Modeling the Friction Boundary Layer of an Entire Brake Pad with an Abstract Cellular Automaton

Abstract

The principle energy exchange of a brake system occurs in the tribological boundary layer between the pad and the disc. The associated phenomena are primarily responsible for the dynamics of brake systems. The wear debris forms flat contact structures, or “patches,” which carry the majority of the normal load in the system and are highly influential on the friction behavior of the system. A new simulation tool is presented, which is capable of rapidly performing simulations of the contact between an entire brake pad and disc. The “Abstract Cellular Automaton” simulations accurately model the patch coverage state of a brake pad surface based on the system’s load history. This can be used to simulate the complex dissipation phenomena within the tribological contact of the entire pad, including time-dependent local friction coefficients, wear and wear debris transport, and vibrational effects on highly differing scales.

Keywords

• dynamic friction
• boundary layer
• brake
• cellular automata simulation
• patch dynamics
• tribology