近场声全息隔声测量技术重建参数的选取

Selection of Reconstruction Parameters for Sound Insulation Measurement Based on Near-Field Acoustic Holography

近场声全息技术在装配式建筑及构件隔声的现场测量中具有广泛应用前景,为了降低全息测量的复杂度和提高声场重建的准确度,文中首先以点声源为例,采用数值仿真和实验验证的方法,对隔声测量精度随参数的变化规律开展了研究;然后,探讨了参数的优选范围;最后,通过实例来验证文中选取的重建参数对隔声测量的有效性。结果表明:仿真值与实验值基本一致,隔声测量精度随重建距离和采样间距的增加而逐渐降低,随全息面孔径边长的增加而逐渐升高;重建距离和采样间距的取值不宜超出最高频率对应的半波长,全息面孔径边长的取值宜为构件尺寸的1.5倍,此条件下精度提升幅度最大;通过对重建参数的优选,不仅能降低隔声测量的复杂度、提高测量效率,而且可以得到较好的隔声测量精度,提升了近场声全息隔声测量技术的工程实用性。

Near-field acoustic holography has wide application prospects in the field measurement related to sound insulation of prefabricated buildings and components.In order to reduce the complexity of holographic measurement and improve the accuracy of sound field reconstruction,this study firstly used point sound source as an example to explore the variation law of sound insulation measurement accuracy with parameters by means of numerical simulation and experimental verification.Then it discussed the optimization range of parameters.Finally,this study veri-fied the effectiveness of the reconstruction parameters selected in this paper about sound insulation measurement.The results show that the simulation values are basically consistent with the experimental values.That is,the accuracy decreases with the increase of reconstruction distance and sampling spacing,while increases with the increase of holographic aperture.In addition,to best improve accuracy,the values of reconstruction distance and sampling spacing should not exceed the half-wavelength corresponding to the highest frequency,and the aperture of the holographic plane should be 1.5 times of the component size.By optimizing the reconstruction parameters,it can not only reduce the complexity of sound insulation measurement,but also improve the measurement accuracy,as well as obtain better sound insulation measurement accuracy,improving the engineering practicability of the near-field acoustic holographic sound insulation measurement technology.