CAE-based Robustness Evaluation of Brake Systems

Abstract

Original Equipment Manufacturers (OEM's) target lower probabilities of brake noise as part of quality requirements for disc brake systems. Since brake noise is significantly controlled by variations in environmental conditions or alterations of brake systems, the brake system needs "in build" robustness against those variations to minimize noise during its lifecycle. In the past, proof of brake noise quality was primarily based on tests. Currently, it is based on a combination of simulation and testing. Due to cost and time schedule constraints, improvement cycles late in the development process need to be reduced. That is only possible with an increase of Computer Aided Engineering (CAE) based robustness evaluation taking into account all relevant sources of variation which may have an influence on brake noise occurrence. Robustness evaluation is a methodology to investigate how input scatter affects response variation and helps to understand how causes connect to variation in responses. The paper will discuss the challenges for software tools, CAEmodelling and CAE-processes to successfully apply a CAE-based robustness evaluation for brake noise application in virtual prototyping. It should be noted that Dynardo is a general purpose engineering consultant for CAE-based robustness evaluation and is not specialized for dealing with brake squeal simulation problems. Thus the paper does not address what methods of CAE modeling are appropriate to reflect the underlying physics of brake squeal accurate enough. However, since simulation is used today to investigate brake squeal and simulation models are successfully validated against hardware tests, it can be stated that appropriate CAE-models are available and can be successfully used to perform robustness evaluation.

Analysis of Friction-Induced Vibration Leading to Brake Squeal Using a Three Degree-of-Freedom Model

“…However, much research showed that brake squeal is actually influenced by many factors such as component geometry, material property, friction coefficient, contact interface, applied load and thermal effect. Because most of the influence factors are time-varying and difficult to model accurately, application of FE method is still far from satisfactory and results often suffer from over -prediction or underprediction [35,36].…”