彈塑性與塑性接觸下球體及橢圓體之界面增長與摩擦係數研究

The Study of Junction Growth and Friction Coefficient on Spherical and Ellipsoid Under Elastic-Plastic and Plastic Contact

黃祺傑(Chi-Jie Huang)

指導教授 ： 洪政豪

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2010年)

https://doi.org/10.6827/NFU.2010.00117

摘要

隨著科技的蓬勃發展，使得研發將隨著產品的需求已朝向微小化、精密、可靠與高效率等趨勢發展，而在追求尺寸微小化的同時，必須兼顧精度的要求，以致界面的特性研究與控制技術逐漸在各項產業中受到重視並尋求突破。目前已經有相當多的研究考慮了受單一正向負荷之靜態接觸的表面接處情況，但在實際接觸情況下之兩物體表面，都伴隨著因受切線負荷，而產生兩表面相對滑移的運動，以致其接觸表面上之微粗糙峰，將從靜態接觸轉變為動態滑動接觸，造成此兩相互接觸面積增加，而黏附力、摩擦力、磨耗及潤滑等都與界面的真實接觸面積有很大關係。因此本文藉由微接觸力學試驗台模擬兩物體表面微粗糙峰接觸過程實驗，以深入探討受正向與側向負荷之表面粗糙峰變形行為與接觸模型對接觸界面成長之影響。
本研究使用光學量測方法進行實驗，觀測半圓體及半橢圓體之紅銅金屬於堅硬之石英玻璃平坦面上，先行施加正向預負荷，再施予一滑動負荷後使紅銅試件於平面上產生滑動，並分別探討不同尺寸及形狀之粗糙峰相對於承受各種不同之正向與滑動速度後，接觸界面面積增長大小及幾何形狀變化，以進一步了解黏附力、摩擦力及磨耗在兩不同接觸界面特性的影響。
實驗結果顯示，當相互接觸之兩物體產生滑動時，其界面增長與壓縮變形趨勢皆為非線性，大部分界面增長與壓縮變形都發生於滑動初始階段。此外界面增長與壓縮變形量都與正向負荷、滑動速度成正比關係；但與曲率半徑、橢圓率成反比。對於非等向之橢圓體當滑動角度為45°時其界面增長量較大，上述實驗誤差均在可接受範圍內。

關鍵字

界面增長 ； 微接觸力學 ； 摩擦 ； 磨損 ； 接觸面積 ； 彈-塑性接觸

並列摘要

With the rapid development of science and technology, the demand of the product has changed towards miniaturization, precision, reliability and high-efficiency. However, in the pursuit of the size miniaturization, we still need to give consideration to the precision of product, so that the characteristics of interface and the control technology are increasingly valued in the industry and seeking a breakthrough. Nowadays, the surface contact condition of single normal load has been considered by a lot of researches, but the real contact condition of two objects surfaces will generate opposite sliding motion between two surfaces by the effect of tangential load, causing the micro-asperity of contact surface change from static contact into dynamic sliding contact and increasing the contact areas between two surfaces. The adhesion, friction, wear, and lubrication all have greatly relationship with real contact area. This study used micro-contact machine to simulate the contact process of micro-asperity on two surfaces, and explored the deformations of surface micro-asperity with positive and tangential load and the effect between contact models to contact surface growth.
This study used optical measurement to observe the hemispherical and semi-elliptical cooper metals with soft and tough properties, putting on hard and flat quartz glass. After applied normal per-load and tangential load, the cooper metals would slid on the platform, then explored the deformations of contact areas and geometric shapes after the asperity with various sizes and shapes applied various positive and sliding rate, and to realize the effects between adhesion, friction, and wear to the properties of two contact surface.
The results of experiment show that when the two contact objects start to slide, the interface growth, compression, and deformation are all nonlinear, these trends always generate at initial sliding stage; otherwise, the interface growth, compression, and deformation are all proportional to forward load and sliding speed, but inverse proportional to radius of curvature and ellipticity. For non-isotropic ellipsoid, when the sliding angle is 45, the interface growth is comparatively large, the error of experiment is acceptable.

並列關鍵字

junction gowth ； micro-contact mechanics ； friction ； wear ； contact area ； elastoplastic contact

參考文獻

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