A third body contact model for particle contaminated electrical contacts

2014 ◽  
Author(s):  
Hamed Ghaednia ◽  
Robert L Jackson ◽  
Jinchun Gao
Keyword(s):  
Electrical Contacts ◽  
Contact Model ◽  
Third Body ◽  
Body Contact

A quantitative investigation of displacement accommodation in third-body contact

Wear ◽  
1993 ◽  
Vol 165 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Y. Sun ◽  
Y. Berthier ◽  
B. Fantino ◽  
M. Godet
Keyword(s):  
Third Body ◽  
Quantitative Investigation ◽  
Body Contact

Solid Third Body Analysis Using a Discrete Approach: Influence of Adhesion and Particle Size on Macroscopic Properties

2002 ◽  
Vol 124 (3) ◽  
pp. 530-538 ◽  
Author(s):  
I. Iordanoff ◽  
B. Seve ◽  
Y. Berthier
Keyword(s):  
Particle Size ◽  
Distinct Element ◽  
Adhesive Force ◽  
Contact Model ◽  
Interacting Particles ◽  
Third Body ◽  
Dry Contact ◽  
Effect Of Particle Size ◽  
Force Displacement ◽  
Weak Influence

The dynamics of solid third bodies sheared between two rubbing bodies is far from being understood. Yet, this interface plays a prominent role in the velocity accommodation and in the load transmission. In the present paper, a simple model, which uses the Distinct Element Method, is operated in order to understand phenomena occurring in dry contact. In this model, the solid third body is considered as an aggregate of discrete interacting particles. Inter-particle forces are determined by force-displacement law and trajectories are calculated using the Newton’s second law. The global behavior of the simulated contact can be analyzed through the evolution versus time of characteristic parameters calculated by averaging over all the particles. The model is used to study the effect of particle size and inter-particle forces. The influence of particle size is studied in presence of repulsive force (based on Hertz contact model), and in presence of adhesive force (based on JKR contact model). Some promising results are highlighted. In particular, with the boundary conditions chosen in this paper, it is shown that the particle size has a weak influence when inter-particle forces are repulsive but has a dramatic influence when inter-particle adhesion is considered: solid third body goes from a quasi-fluid to a quasi-solid behavior.

Transient Thermomechanical Analysis of Sliding Electrical Contacts of Elastoplastic Bodies, Thermal Softening, and Melting Inception

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
W. Wayne Chen ◽  
Q. Jane Wang ◽  
Wansik Kim
Keyword(s):  
Sliding Friction ◽  
Electrical Contact ◽  
Electrical Current ◽  
Thermomechanical Analysis ◽  
Electrical Contacts ◽  
Contact Model ◽  
Welding Temperature ◽  
Computation Efficiency ◽  
Sliding Electrical Contacts ◽  
Transient Contact

Sliding electrical contacts are found in many electromechanical devices, such as relays, switches, and resistance spot welding. Temperature rise due to sliding friction and electrical current may be the major source of sliding electrical contact deterioration. This paper reports the development of a three-dimensional thermo-elasto-plastic contact model of counterformal bodies, which takes into account transient heat flux, temperature-dependent strain hardening behavior, and a realistic heat partition between surfaces. Transient contact simulations induce a significant increase in computational burden. The discrete convolution and fast Fourier transform and the conjugate gradient method are utilized to improve the computation efficiency. The present model is used to study the case of a half-space sliding over a stationary sphere, and both are made of 7075 aluminum alloy; the contact resistance is considered mainly due to the surface oxide film. The simulation results indicate that the transient contact model is able to capture the history of plastic deformation accumulation and the material melting inception.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Microstructure simulation of early paper forming using immersed boundary methods

TAPPI Journal ◽  
2011 ◽  
Vol 11 (11) ◽  
pp. 23-30 ◽  
Author(s):  
ANDREAS MARK ◽  
ERIK SVENNING ◽  
ROBERT RUNDQVIST ◽  
FREDRIK EDELVIK ◽  
ERIK GLATT ◽  
...  
Keyword(s):  
Early Paper ◽  
Contact Model ◽  
Fiber Suspension ◽  
Beam Equation ◽  
Immersed Boundary ◽  
Paper Machine ◽  
Immersed Boundary Methods ◽  
Element Discretization ◽  
Microstructure Simulation ◽  
Boundary Methods

Paper forming is the first step in the paper machine where a fiber suspension leaves the headbox and flows through a forming fabric. Complex physical phenomena occur as the paper forms, during which fibers, fillers, fines, and chemicals added to the suspension interact. Understanding this process is important for the development of improved paper products because the configuration of the fibers during this step greatly influences the final paper quality. Because the effective paper properties depend on the microstructure of the fiber web, a continuum model is inadequate to explain the process and the properties of each fiber need to be accounted for in simulations. This study describes a new framework for microstructure simulation of early paper forming. The simulation framework includes a Navier-Stokes solver and immersed boundary methods to resolve the flow around the fibers. The fibers were modeled with a finite element discretization of the Euler-Bernoulli beam equation in a co-rotational formulation. The contact model is based on a penalty method and includes friction and elastic and inelastic collisions. We validated the fiber model and the contact model against demanding test cases from the literature, with excellent results. The fluid-structure interaction in the model was examined by simulating an elastic beam oscillating in a cross flow. We also simulated early paper formation to demonstrate the potential of the proposed framework.

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