scholarly journals Influence of Material-Dependent Damping on Brake Squeal in the Specific Disc Brake System

2021 ◽  
Author(s):  
Juraj Úradníček ◽  
Miloš Musil ◽  
Ľuboš Gašparovič ◽  
Michal Bachratý
Keyword(s):  
Finite Element ◽  
Complex Model ◽  
System Stability ◽  
Dynamical Instability ◽  
Brake Disc ◽  
Disc Brake ◽  
Complex Eigenvalue ◽  
Brake Squeal ◽  
Friction Forces ◽  
Finite Element Software

The connection of two phenomena - non-conservative friction forces and dissipation-induced instability can lead to many interesting engineering problems. The paper studies general material-dependent damping influence on dynamical instability of disc brake systems leading to brake squeal. The effect of general damping is demonstrated on a minimal and complex model of a disc brake. A complex system including material-dependent damping is defined in the commercial finite element software. The finite element model validated by experimental data on the brake-disc test bench is used to compute the influence of a pad and a disc damping variations on system stability by complex eigenvalue analysis. Analyzes show a significant sensitivity of the experimentally verified unstable mode of the system to the ratio of the damping between the disc and the friction material components.

scholarly journals Influence of Material-Dependent Damping on Brake Squeal in a Specific Disc Brake System

2021 ◽  
Vol 11 (6) ◽  
pp. 2625
Author(s):  
Juraj Úradníček ◽  
Miloš Musil ◽  
L’uboš Gašparovič ◽  
Michal Bachratý
Keyword(s):  
Dynamic Instability ◽  
Friction Material ◽  
System Stability ◽  
Brake System ◽  
Brake Disc ◽  
Disc Brake ◽  
Fe Model ◽  
Brake Squeal ◽  
Friction Forces ◽  
General Material

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 of the damping between the disc and the friction material components.

Numerical Modeling and Simulation Analysis of Temperature Field of Disc Brake on Trains

2011 ◽  
Vol 199-200 ◽  
pp. 1492-1495 ◽  
Author(s):  
Guo Shun Wang ◽  
Rong Fu ◽  
Liang Zhao
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
High Speed ◽  
Large Scale ◽  
Working Condition ◽  
Constant Speed ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Pad ◽  
Finite Element Software

The simulation calculation on the temperature field of the disc brake system on high-speed trains under the working condition of constant speed at 50Km/h is made. A steady-state calculation model is established according to the actual geometric size of a brake disc and a brake pad, and the analog calculation and simulation on the temperature field of the brake disc and the brake pad by using the large-scale nonlinear finite element software ABAQUS are carried out. The distribution rules of the temperature field of the brake disc and the brake pad under the working condition of constant speed are made known. The surface temperature of the brake disc at friction radius is the highest, with a band distribution for temperature. There exists a temperature flex point in the direction of thickness, of which the thickness occupies 15% of that of the brake disc; due to the small volume of the brake pad, the temperature gradient of the whole brake pad is not sharp, and larger temperature gradient occurs only on the contact surface.

scholarly journals A Hybrid Model for Predicting Steering Brake Squeal Based on Multibody Dynamics and Finite Element Methods

2022 ◽  
Vol 2022 ◽  
pp. 1-13
Author(s):  
Lijun Zhang ◽  
Yongchao Dong ◽  
Dejian Meng ◽  
Wenbo Li
Keyword(s):  
Finite Element ◽  
Hybrid Model ◽  
Multibody Dynamics ◽  
Finite Element Methods ◽  
Lateral Force ◽  
Steering Wheel ◽  
Complex Eigenvalue ◽  
Brake Squeal ◽  
Complex Eigenvalue Analysis ◽  
Stress And Deformation

In recent years, the problem of automotive brake squeal during steering braking has attracted attention. Under the conditions of squealing, the loading of sprung mass is transferred, and lateral force is generated on the tire, resulting in stress and deformation of the suspension system. To predict the steering brake squeal propensity and explore its mechanism, we established a hybrid model of multibody dynamics and finite element methods to transfer the displacement values of each suspension connection point between two models. We successfully predicted the occurrence of steering brake squeal using the complex eigenvalue analysis method. Thereafter, we analyzed the interface pressure distribution between the pads and disc, and the results showed that the distribution grew uneven with an increase in the steering wheel angle. In addition, changes in the contact and restraint conditions between the pads and disc are the key mechanisms for steering brake squeal.

Investigation of Friction Temperature in Railway Disc Brake

2012 ◽  
Vol 479-481 ◽  
pp. 202-206
Author(s):  
Wan Hua Nong ◽  
Fei Gao ◽  
Rong Fu ◽  
Xiao Ming Han
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Friction Pair ◽  
Brake Disc ◽  
Finite Element Software ◽  
Disc Surface ◽  
Friction Temperature ◽  
Steel Disc ◽  
Braking Force ◽  
Braking Process

The distribution of temperature on the rubbing surface is an important factor influencing the lifetime of a brake disc. With a copper-base sintered brake pad and a forge steel disc, up-to-brake experiments have been conducted on a full-scale test bench at a highest speed of 200 Km/h and a maximum braking force of 22.5 KN. The temperature distributions on brake disc surface have been acquired by an infrared thermal camera, and the contact pressure on the contact surface of the friction pair has been calculated by the finite element software ABAQUS. The results show that the area and thermal gradient of the hot bands increase with the increase of braking speed and braking force. The hot bands occur in priority at the radial location of r=200 mm and r=300 mm, and move radially in the braking process. The finite element modelling calculation indicates that the distribution of the contact pressure on the disc surface in radial direction is in a "U"-shape. The maximum contact pressure occur at the radial locations of r=200 mm and r=300 mm, and the minimum contact pressure occur in the vicinity of the mean radius of the disc. The conformity of contact pressure distributions with the practical temperature evolutions indicates that the non-uniform distribution of the contact pressure is the factor resulting in the appearance of hot bands on the disc surface.

Estimation of Critical Value of Friction Coefficient for Brake Squeal Analysis

2005 ◽  
Author(s):  
Jinchun Huang ◽  
Charles M. Krousgrill ◽  
Anil K. Bajaj
Keyword(s):  
Friction Coefficient ◽  
Expansion Method ◽  
Critical Value ◽  
System Stability ◽  
Design Parameters ◽  
Complex Eigenvalue ◽  
Brake Squeal ◽  
Modal Expansion ◽  
Eigenvalue And Eigenvector ◽  
Brake Noise

Automotive brake squeal which is generated during brake application has become a major concern in automotive industry. Warranty costs for brake noise have been greatly increasing in recent years. Brake noise and vibration control are important for the improvement of vehicle quietness and passenger comfort. In this work, the mode coupling instability mechanism is discussed, and a method to estimate the critical value of friction coefficient is presented to predict the onset of brake squeal. A modal expansion method is developed to calculate eigenvalue and eigenvector sensitivities. Different types of mode couplings and their relationships with squeal are discussed. A reduced-order characteristic equation method based on the statically coupled eigenvalues and their derivatives is presented to estimate the critical value of friction coefficient. The significance of this method is that the critical value of friction coefficient can be predicted accurately without the need for a full complex eigenvalue analysis, making it possible to determine the sensitivity of system stability with respect to design parameters directly.

Sensitivity of Critical Value of Friction Coefficient for Brake Squeal Analysis

2007 ◽  
Author(s):  
Jinchun Huang ◽  
Charles M. Krousgrill ◽  
Anil K. Bajaj
Keyword(s):  
Sensitivity Analysis ◽  
Friction Coefficient ◽  
Structural Modification ◽  
Critical Value ◽  
System Stability ◽  
Mode Shapes ◽  
Frequency Variation ◽  
Complex Eigenvalue ◽  
Brake Squeal ◽  
Complex Eigenvalue Analysis

Brake squeal has been a major concern throughout the automotive industry. Structural modification is a practical and effective way to reduce brake squeal. However, few if any, systematic techniques exist to guide in this structural modification. In this work, a sensitivity analysis for brake squeal control is presented. The critical value of friction coefficient is used as a measure of squeal propensity. Based on the reduced-order characteristic equation method which can accurately estimate the critical value of friction coefficient, a sensitivity analysis of system stability with respect to lining stiffness and lining geometry is presented for a drum brake system. The sensitivity analysis can be conducted without creating new system models or performing a full complex eigenvalue analysis. Furthermore, the sensitivity analysis reveals the regions of contact area which have strong influence on squeal. It is shown that the separation of elastically coupled frequencies is influenced by the grooves in lining material, and the frequency variation can be related to the mode shapes of the drum and the shoes.

scholarly journals Squeal Frequency of a Railway Disc Brake Evaluation by FE Analyses

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
F. Cascetta ◽  
F. Caputo ◽  
A. De Luca
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Experimental Tests ◽  
Numerical Approach ◽  
System Stability ◽  
Brake System ◽  
Physical Parameters ◽  
Disc Brake ◽  
Complex Eigenvalues ◽  
The Stability

This paper deals with the development of a numerical model, based on the Finite Element (FE) theory for the prediction of the squeal frequency of a railway disc brake. The analytical background has been discussed and presented, as well as the most efficient methods for evaluating the system stability; the attention has been paid particularly to the complex eigenvalues method, which has been adopted within this paper to investigate the railway disc brake system. Numerical results have been compared with measurements from experimental tests in order to validate the proposed numerical approach. At the end of this work, a sensitivity analysis, aimed at understanding the effects of some physical parameters influencing the stability of the brake system and the squeal propensity, has been carried out.

Complex Eigenvalue Analysis Applied to an Aircraft Brake Vibration Problem

1995 ◽  
Author(s):  
Denis J. Feld ◽  
Dana J. Fehr
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Friction Force ◽  
Mode Shape ◽  
Element Model ◽  
Eigenvalue Analysis ◽  
Complex Eigenvalue ◽  
Friction Forces ◽  
Model Complex ◽  
Complex Eigenvalue Analysis

Abstract A conventional finite element model of an aircraft wheel and brake is extended to include forces responsible for friction-induced noise. Responses of aircraft brake vibration modes change the normal force across the brake friction interfaces, and consequently the friction forces. The resulting friction force variations are assembled in the form of a supplemental stiffness matrix and added to the finite element model. Complex eigenvalue analysis that includes the friction force variations provides frequency and mode shape information, as well as an assessment of the predicted mode stability. A predicted unstable vibration mode compares very well to operating mode shape data determined from instrumented tests. Hardware modifications to reduce a brake noise in an aircraft cabin were based on beneficial trends found from exercising the model. Implementation of the hardware modifications on the aircraft successfully suppressed the noise.

Links Between Disc Brake Squeal and Pad In-Plane Motion

2003 ◽  
Author(s):  
Fulun Yang ◽  
Valery Pilipchuk ◽  
Chin An Tan
Keyword(s):  
Degrees Of Freedom ◽  
Time History ◽  
Bending Moment ◽  
Dominant Frequency ◽  
Plane Motion ◽  
Mode Shapes ◽  
Theoretical Interpretation ◽  
Disc Brake ◽  
Brake Squeal ◽  
Friction Forces

This paper is focused on links between disc brake squeal and in-plane vibration of pads. A special experimental setup is developed in order to determine correlation between squeal acoustical signals and longitudinal accelerations of both pads. A strong coherence between spectral properties of squeal and pad vibrations is found and quantified. In particular, the dominant frequency of the acoustical and mechanical responses appears to be same. Essentially unharmonic temporal mode shapes of the pad vibrations are detected. Such mode shapes reveal the information about multiple frequency friction forces applied to the disc and pads with a possibility of resonance with their coupled elastic modes. Experimental time history records also show a significant out-of-phase component in the pad motions, which is associated with a bending moment applied to the disc. Major experimental observations admit theoretical interpretation based on a two degrees of freedom model. Theoretical conclusions and experimental results are found to be in a good agreement.

Structural Modification of Disc Brake Judder Using Finite Element Analysis

2012 ◽  
Vol 165 ◽  
pp. 68-72
Author(s):  
Matthias Edric Bengsoon ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Modification ◽  
Brake Disc ◽  
Disc Brake ◽  
Baseline Model ◽  
Element Analysis ◽  
Structural Modifications ◽  
Long Period ◽  
Commercial Software Package

Brake judder is a phenomenon of noise which its vibration can be felt physically by the driver of a vehicle. If this vibration is exposed to the driver for a long period it can lead to tiredness during driving. There are two types of judder which is cold judder and hot judder. This paper will be focusing on the hot judder. As a disc surface heats up during braking it causes both sides of the disc distort and hence produce a sinusoidal waviness around its edges. In this paper finite element analysis of hot judder is performed using a commercial software package, ABAQUS. An existing brake disc design is simulated and will be used as a baseline model. Various structural modifications made on the disc are proposed in an attempt to reduce brake judder in a disc brake assembly.

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