The generation of impulses from narrow bandwidth signals using resonant spherical chains
The generation of impulses from narrow bandwidth signals using resonant spherical chains
复制标题
使用谐振球链从窄带宽信号生成脉冲
DOI：
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复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
P. Gélat
中科院分区：
文献类型：
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作者：
D. Hutchins;J. Yang;O. Akanji;P. Thomas;L. Davis;S. Freear;S. Harput;N. Saffari;P. Gélat
使用工作频率为 73 kHz 的超声波喇叭来激励钢球链的一端。使用激光振动计在远端测量沿链条传输的信号。已经研究了2-10个球体的各种链长。研究发现，当使用高输入幅度和最小预压缩力时，会产生一组孤立波脉冲。可以观察到输入频率的谐波和分谐波。基于相关的运动方程开发了理论模型，正确地模拟了最终条件，并且他们的预测证实了实验观察。仅当使用一定数量的球体时才会产生孤立波脉冲，这对应于以非线性简正模式（NNM）形式建立共振。研究发现，较长的链会导致更宽的脉冲带宽。增加预压缩往往会抑制这种现象，但会产生弱非线性状态，其中沿着链条传播的时间延迟随着施加的静力而变化。因此确定门控正弦输入可以转化为一组脉冲，这在生物医学应用中很有意义。
An ultrasonic horn operating at 73 kHz has been used to excite one end of a chain of steel spheres. The signal transmitted along the chain was measured at the far end using a laser vibrometer. Various chain lengths, ranging from 2-10 spheres, have been studied. It was found that a set of solitary wave impulses were generated when a high input amplitude and a minimal pre-compression force was used. Both harmonics and sub-harmonics of the input frequency could be observed. Theoretical models were developed, based on the relevant equations of motion, which modelled the end conditions properly, and their predictions confirmed the experimental observations. Solitary wave impulses were generated only when certain numbers of spheres were used, corresponding to the establishment of resonances in the form of nonlinear normal modes (NNMs). It was found that longer chains led to wider impulse bandwidths. Increased pre-compression tended to damp out this phenomenon, but gave a weakly non-linear state where the time delay of propagation along the chain changed with applied static force. It was thus established that a gated sinusoidal input could be transformed into a set of impulses, of interest in biomedical applications.
DOI：
10.1209/0295-5075/109/54002
发表时间：
2015
期刊：
EPL (Europhysics Letters)
影响因子：
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作者：
Hutchins D
通讯作者：
Hutchins D