固体表面菲涅尔阵列产生的声束聚焦的研究

Investigation for the focussing of acoustic beam generatedby a Fresnel array on solid surface

在固体表面上菲涅尔阵列可实现聚焦声束的Ｂ扫描。此阵列产生的弹性波场的分析是固体中会聚声束Ｂ扫描成像的物理基础．给出此聚焦声场的全面分析，包括：纵波和横波会聚声束的频率扫描特性；纵波声场沿对称轴和在焦面上的分布；在主焦点的频率响应；纵波场的全空间分布以及阵列参数对会聚声场的影响．最后还讨论了横波的分布．

The B-scanning of focused acouStic beam in solid by a Fresnel array is realized. The analysesof the elastic wave fields generated by such an array on solid surface lay the physical foundation for the B-scanning foraging of focused acoustic beams in solid. In the paper, complete analyses for such focusingacoustic fields have been given. Our analyses include that the frequency-scanning characteristics forconvergence acoustic beams; the amplitude distributions of longitudinal wave fields along focal tris andon focal plane; the frequency response at the principal focus; all-space distributions of longitudinalwave field and the effects of array parameters on the convergence acoustic fields. Finally, the transversalwave distributions are discussed also.