scholarly journals Assessment of disc brake vibration in rail vehicle operation on the basis of brake stand

2021 ◽  
Vol 23 (2) ◽  
pp. 221-230
Author(s):  
Wojciech Sawczuk ◽  
Agnieszka Merkisz-Guranowska ◽  
Armando-Miguel Rilo Cañás
Keyword(s):  
Mass Distribution ◽  
System Component ◽  
Brake Disc ◽  
Imaging Method ◽  
Disc Brake ◽  
Lever System ◽  
Vehicle Operation ◽  
Lever Mechanism ◽  
The Right ◽  
Vibroacoustic Signals

The scientific aim of the article is to present the relationship between the vibroacoustic signals of the right and left friction pad during braking, depending on the mass distribution, as an element of the lever system. This article presents the results of tests of a railway disc brake in the scope of vibrations generated by pads in various states of wear located on both sides of the brake disc. The tests were carried out on the brake stand using the vibroacoustic method including the analysis of amplitudes and frequencies and the thermal imaging method. Special attention was paid to the analysis of the classic lever mechanism as a multimass system influencing the thermo-mechanical characteristics and vibrations of the pads on the right and left side of the brake disc. Uneven mass distribution of the system translates into uneven wear of the friction components. The scientific aim of this paper is to present the relation between vibroacoustic signals of the right and left friction pad during braking depending on the mass distribution of the lever system component.

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 ECG-gated dynamic magnetic resonance imaging method for examination of the pig heart

2001 ◽  
Vol 49 (3) ◽  
pp. 275-284
Author(s):  
Zs. Petrási ◽  
R. Romvári ◽  
G. Bajzik ◽  
B. Fenyves ◽  
I. Repa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Dynamic Magnetic Resonance Imaging ◽  
Imaging Method ◽  
Resonance Imaging ◽  
Dynamic Magnetic Resonance ◽  
Heart Cycle ◽  
The Right

A dynamic magnetic resonance imaging (MRI) method was developed for in vivo examination of the pig heart. Measurements were carried out on 15 meat-type pigs of different liveweight using a 1.5 T equipment. Inhalation anaesthesia was applied, then data acquisition was synchronised by ECG gating. Depending on the heart rate and heart size, in each case 8 to 10 slices and in each slice 8 to 14 phases were acquired prospectively according to one heart cycle. During the post-processing of the images the left and the right ventricular volumes were determined. The values measured at 106 kg liveweight are 2.5 times higher than those obtained at 22 kg, while the ejection fractions are equal. The calculated cardiac output values were 3.5 l (22 kg, 132 beats/min.), and 6.0 l (106 kg, 91 beats/min.), respectively. After measuring the wall thickness, the contraction values were also determined for the septum (70%), and for the anterior (61%), posterior (41%) and lateral (54%) walls of the left ventricle. Three-dimensional animated models of the ventricles were constructed. Based on the investigations performed, the preconditioning, the anaesthetic procedure, the specific details of ECG measurement and the correct MR imaging technique were worked out.

scholarly journals Influence of Disc Temperature on Ultrafine, Fine, and Coarse Particle Emissions of Passenger Car Disc Brakes with Organic and Inorganic Pad Binder Materials

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1060
Author(s):  
Hartmut Niemann ◽  
Hermann Winner ◽  
Christof Asbach ◽  
Heinz Kaminski ◽  
Georg Frentz ◽  
...  
Keyword(s):  
Systematic Variation ◽  
Coarse Particle ◽  
Brake Disc ◽  
Disc Brake ◽  
Aging Effects ◽  
Passenger Car ◽  
Particle Emissions ◽  
Inorganic Binder ◽  
Disc Brakes ◽  
Pm10 Emissions

Passenger car disc brakes are a source of ultrafine, fine, and coarse particles. It is estimated that 21% of total traffic-related PM10 emissions in urban environments originate from airborne brake wear particles. Particle number emission factors are in the magnitude of 1010 km−1 wheel brake during real-world driving conditions. Due to the complexity of the tribological processes and the limited observability of the friction zone between brake disc and pad, the phenomena causing particle emission of disc brakes are only partially understood. To generate a basis for understanding the emission process and, based on this, to clarify which influencing variables have how much potential for reduction measures, one approach consists in the identification and quantification of influencing variables in the form of emission maps. The subject of this publication is the influence of disc brake temperature on ultrafine, fine, and coarse particle emissions, which was investigated with a systematic variation of temperature during single brake events on an enclosed brake dynamometer. The systematic variation of temperature was achieved by increasing or decreasing the disc temperature stepwise which leads to a triangular temperature variation. Two types of brake pads were used with the main distinction in its chemical composition being organic and inorganic binder materials. The critical disc brake temperature for the generation of ultrafine particles based on nucleation is at approximately 180 °C for pads with an organic binder and at approximately 240 °C for pads with inorganic binder materials. Number concentration during those nucleation events decreased for successive events, probably due to aging effects. PM10 emissions increased by factor 2 due to an increase in temperature from 80 °C to 160 °C. The influence of temperature could be only repeatable measured for disc brake temperatures below 180 °C. Above this temperature, the emission behavior was dependent on the temperature history, which indicates also a critical temperature for PM10 relevant emissions but not in an increasing rather than a decreasing manner.

Experimental Study of Convective Heat Transfer in Standard and Cross-Drilled Brake Discs With Radial Vane and X-Lattice Cores

2018 ◽  
Author(s):  
Hongbin Yan ◽  
Shangsheng Feng ◽  
Wei-Tao Wu ◽  
Tian Jian Lu ◽  
Gongnan Xie
Keyword(s):  
Heat Transfer ◽  
Experimental Comparison ◽  
Brake Disc ◽  
Disc Brake ◽  
Cooling Performance ◽  
Flow And Heat Transfer ◽  
Brake Discs ◽  
Flow Through ◽  
The Cross ◽  
Transfer Mechanisms

To improve the cooling performance of disc brake systems, cross-drilled holes penetrating across the rubbing discs are separately introduced into a commercial radial vane brake disc (as reference) and a novel X-lattice cored brake disc. Prototype samples of both the reference and cross-drilled brake discs are fabricated. A rotating test rig is designed and constructed to characterize and compare the cooling performance of the brake discs with infrared thermography. Within the typical operating range of a vehicle, e.g., 200–1000 rpm, the experimental results show that the introduction of cross-drilled holes can substantially enhance brake disc cooling. For the radial vane brake disc, the overall Nusselt number is enhanced by 31%–44%; for the X-lattice cored brake disc, the cross-drilled holes only lead to 9%–18% enhancement. As the radial vane brake disc and the X-lattice cored brake disc with cross-drilled holes exhibit similar cooling performance, flow through the cross-drilled holes has a more prominent effect on the former than the latter. Corresponding fluid flow and heat transfer mechanisms underlying the enhanced heat transfer by cross-drilled holes and the different effects of cross-drilled holes on the two distinct brake discs are explored. The experimental comparison and the thermo-fluidic physics presented in this paper are beneficial for engineers to further improve disc brake cooling.

Optimizing Proportions of Railway Brake Discs by Temperature Transients Evaluation

1988 ◽  
Vol 202 (2) ◽  
pp. 91-99 ◽  
Author(s):  
S Missori ◽  
A Sili
Keyword(s):  
Thermal Cycle ◽  
Brake Disc ◽  
Disc Brake ◽  
Simple Method ◽  
Brake Discs ◽  
Brake Application ◽  
Dimensional Parameters ◽  
Maximum Temperatures ◽  
Commercial Size

When evaluating the performances of railway brake discs, the ability to accumulate and spread heat to the air plays a major role, since wear of synthetic lining and disc deterioration are strongly dependent on maximum temperatures attained on the surface in contact with the friction pad. The energy developed during brake application gives rise to an increase of disc temperature, which can be correlated to braking power, braking sequences and durations and to disc features. Maximum temperatures are attained on the friction surface of the disc. Determination of the thermal cycle subsequent to brake application can be considered preliminary to the study of lining and disc wear. The present work proposes a simple method using finite difference numerical analysis to evaluate the efficiency of the brake disc in dissipating the heat, both on a constant speed and an up-to-stop brake application. The effect of the various dimensional parameters, such as number of ribs, disc thickness and ribs width, is considered with the aim of achieving a first rough optimization of the required size of disc brake. The results related to a commercial size disc brake are given.

The Dynamics Simulation of Braking Process on Automobile Disc Brake

2010 ◽  
Vol 139-141 ◽  
pp. 2658-2661 ◽  
Author(s):  
Chuan Qi Fu ◽  
Zhou Wang ◽  
Bin Li ◽  
Chi Yu
Keyword(s):  
Initial Velocity ◽  
Dynamics Simulation ◽  
Brake Disc ◽  
Disc Brake ◽  
Stress Concentrations ◽  
Contact Algorithm ◽  
The Face ◽  
Improvement Measures ◽  
Braking Process ◽  
Dynamics Simulations

For a certain type of automobile disc brakes, brake discs and friction linings were modeled by Pro/E. The dynamics simulations of braking process on disc brake were performed by the frictional contact algorithm and nonlinear finite element method. Distribution of stress, strain and displacement on the brake parts were investigated with different initial velocity. Analysis results shown that redistributions of stress and strain had occurred on the face of brake disc and friction linings in braking process. Meanwhile, the increased initial velocity resulted in increased stress and stain. Besides the stress concentrations appeared in brake disc role and friction lining corners at the beginning of braking, however, stress and stain became uniform along the braking. Analysis results provided the research of the optimum design and testing of disc brake with theoretic gist. And some improvement measures to the structure of disc brake were proposed.

scholarly journals ANALYSIS OF MOTOR SPEED EFFECT ON WINDING TENSION IN THE WIND UP CALENDERING PROCESS

2019 ◽  
Vol 1 (1) ◽  
pp. 5-8
Author(s):  
Sugiyarto Sugiyarto ◽  
Widi Setiawan
Keyword(s):  
High Speed ◽  
Rolling Process ◽  
Manufacturing Industries ◽  
Internal Stresses ◽  
Disc Brake ◽  
Typical Characteristic ◽  
Motor Speed ◽  
Speed Effect ◽  
The Right ◽  
Winding Tension

The winding process is widely used in manufacturing industries. For the high speed winding, the centre winding method is used. Irregular internal stresses at the centre of the roll result in major weaknesses such as buckling, spoking and cinching. Therefore, entanglement with the right tension is very important to get a stable wound package. It should be mentioned that winders usually operate based on the principle of precision winding. A typical characteristic of winders is increasing the surface speed as the diameter increases. This will cause the winding to increase which has the potential to cause damage. To overcome damage due to an increase in roll tension, the rolling motor speed must decrease so that the roll tension remains the same or even decreases. And because the rolling process uses additional media in the form of a liner fabric which is tension controlled with pneumatic disc brake, the pressure brake must also be made taper constructing both.

scholarly journals Design and analysis of disc brake system in high speed vehicles

2021 ◽  
Vol 12 ◽  
pp. 19
Author(s):  
Anil Babu Seelam ◽  
Nabil Ahmed Zakir Hussain ◽  
Sachidananda Hassan Krishanmurthy
Keyword(s):  
Stainless Steel ◽  
Cast Iron ◽  
High Speed ◽  
Heat Dissipation ◽  
Optimal Choice ◽  
Grey Cast Iron ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Rotor ◽  
Grey Cast

Brakes are the most important component of any automobile. Brakes provide the ability to reduce or bring automobile to a complete stop. The process of braking is usually achieved by applying pressure to the brake discs. The main objective of this research paper is to propose an appropriate design and to perform analysis of a suitable brake rotor to enhance the performance of the high-speed car. The design of the brake disc is modelled using Solid works and the analysis is carried out using Ansys software. The analysis has been conducted by considering stainless steel and grey cast iron using same brake rotor design so that optimal choice of brake disc can be considered. The analysis considered involves static structural analysis and steady state thermal analysis considering specific parameters on brake rotor to increase the life of brake rotor. From the analysis it is found that the performance and life of disc brake depends upon heat dissipation. From the analysis results it can be concluded that grey cast iron has performed better as compared to stainless steel as this material has anti-fade properties which improves the life of the brake rotor.

Dynamics and Stability of a Nonlinear Brake Model

2001 ◽  
Author(s):  
Jörg Wauer ◽  
Jürgen Heilig
Keyword(s):  
Stability Analysis ◽  
Lyapunov Exponent ◽  
Nonlinear Model ◽  
Numerical Evaluation ◽  
Critical Speed ◽  
Initial Conditions ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Pad ◽  
The Stability

Abstract The dynamics of a nonlinear car disc brake model is investigated and compared with a simplified linear model. The rotating brake disc is approximated by a rotating ring. The brake pad is modeled as a point mass which is in contact with the rotating ring and visco-elastically suspended in axial and circumferential direction. The stability analysis for the nonlinear model is performed by a numerical evaluation of the top Lyapunov-exponent. Several parameter studies for the nonlinear model are discussed. It is shown that dynamic instabilities of the nonlinear model are estimated at subcritical rotating speeds lower than 10% of the critical speed. Further, the sensitivity of the nonlinear model to the initial conditions and the stiffness ratios is demonstrated.

scholarly journals Simulation Study on Friction and Wear Law of Brake Pad in High-Power Disc Brake

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
S. Zhang ◽  
Q. Hao ◽  
Y. Liu ◽  
L. Jin ◽  
F. Ma ◽  
...  
Keyword(s):  
High Power ◽  
Friction And Wear ◽  
Element Model ◽  
Calculation Model ◽  
Brake Disc ◽  
Disc Brake ◽  
Wear Depth ◽  
Brake Pad ◽  
Wear Calculation ◽  
Wear Law

For the serious and uneven wear of the brake pad in the high-power disc brake during braking, the dynamic variation of the brake disc and the brake pad interface variable is considered, the wear calculation model is established based on the friction and wear mechanism, and the wear depth and volume of the brake pad can be calculated by equations. A finite element model of the brake disc and the brake pad is established by DEFORM software which can analyze wear of the brake pad directly. The variation trend of wear during braking is studied, and influences of braking load and initial braking speed on the wear are analyzed. The results show that the amount of the wear increases rapidly in the early wear stage of braking, and it becomes slow in the later stage; the wear of the brake pad is serious at the friction inlet and outlet, and the middle area of the brake pad is lightly worn; heavy braking load and high initial braking speed can exacerbate the wear of the brake pad.

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