敷设粘弹性材料的溜槽的试验模态分析

Experimental Modal Analysis of Chute with Viscoelastic Damping

针对传统溜槽振动和噪声非常大的情况,设计内部自由敷设粘弹性阻尼层的溜槽。应用锤击激励法和LMS test.Lab振动测试系统对内部敷设粘弹性阻尼层的溜槽进行了模态试验,得到了前6阶固有频率、阻尼和振型,经过模态置信准则检验,所测试验模态参数真实有效。通过对试验结果的分析发现溜槽出口处的振动为扭转振动和弯曲振动的叠加,加工时应该加强出口处的强度以减小局部振动。研究结果为敷设粘弹性阻尼层的溜槽的优化设计提供参考。

For very large vibration and noise of traditional chutes,a new chute with a viscoelastic damping layer freely attached to its internal surface is designed.In this paper,hammer excitation method and the LMStest.Lab vibration test system are used to carry out the modal testing for the chute.In this test,the former six order frequencies,modals and damping of the chute are foxmd.The test of MAC matrix shows that the experimental modal parameters measured are truly and effetely.It is found by analysis of the result that the vibration at the exit of the chute is a combination of torsion vibration and bending vibration.The exit should be strengthened to reduce the local vibration.The results offer a reference for the optimal design of chute with a freely attached viscoelastic damping layer.