Abstract
KEYWORDS – squeal, simulation, complex eigenvalue, characterization, comparison
ABSTRACT - Comfort is one of the main indicators of passenger vehicle‟s quality and therefore reduction of the noise level in brake systems is a key aspect to achieve customer‟s quality aspirations. Brake squeal is the most common noise problem and also the most studied one by brake NVH researchers. Despite the huge effort done in experimental, analytical and numerical fields to solve it, there is not any solution yet that can avoid it completely due to the fugitive nature of squeal. Experimental approaches are needed to quantify the nature of squeal and operating conditions affecting it. Nevertheless, the main disadvantages of the experimental approach are cost and time. Therefore numerical approaches are usually employed during design phase. Nowadays, two approaches are most used: complex eigenvalue analysis and transient analysis. Despite the huge development of transient analysis techniques, complex eigenvalue analysis is preferred in the industry, due to its lower computation time. With this method all the possible unstable frequencies can be found in one run for one set of operating conditions.
On the other hand, the main disadvantage of the complex eigenvalue analysis is overprediction. Several techniques like friction material elastic characterization, friction coefficient characterization or damping characterization are employed to reduce overprediction. However these improvements increase computation time. In this work different strategies will be compared in terms of accuracy and computation time. Numerical results are contrasted against experimental tests carried out in a simplified test rig.