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The Effect of Asperity Geometry on Elastic-Plastic Statistical and Multi-scale Rough Surface Contact Models




Chu, Nolan

Type of Degree

Master's Thesis


Mechanical Engineering


The solution to an elastic-plastic contact problem can be applied to many phenomena such as friction, wear, and thermal contact resistance. Many models have been developed to solve it. A deterministic approach accurately describes the entire surface, but its computational time is too long for practical use. Thus, simplified mathematical models have been developed to describe rough surface contact. Older models employed a statistical methodology to solve the contact problem, and they borrowed the solution for spherical contact to represent individual asperities. However, it is believed that a sinusoidal geometry may be more realistic. This geometry has also been applied to a newer mathematical model: the multiscale model. All models predict similar qualitative trends, but their quantitative results diverge. This work highlights the disparities between them when applied to a piston ring-cylinder wall interface as well as two reference surfaces in contact with a rigid flat. For the reference surfaces, they were compared to a deterministic FEM model.