轿车带内饰车身模态试验分析

Analysis and Research of Modal Test for a Trimmed Car Body

针对带内饰车身模态参数难以识别的问题,在结构线性度检验的基础上,分别采用频域识别和时域识别两种方法对某轿车带内饰车身进行模态试验。介绍了试验方案与信号采集技术,重点对识别方法进行比较研究,其中时域随机子空间法的较好应用效果为车身模态试验提供新思路。最后通过有限元分析与试验结果对比,验证了内饰车身建模分析的准确性,所确定的内饰车身模态参数为车身NVH性能分析奠定基础。

In order to solve the problem that modals of the trimmed car body are difficult to identify, both frequencydomain and time-domain identifications are used for the modal test of the trimmed body of a car on the basis of the structure’s linearity inspection. The test scheme and signal acquisition technique are introduced and the identification methods are comparatively studied. Of these methods, the successful application of the stochastic subspace identification provides a new way for the body modal test. Finally, the comparison of results from the test and FEA verifies the accuracy of the trimmed body modeling analysis. The determined modals of the trimmed body lay a foundation for the analysis of NVH performance.