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Advances in Complex Eigenvalue Analysis for Brake Noise
Technical Paper
2001-01-1603
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Brake squeal has been analyzed by finite elements for some time. Among several methods, complex eigenvalue analysis is proving useful in the design process. It requires hardware verification and it falls into a simulation process. However, it is fast and it can provide guidance for resolving engineering problems. There are successes as well as frustrations in implementing this analysis tool. Its capability, robustness and reliability are closely examined in many companies.
Generally, the low frequency squealing mechanism is a rotor axial direction mode that couples the pads, rotor, and other components; while higher frequency squeal mainly exhibits a rotor tangential mode. Design modifications such as selection of rotor design, insulator, chamfer, and lining materials are aimed specifically to cure these noise-generating mechanisms. In GM, complex eigenvalue analysis is used for brake noise analysis and noise reduction. Finite element models are validated with component modal testing. Also dynamometer and vehicle test results are compared with finite element results. From several vehicle level brake noise analyses, our experience shows that complex mode shapes are capable of depicting the noise generating mechanisms, and the complex eigenvalues are able to depict the noise frequencies.
Production brake squeal models using complex root analysis can be stabilized by an optimization procedure that is available in MSC/Nastran V2001. Since there are many closely spaced modes in a brake squeal model, a design change to stabilize roots in a frequency range is a very difficult task. However, with an optimization procedure the stabilization can be automatically achieved.
After identifying noise generating mechanisms and creating representative analysis model, several brake corners were analyzed for brake noise performance in the case studies. Figures showing the analysis results are included. Possible countermeasures were suggested, and the results showed improved noise performance.
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Citation
Shi, T., Dessouki, O., Warzecha, T., Chang, W. et al., "Advances in Complex Eigenvalue Analysis for Brake Noise," SAE Technical Paper 2001-01-1603, 2001, https://doi.org/10.4271/2001-01-1603.Also In
SAE 2001 Transactions Journal of Passenger Cars - Mechanical Systems
Number: V110-6; Published: 2002-09-15
Number: V110-6; Published: 2002-09-15
References
- Nack, W.V. “Brake Squeal Analysis by Finite Elements” SAE 1999-01-1735 1999
- Nack, W.V. Joshi, A.M. “Friction Induced Vibration: Brake Moan” SAE paper 951095
- Tworzydlo, W.W. Oden, J.T. et al. “Numerical Modeling of Friction Induced Vibrations and Dynamic Instabilities” ASME DE-Vol49 1992
- Tworzydlo, W.W. Hamzeh, O.N. Chang, H.J Fryska, S.T. “Analysis of Friction-Induced Instabilities in A Simplified Aircraft Brake” 1999 SAE Brake Colloquium
- Fieldhouse, J.D. “A Proposal to Predict the Noise Frequency of a Disc Brake Based on the Friction Pair Interface Geometry” 1999 SAE Brake Colloquium
- Shi, T.S. “Complex Eigenvalue Analysis of Unstable Mode Related to Brake Noise” 2 nd GM CAE Conf. 1999
- Chen, F. Chen, S-E. Her, J. Harwood, P. “Disc Brake Intermittent Squeal Noise Study Using Experimental Techniques Base Systematic Approach” SAE 2000-01-0731 2000
- Kung, S-W Dunlap, K.B. Ballinger, R.S. “Complex Eigenvalue Analysis for Reducing Low Frequency Brake Squeal” SAE paper 2000-01-0444
- Guan, D.H. Jiang, D. “A Study on Disc Brake Squeal using Finite Element Methods” SAE 980597
- Hu, Y-K. Nagy, L.I. “Brake Squeal Analysis by Using Transient Finite Element Method” SAE 971510
- Mahajan, S.K. Hu, Y-K Zhang, K. “Vehicle Disc Brake Squeal Simulations and Experiences” SAE 1999-01-1738 1999
- Hu, Y-K Mahajan, S.K. Zhang, K. “Brake Squeal DOE Using Nonlinear Transient Analysis” SAE 1999-01-1737
- Dunlap, K.B. Riehle, M.A. Longhouse, R.E. “An Investigative Overview of Automotive Disc Brake Noise” SAE 1999-01-0142 1999
- Pardus, G. Nashif, A. “Controlling Disc Brake Noise with Constrained Layer Damping” SAE 1998
- Yuhas, D. “Modulas Measurements in Friction Material” Presentation Material from Industrial Measurement Systems 1999