The dynamic excitation of a granular chain for biomedical ultrasound applications: contact mechanics finite element analysis and validation
The dynamic excitation of a granular chain for biomedical ultrasound applications: contact mechanics finite element analysis and validation
复制标题
用于生物医学超声应用的颗粒链的动态激励：接触力学有限元分析和验证
DOI：
10.1088/1742-6596/684/1/012005
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Gélat P
中科院分区：
文献类型：
--
作者：
Gélat P
最近，人们对沿着球形珠粒的颗粒链传输声信号以产生与生物医学超声应用相关的波形感兴趣。相邻珠子之间的赫兹接触会在信号传播时引入不同的谐波含量。这种转导机制在诊断和治疗超声应用中都具有潜在的用途，也是本文提出的研究对象。虽然存在这种行为的离散动力学模型，但如果要考虑单个珠子的形状和变形的变化，则必须寻求更全面的解决方案。为此，采用有限元方法研究了在73 kHz的正弦位移信号作用下，一端激励的直径为1 mm的六个铬钢球粒链的动力学行为。将该模型的输出与离散动力学模型提供的解进行了比较，得到了较好的整体一致性。此外，它还能够解决颗粒链的复杂动力学问题，包括发生的多次碰撞。结果表明，在动态激励条件下，离散力学模型无法解释珠粒在失去接触时的弹性变形，这可能导致与实验观测结果不一致。
There has been recent interest in the transmission of acoustic signals along granular chains of spherical beads to produce waveforms of relevance to biomedical ultrasound applications. Hertzian contact between adjacent beads can introduce different harmonic content into the signal as it propagates. This transduction mechanism has the potential to be of use in both diagnostic and therapeutic ultrasound applications, and is the object of the study presented here. Although discrete dynamics models of this behaviour exist, a more comprehensive solution must be sought if changes in shape and deformation of individual beads are to be considered. Thus, the finite element method was used to investigate the dynamics of a granular chain of six, 1 mm diameter chrome steel spherical beads excited at one end using a sinusoidal displacement signal at 73 kHz. Output from this model was compared with the solution provided by the discrete dynamics model, and good overall agreement obtained. In addition, it was able to resolve the complex dynamics of the granular chain, including the multiple collisions which occur. It was demonstrated that under dynamic excitation conditions, the inability of discrete mechanics models to account for elastic deformation of the beads when these lose contact, could lead to discrepancies with experimental observations.
使用 COMSOL 多物理场模拟单分散颗粒链中的孤立波：局部塑性变形作为耗散机制
影响因子：
2.4
作者：
R. W. Musson;W. Carlson
通讯作者：
W. Carlson
DOI：
10.1209/0295-5075/109/54002
发表时间：
2015
期刊：
EPL (Europhysics Letters)
影响因子：
--
作者：
Hutchins D
通讯作者：
Hutchins D