Compression of a Single Transverse Ridge in a Circular Elastohydrodynamic Contact
Compression of a Single Transverse Ridge in a Circular Elastohydrodynamic Contact
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圆形弹流体动力接触中单个横向脊的压缩
DOI：
10.1115/1.1506325
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发表时间：
2003
影响因子：
2.5
通讯作者：
H. Spikes
中科院分区：
文献类型：
--
作者：
R. Glovnea;J. W. Choo;A. Olver;H. Spikes
对100 nm高的横向取向脊线在弹性流体动力接触中的行为进行了详细的实验研究。超薄膜干涉术已被用于在从几纳米到近一微米的非常宽的润滑膜厚度范围内精确测量油膜轮廓。这使得随着EHD膜厚的增加，入口扰动几何形状的幅度的恢复能够被量化，并与数值预测进行比较。在非常薄的薄膜条件下的纯轧制条件下，对应于光滑的表面EHD膜厚度为10 nm，脊线附近的表面被挤压，导致膜的收缩仅为未变形脊线高度的9%左右。随着薄膜厚度的增加，这种变形逐渐恢复，直到薄膜厚度约为1μm时，脊形变恢复到原来高度的90%左右，但这种较快的恢复只发生在纯轧制中，这是由于脊形在入口区产生的局部扰动引起的。它以表面的平均速度通过接触传播，并且--在纯滚动中--起到减弱局部挤压的作用。当存在滑动时，即使当平均膜厚是原始脊高的两倍时，脊线仍保持几乎完全变形。在这种情况下，脊线通过接触点的速度与两个曲面的平均值不同。随后脊线的解耦和收敛扰动导致了由于挤压而产生的大的局域压力，从而抑制了脊线的恢复。结果表明，润滑脊的运动规律与前人的理论结果基本一致。
A detailed experimental study has been made of the behavior of a 100 nm high transversely oriented ridge in an elastohydrodynamic (EHD) contact. Ultra-thin film interferometry has been used to measure film profiles accurately over a very wide range of lubricant film thicknesses, from a few nanometers up to nearly one micron. This enables the recovery of the amplitude of the inlet perturbation geometry with increasing EHD film thickness to be quantified and compared with numerical predictions. In pure rolling under very thin film conditions, corresponding to a smooth surface EHD film thickness of 10 nm, the surfaces near the ridge were squashed down, leading to a constriction in the film of only about 9 percent of the height of the un-deformed ridge. As the EHD film thickness increased, this deformation recovered until the ridge constriction regained about 90 percent of its original height at film thicknesses of about 1 μm. However this relatively rapid recovery only occurred in pure rolling and is attributed to the local perturbation of film convergence which the ridge generates while in the inlet region. This propagates through the contact at the mean speed of the surfaces and-in pure rolling-acts to diminish the effect of local squeeze. When sliding was present, the ridge remained almost fully deformed even when the mean film thickness was as much as twice the height of the original ridge. In this case, the ridge travels through the contact at a different speed from the mean of the two surfaces. The consequent decoupling of the ridge and the convergence perturbation results in a large local pressure due to squeeze which acts to inhibit recovery of the ridge. The general trend of the behavior of the lubricated ridge is shown to be in good agreement with earlier theoretical results.