Dynamic Analysis of Dry Frictional Disc Brake System Based on the Rigid-Flexible Coupled Model

2015 ◽  
Vol 07 (03) ◽  
pp. 1550044 ◽  
Author(s):  
Yini Zhao ◽  
Qian Ding
Keyword(s):  
Critical Speed ◽  
Plate Theory ◽  
Coupled Model ◽  
Exponential Model ◽  
Brake System ◽  
Disc Brake ◽  
Transverse Displacement ◽  
Stick Slip ◽  
Coupling Case ◽  
Frictional Disc

A rigid-flexible coupled dynamic model is established to investigate the dynamic behaviors of a disc brake system. The analytical model of the pad includes transverse and circumferential displacements. The disc is modeled using the thin plate theory. A governing equation of the motion of the disc is established. Then the first-order vibration equation is obtained using Galerkin method, considering only the transverse displacement. The friction between the pad and disk among the contacting area is estimated using an exponential model, in which the Stribeck effect is included. Numerical method is applied to reveal the influences of coupling dynamical relationships between the pad and disc on the whole system. The results show that with the variation of disc annular speed, the pad keeps vibrating with small amplitude due to the sustaining variation of the contacting pressure and friction. Stick-slip flutter happens as the velocity is lower than a critical speed and strong movement coupling between elements of the system brings earlier occurrence of the frictional flutter. Besides, for strong movement coupling case, before the critical speed, there are intermittent frequency ranges among which the amplitude is quite higher, which is due to a redistribution of friction and contacting pressure.

Dynamic surface characteristics during disc brake squeal: non-linear modelling and simulation

2011 ◽  
Vol 225 (6) ◽  
pp. 1341-1348
Author(s):  
J Kang
Keyword(s):  
Contact Area ◽  
Travelling Wave ◽  
Friction Material ◽  
Brake System ◽  
Surface Pattern ◽  
Disc Brake ◽  
Dynamic Surface ◽  
Stick Slip ◽  
Non Linear ◽  
Lift Off

This article studies the non-linear dynamic behaviour of a disc brake system during squealing induced by a disc doublet mode. The disc brake system is modelled as a rotating annular plate in contact with annular sector-friction material. In order to investigate the possibility of detachment over the contact area between the disc surface and friction material during squealing, the lift-off condition is applied to this model. Also, the non-linearity arising from the contact stiffness is considered on the basis of the load–deflection test for the friction material. Numerical results show that the vibration after the onset of squeal reaches the limit cycle. In the steady-squealing response, several interesting phenomena are observed: the stick-slip and lift-off over the specific regime of the contact area. It is shown that the dynamic surface pattern rotates due to the forward travelling wave of the squealing surface. However, the mark of the surface pattern does not seem to move because the speed of the travelling wave fluctuates at a double frequency of squeal vibration.

Noise and vibration analysis of a disc–brake system using a stick–slip friction model involving coupling stiffness

2005 ◽  
Vol 282 (3-5) ◽  
pp. 1273-1284 ◽  
Author(s):  
Manish Paliwal ◽  
Ajay Mahajan ◽  
Jarlen Don ◽  
Tsuchin Chu ◽  
Peter Filip
Keyword(s):  
Vibration Analysis ◽  
Friction Model ◽  
Brake System ◽  
Disc Brake ◽  
Stick Slip ◽  
Noise And Vibration ◽  
Coupling Stiffness

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.

A closed form solution for bending/stretching analysis of functionally graded circular plates under asymmetric loading using the Green function

2010 ◽  
Vol 224 (6) ◽  
pp. 1153-1163 ◽  
Author(s):  
A R Saidi ◽  
A Naderi ◽  
E Jomehzadeh
Keyword(s):  
Green Function ◽  
Closed Form ◽  
Volume Fraction ◽  
Plate Theory ◽  
Closed Form Solution ◽  
Form Solution ◽  
Functionally Graded ◽  
Transverse Displacement ◽  
Circular Plates ◽  
Equilibrium Equations

In this article, a closed-form solution for bending/stretching analysis of functionally graded (FG) circular plates under asymmetric loads is presented. It is assumed that the material properties of the FG plate are described by a power function of the thickness variable. The equilibrium equations are derived according to the classical plate theory using the principle of total potential energy. Two new functions are introduced to decouple the governing equilibrium equations. The three highly coupled partial differential equations are then converted into an independent equation in terms of transverse displacement. A closed-form solution for deflection of FG circular plates under arbitrary lateral eccentric concentrated force is obtained by defining a new coordinate system. This solution can be used as a Green function to obtain the closed-form solution of the FG plate under arbitrary loadings. Also, the solution is employed to solve some different asymmetric problems. Finally, the stress and displacement components are obtained exactly for each problem and the effect of volume fraction is also studied.

Sharp Corner Functions for Mindlin Plates

2005 ◽  
Vol 72 (1) ◽  
pp. 1-9 ◽  
Author(s):  
O. G. McGee ◽  
J. W. Kim ◽  
A. W. Leissa
Keyword(s):  
Plate Theory ◽  
Thin Plates ◽  
Mode Shapes ◽  
Mindlin Plate ◽  
Transverse Displacement ◽  
Thick Plates ◽  
Thin Plate Theory ◽  
Mindlin Plate Theory ◽  
Moderately Thick Plates ◽  
Sharp Corners

Transverse displacement and rotation eigenfunctions for the bending of moderately thick plates are derived for the Mindlin plate theory so as to satisfy exactly the differential equations of equilibrium and the boundary conditions along two intersecting straight edges. These eigenfunctions are in some ways similar to those derived by Max Williams for thin plates a half century ago. The eigenfunctions are called “corner functions,” for they represent the state of stress currently in sharp corners, demonstrating the singularities that arise there for larger angles. The corner functions, together with others, may be used with energy approaches to obtain accurate results for global behavior of moderately thick plates, such as static deflections, free vibration frequencies, buckling loads, and mode shapes. Comparisons of Mindlin corner functions with those of thin-plate theory are made in this work, and remarkable differences are found.

Friction Induced Brake Vibrations at Low Speeds: Experiments, State-Space Reconstruction and Implications on Modeling

2006 ◽  
Author(s):  
Hartmut Hetzler ◽  
Wolfgang Seemann
Keyword(s):  
Classical Model ◽  
A Priori ◽  
Experimental Studies ◽  
Low Frequency ◽  
Disc Brake ◽  
Minimal Models ◽  
Stick Slip ◽  
Cast Doubt ◽  
Vibration Pattern ◽  
Embedding Methods

Today, low frequency disc-brake noises are commonly explained as self-sustained stick-slip oscillations. Although, at a first glance this explanation seems reasonable, there are indices that cast doubt on it. For instance, the basic frequency of the observed oscillations does not scale with the disc-speed as it is with stick-slip oscillations and the classical model does not explain the observed ending of the vibrations beyond a certain speed. Indeed, our experimental studies on groaning noises reveal two different vibration patterns: stick-slip vibrations at almost vanishing relative speed and a second, differing vibration pattern at low to moderate relative speeds. Yet, these two patterns produce a very similar acoustic impression. While the experiment provides a vast amount of data, the dimension and structure of the underlying oscillation is not known a priori – hence, constructing phenomenological minimal models usually must rely on assumptions, e.g. about the number of DOF, etc. Due to noise and complexity, the measured raw data did only allow for a first straight forward insight, rendering further analysis necessary. Hence, time-delay embedding methods together with a principle component analysis were used to reconstruct a pseudo-phase space together with the embedded attractor to analyse for the system's dimension and to separate signal from noise.

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