移动质量作用下轴向运动悬臂梁振动特性分析  

Vibration property analysis of axially moving cantilever beam considering the effect of moving mass

作　　者：刘宁[1] 杨国来[1] 

机构地区：[1]南京理工大学机械工程学院,南京210094

出　　处：《振动与冲击》2012年第3期102-105,共4页Journal of Vibration and Shock

基　　金：国家重点基础研究发展计划973项目(61311603);南京理工大学自主科研专项计划资助项目(2010ZYTS004)

摘　　要：将弹炮发射系统简化为移动质量作用下的轴向运动悬臂梁系统,推导了轴向运动梁的振动方程,采用修正的Galerkin法离散求解该偏微分方程,得到以模态坐标表示的二阶时变常微分方程组,通过Newmark-β法对方程组进行了求解。计算结果表明,移动质量载荷主要使梁的一阶模态受到激励,移动质量的大小和运动速度对悬臂梁的振动响应影响较大,在移动质量作用下梁的伸缩运动都处于不稳定状态;在移动质量脱离悬臂梁后,梁的轴向收缩运动使得梁的瞬时振动频率不断减小,振动位移逐渐衰减,而振动速度逐渐增大,梁的运动处于不稳定状态,伸展时梁的自由振动规律相反。The projectile-barrel launching system was simplified as an axially moving cantilever beam system under the effect of a moving mass.The vibration equation of the axially moving beam was derived.The modified Galerkin＇s method was employed to resolve the governing partial differential equation of the translating beam to a set of second order time-varying ordinary differential equations.Then the equations were solved based on Newmark-β time integration method.The results show that moving mass excites mainly the first order mode vibration of beam.The magnitude of moving mass and its moving speed have important effects on the beam vibration response and under the action of moving mass,the constricting and extending movements of the beam are both in unsteady vibration state.After the moving mass disengages the beam while constricting,the axial constriting motion of the beam makes the instantaneous vibration frequency continuously reduce and the vibration displacement gradually decrease while the vibration speed increases,and the movement of beam is still in unsteady state.The unrestricted vibration rules of the beam while extending are reverse.

关 键 词：轴向运动梁 移动质量 时变系统 振动响应 火炮 

分 类 号：TJ301[兵器科学与技术—火炮、自动武器与弹药工程] O328[理学—一般力学与力学基础]