Study And Improving Of Dynamic Electric Contact Testing System

There is a great deal of electric contact between the components, circuits, facilities in electric system, even so inside the components. Under influence of external environment such as mechanical vibration, electromagnetic force, heat stress cycles, between contact surfaces may generate small amplitude relative position movement called micro-motion. The fretting caused by micro-motion may result in contact resistance value increasing which lowers contact performance.Dynamic Electric Contact Testing System (D-ECTS) is a generic term of testing system which is to test dynamic contact performance for plane-spherical surface. D-ECTS is mainly applied to fretting simulation for electric contact failure mechanism analysis. It currently consists of two subsystems: Fretting Electric Contact Testing System (F-ECTS) and Precise Locating Electric Contact Testing System (PL-ECTS).F-ECTS is mainly focusing on testing electric contact performance of the coupon under fretting simulation. PL-ECTS is able to locate precisely the corrosion failure area to make known the influence level of electric contact performance caused by fretting corrosion. The two subsystems mainly focus on an electric contact performance index: contact resistance.The improving of F-ECTS is composed of three parts: analyzing the major influence factor of fretting length precision; importing force sensor to monitor the dynamic change of contact force during fretting experiment and modification of current contact force applying and hold structure of the system with force sensor linked; analyzing the connection stability of four wires concerned with "four-point" method and improving the way of contact resistance sampling and recording in order to decrease data redundancy. The improving of PL-ECTS includes: the refinement of contact force applying and removing way to boost useful time of the servo-motor; reducing the shock to coupon caused by servo-motor during contact force applying.