The Study And Design Of Friction Testing For Fretting

Fretting is a phenomenon that concerns mechanical components in contact that are designed to be static but having small relative displacements in practically due to external disturbances (typically in micro scale). Fretting between two contact surfaces always result in fretting wear and fretting corrosion. Combination effect of wear and corrosion can cause contact resistance increase and contact failure of electric connectors.Research of tribology property of contact pairs during fretting process and its influence to electric contact, it is necessary to simulate the connector fretting progress and measure friction between contact pairs during fretting. In tribology field, present apparatuses are designed for macro or nano friction testing. However, with the normal force between 10mN and 2N, friction in fretting is neither macro friction nor nano one. The key technology in design is the measurement of micro scale force, whose range; precision and sensitivity are crucial parameters.In this thesis, the structure design of fiction testing apparatus in fretting is performed. Several feasible structure schemes are proposed and compared. To each scheme, the structure design principles are introduced and formulas for friction measurement are derived. The best one for measuring of friction force of elastic connectors is chose. Then according to this scheme, the mechanical structure of friction measurement is designed. By means of finite element analysis and testing experiments, it has been found that the structure can meet the needs of design.