农用运输车联体后桥试验模态分析

以试验模态分析技术为手段，研究了新开发的某农用运输车联体后桥的振动模态特征，得到其固有频率、阻尼、模态振型等模态参数。试验模态分析结果表明：联体后桥垂直振动的前三阶固有频率较低，易于引起联体后桥产生俯仰振动；另外，变速器箱体左右侧面的刚度较差，导致变速器产生明显的局部振动。

Experimental Modality Analysis on the United Rear Axle of a Farm Transport Vehicle

In this paper modal characteristics of vibration for a new designed united rear axle of farm transport vehicle were studied with experimental modality analysis. The arrangement of the excitation points and measuring places, as well as the measuring and testing techniques were also introduced. The upper limit of analysis frequency is 400 Hz. The vertical vibration and side vibration of the united rear axle were analysed by means of modal frequencies and modal shapes. There are three order modal frequencies of vertical vibration within the frequency domain of vibration sources. The rear axle is easy to pitch due to the sympathetic vibration of vertical vibration. The first order modal frequency of side vibration exceeds the highest frequency of vibration sources. The poor rigidity of the both sides of transmission box results in the obvious local vibration of the transmission.