考虑炮弹质心偏离影响的摆弹机系统振动特性分析

Analysis of the Vibration Characteristics of a Shell-Swinging System Considering the Influence of Projectile Center of Mass Deviation

大口径舰炮摆弹机构在实际工作过程中,存在偏心问题,由此引起的惯性激励力将导致摆弹臂呈现弯扭耦合振动特性,这对于摆弹机转运弹药的可靠性造成较大影响。针对这个问题,建立摆弹机系统弯扭耦合动力学模型,采用模态截断法将时变方程离散,根据炮弹姿态控制方程确定振型函数,运用四阶龙格-库塔法进行数值计算,考虑炮弹和摆弹臂耦合系统质量分布对振型函数的影响,研究了炮弹惯性效应作用下摆弹臂振动响应规律。研究表明:炮弹质心偏心距是影响摆弹臂振型函数的重要因素;炮弹质心偏离引起摆弹臂振动响应幅值增大,影响交接动作可靠性;减小炮弹质心离心距有利于控制上摆运动时间误差。研究结果可为摆弹机系统的设计和优化工作提供理论依据。

There is the eccentricity problem in the shell-swinging mechanism of large caliber naval guns in the actual operating process.The inertial excitation force caused by eccentricity will cause the swing arm to exhibit the characteristics of bending-torsional coupling vibration,which has a great impact on the projectile-transferring reliability of the shell-swinging mechanism.To solve this problem,the bending-torsional coupling dynamic model was established.The discrete time-varying equation was derived with the mode truncation method.And the vibration mode function was determined by using the projectile attitude control equation.Considering the influence of mass distribution of the projectile and swing arm coupling system on mode function,the vibration response law of the swing arm under the projectile inertia effect was studied based on the results generated by the fourth-order Runge-Kutta method.Results show that the eccentric distance of the projectile center of mass plays an important role in affecting the vibration mode function;the vibration response amplitude of the swing arm increases due to the deviation of projectile mass center,which affects the reliability of handover action;reducing the centrifugal distance of the projectile center of mass is helpful for controlling the time error of swin-ging action.Research results are helpful for the design and optimization of the shell-swinging system.