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Article
Publication date: 14 June 2013

Zhencai Zhu, Jiusheng Bao, Yan Yin and Guoan Chen

In order to improve the braking safety of mine hoisters, this paper aims to focus on the continuous repetitious emergency braking conditions to investigate an abnormal frictional…

Abstract

Purpose

In order to improve the braking safety of mine hoisters, this paper aims to focus on the continuous repetitious emergency braking conditions to investigate an abnormal frictional phenomena called “Frictional catastrophe (FC)” and its mechanisms.

Design/methodology/approach

The non‐asbestos brake shoe of a mine hoister was selected as frictional material and its paring material is 16Mn steel. The tribological properties of the brake shoe were tested on the pad‐on‐disc friction tester by the simulation of continuous emergency braking conditions. The thermal analysis experiments, the temperature field simulations and the SEM analysis of the brake shoe were accomplished to reveal the mechanisms of the FC.

Findings

It was found that the friction coefficient of the brake shoe sometimes falls suddenly during braking. This abnormal frictional phenomena is called “Frictional catastrophe (FC)”. It is considered that the friction heat, which is accumulated rapidly by the braking on the surface of the brake shoe, makes the surface layer material qualitatively change from the solid state to a mixed state composed of gases, liquids and solid. The frictional modality of the braking changes accordingly from dry friction to lubrication with gases and liquids. The sudden lubrication makes the friction coefficient fall suddenly and induces the FC phenomena.

Originality/value

An abnormal tribological phenomena called “Frictional catastrophe (FC)” was found in this paper. The investigations about the behaviors and mechanisms of the FC are considered helpful for improving the braking safety of mine hoisters and other machines.

Details

Industrial Lubrication and Tribology, vol. 65 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 15 June 2012

Jiusheng Bao, Zhencai Zhu, Minming Tong, Yan Yin and Yuxing Peng

The purpose of this paper is to describe some tribological experiments which were executed to find the influence of braking pressure on tribological performance of non‐asbestos…

Abstract

Purpose

The purpose of this paper is to describe some tribological experiments which were executed to find the influence of braking pressure on tribological performance of non‐asbestos brake shoe used in mine hoister during its emergency braking.

Design/methodology/approach

The WSM‐3 non‐asbestos brake shoe, which has been widely used in mine hoister, was selected as experimental material. Some tribological experiments of the brake shoe sliding on 16Mn steel were investigated on the X‐DM friction tester by simulating of emergency braking conditions of mine hoister. Three kinds of tribological indexes: friction coefficient, stability coefficient of friction coefficient, and wear rate were considered to score the tribological performance and the morphology of worn surfaces were observed through the S‐3000N scanning electron microscopy (SEM) to explore the tribological mechanisms.

Findings

It was found first, that the instant friction coefficient is not constant during emergency braking. After a short climbing period, it rises gradually to steady value. Second, with the increasing of braking pressure, the mean friction coefficient rises first then falls, while its stability coefficient falls gradually. The wear rate rises continuously with the braking pressure increasing. Also, the rising velocity of wear rate at high pressure is higher than it is at low pressure. Third, the instant surface temperature rises first then falls during braking and the mean surface temperature rises continuously with the braking pressure increasing.

Originality/value

It is found that the increasing of braking pressure within a certain range is helpful for achieving a high friction coefficient and a steady wear rate. But too high pressure will cause contrarily the falling of frictional performance and serious of wear performance. So it is not reliable to rise the braking pressure without limited during emergency braking.

Details

Industrial Lubrication and Tribology, vol. 64 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 25 September 2009

Bao Jiusheng, Zhu Zhencai, Yin Yan and Chen Guoan

The purpose of this paper is to find the influence of the initial braking velocity and braking frequency on the tribological performance of the non‐asbestos brake shoe used in mine

Abstract

Purpose

The purpose of this paper is to find the influence of the initial braking velocity and braking frequency on the tribological performance of the non‐asbestos brake shoe used in mine hoisters during some continuous emergency brakings.

Design/methodology/approach

The tribological performance experiments of the WSM‐3 non‐asbestos brake shoe braking on the 16 Mn steel are investigated on the X‐DM friction tester, by simulating continuous emergency brakings of a mine hoister ten times. Three kinds of tribological indexes: friction coefficient, its stability coefficient, and wearing rate are considered to score the tribological performance of the brake shoe.

Findings

When the initial braking velocity increases, the mean friction coefficient of the brake shoe decreases at first, then rises, and falls again finally. But when the braking frequency exceeds seven times, the falling process of the friction coefficient at low‐velocity period does not appear again. Second, when the initial braking velocity is no higher than 10 m/s, the mean friction coefficient rises with the braking frequency increasing. But when the velocity exceeds 10 m/s, the mean friction coefficient rises with the braking frequency increasing at first, then falls. Third, when the initial braking velocity is no higher than 12.5 m/s, the friction coefficient of the brake shoe has quite a favorable stability with the coefficient is no bigger than 75 percent. But when the velocity exceeds 12.5 m/s, the stability of the friction coefficient is diminishing obviously. Fourth, the wearing rate of the brake shoe increases quickly, during the process that the velocity rising from 10 to 12.5 m/s, but increases much more slowly after that period.

Originality/value

The paper investigates the tribological performance of the WSM‐3 non‐asbestos brake shoe during some continuous emergency brakings and finds that, when the initial braking velocity is no higher than 12.5 m/s and the braking frequency is no more than seven times, the WSM‐3 non‐asbestos brake shoe has quite a high friction coefficient, a good friction stability, and a low‐wearing rate, which indicate that it is very appropriate for using in the disk brake of mine hoisters in China.

Details

Industrial Lubrication and Tribology, vol. 61 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 February 2016

Yan Yin, Xingming Xiao, Jiusheng Bao, Jinge Liu, Yuhao Lu and Yangyang Ji

The purpose of this study is to establish a new temperature set for characterizing the frictional temperature rise (FTR) of disc brakes. The FTR produced by braking is an…

Abstract

Purpose

The purpose of this study is to establish a new temperature set for characterizing the frictional temperature rise (FTR) of disc brakes. The FTR produced by braking is an important factor which directly affects the tribological properties of disc brakes. Presently, most existing researches characterize the FTR only by several static parameters such as average temperature or maximum temperature, which cannot reflect accurately the dynamic characteristics of temperature variation in the process of braking. In this paper, a new temperature parameter set was extracted and the influences of braking conditions on these parameters were investigated by experiments.

Design/methodology/approach

First, several simulated braking experiments of disc brakes were conducted to reveal the dynamic variation rules and mechanisms of the FTR in braking. Second, the characteristic parameter subset of the FTR was extracted with five significant parameters, namely, initial temperature, average temperature, end temperature, maximum temperature and the ratio of maximum temperature time. Furthermore, the fitting parameter subset of the FTR was constructed based on the temperature rise curve. Finally, the influence and mechanisms of initial braking velocity and braking pressure on the new temperature parameter set were investigated through braking experiments.

Findings

This paper extracted a new temperature parameter set including a characteristic parameter subset and a fitting parameter subset and revealed the influences of braking conditions on it by experiments.

Originality/value

The results showed that the new temperature parameter set extracted in this paper can characterize the dynamic characteristics of disc brake’s FTR variations more objectively and comprehensively. The research results will provide a theoretical basis for extracting the fault feature of friction properties.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 19 July 2019

Shaodi Zhao, Yan Yin, Jiusheng Bao, Xingming Xiao, Zengsong Li and Guoan Chen

The friction between brake pair causes an intense temperature rise on interface during braking, which affects the braking performance seriously. Therefore, building an accurate…

Abstract

Purpose

The friction between brake pair causes an intense temperature rise on interface during braking, which affects the braking performance seriously. Therefore, building an accurate testing method for frictional temperature rise (FTR) is a prerequisite.

Design/methodology/approach

Facing braking conditions of automobiles, an experimental system for testing of FTR based on preset thermometry method (PTM) was established. The FTR was collected by the PTM and the variation laws as well as the cause of errors were analyzed by experiments. The deviations between tested and real temperature were corrected based on tribology and heat theories. Finally, an online prediction method for FTR was pointed out.

Findings

After correction, the temperature curve accords well with the laws of tribology and thermal theories. The corrected FTR at braking end point is approximately equal to the authentic temperature test by hand thermometer.

Originality/value

This study eliminated the hysteresis phenomenon of temperature rise sequence and lays a foundation for online accurate monitoring and warning of brake friction temperature rise. It has important theoretical and practical value for expanding the monitoring and improvement of brake performance.

Details

Industrial Lubrication and Tribology, vol. 71 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 January 2018

Jiusheng Bao, Yan Yin, Lijian Lu and Tonggang Liu

The purpose of this study is to establish an effective method for characterizing the tribological properties of friction brakes during continuous braking because they have direct…

Abstract

Purpose

The purpose of this study is to establish an effective method for characterizing the tribological properties of friction brakes during continuous braking because they have direct influences on the reliable operation of transport vehicles and industrial equipments.

Design/methodology/approach

First, tribological tests were carried out with the X-DM type friction tester, and changing curves of friction coefficient and temperature were obtained. Second, a novel tribological characteristic parameter set characterizing the tribological properties of brake pair in continuous braking was extracted from some important experimental data such as friction coefficient, wear rate and temperature. Finally, the influence of law and mechanism of braking number on dynamic tribological parameters was studied through continuous braking experiments.

Findings

The extracted tribological characteristic parameter set includes two subsets: dynamic characteristic parameter subset and overall characteristic parameter subset, which is composed of ten parameters: dynamic parameters of friction coefficient (including average, trend coefficient and stability coefficient), dynamic wear rate, dynamic average temperature, dynamic temperature rise, overall average friction coefficient, overall wear rate, overall average temperature and overall temperature rise.

Originality/value

Conclusively, the novel tribological characteristic parameter set is more comprehensive and objective, and it can provide a theoretical basis for the study of tribological properties in continuous braking.

Details

Industrial Lubrication and Tribology, vol. 70 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 29 January 2021

Xiaoyang Wang, Jiusheng Bao, Jinge Liu, Yan Yin, Tonggang Liu and Shaodi Zhao

This paper aims to develop of magnetic field controlled friction braking technology, a novel brake friction material with magnetic was designed and prepared in this paper.

Abstract

Purpose

This paper aims to develop of magnetic field controlled friction braking technology, a novel brake friction material with magnetic was designed and prepared in this paper.

Design/methodology/approach

The permalloy, a soft magnetic material, was selected as an additive to design and prepare the magnetic brake material. The friction, wear performance and permeability of each brake pads were investigated by experiments. By choosing the performance of friction coefficient fluctuation, friction coefficient deviation and mean wear rate as optimization parameters, the formulation of the magnetic friction material was optimized based on Fuzzy theory by using analytic hierarchy process methods and SPSS software.

Findings

The results showed that the developed soft magnetic friction material has not only superior friction coefficient, permeability and inferior wear rate but also good physical and mechanical properties.

Originality/value

Permalloy powder was added to the formulation of friction material to achieve a new functional friction material with high magnetic permeability. It is believed that this research will be of great theoretical and practical significance to develop both new brake materials and active control technology of the braking process in the future.

Details

Industrial Lubrication and Tribology, vol. 73 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 May 2020

Yan Yin, Heng Zhou, Jiusheng Bao, Zengsong Li, Xingming Xiao and Shaodi Zhao

This paper aims to overcome the defect of single-source temperature measurement method and improve the measurement accuracy of FTR. The friction temperature rise (FTR) of brake…

Abstract

Purpose

This paper aims to overcome the defect of single-source temperature measurement method and improve the measurement accuracy of FTR. The friction temperature rise (FTR) of brake affects braking performance seriously. However, it was mainly detected by single-source indirect thermometry, which has obvious deviations.

Design/methodology/approach

A three-point temperature measurement system was built based on three kinds of single-resource thermometry. Temperature characteristics of these thermometry were analyzed to achieve a standard FTR curve. Two fusion-monitoring models for FTR based on multi-source information were established by artificial neural network (ANN) and support vector machine (SVM).

Findings

Finally, the two models were verified based on the experimental results. The results showed that the fusion-monitoring model of SVM was more accurate than that of ANN in monitoring of FTR.

Originality/value

Then the temperature characteristics of the three single-source thermometry were analyzed, and the fusion-monitoring models based on multi-source information were established by ANN and SVM. Finally, the accuracy of the two models was compared by the experimental results. The more suitable fusion-monitoring model for FTR monitoring was determined which would be of theoretical and practical significance for remedying the monitoring defect of FTR.

Article
Publication date: 17 June 2021

Fikrat Yusubov

The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified…

Abstract

Purpose

The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified by N-Methylaniline.

Design/methodology/approach

Four different friction materials have been fabricated by varying modified phenolic resin content. The samples were prepared by the conventional powder metallurgy methods following ball milling, mixing, pre-forming, hot pressing and post-curing processes. Thermogravimetric analysis was used to determination of the degradation mechanism of organic components and study of thermal stability of the samples. A friction test was carried out in dry conditions using a vertical tribometer. Analysis of worn surfaces was performed using a scanning electron microscope.

Findings

The experimental results revealed that the sample containing 25 Wt.% phenolic resin has good mechanical and thermal properties with stable friction characteristics.

Originality/value

This paper presents the effect of N-methylaniline modified phenolic resin on friction composites to improve tribological performance by its thermal properties.

Details

Industrial Lubrication and Tribology, vol. 73 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 March 1980

The National Transportation Safety Board reported on 21st December 1979, that the American Airlines McDonnell Douglas DC‐10 stalled, rolled and crashed after takeoff in Chicago…

Abstract

The National Transportation Safety Board reported on 21st December 1979, that the American Airlines McDonnell Douglas DC‐10 stalled, rolled and crashed after takeoff in Chicago because of partial left wing slat retraction and the loss of two cockpit warning systems — all the end result of maintenance damage which caused separation of the left engine and pylon.

Details

Aircraft Engineering and Aerospace Technology, vol. 52 no. 3
Type: Research Article
ISSN: 0002-2667

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