Research On Influence Of Projectile Parameters On Dispersion Of Falling Deviation Of The Projectile

Deviation of the projectile is a significant source of falling points,which result from deviations in producing process.In order to reveal the internal relation of deviation and dispersion of falling points,this thesis concentrates on the flowing three aspects of contents.the classical interior ballistic equation and stochastic is used.The infect of the projectile parameters on the projectile velocity is studied by simulation.By analyzing the force condition inside the chamber,the model of contact and friction force are established.In order to solve the catastrophe of damping coefficient when a projectile collides with a tube,a modified damping coefficient is introduced and a step function is used to correct the coefficient of impact damping.A simulation model of initial disturbance of projectile is established,and the initial disturbance of projectile at muzzle is calculated using the projectile parameter.Conclusions are as follows: the initial perturbation of projectile increases with the increase of mass eccentricity of projectile,increases with the increase of projectile principal axis shift,and decreases with the increase of projectile clearance.Using the interior ballistic model,the model of initial disturbance of projectile and the model of six degree of freedom rigid body trajectory,the method of calculating the point of projectile when the parameter of projectile is given is established.The uniform design method is used,6 factors and 17 levels of simulation is drawn.simulation results are analyzed by linear regression and quadratic regression.Respectively the quadratic regression results contain more factors,so the quadratic regression analysis results is chosen.The regression results show that the main parameters affecting the dispersion of projectile X are mass m,center of mass position L and mass eccentricity e.Among them,the impact of projectile quality is the largest,accounting for 74.48%,and the mass center position and mass eccentricity account for 4.58% and 20.94% respectively.The main parameters affecting the Z direction dispersion are the mass eccentricity e of the projectile,the offset of the main axis of the projectile and the clearance between the projectile and the chamber d.Among them,the impact of mass eccentricity is the largest,accounting for 79.03%,and the influence of the inertial spindle offset and the projectile gun gap is 12.73% and 8.24% respectively.The method of range analysis is used to analyze the dispersion of projectile points.The following conclusions are obtained: under the influence of projectile parameter the,dispersion of projectile in range and transverse direction is (?) and (?).