中国物理B ›› 2015, Vol. 24 ›› Issue (1): 14601-014601.doi: 10.1088/1674-1056/24/1/014601

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

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

宋保江, 阎绍泽, 向吴维凯   

  1. State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
  • 收稿日期:2014-04-11 修回日期:2014-07-02 出版日期:2015-01-05 发布日期:2015-01-05
  • 基金资助:

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

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

Song Bao-Jiang (宋保江), Yan Shao-Ze (阎绍泽), Xiang Wu-Wei-Kai (向吴维凯)   

  1. State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2014-04-11 Revised:2014-07-02 Online:2015-01-05 Published:2015-01-05
  • Contact: Yan Shao-Ze E-mail:yansz@mail.tsinghua.edu.cn
  • Supported by:

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

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.

关键词: real contact area, total internal reflection, improved Otsu method, hysteresis phenomenon

Abstract:

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.

Key words: real contact area, total internal reflection, improved Otsu method, hysteresis phenomenon

中图分类号:  (Tribology and mechanical contacts)

  • 46.55.+d
42.30.Va (Image forming and processing) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))