基于刚柔耦合模型的微耕机振动特性分析

Analysis of vibration characteristics for power tillers based on a rigid-flexible coupling model

针对微耕机作业时振动剧烈、操控舒适性差等缺陷开展研究。以南方丘陵地区常用的某型自走式微耕机为对象,依据结构分析及非作业状态下微耕机振动测试结果,结合多体动力学方法,考虑保险杠、发动机托架和扶手架(手柄)为空间柔性体,建立了基于约束的微耕机刚柔耦合动力学模型,并进行了整机系统动力学仿真。同时,开展了微耕机作业工况下振动特性的土槽测试试验。对比分析结果表明:仿真所得到的该型微耕机典型转速工况下手柄处的振动特性曲线与试验曲线吻合,加速度有效值误差小于5. 4%,频谱成分接近,这说明所建立的微耕机刚柔耦合动力学模型是有效的,运用多体系统刚柔耦合动力学建模理论与有限元相结合的方法研究微耕机整机振动特性是可行的。研究结论对于微耕机振动特性研究有一定的参考价值。

Aiming at the defect of power tillers such as violent vibration as well as poor comfort,a self-propelled power tiller commonly used in southern hilly region was studied.According to structural analysis and test results of vibration characteristics for the power tiller in the non-operational state,a new rigid-flexible coupling dynamic model of the power tiller was established based on the multi-body dynamic method with considering the influence of flexibility of the parts such as bumper-bar,E-bracket and handle.At the same time,soil test on the vibration characteristics of the power tiller was performed.The comparative results show that the vibration characteristic curve of the handle by simulation is consistent with that of the test.The error of the vibration acceleration effective value is less than5.4%,and the spectral components are close.This indicates that the established rigid-flexible coupling dynamic model of the power tiller is effective.