Abstract: For traditional chute vibration and noise is very large, chute with viscoelastic damping layer free on it is designed. In this paper, hammer excitation method and the LMS test. Lab vibration test system are used to carry out modal testing for chute with viscoelastic damping layer. In this test, we find the former six ranks mode frequencies，damping and modal shape of the chute. The test of MAC matrix proves that the experimental modal parameters measured are true and valid. It is found by analysis of the result that the vibration on the exit of the chute is lapped over by the torsional vibration and bending vibration. It should be strengthened to reduce the local vibration. The results offer reference for the optimization design of chute with viscoelastic damping layer free on it

Key words: experimental modal, modal parameter, viscoelastic, chute

摘要： 针对传统溜槽振动和噪声非常大的情况，设计了内部自由敷设粘弹性阻尼层的溜槽。文中应用了锤击激励法和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了参考。

关键词: 试验模态, 模态参数, 粘弹性, 溜槽