Effective Simulation of the Boundary Layer of an Entire Brake Pad
Published September 27, 2015 by SAE International in United States
Annotation of this paper is available
The dynamic friction behavior of automotive brakes is generated by the boundary layer dynamics between pad and disk [OST01]. A key component of the Friction Interface is the influence of mesoscopic surface contact structures known as patches, upon which the friction power is concentrated, and whose sizes vary with time. Through this dynamic process, time and load history-dependent effects come about, which cause, for example, the brake moment behavior commonly observed in an AK-Master test.
In recent years, several simulation tools have been developed in order to predict the complex friction behavior caused by the patch dynamics in the friction boundary layer. Such simulations are often based on a two or three-dimensional spatial grid, where the explicit physical phenomena at all locations in the boundary layer are modeled by time-consuming calculations of local material dependent balance equations.
A new abstract Cellular Automata simulation tool is introduced, which reduces the necessary computation to the patches in the friction boundary layer. Rather than making use of a spatial grid, each patch is considered a single cell, whose size can be adjusted without added computation costs. Using this method, the friction and wear behavior of an entire brake pad can be computed more quickly than, and at least as accurately as previous simulation tools could simulate a small subsection of the pad.
CitationOstermeyer, G. and Merlis, J., "Effective Simulation of the Boundary Layer of an Entire Brake Pad," SAE Technical Paper 2015-01-2664, 2015, https://doi.org/10.4271/2015-01-2664.
- Bode, K. and Ostermeyer, G., “Spatially Resolved Temperatures in Inhomogeneous and Continuously Changing Disk Brake Interfaces,” SAE Int. J. Passeng. Cars - Mech. Syst. 4(3):1377-1386, 2011, doi:10.4271/2011-01-2347.
- Center for Automotive Research: 2014 CAR REPORT, Alliance of Automobile Manufacturers, http://www.autoalliance.org/auto-innovation/2014-car-report, (2014).
- Eriksson, M.; Jacobson, S.: Tribological surfaces of organic brake pads, Tribological International 33, (2000), 817-827.
- Lee, K.; Barber, J. R.: An Experimental Investigation of Frictionally-Excited Thermoelastic Instability in Automotive Disc Brakes Under a Drag Brake Application, Transactions of the ASME, Journal of Tribology Vol 116, (1994), 409-414.
- Müller, M.; Ostermeyer, G.-P.: Third Body Simulations of Brake Systems on a Mesoscopic Scale, Proceedings of the 25th SAE Brake Colloquium and Exhibition, SAE Paper 08BC-0010 (2008), San Antonio.
- Ostermeyer, G.-P.: Friction and wear of brake systems, Forschung im Ingenieurwesen 66, (2001), 267-272.
- Ostermeyer, G.-P.; Mueller, M.: Dynamic Interaction of Friction and Surface Topography in Brake Systems, Tribology International, Volume 39 No. 5 (2006), 370-380.
- Ostermeyer, G. and Müller, M., “New Developments of Friction Models in Brake Systems,” SAE Technical Paper 2005-01-3942, 2005, doi:10.4271/2005-01-3942.
- Ostermeyer, G.-P.; Müller, M.: New insights into the tribology of brake systems, Proc. IMechE Vol. 222 Part D: J. Automobile Engineering, (2008).
- Ostermeyer, G., “Dynamic Friction Laws and Their Impact on Friction Induced Vibrations,” SAE Technical Paper 2010-01-1717, 2010, doi:10.4271/2010-01-1717.
- Ostermeyer, G.-P.; Dilnot, A.; Lange, J.: Analysis of Friction in Brakes on a Virtual AK-Master Test Rig, SXXXIst International μ Symposium Reihe 12 Nr. 759, (2012), 168-182.
- Ostermeyer, G.-P.; Graf, M.: Hot Banding with oscillating Radii: Models including Wear and Temperature, Eurobrake Conference Proceedings EB2012-IFD-04, (2012).