Abstract: Aims: The performances of assembly connection surfaces directly influence the static and dynamic performances of the involved mechanical equipment, such as the stiffness, damping and vibration, etc. According to the state of motion, assembly connection surfaces can be divided into static assembly surfaces (e.g., bolt-flange assembly connection surfaces) and dynamic assembly surfaces (e.g., journal bearing assembly surfaces). Traditionally, to improve the performances of assembly connection surfaces, the adopted method is to design their surface topographies, optimize layout of the fasteners or optimize the assembly process. A novel design concept for enhancing the assembly connection surfaces’ performances will be presented here.

Methods: Besides the surface topography, the surface mechanical and physical characteristics (such as surface hardness, material stiffness and velocity slip characteristic, etc.) could be utilized as design variables to improve the performances of assembly connection surfaces. The design approach of surface hardness and material stiffness near the assembly surfaces is developed to improve the uniformity of contact stress distribution for the bolt-flange assembly connection surfaces. The optimization of the velocity slip surfaces’ location and area in the bearing bush is conducted to enhance the load carrying capacity for journal bearing assembly surfaces.

Results: After the design of surface hardness and material stiffness near the bolt-flange assembly connection surfaces, the distribution uniformity of contact stress increases more than 95%, and the effective contact area can be doubled. The velocity slip surfaces located in the pressure build-up region will enhance the load carrying capacity of journal bearings, slip surfaces located in the pressure drop region will reduce the load carrying capacity, and this detrimental influence also increases with the region area of velocity surface.

Conclusions: In addition to the surface topography, the design of surface mechanical and physical characteristics is an innovative and effective approach to improve the performances of both static and dynamic assembly connection surfaces.

Biography: Qiyin Lin is an associate professor from the School of Mechanical Engineering in Xi’an Jiaotong University. He got his Ph.D. in Mechanical Engineering from Xi’an Jiaotong University at March 2014, and got his B.S. in Vehicle Engineering of Mechanical Engineering from the Harbin Institute of Technology at July 2009. Dr. Lin’s researches are in the area of design theory & method of mechanical functional surfaces/interfaces and structures, which includes the design theory & method based on deep learning and topology optimization, design methods of assembly connection interfaces and tribological surfaces, and design methods of functional structures for conductive heat transfer, and so on. He is the holder of more than 30 research papers. Dr. Lin also is the recipient of several research awards including the Outstanding Prize of the China Machinery Industry Science & Technology Award in 2018, and the First Prize of the Shaanxi University Science & Technology Award in 2018.

Dr. Lin now serves as the committee member of Group & Intelligent Integration Technology Branch of the Chinese Mechanical Engineering Society, the committee member of Machinery Industry Automation Branch of the Chinese Mechanical Engineering Society, the committee member & deputy secretary-general of Manufacturing Technology Professional Committee of the Chinese Association of Automation, the council member of Tribology Branch of the Shaanxi Province Mechanical Engineering Society.