Contact Temperature and Thermal Contact Resistance Based on a Random Cantor Set Surface Model

• Main Authors: Tsung-Hsin Lin, 林宗信
• Other Authors: 盧中仁
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/10661054557548262413

碩士 === 國立臺灣大學 === 機械工程學研究所 === 96 === This paper studies the contact temperature and thermal resistance at the interface of two solids. Two different cases are considered: (1) sliding contact with Coulomb friction and (2) static contact while the two surfaces have different temperatures. When two surfaces are in contact, the load-displacement relationship and the interfacial heat conduction depend on the surface topography as well as the material properties of the contact solids. Most surface models treat the rough surface as a collection of asperities with a fixed shape. The heights of the asperities are distributed stochastically. However, recent studies showed that conventional geometrical parameters used to characterize the shape of the asperities depend on the resolution of the roughness-measuring instrument. This result suggests the use of fractal geometry for the characterization of surface roughness. In this thesis, we construct a random fractal surface model based on the Cantor set. We study the situation where a random Cantor surface is in contact with a rigid insulated smooth surface. Given the probability density functions of the random fractal parameters, we derive the expectations and standard deviations of the applied load, contact temperature, and thermal resistance. Finally, the Monte-Carlo simulation is employed to verify the analytical results.