约束阻尼结构阻尼效果的有限元预测方法研究

Prediction of the Damping Efficiency of Constrained Damping Structures by Finite Element Method

阻尼消振作为减振降噪方法在工程中应用很多,约束阻尼结构铺设阻尼材料后总阻尼因子的计算是一个很重要的问题,经典的含约束阻尼双层梁结构和三层梁结构的阻尼解析计算方法对复杂结构不适用,目前急需可靠实用的工程计算和设计方法。基于模态应变能给出复杂结构的阻尼有限元计算方法,同时基于统计能量分析原理提出一种宽带激励下总阻尼效果的评价公式,以及基于该评价公式的有限元优化设计方法。通过对双层阻尼梁结构和含约束面板的三层阻尼梁结构的阻尼解析计算和有限元计算法预报对比,验证有限元计算方法的正确性。依据阻尼效果评价公式对某约束阻尼平板的阻尼层和约束面板厚度进行优化设计,并通过谐波响应分析验证优化方法的正确性。基于ANSYS软件的分析方法可供工程中复杂结构阻尼设计参考。

The constrained damping treatment, as a vibration and noise reduction method, has great engineering application. Calculation of the global damping factor of the damping treated structure is an important problem in engineering. Traditional analytical calculation method for beams with constrained layer damping such, as double-layer treatment and constrained triple-layer treatment, is not suitable for complex composite structures. Reliable and practical engineering calculation and design methods are needed urgently. In this paper, the finite element analysis method of complex structure ' s damping loss factor based on modal strain energy theory is studied. The effective evaluation formula of global damping is proposed based on the statistical energy analysis, and the finite element optimization method based on this evaluation formula are proposed. Through the analysis of the beams with the double-layer and the triple-layer damping treatments and using both the analytical method and the finite element method, the accuracy of the finite element method is verified. The optimal design of the thickness of the damping layer of a constrained damping plate is optimized according to the damping effect evaluation formula. The correctness of the optimization method is verified by a harmonic response analysis. All the analysis in this paper is done by ANSYS software;it can be referred in damping design of more complex structures.