Analytical modeling and simulation of electrical contact resistance for elastic rough electrode surface contact including frictional temperature rise

Abstract

An improved electrical contact resistance (ECR) model for elastic rough electrode contact is proposed, incorporating the effects of asperity interactions and temperature rise by frictional and joule heating. The analytical simulation results show that the ECR decreases steeply at the beginning of the contact between Al and Cu. However, it becomes stabilized after reaching a specific contact force. It is also found that the longer elapsed sliding contact time, the higher ECR due to the increase in electrical resistivity of electrode materials by the frictional temperature rise at the interface. The effects of surface roughness parameters on ECR are studied through the 32 full-factorial design-of-experiment analysis. Based on the two representative roughness parameters, i.e., root-mean-square (rms) roughness and asperity radius, their individual and coupled effects on the saturated ECR are examined. The saturated ECR increases with the rms roughness for a rough machined surface condition, but it is hardly affected by the asperity radius. On the other hand, the saturated ECR increases with both the rms roughness and the asperity radius under a smooth thin film surface condition.

Dynamic response of electrical contact resistance (ECR) under structural vibration

“…During the structural vibration, the contacting electrodes can experience a tangential sliding contact as well as normal contact. Accordingly, the frictional heat flux (q) generated at the contact area is obtained by q = µVpm [33] , where V is the sliding velocity, pm is the mean contact pressure, and µ is the coefficient of friction. In this study, the sliding velocity of the contacting electrodes is assumed to be the same as the normal velocity that is given by the oscillation input.…”

“…Then, the frictional heat flux is applied into the transient heat transfer theory so as to calculate the temperature rise on the contact surface (the detailed procedures are found in the authors' previous work [33]). Therefore, the surface temperature of the stationary heat source body (i.e., hemispherical body in this study) can be determined by:…”

“…As metallic electrodes are usually exposed to, and are required to operate in, an atmospheric environment, a thin metal oxide layer can be formed on the surface. In addition, when an electrical connector operates under structural vibration, the electrodes can develop dynamic surface contact in both normal and tangential directions, by which the thin oxide layer can be easily sheared off, thereby exposing the bare metal surfaces at the interface [4,33,35]. In such case, the actual electromechanical behavior at the contact interface would be described by the properties of underlying metal substrates.…”

“…1) does not include an oxide layer within the contact area, and the hemispherical body is modeled with aluminum, while the flat body is made of copper. The material properties of Al and Cu are summarized in Table I [33]. It is assumed that the upper flat body has a mass of 5 mg, and the lower hemispherical body has the radius of 0.2 mm.…”

Numerical Simulation and Modeling of Mechano–Electro–Thermal Behavior of Electrical Contact Using COMSOL Multiphysics

“…First, there are theoretical analyses based on model types such as the single point (or Holm tube) contact model [15,16], the multi-point contact model [17,18], or the fractal geometry theory model [19][20][21]. A number of several other scholars used analytical models to study electrical contact behavior with authors of [22] presenting a study built on the improved elastic rough surface model, [23] introducing a new analytical model for the analysis of switching devices contact area for different voltage and current magnitudes and [24] proposing a semi-analytical model based on the single asperity concept to highlight the flow of current between two contacting surfaces.…”