Elastic feature of cylindrical shells extraction in time-frequency domain using biomimetic dolphin click.
Elastic feature of cylindrical shells extraction in time-frequency domain using biomimetic dolphin click.
复制标题
DOI：
10.1121/1.5017835
复制
发表时间：
2017-12
期刊：
影响因子：
--
通讯作者：
Gang Qiao;Xin Qing;W. Feng;Songzuo Liu;Donghu Nie;Yu Zhang
中科院分区：
文献类型：
--
作者：
Gang Qiao;Xin Qing;W. Feng;Songzuo Liu;Donghu Nie;Yu Zhang
海豚的生物声纳可以有效地区分目标之间的细微差别。为了研究目标识别的可能物理机制，在本研究中，提出了一个仿生点击脉冲激励的有限元模型。对不锈钢壳体的声散射场和应力分布进行了数值模拟。然后，在消声池中进行了仿生滴答声实验，以验证理论预测。实验结果与模型模拟结果吻合较好。在此基础上，利用分数阶傅立叶变换滤波法消除镜面反射和交叉项干扰，得到了三个不同壁厚圆柱壳的弹性时频特征。为了比较有无镜面反射时的时频特征的分辨能力，采用时频相关器计算了不同弹壳之间的相关系数。结果表明，时频特征具有较高的分辨率和较小的交叉项干扰，且无镜面反射，对不同壁厚的壳体具有较好的区分能力。
A dolphin's biosonar may effectively discriminate subtle differences among targets. In order to investigate the possible physical mechanism of target discrimination, in this study, a finite element model excited by a biomimetic click pulse was proposed. The acoustic scattering field and stress distribution of a stainless steel shell were simulated. The biomimetic click experiments were then conducted to verify the theoretical predictions in an anechoic tank. The experimental results showed a good agreement with the model simulations. Furthermore, the elastic time-frequency features of three cylindrical shells with different wall thickness were obtained using a fractional Fourier transform filter to eliminate specular reflection and cross-term interference. To compare discrimination capacity of the time-frequency features with and without the specular reflection, a time-frequency correlator was applied to calculate the correlation coefficient between different shells. The results indicated that the time-frequency features can be represented in high resolution with less cross-term interference, and these features without specular reflection showed a good capacity to discriminate the shells with different wall thickness.