摘要
针对使用近场声全息技术测量表面阻抗时必须在消声室内测量的问题,提出一种基于等效源法的表面阻抗现场测量方法。该方法在材料上方构造一个虚拟腔体,且在腔体内部使用封闭的测量面采集声压,利用基于等效源法的近场声全息技术计算材料表面阻抗。选用单极子和偶极子作为主动声源,对测量环境添加干扰声源进行仿真分析,结果证明了该方法的有效性以及对测量环境的适应性。同时对主动声源以及等效源的位置进行分析,结果表明主动声源在材料表面上方0.2 m～0.4 m处位置为最优,等效源封闭面的上下表面关于材料表面对称,且距离材料表面0.075 m～0.175 m时,测量效果最佳。
Currently existing acoustic impedance measurement methods based on nearfield acoustic holographyare highly dependent on the anechoic chamber and need to measure the material properties in large areas. A surface impedance measurement method based on equivalent source approach is proposed in this paper. In this method, a virtual cavity above the material is constructed. Meanwhile, the closed measurement surface is used to collect the sound pressure inside the virtual cavity. The near-field acoustic holography technique based on the equivalent source method is used to calculate the surface impedance. Monopole and dipole are selected as the active sources, and the interference sources are simulated and analyzed in the measurement environment. The validity of the method and the adaptability to in-situ measurement environment are proved by the results. The analysis of the locations of active sound source and the equivalent source shows that the location of 0.2 m-0.4 m above the material surface is the optimum for the active sound source;when the upper and lower surfaces of the closed surface of the equivalent source are symmetrical about the surface of the material and are 0.075 m-0.175 m away from the surface, the measurement effect is the best.
作者
李曷冰
胡定玉
刘馨悦
方宇
LI Hebing;HU Dingyu;Liu Xinyue;FANG Yu(School of Urban Rail Transportation, Shanghai University of Engineering Science,Shanghai 201620, China)
出处
《噪声与振动控制》
CSCD
2019年第2期226-229,248,共5页
Noise and Vibration Control
基金
国家自然科学基金青年基金资助项目(51605274)
关键词
振动与波
表面阻抗
等效源法
近场声全息
现场测量
vibration and wave
surface impedance
equivalent source method
near-field acoustical holography
in-situ measurement
