CAJ | 학술논문

由于水中结构的振动声辐射要考虑流体加载效应，因此水中结构声辐射的模态分析也与空气中的有所不同。基于辐射声功率的二次型表达式，采用有限元和 Rayleigh 积分耦合方法，对板结构的水下声功率模态进行了计算分析研究，通过辐射效率、模态振型和辐射声功率等探讨了其特点。结果表明以激励力为变量、考虑了结构阻抗的水下声功率模态具有各阶模态声辐射独立、低频时前几阶模态(特别是第1阶模态)的声辐射占主导地位、模态辐射效率峰值和模态振型物理意义清楚等特点，在水下结构振动声辐射的分析和控制方面有一定实用价值。
유우수중결구적진동성복사요고필류체가재효응，인차수중결구성복사적모태분석야여공기중적유소불동。기우복사성공솔적이차형표체식，채용유한원화 Rayleigh 적분우합방법，대판결구적수하성공솔모태진행료계산분석연구，통과복사효솔、모태진형화복사성공솔등탐토료기특점。결과표명이격려력위변량、고필료결구조항적수하성공솔모태구유각계모태성복사독립、저빈시전궤계모태(특별시제1계모태)적성복사점주도지위、모태복사효솔봉치화모태진형물리의의청초등특점，재수하결구진동성복사적분석화공제방면유일정실용개치。
Because of fluid loading, the modal analysis of sound radiation of underwater structure is different from that in air. The modal analysis of sound radiation from an underwater plate is carried out by using coupled finite element/Rayleigh integral method. The expressions of acoustic power modes are obtained based on the quadratic form of acoustic power. The characteristics of the acoustic power modes are compared in their radiation efficiencies, mode shapes and radiated power contributions. The numerical results show that the acoustic power modes expressed by the excitation force have the advantages in taking account of the structural impedance, no modal coupling of sound radia-tion between modes, the first few modes (especially the first mode) dominating the total sound radiation, direct physical explanations of the mode shapes and the peak values of the mode-radiation efficiency. So, the acoustic power-mode analysis is more favorable in analysis and control of sound radiation from underwater structure.