二维复杂弹性空腔的边光滑有限元建模及分析  

Edge smoothed finite element modeling and analysis of two-dimensional composite elastic cavity

作　　者：刘嘉明 袁丽芸[1,2] 陆静[1,2] 陈莎 文润旭 LIU Jiaming;YUAN Liyun;LU Jing;CHEN Sha;WEN Runxu(School of Mechanical and Automotive Engineering,Guangxi University of Science and Technology,545006 Liuzhou,China;Guangxi Key Laboratory of Automobile parts and vehicle Technology,Guangxi University of Science and Technology,545006 Liuzhou,China)

机构地区：[1]广西科技大学机械与汽车工程学院,柳州545006 [2]广西科技大学广西汽车零部件与整车技术重点实验室,柳州545006

出　　处：《应用力学学报》2024年第1期225-232,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.51665006);国家自然科学基金青年基金资助项目(No.11502056);广西科技大学研究生教育创新计划资助项目(No.GKYC202001,GKYC202002)。

摘　　要：在弹性空腔结构上敷设被动约束层阻尼(passive constraint layer damping, PCLD)可达到减振降噪的效果,针对这类复杂结构建立了二维复合弹性空腔的边光滑有限元耦合动力学模型。其中,PCLD结构采用两节点四自由度的PCLD梁单元,声场采用边光滑有限元模型。以二维全敷设复合矩形空腔模型为数值算例,以精细网格下的有限元法结果作为参考解,对比研究了在相同背景网格下,边光滑有限元法和有限元法的频响结果,发现前者更接近参考解,说明同样的计算成本下,边光滑有限元法具有更高的精确性,特别是在中频计算中。最后,分析了PCLD结构对某汽车驾驶舱的降噪效果,以及黏弹层和约束层厚度参数的影响规律,发现黏弹层厚度增大,可一定程度上降低空腔噪声,而约束层厚度增大,并不能在整个频段得到很好的降噪效果。Laying passive constraint layer damping(PCLD)on elastic cavity structure can achieve the effect of vibration and noise reduction.In this paper,an edge-smoothed finite element coupling model for a two-dimensional composite elastic cavity is established.With the PCLD structure discretized by the two nodes and four freedoms PCLD beam element,the sound field adopts the edge smoothed finite element model.Taking the two-dimensional fully layered composite rectangular cavity model as a numerical example,by comparing the three results with the two finite element methods with rough mesh and fine mesh,and with the present method,it is proved that the result obtained by the present method is closer to the one of FEM with fine mesh compared with the result gained by the FEM with the same background mesh.It has higher accuracy and convergence than those of the finite element method,especially in the calculation of intermediate-high frequency.Finally,the noise reduction effect of the PCLD structure on the driving cavity of an automobile and the influence of the thickness parameters of viscoelastic layer and constraint layer on the noise reduction performance of the coupling system are analyzed,and a conclusion is drawn that the thicker viscoelastic layer could bring better damping effect to some extent,while thicker constrained layer could achieve worse damping effect in some peaks.

关 键 词：边光滑有限元法 被动约束层阻尼 二维复合弹性空腔 降噪 声振耦合 

分 类 号：TB52[理学—物理]