• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.10
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• pp.749-755
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• 2014

The analytical-finite element(FE) squeal model is applied to investigate the squeal propensity associated with contact stiffness of the disc brake system. The system contact stiffness is incorporated into the perturbed equations of motion in the analytical manner where the brake components are modeled by FE method. The results show that the contact stiffness of the friction material and the contact stiffness between the pads and caliper are the influential factors on the squeal propensity. Particularly, the modal instability of the 3200 Hz squeal mode drastically changes with respect to the contact stiffness between the pads and caliper.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.223-228
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• 1996

The frequency of the brake squeal noise can be changed during braking, and this frequency shifting is due to variation of braking deceleration rate. The natural frequency of the brake system also shifted according to deceleration rate. It makes difficult to treat this problem. This paper shows an experimental study on the brake squeal noise having main frequencies of about 450~500Hz. And it shows how to improve the brake squeal noise problem.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.118-124
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• 2004

To investigate the mechanics of brake squeal noise, the sound and vibration of an actual brake system was measured using a brake dynamometer. The experimental results show that disk run-out due to the misalignment of brake disk varies with brake line pressure and becomes the important factor of brake squeal noise generation. Also, it was confirmed that the frequency of the squeal noise equals to the natural frequency of the disk bending mode.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.66-71
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• 2002

Squeal noise is generated by railway vehicles transversing tight curves. This squeal has always been noticed as one of the most disturbing noise sources of railway systems. At present we cannot predicted squeal noise that is influenced by a large number of dependent parameters. In this study, we performed structural analysis to find out the frequency of the wheel and also measured squeal noise at Seoul subway line 1, line 2, line 4 for domestic EMU(Electrical Multiple Unit).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.996-1002
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• 2009

Elimination of squeal noise occurred during brake application is an important task for the improvement of comforts in an industrial forklift. In this paper, a test rig was developed which was possible for testing of brake noise and an experimental measurement on squeal noise was performed. The causes of the brake noise are identified by experimenting how the factors such as automatic transmission fluid and rpm of drive axle affect the squeal. In order to identify the squeal characteristics, the signal analyses for noise are performed by using frequency spectrums. Also, brake test using a forklift was carried out to confirm the reliability of test results by using a test rig comparing with the occurrence of squeal noise. Experimental results showed that the tendencies of occurrence of squeal noise are well agreed at two test methods by using the test rig and forklift.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.10
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• pp.1074-1080
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• 2009

A method for determining the geometric stability characteristics of a brake corner module (BCM) is presented. Since disc brake "squeal" noise typically occurs at unstable resonant frequencies of a system, the likelihood of disc brake squeal for a particular design can be determined. Finite element methods are used to derive complex eigenvalue for a brake corner module. Some unstable modes calculated by finite element methods correspond to squeal noise data. Through kinetic energy participation analysis for each part of BCM, we can efficiently predict squeal noise data.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1690-1695
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• 2003

In order to investigate the mechanism of brake squeal noise, the sound and vibration of an actua1 brake system were measured using a brake dynamometer. The experimental results show that disc run-out varies with brake line pressure and the factor of squeal generation is the run-out due to the misalignment of brake disk. A three degrees of freedom friction model is developed for the disk brake system where the run-out effect and nonlinear friction characteristic are considered. The results of numerical analysis of the model agree well with the experimental results. Also, the stability analysis of the model was performed to predict the generation of brake squeal due to the design parameter modification of brake systems. The results show that the squeal generation depends on the nm-out rather than the friction characteristic between the pad and the disk of brake.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.5
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• pp.374-380
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• 2014

This article proposes a design guideline to reduce squeal noise generated by an automobile wiper blade. In order to explain the squeal noise phenomenon, a source of squeal noise is experimentally investigated using a rotating disk equipment, and then a single-degree-of-freedom stick-slip vibration model is established for a blade tip. Based on analytical results, we discuss a tendency of the squeal noise for various physical parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.320-325
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• 2006

The phenomenon of squeal in disc brakes has been, and stin is, a problem for the automotive industry. Extensive research has been done in an attempt to understand the mechanisms that cause it and in developing design procedures to reduce it to make vehicles more comfortable. In this paper, the study on squeal noise of disc brake is performed using complex eigen-value analysis, The first part describes the chassis-dynamometer and the testing procedure, and second part explains how the analysis is performed and shows some of the results from typical squeal tests. Finally, to reduce squeal nose of disc brake is investigated by the effects of brake design parameter.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.170-175
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• 2005

In this study, experimental and theoretical methods were applied to understand brake squeal noise VVVF rolling stock on tracks. Trailer cars needed to payed a particular attention, because they were the major source of brake noise. VVVF rolling stocks for lines no 1 of the subway system in Seoul were used for experimental analyses. In order to study brake squeal noise, a dynamometer test at the S&T Brake, Co., which was a manufacturer of brake pads had performed. For measuring vibration and noise, vibration tests of brake parts (brake lining, brake lining head, back plates, etc.) at the SNUT were executed. Also, vibration tests of disc assembly and lining block at the heavy maintenance shop of the Gunja depot were performed. The modal analyses by using an ANSYS which was one of the CAE commercial program were simulated to know the relationship to the mechanism of brake noise. On the based of the tests and the simulations it was found that specific frequencies of the brake parts affected squeal noise, and improvements for reducing squeal noise were proposed.