Dynamic Friction Heat Model for Disc Brake During Emergency Braking

2011 ◽  
Vol 4 (11) ◽  
pp. 3716-3720 ◽  
Author(s):  
Jiusheng Bao ◽  
Zhencai Zhu ◽  
Minming Tong ◽  
Yan Yin
Keyword(s):  
Disc Brake ◽  
Dynamic Friction ◽  
Friction Heat ◽  
Emergency Braking

Simulator Study of Heavy Truck Air Disc Brake Effectiveness During Emergency Braking

2008 ◽  
Author(s):  
Mohamed Kamel Salaani ◽  
Gary J. Heydinger ◽  
Paul A. Grygier ◽  
W. Riley Garrott
Keyword(s):  
Disc Brake ◽  
Emergency Braking ◽  
Heavy Truck ◽  
Simulator Study

Study on Influence of Air Pressure on Braking Condition

2005 ◽  
Author(s):  
D. Chen ◽  
P. Huang
Keyword(s):  
Friction Coefficient ◽  
Applied Load ◽  
Polymer Matrix Composite ◽  
Air Pressure ◽  
Experimental Results ◽  
Disc Brake ◽  
Temperature Peak ◽  
Brake Pads ◽  
Friction Heat ◽  
Disc Brakes

In the present paper, air pressure and temperature on the interface of the polymer matrix composite (PMC) brake pads are measured by disc brake under braking condition, and their influences are studied as well. The experimental results show that the air temperature peak is not as high as that on the surface. The air pressure of the interface varies with the applied load. The air pressure is negative under the small applied load, but positive under the large applied load. The analysis of the experimental results shows that the phenomena are caused by the friction heat and the rotate disc. Since the air pressure is very small comparing with applied load, it influences on the friction coefficient slightly. But, the negative air pressure of the interface increases the chance of the drag friction in the non-braking mode for disc brakes.

scholarly journals Numerical Modeling of Mine Hoist Disc Brake Temperature for Safer Operation

2021 ◽  
Vol 13 (5) ◽  
pp. 2874
Author(s):  
Florin Dumitru Popescu ◽  
Sorin Mihai Radu ◽  
Andrei Andraș ◽  
Ildiko Brînaș
Keyword(s):  
Raw Materials ◽  
Calculation Model ◽  
Scale Model ◽  
Temperature Threshold ◽  
Disc Brake ◽  
Emergency Braking ◽  
Drive Wheel ◽  
Real Material ◽  
Cable Drive ◽  
Mine Hoist

The sustainable exploitation of raw materials, with improved safety and increased productivity, is closely linked to the development of mechanical mining installations. Mine hoists are designed for the transport of material, equipment and personnel between the mine surface and the underground. The mine hoist braking system is of paramount importance in its safe operation. Thus, for both drum and disc brake systems, the temperature of the friction surfaces is important for ensuring efficient braking, as exceeding the temperature threshold causes a decrease in the braking capacity. In this paper we present a numerical calculation model for the temperature of the braking disc of a mine hoist in the case of emergency braking. A real-scale model was built, based on the cable drive wheel and disc brake system of a hoisting machine used in Romania. Real material characteristics were imposed for the brake discs, the cable drive wheel and the brake pads. The simulation was performed for decelerations of 3, 3.5, 4 and 4.5 m/s2. The analysis shows that regardless of the acceleration and time simulated, the disc temperature reaches its maximum after 1.35 s of emergency braking. This value does not exceed the 327 °C limit where, according to previous studies, the braking power starts to fade. It means that the emergency braking is safe for the acceleration and masses under consideration, in the case of the studied mine hoist.

scholarly journals Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091809
Author(s):  
Dagang Wang ◽  
Ruixin Wang ◽  
Jun Zhang
Keyword(s):  
Effective Mass ◽  
Coal Mine ◽  
Equivalent Stress ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Shoe ◽  
Brake Torque ◽  
Emergency Braking ◽  
Deep Coal Mine ◽  
Mine Hoist

Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist were investigated in the present study. The theoretical model of dynamic brake torque of disc brake during emergency braking was given to explore dynamic brake torque properties of disc brake. The three-dimensional thermo-mechanical coupled finite element model of brake disc–brake shoe was established to explore thermo-mechanical characteristics of disc brake during emergency braking. Effects of effective mass, hoisting acceleration and deceleration, and maximum hoisting speed on dynamic brake torques, equivalent von Mises stress, and temperature fields of disc brake during emergency braking were presented. The results show that the evolutions of brake torque, equivalent stress, and temperature of disc brake present fluctuating characteristics. The dynamic brake torque shows the largest change amplitude during emergency braking in the hoisting stage of constant speed. The largest equivalent stress and temperature are both located near the third brake shoe along the rotational direction at each side. An increase in effective mass causes overall decreases in the peak values of brake torque, equivalent stress, and temperature during emergency braking. Increases in hoisting acceleration/deceleration and maximum hoisting speed cause the increases in the maximum equivalent stress and temperature during emergency braking as compared to the slight decrease in the maximum brake torque.

scholarly journals Research on Contact Pressure Distribution of Pad

2018 ◽  
Vol 198 ◽  
pp. 01002
Author(s):  
Dong Chen ◽  
Guofeng Zou
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Working Condition ◽  
Great Influence ◽  
Element Model ◽  
Disc Brake ◽  
Contact Pressure Distribution ◽  
Structural Coupling ◽  
Emergency Braking ◽  
Force Characteristics

A simplified thermo-structural coupling finite element model of disc brake was developed. The contact pressure distribution of new pad was simulated under an emergency braking condition. The result shows that the contact pressure distribution of pad is not uniform when the new pad is in normal working condition. The inhomogeneity of the contact pressure is a critical cause of tangential partial wear. Compared the contact pressure distribution of new pad, uniform wear pad and tangential partial wear pad, the influence of wear amount and tangential partial wear on the contact pressure of pad was investigated. The results prove that the influence of wear amount on the contact pressure of pad is very small, while tangential partial wear has a great influence on the contact pressure of pad. The wear and force characteristics of pad are analyzed. The wear of its life cycle of pad is obtained, and the reliability and accuracy of the simulation are verified.

scholarly journals Optimal emergency vehicle braking control based on dynamic friction model

2005 ◽  
Vol 3 (01) ◽  
Author(s):  
L. Olmos ◽  
L. Álvarez-Icaza
Keyword(s):  
Optimal Control ◽  
Friction Model ◽  
Minimum Time ◽  
Dynamic Friction ◽  
Emergency Vehicle ◽  
Emergency Braking ◽  
Control Scheme ◽  
Time Optimal ◽  
Braking Control ◽  
Optimal Control Scheme

A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking of vehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking in minimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem. The final goal of the control is to improve the safety levels in highway transportation.

Simulation Study of Temperature Field and Stress Field of Disc Brake Based on Direct Coupling Method

2009 ◽  
Vol 628-629 ◽  
pp. 287-292 ◽  
Author(s):  
Xun Yang ◽  
Ji Xin Wang ◽  
J.C. Fan
Keyword(s):  
Temperature Field ◽  
Stress Field ◽  
Material Selection ◽  
Three Dimensional ◽  
Element Model ◽  
Direct Coupling ◽  
Coupling Method ◽  
Disc Brake ◽  
Emergency Braking ◽  
Sequential Coupling

In the process of automobile braking, the interaction between the temperature and the dynamic stress of disc brake is a very complex work. In order to simulate this problem accurately, a three-dimensional finite element model was built. Meanwhile the displacement and thermal boundary conditions for solution were determined, in which the coefficient of convection varies with the transient changing of temperature and time. The distributions of stress field and temperature field of the rotor and pads in an emergency braking were analyzed by the direct coupling method. The results of analysis prove that the thermal-structural direct coupling method can simulate the interaction between the stress field and the temperature field more exactly than the axisymmetric method and sequential coupling method do. The changing of stress field is mainly influenced by the temperature field. The results extracted from coupled simulation can give references for the material selection and structural designs in the development of disc brake.

Objective Characterization on the Dynamic Friction Coefficient of Disc Brake

2016 ◽  
Vol 59 (6) ◽  
pp. 1122-1133 ◽  
Author(s):  
Yan Yin ◽  
Jiusheng Bao ◽  
Xingming Xiao ◽  
Jinge Liu ◽  
Yuhao Lu
Keyword(s):  
Friction Coefficient ◽  
Disc Brake ◽  
Dynamic Friction ◽  
Dynamic Friction Coefficient
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