin eccentricity is analyzed and its spin eccentricity is calculated with Monte-Carlo simulating method. The values of spin eccentricity are skew distribution that approximate to Rayleigh distribution and its direction angles is symmetrical about zero degree.