Yoshida Hiroaki, Tada Mitsunori, Mochimaru Masaaki
Kansei Engineering Course, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, Japan.
Mol Cell Biomech. 2011 Mar;8(1):61-71.
Since the tactile perception detects skin deformation due to the contact of an object, it is important to understand contact mechanics, especially, frictional behavior of the human fingertip. The coefficient of friction is recently modeled as a function of the applied normal load in which case the traditional Coulomb's law does not provide a description for the skin surface. When a surface is a rubber-like material, the frictional behavior follows the frictional law of the rubber-like material. Therefore, we developed a three-dimensional Finite Element model of the fingertip and analyzed frictional behavior based on the frictional law of rubber-like material. We proposed a combined technique using both experimental and Finite Element analyses in order to investigate the frictional property of the fingertip. A three-dimensional Finite Element model of the fingertip was developed using MRI images. We hypothesized a frictional equation of the critical shear stress. Squared differences between equivalent coefficient of friction of the FE analysis and the coefficient of kinetic friction of the experiment while sliding was decreased and the Finite Element analysis iterated until the error was minimized, and thus the frictional equation was determined. We obtained the equation of the critical shear stress and simulated kinetic friction of the fingertip while sliding under arbitrary normal loading condition by using the Finite Element analysis. We think this study is an appropriate method for understanding the frictional property of the human fingertip using the Finite Element analysis.
由于触觉感知能检测到因物体接触而导致的皮肤变形，所以理解接触力学，尤其是人类指尖的摩擦行为非常重要。摩擦系数最近被建模为所施加法向载荷的函数，在这种情况下，传统的库仑定律无法描述皮肤表面。当表面是橡胶状材料时，摩擦行为遵循橡胶状材料的摩擦定律。因此，我们建立了指尖的三维有限元模型，并基于橡胶状材料的摩擦定律分析了摩擦行为。我们提出了一种结合实验分析和有限元分析的技术，以研究指尖的摩擦特性。利用磁共振成像（MRI）图像建立了指尖的三维有限元模型。我们假设了临界剪应力的摩擦方程。在滑动过程中，有限元分析的等效摩擦系数与实验动摩擦系数之间的平方差不断减小，并且有限元分析不断迭代，直到误差最小化，从而确定摩擦方程。通过有限元分析，我们得到了临界剪应力方程，并模拟了指尖在任意法向载荷条件下滑动时的动摩擦。我们认为这项研究是利用有限元分析来理解人类指尖摩擦特性的一种合适方法。
