scholarly journals Stability Optimization of a Disc Brake System with Hybrid Uncertainties for Squeal Reduction

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Lü ◽  
Dejie Yu
Keyword(s):  
System Stability ◽  
Brake System ◽  
Disc Brake ◽  
Uncertain Parameters ◽  
Design Component ◽  
Optimization Constraints ◽  
Reliability Based Design ◽  
Uncertain Model ◽  
Interval Variables ◽  
Distribution Parameters

A hybrid uncertain model is introduced to deal with the uncertainties existing in a disc brake system in this paper. By the hybrid uncertain model, the uncertain parameters of the brake with enough sampling data are treated as probabilistic variables, while the uncertain parameters with limited data are treated as interval probabilistic variables whose distribution parameters are expressed as interval variables. Based on the hybrid uncertain model, the reliability-based design optimization (RBDO) of a disc brake with hybrid uncertainties is proposed to explore the optimal design for squeal reduction. In the optimization, the surrogate model of the real part of domain unstable eigenvalue of the brake system is established, and the upper bound of its expectation is adopted as the optimization objective. The lower bounds of the functions related to system stability, the mass, and the stiffness of design component are adopted as the optimization constraints. The combinational algorithm of Genetic Algorithm and Monte-Carlo method is employed to perform the optimization. The results of a numerical example demonstrate the effectiveness of the proposed optimization on improving system stability and reducing squeal propensity of a disc brake under hybrid uncertainties.

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.

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.

scholarly journals Three-dimensional CFD modeling of thermal behavior of a disc brake and pad for an automobile

2020 ◽  
Vol 15 (4) ◽  
pp. 543-549
Author(s):  
Haydar Kepekci ◽  
Ergin Kosa ◽  
Cüneyt Ezgi ◽  
Ahmet Cihan
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Elevated Temperatures ◽  
Gray Cast Iron ◽  
Three Dimensional ◽  
Brake System ◽  
Gray Cast ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Disc Material

Abstract The brake system of an automobile is composed of disc brake and pad which are co-working components in braking and accelerating. In the braking period, due to friction between the surface of the disc and pad, the thermal heat is generated. It should be avoided to reach elevated temperatures in disc and pad. It is focused on different disc materials that are gray cast iron and carbon ceramics, whereas pad is made up of a composite material. In this study, the CFD model of the brake system is analyzed to get a realistic approach in the amount of transferred heat. The amount of produced heat can be affected by some parameters such as velocity and friction coefficient. The results show that surface temperature for carbon-ceramic disc material can change between 290 and 650 K according to the friction coefficient and velocity in transient mode. Also, if the disc material gray cast iron is selected, it can change between 295 and 500 K. It is claimed that the amount of dissipated heat depends on the different heat transfer coefficient of gray cast iron and carbon ceramics.

Influences of Initial DTV on Thermomechnical Coupling in Disc Brake System

2017 ◽  
Author(s):  
Dejian Meng ◽  
Ziyi Wang ◽  
Lijun Zhang ◽  
Zhuoping Yu
Keyword(s):  
Brake System ◽  
Disc Brake

scholarly journals AGV Brake System Simulation

2019 ◽  
Vol 10 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Varecha ◽  
Robert Kohar ◽  
Frantisek Brumercik
Keyword(s):  
Mathematical Model ◽  
Input Data ◽  
Initial Conditions ◽  
Brake System ◽  
Disc Brake ◽  
Hydraulic Control ◽  
Stopping Distance ◽  
Braking Force ◽  
Braking Process ◽  
The Mathematical Model

Abstract The article is focused on braking simulation of automated guided vehicle (AGV). The brake system is used with a disc brake and with hydraulic control. In the first step, the formula necessary for braking force at the start of braking is derived. The stopping distance is 1.5 meters. Subsequently, a mathematical model of braking is created into which the formula of the necessary braking force is applied. The mathematical model represents a motion equation that is solved in the software Matlab by an approximation method. Next a simulation is created using Matlab software and the data of simulation are displayed in the graph. The transport speed of the vehicle is 1 〖m.s〗^(-1) and the weight of the vehicle is 6000 kg including load. The aim of this article is to determine the braking time of the device depending from the input data entered, which represent the initial conditions of the braking process.

No Breaks for Noise

1999 ◽  
Vol 121 (08) ◽  
pp. 62-63 ◽  
Author(s):  
Paul Sharke
Keyword(s):  
Brake System ◽  
Disc Brake ◽  
Brake Pedal ◽  
Passenger Compartment ◽  
Engine Noise ◽  
Master Cylinder ◽  
Noise And Vibration ◽  
Brake Pads ◽  
Mechanical Components ◽  
To Come

This article highlights the fact that engineers who design and test anti-lock brake systems (ABS) have been trying to come up with ways to minimize the noise and vibration that drivers hear and feel when they stomp on the brake pedals. The ABS engineers want drivers to do during a panic stop is to let their feet off the brakes. According to the engineers, braking should be the concern, because the less time the driver worries about stopping the car, the more time there is to concentrate on steering it. The mechanical components in both systems are functionally identical, consisting of a brake pedal, a master cylinder and booster, hydraulic lines and fluid, wheel calipers, brake pads, and rotors. In fact, unless the system is actuated by hard braking, ABS acts just like an ordinary disc brake system. Engine noise would only mask the ABS noise reaching the binaural head, which sits inside the passenger compartment where a driver would normally be.

Sign in / Sign up

Export Citation Format

Share Document