平面弹性五杆机构的振动与构件弹性振动的平衡优化

Vibration Balancing Optimization of Elastic Five-Bar Planar Linkages

采用SPACAR软件建立平面弹性五杆机构的有限元模型,在Matlab环境下对其进行动力学仿真分析.仿真结果表明,通过不断增大曲柄转速,机构的振动和构件的弹性振动均不断加剧.将机构的振动、构件的弹性振动以及二者的综合作为3种不同的优化目标,利用部分冗余伺服电机(PRSM)法对SPACAR建立的有限元模型进行平衡优化,探讨3种优化目标的优化效果.结果表明:以构件的振动为目标函数虽然可以改善杆件的弹性振动,但是会使机构的整体振动加剧;以机构振动力矩为目标函数或者以构件的振动和机构的振动二者的综合为目标函数均可同时平衡机构的振动和构件的弹性振动,但前者对机构振动的平衡效果更好.

An elastic five-bar finite model is directly established with the SPACAR program and the dynamic simulation analysis is discussed in the Matlab environment. Increasing gradually the speed of the cranks, the simulation results show that the shaking of the whole mechanism and the vibration of the elastic bars are continually aggrandized. Regarding the shaking of the mechanism, the vibration of two connecting rods and the integrated function of both as three different optimization goals, the dynamic property of the elastic five-bar linkages is optimized based on partial redundant servo motor （PRSM） approach, and then the optimization results of three different goals are analyzed. Taking comprehensive analyses into account, the conclusion is firmly achieved. On one hand, considering the vibration of linkages as the objective function, it is possible to decrease the elastic vibration of bars, yet the shaking is intensified in the meantime. On the other hand, with shaking moment or the integrated function of both as the objective function, both the vibration and the shaking can be diminished at the same time, while the effect of the former on balancing of the shaking is better.