Wear Simulation of Electrical Contacts Subjected to Vibrations

Abstract

Electrical contacts may be subjected to wear because of shock, vibration, and thermo-mechanical stresses resulting in fretting, increase in contact resistance, and eventual failure over the lifetime of the product. Previously, models have been constructed for various applications to simulate wear for dry unidirectional-sliding wear of a square-pin, unidirectional sliding of pin on disk, and wear mechanism maps for steel-on-steel contacts. In this paper, a wear simulation model for fretting of reciprocating curved spring-loaded contacts has been proposed, based on instantaneous estimation of wear rate, which is time-integrated over a larger number of cycles, with continual update of the contact geometry during the simulation process. Arbitrary Lagrangian-Eulerian adaptive meshing has been used to simulate the wear phenomena. Model predictions of wear have been compared to experimental data plots, available from existing literature, to validate both, the 2D and 3D models. A large number of wear cycles have been simulated for common contact geometries, and the wear accrued computed in conjunction with the wear surface updates. The modeling methodology extends the state-of-art by enabling the continuous wear evolution of the contact surfaces through computation of accrued wear. The proposed methodology is intended for reducing the number of design iterations in deployment and selection of electrical contact systems in consumer and defense electronics. The presented analysis is applicable to wide variety of contact systems found in consumer and defense applications including, RAM memory-card sockets, SD-card sockets, microprocessor, ZIF sockets, and fuzz button contacts.