基于滑窗包络线法辨识复合圆柱壳结构的模态阻尼

由于复合圆柱壳阻尼机理的复杂性,目前还没有通用而有效的方法辨识该类结构的模态阻尼,因此提出一种基于滑窗包络线法的模态阻尼测试方法.首先,详细说明了滑窗包络线法测试复合圆柱壳阻尼的原理和总体思路;然后,提出了具体的测试复合圆柱壳结构模态阻尼的流程;最后,以局部涂敷约束层阻尼材料的复合圆柱壳为研究对象,对其阻尼特性进行了测试,并讨论了激励幅度对模态阻尼的影响.测试结果表明,所提出的方法获得的前5阶阻尼结果对应的方差最大不超过0.02%,具有较好的可重复性,从而确保具有较高的测试精度. 

Identification of modal damping of composite cylindrical shell based on sliding-envelop method

Due to the complexity of the damping mechanism of composite cylindrical shell, there is no practical and effective method to identify such structural damping.A modal damping test method based on sliding-envelop method was proposed.First, damping test principle and overall plan of sliding-envelop method for modal damping of composite cylindrical shell were clarified in details.Then, its test procedures in the actual test of modal damping of composite cylindrical shell were summarized.At last, a composite cylindrical shell coated with constrained layer damping materials was used as a study object, and its modal damping were well identified and the relation between external excitation level and modal damping was discussed.Test results showed that the maximum variance obtained by the proposed method corresponding to the first five orders damping result was less than 0.02%, and the damping results had good repeatability, thus ensuring high testing precision.