基于有限元能量流的混合结构间耦合损耗因子

The coupling loss factor of mixed structures based on the finite element energy flow model

为了减轻船舶结构重量,降低重心,高速船往往采用钢、铝混合结构,两者之间采用过渡接头进行连接会影响结构声波的传递。耦合损耗因子(CLF)作为统计能量分析法的一个关键参数,对船舶舱室噪声预报有着重要影响。基于有限元能量流法构建了相应的数值计算模型,采用Matlab软件编写计算程序,将其应用于某典型钢、铝混合结构的计算中并对其进行了验证,同时还研究了连接接头参数及加筋板对结构耦合损耗因子的影响,结果表明:增加接头的重量或横截面积可以减小中高频段的耦合损耗因子。所编程序可以为该类型船舶的噪声预报及减振降噪提供建议与指导。

The aluminum-steel structure is often applied to high speed vessels for the purpose of weight reduction, declining center of gravity, and high speed. The transition joint between the steel-made main hull and aluminum alloy superstructure could affect the propagation of structure acoustic waves, thus affecting the Coupling Loss Factor (CLF) between these structures, a key parameter of Statistical Energy Analysis (SEA) and significantly impacts the prediction of noise. Based on the finite element energy flow method, a numerical computation model and corresponding calculation program in Matlab are developed, which are then verified with experiment and L model's wave approach results. The influence of calculation parameters on accuracy is studied and relevant suggestions are given. Particularly, the effect of joint parameters on CLF is studied, suggesting that the thickness ratio of plate and joint has a large impact to the CLF; the energy flow features of the stiffened plate model is studied, indicating that compared with the flat model, the CLF curve of the stiffened plate model is more mild. Overall, the proposed program and the findings in this paper provide guidance for noise prediction and reduction in marine engineering.