scholarly journals COMPARATIVE STUDY ON THE EFFECT OF FIBRE SUBSTITUTION ON THE PROPERTIES OF COMPOSITE RAILWAY BRAKE SHOE

2017 ◽  
Author(s):  
P. Wasilewski ◽  
M. Kuciej
Keyword(s):  
Comparative Study ◽  
Design Process ◽  
Glass Fibre ◽  
Laboratory Tests ◽  
Friction Material ◽  
Test Results ◽  
Steel Wool ◽  
Noticeable Effect ◽  
Brake Shoe ◽  
Friction Materials

During the design process, railway friction materials are subject to extensive testing which allows for a thorough assessment of their compliance with versatile requirements and expected characteristics. These tests include, among other, laboratory tests of mechanical, physicochemical, thermophysical and tribological properties. For a designer it is crucial to understand how formulation modification influences characteristics of the friction material. One of the key ingredients in the formulation of friction materials is reinforcing fibre. In this study, two composite, organic railway brake shoes with equal amount of two different reinforcing fibres, namely steel wool and glass fibre, were tested according to the procedures of a railway friction materials manufacturer. Test results were analysed and compared. The substitution of reinforcing fibre had a noticeable effect on each of the properties of the composites considered in this study.

scholarly journals Full-Scale Dynamometer Test of Composite Railway Brake Shoes – Study on the Effect of the Reinforcing Fibre Type

2018 ◽  
Vol 12 (3) ◽  
pp. 204-208 ◽  
Author(s):  
Piotr Wasilewski
Keyword(s):  
Thermal Conductivity ◽  
Glass Fibre ◽  
Steel Fibre ◽  
Friction Material ◽  
Full Scale ◽  
Test Results ◽  
Friction Materials ◽  
Average Temperature ◽  
The Difference ◽  
Dynamometer Test

Abstract When designing or developing friction materials, it is crucial to predict how the modification of the formulation will affect their properties. Fibres are introduced in the composition of the phenolic-based brake friction materials to improve their mechanical strength. Apart from reinforcing the composite, fibres can also affect its tribological and thermophysical properties. In this study two composite friction materials are compared. The difference between the materials was the type of reinforcing fibre used in the formulation – in one case it was glass fibre, in the other steel fibre. Thermal diffusivity of both materials was measured and thermal conductivity was calculated. Frictional characteristics determined by means of full-scale dynamometer tests are analysed and discussed. Substitution of glass fibre with steel fibre led to increase in the friction coefficient. Maximum average temperature below wheel surface, observed during the test of the material containing steel fibre, was lower as compared to the test results of the material with glass fibre in its formulation, despite higher heat flux in the course of brake applications. Thermal conductivity of the friction material was enhanced by including steel fibre in the formulation.

Application and comparative study of new optimization method for performance ranking of friction materials

2017 ◽  
Vol 232 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Vishal Mahale ◽  
Jayashree Bijwe ◽  
Sujeet Sinha
Keyword(s):  
Decision Making ◽  
Comparative Study ◽  
Decision Model ◽  
Evaluation Method ◽  
Multiple Criteria Decision Making ◽  
Optimization Method ◽  
Friction Material ◽  
Multiple Criteria ◽  
Friction Materials ◽  
Performance Ranking

Good friction materials should satisfy diverse and contradictory performance requirements such as adequate friction ( µ ≈ 0.35–0.45), resistance to wear, fade, squeal, judder, etc. in consort with good recovery and less noise producing tendency. To achieve center point of all these conflicting criteria and selection of best overall performing friction material is multiple criteria decision making (MCDM) problem and very difficult task. Decision maker can easily make decision with single criteria without the help of any optimization tool by maximizing beneficial criteria and minimizing non-beneficial criteria. However, it is extremely challenging task if decision making involves several number of conflicting criteria. Few techniques are reported in the literature such as ‘multiple criteria decision model’, ‘Multi-attribute decision model’, ‘extension evaluation method’ (EEM), etc. for performance ranking of friction materials. However, the simplicity, reliability, applicability, time devoted for the analysis, etc. are always most important aspects of selecting a right tool for the analysis. In this paper application of a technique ‘multiple objective optimization on the basis of ratio analysis’ (MOORA) has been first time employed for performance ranking of friction materials. A comparative study of MOORA and currently used methods MCDM and EEM are also presented. MOORA proved to be the best tool based on the criteria such as simple to use, fast, flexible, and efficient one.

scholarly journals Effects of the brake shoe friction material on the railway wheel damage

2018 ◽  
Vol 149 ◽  
pp. 01090 ◽  
Author(s):  
Abdelmajid Hamdaoui ◽  
El Houcine Jaddi
Keyword(s):  
Wear Rate ◽  
Dynamic Stability ◽  
Friction Material ◽  
Brake Shoe ◽  
Friction Materials ◽  
Railway Wheel ◽  
Railway Vehicles ◽  
Railway Axle ◽  
Critical Components

The wheels of a railway axle are the most critical components of a train. These wheels are subjected to several forms of deterioration, including wear, which significantly influences the safety of traffic as well as the dynamic stability of railway vehicles and the lifetime of wheelsets. The objective of this work is to compare the effect of two friction materials of brake shoes at the damage and the wear rate of the ER8 steel wheels.

Application of Metal Powder Metallurgy Technology in Prepartion of Friction Materials of the Railway Vehicles

2011 ◽  
Vol 287-290 ◽  
pp. 2987-2990 ◽  
Author(s):  
Feng Shang ◽  
Hai Xia Zhou ◽  
Bin Qiao ◽  
Hua Qiang Li ◽  
Yi Qiang He
Keyword(s):  
Powder Metallurgy ◽  
Metal Powder ◽  
Friction Material ◽  
Superior Performance ◽  
Electric Locomotive ◽  
Maglev Train ◽  
Brake Shoe ◽  
Friction Materials ◽  
Railway Vehicles ◽  
Brake Lining

With the speed up of the train, higher performance demands are put forward to the materials which have friction function. The friction materials produced by power metallurgy technology have a lot of advantages, such as good wear resistance, better thermal conductivity, bearing high lord, work reliably and so on. So they are used widely in the fields such as auto industry, aerospace and so on. The application of metal powder metallurgy technology in preparation friction materials of railway vehicles was researched in this paper, such as brake-shoe, brake lining of train braking, pantograph slide of electric locomotive, electrify boots slider of the maglev train and so on. This kind of friction material has superior performance and better prospects.

KARAKTERISASI KEAUSAN KOMPOSIT CANGKANG KEMIRI DAN TEMPURUNG KELAPA SEBAGAI BAHAN PEMBUATAN KAMPAS REM (BRAKE PAD)

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Juan Randy Simamora ◽  
Chandra Kurniawan
Keyword(s):  
Data Analysis ◽  
Wear Test ◽  
Friction Material ◽  
Test Results ◽  
Brake Pad ◽  
Friction Materials ◽  
Brake Pads ◽  
Reinforcing Fibers ◽  
Coconut Shells ◽  
Shell Powder

The research has been conducted on the use of candlenut shells and coconut shells as composite materials in the manufacture of brake pads. The design of friction composite formulations is carried out based on four classes of friction material namely fillers, binders, reinforcing fibers and property modifiers with a fixed percentage based on weight. Comparison of the composition of Candlenut shell powder and coconut shell for each sample S-01 (35: 25) wt .-%, S-02 (30: 20) wt .-%, and S-03 (25: 15) wt. -%. From the results of data analysis, the values of water absorption for each sample were S-01 (0.00706%), S-02 (0.000496%), S-03 (0.00584%). The lowest wear test was found in the S-03 sample of 3.67 x 10-5 g / mm2.s. The SEM-EDS test results show the distribution of particles in different friction materials for each sample and show that carbon is present in approximately equal amounts in all formulations. The predominance of the presence of metals in brake linings includes: iron (Fe), magnesium (Mg), carbon (C), and aluminum (Al), silicon (Si), potassium (K)

How to interpret borderline HCV antibody test results? A comparative study investigating four different anti-HCV assays

2013 ◽  
Vol 51 (01) ◽  
Author(s):  
B Maasoumy ◽  
B Bremer ◽  
R Raupach ◽  
P Lehmann ◽  
MP Manns ◽  
...  
Keyword(s):  
Comparative Study ◽  
Antibody Test ◽  
Test Results ◽  
Hcv Antibody

UJI TARIK HIDRODINAMIKMODEL KAPAL BERSAYAP WiSE DENGAN LAMBUNG DASAR BERSTEP

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Iskendar Iskendar ◽  
Andi Jamaludin ◽  
Paulus Indiyono
Keyword(s):  
Comparative Study ◽  
Model Test ◽  
Hydrodynamic Model ◽  
Surface Effect ◽  
Center Of Gravity ◽  
Test Results ◽  
Flat Bottom ◽  
Towing Tank ◽  
Test Models ◽  
Wetted Surface Area

This paper describes hydrodynamic model tests of Wing in Surface Effect (WiSE) Craft. These craft  was fitted with  stephull  form in different location on longitudinal flat bottom (stepedhull planning craft) to determine the influences of sticking and porpoising motion performances. These motions are usually occured when the craft start to take-off from water surfaces. The test models with scale of 1 : 7 were comprised of 4 (four) stephull models and 1 (one) non-stephull model  as a comparative study. The hydrodynamic  tests were performed with craft speed of 16 – 32 knots (prototype values) in Towing Tank at UPT. Balai Pengkajian dan Penelitian Hidrodinamika (BPPH), BPPT, Surabaya. The resistance (drag) was measured by dynamo meter and the trim of model (draft changing at fore and aft  of model due to model speed) was measured by trim meter. By knowing the value of model trim, the wetted surface area can be determined. Then, the lift forces were calculated based on these measured values. The model test results were presented on tables and curves.  Test results show that models  with step located far away from center of gravity of the WiSE craft tend to porpoising and sticking condition, except if the step location on the below of these center of gravity. While model without step tends to sticking conditions.

Experimental and Numerical Investigation of Critical Buckle Load of Composite Specimens

2015 ◽  
Vol 732 ◽  
pp. 85-90
Author(s):  
Lukáš Bek ◽  
Radek Kottner ◽  
Jan Krystek ◽  
Tomáš Kroupa
Keyword(s):  
Static Analysis ◽  
Glass Fibre ◽  
Large Deformations ◽  
Bending Test ◽  
Test Results ◽  
Beam Test ◽  
Three Point Bending ◽  
Box Beams ◽  
Buckle Beam ◽  
Thin Walled

Different carbon and glass fibre strips were subjected to the double clamp buckle beam test. Furthermore, thin-walled glass fibre box-beams were subjected to the three-point bending test. Results of experiments were compared to different numerical simulations using buckling analysis or static analysis considering large deformations.

Predicting abnormal laboratory blood test results in the intensive care unit using novel features based on information theory and historical conditional probability (Preprint)

2021 ◽  
Author(s):  
Camilo E. Valderrama ◽  
Daniel J. Niven ◽  
Henry T. Stelfox ◽  
Joon Lee
Keyword(s):  
Machine Learning ◽  
Intensive Care ◽  
Conditional Probability ◽  
Blood Test ◽  
Laboratory Tests ◽  
Conditional Entropy ◽  
Admission Diagnosis ◽  
Test Results ◽  
Abnormal Laboratory ◽  
Blood Tests

BACKGROUND Redundancy in laboratory blood tests is common in intensive care units (ICU), affecting patients' health and increasing healthcare expenses. Medical communities have made recommendations to order laboratory tests more judiciously. Wise selection can rely on modern data-driven approaches that have been shown to help identify redundant laboratory blood tests in ICUs. However, most of these works have been developed for highly selected clinical conditions such as gastrointestinal bleeding. Moreover, features based on conditional entropy and conditional probability distribution have not been used to inform the need for performing a new test. OBJECTIVE We aimed to address the limitations of previous works by adapting conditional entropy and conditional probability to extract features to predict abnormal laboratory blood test results. METHODS We used an ICU dataset collected across Alberta, Canada which included 55,689 ICU admissions from 48,672 patients with different diagnoses. We investigated conditional entropy and conditional probability-based features by comparing the performances of two machine learning approaches to predict normal and abnormal results for 18 blood laboratory tests. Approach 1 used patients' vitals, age, sex, admission diagnosis, and other laboratory blood test results as features. Approach 2 used the same features plus the new conditional entropy and conditional probability-based features. RESULTS Across the 18 blood laboratory tests, both Approach 1 and Approach 2 achieved a median F1-score, AUC, precision-recall AUC, and Gmean above 80%. We found that the inclusion of the new features statistically significantly improved the capacity to predict abnormal laboratory blood test results in between ten and fifteen laboratory blood tests depending on the machine learning model. CONCLUSIONS Our novel approach with promising prediction results can help reduce over-testing in ICUs, as well as risks for patients and healthcare systems. CLINICALTRIAL N/A

A Review on Non-Asbestos Friction Materials: Material Composition and Manufacturing

2018 ◽  
Vol 1150 ◽  
pp. 22-42
Author(s):  
Dinesh Shinde ◽  
Kishore N. Mistry ◽  
Suyog Jhavar ◽  
Sunil Pathak
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Single Phase ◽  
Friction Material ◽  
Material Surface ◽  
Surface Wear ◽  
Friction Modifier ◽  
Friction Materials ◽  
Morphological Studies ◽  
The Impact

The peculiar feature of friction materials to absorb the kinetic energy of rotating wheels of an automobile to control the speed makes them remarkable in automobile field. The regulation of speed cannot be achieved with the use of single phase material as a friction material. Consequently, the friction material should be comprised of composite materials which consist of several ingredients. Incidentally, the friction materials were formulated with friction modifier, binders, fillers and reinforcements. Due to its pleasant physical properties, asbestos was being used as a filler. Past few decades, it is found that asbestos causes dangerous cancer to its inhaler, which provides a scope its replacement. Several attempts have been made to find an alternative to the hazardous asbestos. The efforts made by different researchers for the impact of every composition of composite friction material in the field are reviewed and studied for their effect on the properties of friction material. Surface morphological studies of different friction material are compared to interpret the concept of surface wear and its correlation with material properties.

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