Research On Fretting For Pluggable Micro-rectangular Electrical Connector

Electrical connector is facing to have a strong resistance to variously harsh environment, be portable and convenient to store, while maintaining high reliability and long working lifetime. This is resulted from the requirement of its application field broadening to outer and deeper space, expanding to more complex system, extending to Miniaturization equipment. Micro-rectangular electrical connector is and will be widely used due to its characters of high reliability, small size, light weight and being intensively assembled. Fretting has been recognized as one of the main factors leading to the failure of electrical connector. However, vibration-induced fretting is hardly to avoid. Therefore, research on fretting behavior of electrical connector as to improve its performance has theoretical and engineering significance.Based on the survey about researchers at home and abroad who are engaged in electrical contact and fretting investigations and their achievement, a finite element simulation analysis was did on vibration-induced fretting and for contacts of a certain type of micro-rectangular electrical connector.The male micro-rectangular connector contact is made up of several strands of beryllium-copper, welded then bumped. A 3-D model was built based on its real dimension, then imported into ABAQUS. With reasonable boundary conditions, material properties and interactions defined and being meshed suitable, the finite element model of the contact pair was obtained.to simulate the mechanics and kinematics performance for twist pin and socket during the fretting process.The present investigation implement the simulation of insertion process between the twist pin and socket so as to obtain the initial deformation and stress state of this certain mated connector pair, while in many research on fretting, a force or stress was loaded directly on the contact body. Fretting occurs between twist pin and socket when they are mated. Then, the fretting process induced by small amplitude vibration between the finite model contact pair was simulated with ABAQUS software. The outputs of the twist pin were got during both insertion and fretting process, displacement, contact force, contact area and stress included. These outputs increase gradually as twist pin insert into the socket and maintain stable at a bit smaler magnitude after reaching the peak. While during the vibration condition, the four results mentioned above fluctuate in a small range around the stable magnitude and reflect the periodic feature related to the movement of the mated socket.The pin-socket contact pair was applied a very small amplitude sinusoidal vibration load to simulate the fret between the contact faces. Calculated results such as Contact force, relative transfer function and stress state were extracted. A series of simulation were implemented according to orthogonal method. Four variables including fretting amplitude(A), vibration frequency(f), inner diameter of the socket(D, or positive pressure) and Coefficient of friction(μ) were selected. Range analysis indicate that inner diameter of the socket is the major effect factor compared to other three parameters when the value of the relative transfer function and the contact force were taken as the test target to describe the fretting of contact pair in micro-rectangular electrical connector. Finally, the effect trend and degree of these four factors to fretting characteristics between twist pin and socket contact pair present not totally identical.