水声无源材料测试衍射效应影响抑制技术研究

提出了分别评估衍射效应声场贡献程度和衍射效应影响抑制技术有效程度的两个量化评价参数——衍射贡献量和衍射抑制量，使得衍射效应的作用和抑制可以实现量化研究；分析了在水声无源材料自由场声学测试中传统偏轴向接收技术在抑制衍射效应方面的局限性。并提出了样品或试件的边缘声学结构设计的衍射效应影响抑制技术，为拓展现有测试方法有效测试频带宽度和衍射时域分离技术在实际测试中的推广应用创造了更有利的外部条件。

Investigation on Technologies Suppressing Influence Originated from Diffraction Effect in Underwater Acoustic Measurement for Passive Materials

DCQ（Diffracted Contribution Quantity） and DSQ（Diffracted Suppressing Quantity）, which evaluate contributing extent of diffraction effect to acoustic field and represent effective extent of suppressing technologies of the influence originated from diffraction effect respectively, are proposed to realize the quantitative study in the influence of diffraction effect and suppression. The effective degree of traditional off-axial receiving technology in suppressing diffraction effect is analyzed, and then the acoustic design of the edge structure of the sample panel as a means of suppressing technology for diffraction effect is presented for the first time in the acoustical measurement by the free-field method for underwater acoustical passive material, which broadens the effective testing frequency range of the current testing approach and creates favorable external conditions to further apply diffraction separated technology in the time domain to the practical testing.