Design and Analysis of Disc Brake for Low Brake Squeal
International Journal of Latest Technology in Engineering, Management & Applied Science -IJLTEMAS (www.ijltemas.in)
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
Vibration induced due to friction in disc brake is a theme of major interest and related to the automotive industry. Squeal noise generated during braking action is an indication of a complicated dynamic problem which automobile industries have faced for decades. For the current study, disc brake of 150 cc is considered. Vibration and sound level for different speed are measured. Finite element and experimentation for modal analysis of different element of disc brake and assembly are carried out. In order to check that precision of the finite element with those of experimentation, two stages are used both component level and assembly level. Mesh sensitivity of the disc brake component is considered. FE updating is utilized to reduce the relative errors between the two measurements by tuning the material. Different viscoelastic materials are selected and constrained layer damping is designed. Constrained layer damping applied on the back side of friction pads and compared vibration and sound level of disc brake assembly without constrained layer damping with disc brake assembly having constrained layer. It was observed that there were reduction in vibration and sound level. Nitrile rubber is most effective material for constrained layer damping.
Related papers
STUDY OF FRICTION AND WEAR FOR OPTIMIZATION OF DISC BREAK MATERIAL FOR REDUCTION OF BRAKE SOUND
There is some sort of noise which is generating during the braking action called as Brake Squeal. Disc brake squeal still continues to be a major concern for the automotive industry despite the efforts to reduce its occurrence during the past decades. It has been the subject of both experimental and numerical modeling since 1930s the continuously evolving expectations related to vehicle performance have resulted in the car manufacturer having to strive to provide not only a competitive and efficient braking system, but also a 'quiet' braking system. The elimination of brake squeal noise is very important as it causes discomfort of the vehicle occupants as well as any pedestrians. Squeal problems may cause the car manufacturer substantial revenue loss from warranty claims associated with the quality of noise produced by the brake despite the fact that the brake remains fully functional and safe. The trade-offs involved in this process continue to challenge engineers to understand and control brake noise and vibration phenomena. From a theoretical perspective, disc brake squeal can be classified as a form of friction-induced vibration. The characteristic and the understanding of this problem are complicated by the fact that it is a transient phenomenon. The disc rotor, while acting like a speaker, is a rotating component and the assembled brake combines many components with complex interfaces.
Effects of material properties on generation of brake squeal noise using finite element method
Latin American Journal of Solids and Structures, 2015
This research paper is concerned with the disc brake squeal problem for passenger cars. The aim of the present research is developing a finite element model of the disc brake assembly in order to improve understanding of the influence of Young's modulus on squeal generation. A detailed finite element model of the whole disc brake assembly that integrates the wheel hub and steering knuckle is eveloped and validated using experimental modal analysis. Stability analysis of the disc brake assembly is accomplished to find unstable frequencies. A parametric study is carried to look into the effect of changing Young's modulus of each brake components on squeal generation. The results of simulation indicated that Young's modulus of disc brake components play a substantial role in generating the squeal noise.
The Influence of Material Characteristics and Altered Geometry Due to Process on the Vibrational Behaviour of the Brake Disk
2014
Lately, in the field of car design, the level of noise perceived by the client has been continuously decreased as a result of progress. An important element of this approach is the study of vibration induced by braking behavior of the coupling pad / disk brake. Based on observations made over time regarding brake noise of various combinations of pad / disk, this paper proposes a method to anticipate the possibility of producing noise when braking due to brake disc , as well as control the manufacture, to avoid possibility of its occurrence . This article does not address the mechanism which produces noise brake in the coupling pad / disk, which is fully yet unexplained by researchers. The disk is considered in two cases (made of different materials or geometric errors caused by drift in the manufacturing process), at a standard definition of the pad. A disk identified as " noisy " brake (type β ) and a disk identified " silent " (type α ) are compared and the inf...
Evaluation of Disc Brake Materials for Squeal Reduction
Tribology …, 2011
Finite element parametric study of the influence of friction pad material and morphological characteristics on disc brake vibration phenomena
Journal of Physics: Conference Series, 2016
Since nowadays the NVH performance of vehicles has become an important priority, the noise radiating from brakes is considered a source of considerable passenger discomfort and dissatisfaction. Creep groan and squeal that show up with annoying vibrations and noise in specific frequency ranges are typical examples of self-excited brake vibrations caused by the stick-slip effect, the former, by the mode coupling of brake disc and friction pads or calliper, the latter. In both cases, the friction coefficient, which depends, among other factors, on the morphology of the mating surfaces and on the operating conditions, is a fundamental parameter but not the only one for the occurrence of the vibratory phenomena. Finite element complex eigenvalue parametric analyses were performed on a disc brake assembly to evaluate propensity to dynamic instability of brakes with multiple pads, as in railway brakes, as a function of the number of pads, pad shape and size, and material parameters.
Numerical Analysis of Disc Brake Squeal Considering Temperature Dependent Friction Coefficient
Passenger cars have become one of the main transportations for people travelling from one place to another. Indeed, vehicle quietness and passenger comfort issues are a major concern. One of vehicle components that occasionally generate unwanted vibration and unpleasant noise is the brake system. Brake squeal noise is the most troublesome and irritant one to both car passenger and the environment, and is expensive to brakes and carmakers in terms of warranty costs. It is well accepted that brake squeal is due to a friction-induced dynamic instability and it frequently occurs at frequency above 1 kHz and is described as sound pressure level above 78 dB. Brake squeal has been studied over 20 years ago through experimental, analytical and numerical methods in an attempt to understand, to predict and to prevent squeal occurrence. In recent years, the finite element (FE) method has become the preferred method due to inadequacy of experimental methods in predicting squeal at early stage in the design process. However, the drawbacks of the FE method are over-predictions and missing unstable modes in the squeal frequency range. This paper attempts to improve the drawbacks by considering temperature dependent friction coefficient (T-µ dependency), which is typically neglected by many previous investigators. Prediction of disc brake squeal is performed using complex eigenvalue analysis that available in ABAQUS V6.4. In doing so, a validated and detailed 3-D finite element model of a real disc brake is used. Predicted results are then compared to those obtained in the experimental results with and without T-µ dependency.
NUMERICAL AND EXPERIMENTAL INVESTIGATION OF SQUEAL NOISE GENERATED IN A DISC BRAKE SYSTEM AND REDUCTION OF IT
Disc brake squeal is considered as one of the major problem in NVH sector in automotive industries. The instability generated in disc brake system is mainly due to coupling of free modes of the disc rotor and brake pad. To evaluate instability, complex modal analysis is applied numerically in Ansys. A brief parametric study is done to analyze the effect of operational and material parameters in generation of instability. To validate the numerical analysis experimental modal analysis is performed. Ten different modifications were studied numerically so as to reduce the instability. A suitable modification was chosen based on numerical simulation and was modified for experimental validation. Squeal tests performed in experimental analysis also evaluate the reduction of squeal noise between unmodified disc brake system and modified disc brake system.
Reducing disc brake squeal through FEM approach and experimental design technique
International Journal of …, 2010
This paper presents a novel approach to understand the influencing factors of the brake pad on the disc brake squeal by integrating finite element simulations with statistical regression techniques. The complex eigenvalue analysis has been widely used to predict unstable frequencies in brake system models and to provide design guidance. The 'input-output' relationships between the brake squeal and the brake pad geometry is constructed for possible prediction of the squeal using various geometrical configurations of the disc brake. Influences of the various factors, namely back plate Young's modulus, back plate thickness, chamfer, distance between two slots, slots width and angle of slots, are investigated using design of experiments technique. The proposed approach is aimed towards prediction of optimal pad design to reduce the damping ratio of the dominant unstable modes through the various factors of the brake pad geometrical construction. The damping ratio is analysed and a non-linear mathematical prediction model is developed based on the most influencing factors.
Experimental Studies of Automotive Disc Brake Noise and Vibration: A Review
In the last few decades, there have been extensive studies on analysis and investigation of disc brake vibrations done by many researchers around the world on the possibility of eliminating brake vibration to improve vehicle users' comfort. Despite these efforts, still no general solution exists. Therefore, it is one of the most important issues that require a detailed and in-depth study for investigation brake noise and vibration. Research on brake noise and vibration has been conducted using theoretical, experimental and numerical approaches. Experimental methods can provide real measured data and they are trustworthy. This paper aims to focus on experimental investigations and summarized recent studies on automotive disc brake noise and vibration for measuring instable frequencies and mode shapes for the system in vibration and to verify possible numerical solutions. Finally, the critical areas where further research directions are needed for reducing vibration of disc brake are suggested in the conclusions.
Recent studies of car disc brake squeal
2008
Friction-induced vibration and noise emanating from car disc brakes is a source of considerable discomfort and leads to customer dissatisfaction. The high frequency noise above 1 kHz, known as squeal, is very annoying and very difficult to eliminate. There are typically two methods available to study car disc brake squeal, namely complex eigenvalue analysis and dynamic transient analysis. Although complex eigenvalue analysis is the standard methodology used in the brake research community, transient analysis is gradually gaining popularity. In contrast with complex eigenvalues analysis for assessing only the stability of a system, transient analysis is capable of determining the vibration level and in theory may cover the influence of the temperature distribution due to heat transfer between brake components and into the environment, and other time-variant physical processes, and nonlinearities. Wear is another distinct aspect of a brake system that influences squeal generation and itself is affected by the surface roughness of the components in sliding contact. This chapter reports recent research into car disc brake squeal conducted at the University of Liverpool. The detailed and refined finite element model of a real disc brake considers the surface roughness of brake pads and allows the investigation into the contact pressure distribution affected by the surface roughness and wear. It also includes transient analysis of heat transfer and its influence on the contact pressure distribution. Finally transient analysis of the vibration of the brake with the thermal effect is presented. These studies represent recent advances in the numerical studies of car brake squeal.
Related topics
Related papers
Simulation of the structural modifications of a disc brake system to reduce brake squeal
Proceedings of the Institution of …, 2011
The noise and vibration generated by the braking system in passenger cars are important technical and economic problems in the automotive industry. In recent years, the finite element (FE) method has been found to be a useful tool in predicting the occurrence of noise in a particular brake system during the design stage. This paper presents a more refined FE model of the disc brake corner that includes the wheel hub and steering knuckle. The model is an extension of earlier FE disc brake models. Experimental modal analysis of the disc brake system is initially used to validate the FE model. The unstable frequencies were then predicted by applying a complex eigenvalue analysis to the FE model. Finally, a number of structural modifications are made and simulated to evaluate brake squeal at the design stage. From the predicted results, it is found that the most significant improvements in brake squeal performance could be achieved by using an aluminium metal matrix composite brake rotor, steel calliper, and steel bracket. It is also found that a stiffer friction material with a diagonal slot could reduce the propensity for brake squeal.
Finite Element Modelling and Analysis of Brake Squeal
Abstract-- It is well-known fact that automobile brakes generate several kinds of noises like squeal, groan, chatter, judder, moan, hum and squeak. Squeal is the most prevalent, annoying and can be reduced by variations in geometry, parameters such as coefficient of friction, stiffness of material. The brake squeal generally occurs in the range of 1-16 kHz. Basically, two methods are available to study the disc brake squeal, namely complex eigenvalue analysis and dynamic transient analysis. Complex eigenvalue analysis is the standard method used for squeal analysis. Analytically it is very difficult to solve because of complex brake mechanisms. Experimental and numerical techniques have been developed by various researchers in order to study brake squeal. Experimental techniques are unable to predict brake squeal at the early stages of design process and also very costly due to associated design iterations. Therefore, finite element analysis has emerged as a viable approach for brake squeal analysis. This work presents Finite Element modelling and modal analysis of disc-pad assembly using high end software tools. Linear non-prestressed modal analysis and full nonlinear perturbed modal analysis is applied to predict frequency at which squeal occurs. Real and imaginary eigenfrequencies of unstable modes are obtained. Analysis is performed by varying the coefficient of friction and outer diameter of disc-pad assembly. Increasing friction coefficient has no desirable effect on squeal frequency while squeal propensity decreases as the outer diameter of disc is increased.
Reduction of Disc Brake Squeal Noise Using Constrained Layer Dampers
Jurnal Teknologi, 2017
Brakes squeal has remained to be one of the major Noise, Vibration and Harshness (NSH) challenges in brake system design and development. It has been a concern for automotive industry for decade. Brake researchers have proposed many brake squeal reduction and prevention methods in order to overcome and reduce the squeal that emanates from the brake disc systems. In this paper, the effectiveness of constrained layer dampers (CLD) in reducing disc brake squeal noise was investigated. CLD isolates the brake squeal noise through shear deformations of the viscoelastic materials. Two sets of brake tests were conducted using the brake test dynamometer with the application of CLD. Two different types of CLD were used which are three-layer constrained layer damper and four-layer constrained layer damper. Squeal tests were carried out using brake noise test rig based on the global standard procedure SAE J2521. From the test, four-layer CLD configuration works more efficient than three-layer CLD configuration. CLD made up of nitrile butadiene rubber, silicone rubber and mild steel proved to be the most effective noise insulator at hydraulic pressure range of 5 bar to 30 bar and temperature range of 50 o C to 200 o C with a maximum noise reduction of 11.3 dBA. Thus, CLD technique was proven to be an effective method in reducing brake squeal noise.
Numerical and Experimental Evaluation of Brake Squeal
It is widely known that a typical brake system works by mitigating vehicle kinetic energy and transforming it into thermal energy, ultimately leading to energy dissipation. The main concerns related to this kind of system are: 1) low frequency vibration energy propagating throughout the vehicle structure when the system begins its unblocking action; and 2) high frequency vibration energy propagation which induces undesirable noise levels. Modal analysis of the system can provide important information about its vibration characteristics. Provided that coupling between the dynamic behavior, the pre-stress caused by the applied load, and friction characteristics will certainly occur, it is required that analyses be performed on the entire assembly. As such, this paper presents evaluation of a brake disc system regarding the brake squeal using finite element method comparing with experimental assessment.
Study and Analysis of Disc Brake to Reduce Disc Brake Squeal
International Journal for Research in Applied Science and Engineering Technology, 2018
Brake squeal noise has been under investigation by automotive manufactures for many years due to consistent customer complaints and high warranty costs. Disc brake squeal remains a complex problem in the automotive industry, since the early 20th century, many researchers have examined the problem with experimental, analytical and computational techniques. Although brake squeal do not affect braking performance, still it is not acceptable. So brake noise issues have led vehicle manufacturers, brake and friction material suppliers to investigate various ways of improving their processes in order to reduce vehicle noise and increasing passenger comfort. In this paper various parameters influencing disc brake squeal are studied from literatures. Various parameters are braking pressure, rotational velocity, coefficient of friction, damping, modifications in disc and pad. During braking operation braking pressure, rotational velocity are not in control. Decrease in coefficient of friction reduces the brake squeal, but it is not applicable because it lowers the braking performance. Damping shims to reduce squeal increases the cost of damping material. So best way to reduce disc brake squeal is structural modification in disc brake assembly.
Effects of Young's Modulus on Disc Brake Squeal using Finite Element Analysis
The International Journal of Acoustics and Vibration
This paper is concerned with the disc brake squeal problem of passenger cars. The objective of this study is to develop a finite element model of the disc brake assembly in order to improve the understanding of the influence of Young's modulus on squeal generation. A detailed finite element model of the whole disc brake assembly that integrates the wheel hub and steering knuckle is developed and validated by using experimental modal analysis. Stability analysis of the disc brake assembly is conducted to find unstable frequencies. A parametric study is carried out to look into the effect of changing Young's modulus of each brake's components on squeal generation. The simulation results indicate that Young's modulus of the disc brake components plays an important role in generating the squeal noise.
Parametric studies of disc brake squeal using finite element approach
Disc brake squeal noise is a very complicated phenomenon, which automobile manufacturers have confronted for decades due to consistent customer complaints and high warranty costs. In recent years, the finite element method (FEM) has become the preferred method due to high hardware costs of experimental methods. In this study, a simplified model for the disc brake is presented using the ABAQUS/Standard finite element software. The analysis process uses a nonlinear static simulation sequence followed by a complex eigenvalue extraction to determine the squeal propensity. The effect of the main operational parameters (braking pressure, and friction coefficient) on the squeal propensity is performed. The influence of changing the rotor stiffness and back plates stiffness under different operation condition are investigated. The results of this analysis show that the squeal noise can be reduced by increasing the rotor stiffness and decreasing the back plate stiffness of the pads.
Vibration and squeal of a disc brake: modelling and experimental results
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 2003
This paper presents a method for analysing the unstable vibration of a car disc brake, and numerical results are compared with squeal frequencies from an experimental test. The stationary components of the disc brake are modelled using many thousands of solid and special nite elements, and the contacts between the stationary components and between the pads and the disc are considered. The disc is modelled as a thin plate and its modes are obtained analytically. These two parts (stationary and rotating) of the disc brake are brought together with the contact conditions at the disc/pads interface in such a way that the friction-induced vibration of the disc brake is treated as a moving load problem. Predicted unstable frequencies are seen to be close to experimental squeal frequencies.
Influence of Material-Dependent Damping on Brake Squeal in a Specific Disc Brake System
Applied Sciences, 2021
The connection of two phenomena, nonconservative friction forces and dissipation-induced instability, can lead to many interesting engineering problems. We study the general material-dependent damping influence on the dynamic instability of disc brake systems leading to brake squeal. The effect of general damping is demonstrated on minimal and complex models of a disc brake. Experimental analyses through the frequency response function (FRF) show different damping of the brake system coalescent modes, indicating possible dissipation-induced instability. A complex system including material-dependent damping is defined in commercial finite element (FE) software. A FE model validated by experimental data on the brake-disc test bench is used to compute the influence of a pad and disc damping variations on the system stability using complexe igenvalue analysis (CEVA). Numerical analyses show a significant sensitivity of the experimentally verified unstable mode of the system to the ratio...
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.