摘要：变幅杆节点位置的选取直接影响着声学系统的传输效率，圆锥形复合变幅杆节点位置随着变幅杆的直径比N、长度l和外激频率f三个变量的变化而变化，固定其中任意两个变量，利用有限元软件MATLAB对第三个变量进行抽样计算得到节点样本值并将其拟合成图。应用有限元软件对其进行仿真，通过位移云图发现节点处径向截面外轮廓处位移并不为零。为了提高传输效率，降低节点位置选取所带来的振动，通过有限元软件MATLAB对节点进行优化设计。实验结果表明：以谐振频率20kHz为例，优化后的振幅有所增大，传输效率进一步提高，谐振频率更加接近设计频率。

关键词：节点；圆锥形复合变幅杆；有限元分析；优化设计

中图分类号：TG663；TH122；TB5文献标志码：A

Dynamic Analysis and Optimal Design of Node of Coniform Horn

Tong Jinglin，Feng Zhibin，Zhao Bo

Abstract:The node’s location of a horn affects the transmission efficiency of the acoustic system directly.For a conical compound horn，the location of the node will be changed along with the variation of the following three variables——the diameter ratio N，the length of the horn l and the external excitation frequency f.MATLAB is used to calculate the third variable to get the sample value of the nodes，then a figure can be achieved，when any two variables are fixed.The diagram of displacement simulated by the finite element software indicated the displacement on the outer contour of the radial section of the node is not zero.The location of the node is optimized，for the promotion of the transmission efficiency and reduction of the vibration caused by the selection process.The results show that taking resonant frequency 20kHz as an example，the transmission efficiency of the optimized horn improves with the increase of the amplitude，the resonant frequency of that becomes closer to the designed frequency as well.

Keywords:node； conical composite horn； finite element analysis； optimization design