Progress on Friction-contact Mechanics Research: From Single-to Multi-Asperity

Friction is a ubiquitous physical phenomenon in nature and daily life. The demand for energy conservation and green development in industrial development has led to increasing attention being paid to tribology research. Despite significant achievements in tribology, many friction problems remain unsolved, particularly the lack of a unified friction theory applicable to all friction issues. The fundamental conditions for occurrence of friction are contact and relative motion between two surfaces, so the advancement of contact theories has significantly contributed to the development of tribology. Not only the models of contact theory across different scales in the past development of tribology were reviewed in this paper, also the assumptions and applicability limitations of each model were summarized and compared. The limitations of theoretical calculations of friction-contact research have been concerned. Now the study of contact mechanics and tribology is facing new opportunities for further progress under the era of the emergence of the big data and artificial intelligence based on sufficient data and computing power. The preliminary prospect on the research of tribology has been carried out. A novel research strategy that combines artificial intelligence, experimentation, and contact theory was proposed to investigate the contact problem in tribology field. This strategy may also be online collaborative research between different research groups all over the world.