预应力下微耕机扶手振动响应仿真及试验研究

Simulation and Experimental Study on the Vibration Response of the Pre-stressed Mini-tiller Handle

针对微耕机在作业过程中扶手振动强烈的问题,采用预应力下的谐响应分析及振动测试试验,研究其振动响应,克服了仅通过自由模态分析扶手振动响应特性与实际作业情况相比误差较大的缺点。利用有限元法对扶手进行考虑人体手臂对扶手作用力的静力学分析及约束模态分析,并对扶手的把手处进行强迫激励下的谐响应分析,获得把手处加速度最大谐峰值及其对应频率,最后进行扶手把手处振动测试田间试验。结果表明:试验与仿真结果一致,在2、4阶固有频率处的振动响应对扶手的把手处振动贡献较大,这主要来自发动机混合气燃烧激振力及发动机二阶惯性力。这一结论为微耕机扶手减振提供了理论依据。

Directing at the strong vibration of the handle of the mini-tiller,the harmonic response analysis and vibration test were carried out to study the vibration response under the pre-stressed condition,which overcame the big error of the handle vibration response characteristic compared with the actual operation situation only by the free modal analysis.The finite element method was used to solve the prestressed static analysis and the constrained mode analysis of the handle,then the harmonic response analysis under the forced excitation of the handle was carried out to obtain its maximum harmonic peak and corresponding frequency,finally,the vibration test on the field of the handle was carried out. The results show that the test results are consistent with the simulation results,the vibration response in 2 and 4 order natural frequency contributed greatly to the handrail＇s handle vibration,which is mainly from the engine gas mixture combusting force and second-order inertial force of engine. The conclusion provides a theoretical basis for the optimization of the vibration reduction of the mini-tiller handle.