A measurement method for distinguishing the real contact area of rough surfaces of transparent solids using improved Otsu technique

作     者：宋保江 阎绍泽 向吴维凯 

作者机构：State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2015年第24卷第1期

页      面：354-360页

核心收录：

学科分类：07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11272171) the Beijing Natural Science Foundation,China(Grant No.3132030) the Education Ministry Doctoral Fund of China(Grant No.20120002110070) 

主　　题：real contact area total internal reflection improved Otsu method hysteresis phenomenon 

摘      要：An experimental method of measuring the real contact area of transparent blocks based on the principle of total internal reflection is presented, intending to support the investigation of friction characteristics, heat conduction, and energy dissipation at the contact interface. A laser sheet illuminates the contact interface, and the transmitted laser sheet is projected onto a screen. Then the contact information is acquired from the screen by a camera. An improved Otsu method is proposed to process the data of experimental images. It can compute the threshold of the overall image and filter out all the pixels one by one. Through analyzing the experimental results, we describe the relationship between the real contact area and the positive pressure during a continuous loading process, at different loading rates, with the polymethyl methacrylate（PMMA）material. A hysteresis phenomenon in the relationship between the real contact area and the positive pressure is found and explained.