水声材料宽带隔声测试方法研究

Broadband measurement of sound insulation for underwater acoustical materials

水声材料声学测试主要包括吸声测试和隔声测试等,在水声工程中,水声材料声学测试具有非常重要的地位。为解决传统自由场方法测试频率下限过高而无法完全满足实际工程应用和研究需要的难题,基于B&K3560C数据采集分析系统和大型消声水池,提出了一种以脉冲调制的宽带白噪声为测试信号、以组合宽带换能器为发射系统、以虚拟仪器测试技术为基础的新的水声材料宽带隔声测试方法,并用于钢板的水下隔声测试。实测结果表明:在测试频带500Hz～20kHz范围内,平均偏差仅为0.25dB,低频限达到2kHz左右。与常规测试方法相比,该方法在测试效率、测试精度和低频限等方面改善效果明显,且易实现,值得推广。

Measurements of underwater acoustical materials mainly include sound insulation, which is important in underwater acoustical engineering sound absorption and In order to overcome drawbacks of the traditional free-field method, a new broadband method of sound insulation measurement for underwater acoustical material is investigated. With a B＆K3560C data acquisition and analysis system and in a large anechoic tank, white noise, combined broadband projectors, and a virtual instrument platform are used. In underwater sound insulation measurement of steel plates, a broadband method is used. The results show that the average deviation is only 0.25dB and the lowest effective frequency is 2kHz in the range of 500Hz-20kHz. Compared with the traditional testing, the measurement efficiency, precision, and the low frequency bound are all remarkably improved.