基于波叠加法的patch近场声全息及其实验研究

提出了基于波叠加法的patch近场声全息技术(PNAH).该方法首先通过线性叠加在振动体内部“虚置”的若干不同强度的简单源产生的波场来拟合实际声场，实现近场外推，然后采用计算简便的FFT方法进行全息重建.该方法解决了现有PNAH技术近场外推过程中存在的外推精度和计算效率问题，具有外推精度高、计算速度快、实现方法简单等特点，更适用于工程计算.为了验证本方法的正确性与有效性，将其用于单点激励固支板的全息实验中，取得了令人满意的结果.

Algorithm and experimental investigation of patch nearfield acoustic holography based on wave superposition approach

A new patch nearfield acoustic holography (PNAH) based on wave superposition approach is proposed in this paper. In the method, the sound field is extrapolated by superposing wave fields produced by a number of fictitious sources placed inside the radiator, and then the FFT is used for reconstructing the normal velocity or the field on and near the radiator. This method has higher computational accuracy and efficiency than other PNAH techniques, and is very easy for applications. In order to prove its validity, the method was used in the experiment to reconstruct the normal velocity of a clamped point-driven steel plate, and satisfactory results were obtained.