A study of the interaction between ultrasound and a partially contacting solid-solid interface
A study of the interaction between ultrasound and a partially contacting solid-solid interface
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DOI：
10.1098/rspa.1996.0139
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发表时间：
1996-12-08
影响因子：
3.5
通讯作者：
Cawley, P
中科院分区：
文献类型：
--
作者：
Drinkwater, BW;DwyerJoyce, RS;Cawley, P
测量部分接触的固-固界面反射的超声波可以用来研究该界面处的接触条件。本文描述了超声波从部分接触铝-铝界面反射的测量和预测，在低频状态下进行，其中超声波的波长与间隙的大小相比较大。用单个宽带超声换能器测量了入射波在界面处反射的比例（反射系数）与频率的关系。当载荷在界面上施加时，可以看到三个接触区域；无接触、部分接触和完全接触。在无接触区域，测量到的反射系数在所有频率上都是一致的。在部分接触区，反射系数随频率增加而增加。在完美接触区域中，反射系数在所有频率下都为零，因为这种状态与连续的铝片相同，因此没有进行测量。利用弹簧模型模拟了反射系数随频率的变化，实验结果与预测结果吻合较好。然后使用反射系数测量来研究重复加载和卸载循环下两个铝表面之间的接触。塑性流动在第一次加载是明显的，而随后的加载循环显示出很大的弹性行为。采用弹性、塑性统计接触模型和数值接触模型预测了界面刚度随压力的变化。这些模型在质量上与实验确定的刚度变化一致，并且在所有情况下预测的刚度都在实测值的一个数量级内。
The measurement of the reflection of ultrasonic waves from a partially contacting solid-solid interface can be used to study the contact conditions at that interface. This paper describes measurements and predictions of the reflection of ultrasonic waves from partially contacting aluminium-aluminium interfaces, performed in the low frequency regime where the wavelength of the ultrasound is large compared to the size of the gaps. The proportion of the incident wave which is reflected at the interface (the reflection coefficient) was measured as a function of frequency with a single wideband ultrasonic transducer. When load was applied across the interface three regions of contact can be seen; no contact, partial contact and perfect contact. In the no contact region the measured reflection coefficient was unity at all frequencies. In the partial contact region the measured reflection coefficient increased with frequency. No measurements were taken in the perfect contact region in which the reflection coefficient is known to be zero at all frequencies as this state is the same as a continuous piece of aluminium. The reflection coefficient variation with frequency was modelled using a spring model, good agreement between experiments and predictions being achieved.Reflection coefficient measurements were then used to study the contact between two aluminium surfaces under repeated loading and unloading cycles. Plastic flow on first loading was evident while subsequent loading cycles revealed largely elastic behaviour. Both elastic and plastic statistical contact models, as well as a numerical contact model, were used to predict the variation of interfacial stiffness with pressure. These models agreed qualitatively with the experimentally determined stiffness variations and the predicted stiffness was within an order of magnitude of the measured value in all cases.