不同滑动方向下手指接触摩擦及振动特性的研究

发布时间：2018-06-30 22:08

本文选题：手指摩擦 + 试验装置　；参考：《西南交通大学》2017年硕士论文

【摘要】：手指触摸行为是人类认知外界事物的重要方式之一,通过手指在物体上沿着不同方向滑动来感知物体表面的纹理、材质、温湿度等信息。生活中随处可见人类的触摸、抓握行为:使用键盘鼠标、餐具、厨具;打开瓶盖、打开食品包装、进行体育运动;驾驶车辆等。近年来,手指接触摩擦行为得到了广泛的研究,然而,鉴于手指特殊的生理结构以及表面皮肤复杂的力学特性以及影响这一接触摩擦行为的因素众多,致使手指接触摩擦的试验、仿真研究的困难性,到目前为止手指接触摩擦机理未被深刻认知。因此,设计新型摩擦试验装置,来提高手指接触摩擦试验的稳定性和重复性,对深入认知手指接触摩擦机理具有重要意义,同时,为生产生活产品的表面设计提供更多的试验依据。在本研究中,为了有效地克服手指接触摩擦试验中法向力、接触摩擦角度难以控制的问题,设计出一种新型手指接触摩擦试验装置,极大提高了手指接触摩擦试验的可靠性,从而能更准确地考察各种因素对手指接触摩擦学行为的影响。本论文中试验选用铝合金样品作为对磨副,采用砂纸打磨的方法在样品表面加工出一定间距的纹理织构。通过改变手指和样品表面接触摩擦过程中粗糙度、法向力、接触角度的大小,来考察不同滑动方向下摩擦力、法向力、摩擦系数、振动加速度的频率变化规律。主要结论如下:1、研制的新型手指接触摩擦试验装置结构简单、加工方便。该新型试验装置中的手指托架和加载装置可以很好地控制法向力和接触角度等因素,在手指接触摩擦试验中所测量的法向力和摩擦力曲线在很小的范围内波动,从而提高了试验的稳定性与可靠性;2、手指在不同的相对滑动方向下滑动时,随着粗糙度和法向力的增加,手指接触摩擦摩擦系数逐渐降低。随着接触角度的增加,接触摩擦区域由指腹部位过渡到指尖部位,摩擦系数先降低后增加。3、在某一滑动方向下,皮肤上的指纹受到拉伸时,指纹纹理间的间距增大,导致指纹纹理与样品表面微凸体"啮合"地更加充分使得实际接触面积增加,则摩擦系数增加。反之当指纹受到挤压时,指纹向滑动方向进行堆积使得指尖皮肤变得更加平滑。导致皮肤与样品的实际接触面积下降,则摩擦系数降低。在同一个滑动方向下相对滑动时,指腹指纹的变形状况与指尖处指纹变形状况相反。4、手指和样品相对滑动时,由于指纹的存在,相当于两织构间的运动,振动的频率主要由纹理间距较小的织构所决定。随着样品粗糙度的降低,不同的滑动方向下手指摩擦振动的频率逐渐增加。当指纹被挤压堆积时皮肤表面纹理变得密集,反之纹理变得稀疏。在相同的试验条件下,密集处接触摩擦时振动频率大于稀疏处的频率。
[Abstract]:Finger touch behavior is one of the most important ways for human beings to recognize the outside world. The fingers move along different directions to perceive the texture, material, temperature and humidity of the surface of the object. Life is full of human touch, grasping behavior: use keyboard, mouse, tableware, kitchen utensils; open bottle cap, open food packaging, sports, driving vehicles, etc. In recent years, finger contact friction behavior has been widely studied. However, in view of the special physiological structure of the finger, the complex mechanical properties of the surface skin and the factors affecting the contact friction behavior, So far, the mechanism of finger contact friction has not been deeply understood. Therefore, the design of a new friction test device to improve the stability and repeatability of the finger contact friction test is of great significance to deeply understand the mechanism of finger contact friction, and at the same time, For the production of life products surface design to provide more experimental basis. In this study, in order to effectively overcome the problem of the normal force and the uncontrollable contact angle in the finger contact friction test, a new type of finger contact friction test device is designed, which greatly improves the reliability of the finger contact friction test. Thus, the influence of various factors on the tribological behavior of finger contact can be investigated more accurately. In this paper, aluminum alloy samples were selected as pairs of grinding, and textured texture with certain spacing was obtained by sandpaper grinding method on the surface of the samples. By changing the roughness, normal force and contact angle in the contact friction process between finger and sample, the frequency variation of friction force, normal force, friction coefficient and vibration acceleration in different sliding directions were investigated. The main conclusions are as follows: 1. The developed new finger contact friction test device is simple in structure and convenient in processing. The normal force and contact angle can be well controlled by the finger bracket and loading device. The normal force and friction curves measured in the finger contact friction test fluctuate in a very small range. Thus, the stability and reliability of the experiment are improved. When the fingers slide in different relative sliding directions, the friction coefficient of fingers decreases with the increase of roughness and normal force. With the increase of contact angle, the contact friction region changes from the ventral part of the finger to the tip of the finger, and the friction coefficient decreases first and then increases by .3. in a certain sliding direction, when the fingerprint on the skin is stretched, the distance between the fingerprint textures increases. As a result, the contact area between the fingerprint texture and the micro-convex body on the surface of the sample is more fully increased, and the friction coefficient increases when the actual contact area is increased. On the other hand, when the fingerprint is squeezed, the finger skin becomes smoother when the fingerprint accumulates in the sliding direction. The friction coefficient decreases when the actual contact area between the skin and the sample decreases. When relative sliding in the same sliding direction, the deformation of finger fingerprint is opposite to that of finger tip. When finger and sample slip, the existence of fingerprint is equivalent to the movement between two textures. The frequency of vibration is mainly determined by texture with small texture spacing. With the decrease of sample roughness, the frequency of finger friction vibration increases with different sliding directions. When the fingerprint is pressed and piled, the skin surface texture becomes dense, whereas the texture becomes sparse. Under the same experimental conditions, the vibration frequency of contact friction is greater than that of sparsity.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O313.5

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