论文标题
滑动过程中的圆柱板接触力学
Cylinder-flat contact mechanics during sliding
论文作者
论文摘要
使用分子动力学（MD），我们研究接触力学对滑动速度的依赖性，当具有$ {\ rm cos}（\ rm cos}（Q_0 x）$表面高度曲线的弹性块（圆柱）时不一致的接触。对于不一致的系统，摩擦力在正值和负值之间波动，幅度与滑动速度成正比，但平均值接近零。对于相称的系统，（时间平均）摩擦力更大，并且几乎远不到速度。对于两种类型的系统，即使对于相称的情况，接触区域的宽度也是独立的，即使在滑动过程中，摩擦剪切应力从零（滑动之前）增加到$ \ \ \ of \ of \ of \ of约0.1 \ {\ rm mpa} $。这种摩擦剪切应力以及所使用的弹性模量对于聚二甲基硅氧烷（PDMS）橡胶在玻璃表面上滑动是典型的，我们得出的结论是，在某些实验中观察到的接触区域的减小在增加切向力时必须是由于在我们的模型研究中不包括在内的效果时，例如粘弹性或弹性非细性，
Using molecular dynamics (MD) we study the dependency of the contact mechanics on the sliding speed when an elastic block (cylinder) with a ${\rm cos} (q_0 x)$ surface height profile is sliding in adhesive contact on a rigid flat substrate.The atoms on the block interact with the substrate atoms by Lennard-Jones (LJ) potentials, and we consider both commensurate and(nearly) incommensurate contacts. For the incommensurate system the friction force fluctuates between positive and negative values, with an amplitude proportional to the sliding speed, but with the average close to zero. For the commensurate system the (time-averaged) friction force is much larger and nearly velocity independent. For both type of systems the width of the contact region is velocity independent even when, for the commensurate case, the frictional shear stress increases from zero (before sliding) to $\approx 0.1 \ {\rm MPa}$ during sliding. This frictional shear stress, and the elastic modulus used, are typical for Polydimethylsiloxan (PDMS) rubber sliding on a glass surface, and we conclude that the reduction in the contact area observed in some experiments when increasing the tangential force must be due to effects not included in our model study, such as viscoelasticity or elastic nonlinearity
