Browse Topic: Friction materials

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Regression Test 08/22/24 - Tatsiana twrtwtwSAE-PP-0944808/22/2024
QA Test
Mutagaana, Festo
Dynamic Mechanical and Thermal Properties of Polymer-Coated Jute Fibers for Enhanced Automotive Parts2024-01-501902/12/2024
Automobile parts often require materials that offer high strength and durability. With the continuous push for environmentally friendly solutions, natural fibers such as jute have emerged as a potential alternative for synthetic fibers in automobile components. In this study, we aim to enhance the properties of jute fibers by coating them with different polymers and assessing their suitability for automotive applications. We treated jute fibers with various polymers—low-density polyethylene, polyester, and araldite epoxy. The performance of these treated fibers was compared using fiber tensile experimentation, differential calorimetry, and dynamic mechanical evaluation. Our findings reveal that the treated jute fibers exhibit a tensile strength of 598 MPa. However, when coated with polymers, there’s a variance in strength: polyethylene (263 MPa), polyester (191 MPa), and epoxy (281 MPa). Among these, epoxy-coated fibers displayed the least tensile strength, while polyethylene-coated
Natrayan, L., Kaliappan, Seeniappan, Balaji, N., Mahesh, V.
Reliability prediction and demonstration for wear failure mechanism2024-26-032301/16/2024
This paper presents a methodology of integrating wear models in a system level model to assess the risk of failure in a field application, through endurance testing at the system level. Correlation of the wear prediction by the system-integrated wear model with actual measurement was performed and used to estimate the field operation reliability. Results are shown for sliding wear as well as impact wear phenomenon in this paper. The methodology adopted is to develop a system level dynamic model of its operation to capture the forces at the wear interfaces which is then integrated with Archard’s wear model. This model is then run using the system level sensor data captured during endurance testing to replicate the wear interface dynamics and predict the wear phenomenon. Since this wear cannot be measured during system operation, the effect of wear which results in a system level performance change is also modelled. This enables to track the actual system level performance change during
sr, Ranjith Kumar, Soma, Nagaraju
Tutorial: Building the Bridge Testing Measurement and Tribology1335210/12/2022
Different ingredients of the friction material have different effects on its tribological behavior, some of them conflicting and interfering among themselves (abrasives can increase performance, but also reduce lining life and cause overheating�). This tutorial will try to explain some of the features of dyno/vehicle tests that can be affected by friction materials, and what on the contrary is typically out of the scope of its characterization, and more pertinent to caliper, rotor or system functionalities. The goal is to give the audience an overview of how �chemists�, compounders, look at brake testing, and what they can learn when working on new developments. Outline: � Introduction (classes of raw materials, with their main effect & drawbacks to determine the main tribological effects: Friction level, wear, noise, thermals�) � A formulation approach to Design. Overview of design considerations based on the most relevant tests: how are formulators looking at these tests, to define
Schandelmeier, Brandie
Effect of Humidity Levels on the Compressibility of Automotive Brake Friction Materials2022-01-116409/19/2022
The load-deflection relationship of automotive brake friction materials (also known as “compressibility”) is a characteristic which may both influence and advise as to brake performance, including driver experience, noise and vibration behavior, and manufacturer quality control. It has been reported that changes in environmental humidity may significantly alter friction material compressibility in a formulation-dependent fashion – effects which are important considerations for testing protocols and real-world applicability. Greening’s presentation includes a rigorous investigation of humidity-dependent properties across differing friction materials and manufacturers, taking advantage of the high resolution and excellent repeatability of the Greening Model 1140 Compressibility Test Machine. Sets of brake pads from (at least) two different manufacturers and of varied material type (non-asbestos organic, semi-metallic, low-metallic, etc.) will be weighed to assess changes to moisture
Sendler, Edward, Greening, Brent, Greening, Chuck
Kinetics of Moisture Adsorption and Its Impact on Brake Pad Compression Modulus and Compressibility: Compression Modulus vs. Dynamic Modulus and Friction Variation2022-01-116509/19/2022
The kinetics of moisture adsorption is studied for copper-free brake pads. The pad weight gain is found to increase linearly with the square root of exposure time to humidity at a given temperature – the higher the humidity, the higher the weight gain. As the moisture content in the pad increases, the tangent modulus increases while the secant modulus decreases, resulting in decreasing compressibility associated with the tangent modulus of compression and increasing compressibility associated with the secant modulus of compression – compressibility defined as a reciprocal of compression modulus. Compression modulus and dynamic modulus are compared, and implications for friction coefficient variation are discussed. A rate constant of adsorption is proposed to define and compare moisture sensitivity of friction materials.
Rhee, Seong Kwan, Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra
A Novel Analytical Approach Using TOF-SIMS for Imaging the Distributed States of Constituent Components in Friction Materials2022-01-116209/19/2022
Friction materials are consisted of mixed organic and inorganic raw materials to achieve aimed brake performance and physical properties. In order to manufacture friction materials with stable quality, it is desired that these raw materials are uniformly dispersed, and at the same time it is important to understand the state of distribution during material developments. However, it is difficult for visualizing the dispersion of organic materials, and there are few reports of effective methods. In this study, a use of TOF-SIMS is established as a novel analytical approach for imaging the distributed states of constituent components in friction materials.
Kurimoto, Kenta, Shishido, Yuji, Shimada, Wataru Wyatt, Yaguchi, Mitsuaki
Investigation and Analysis of Brake Factor variation and its relation with Brake Pulling.2022-01-117109/19/2022
Vehicles pull during braking can be defined as the deviation of vehicle travel from intended path of the vehicle by a margin of half a wheel track or more. It is a dynamic phenomenon with very complex inter-dependencies among the combined functioning of various aggregates such as steering system, suspension system, axles, brakes. The problem is aggravated with shorter wheelbase & higher CG (Centre of Gravity) height, where the instantaneous load transfers are sudden and of relatively high magnitude which can lead to a combination of forces that are responsible for vehicle drifting or pulling to anyone side of center-line travel. Vehicle with shorter wheelbases, high GVW and high CG heights are more prone to this unstable behavior due to sudden change in dynamic forces acting on the tires while turning and braking. Although these vehicles have some disadvantages, they are required for important applications such as stage and intercity operations and hence cannot be stopped producing due
Pandey, Prashant, Pujari, Sachin, Nagrikar, Ravi
Uncertainty Quantification of Wet Clutch Actuator Behaviors in P2 Hybrid Engine Restart Process2022-01-079103/29/2022
Advanced features in automotive systems often necessitate the management of complex interactions between system components. To accomplish this task, closed-loop feedback is commonly used for effective real-time controls. Alternatively, open-loop schemes with adaptive parameters can be applied when real-time feedback is infeasible. Although these strategies possess certain levels of robustness, their performance can deteriorate in the presence of significant uncertainties, resulting in undesirable system behaviors. This limitation is often further amplified in systems with complex nonlinear dynamics. A hydro-mechanical clutch actuator is among those systems whose behaviors are highly sensitive to variations in sub-component characteristics and operating environment. In a P2 hybrid system, a wet clutch is utilized for cranking the engine during EV-HEV mode switching. It is critical that a controller is capable of stroking hydro-mechanical clutch actuator as quickly and as consistently as
Yang, Hang, Fujii, Yuji, Zhang, Yijing, Haria, Hiral, Devendran, Ram Sudarsan, Saini, Ankit, Gorodetsky, Alex, Wang, Kon-Well
Pseudo Transient Torque Converter Clutch Engagement Process Using Fluid-Structure Interaction Simulation2022-01-078103/29/2022
This investigation utilizes a correlated fluid-structure interaction (FSI) model of the torque converter and clutch assembly to perform a pseudo transient clutch engagement at steady state operating conditions. The pseudo transient condition consists of a series of nine steady state simulations that transition the torque converter clutch from fully released to near full lockup at a constant input torque and output speed representative of a highway cruising speed. The flow and pressured field of the torque converter torus and clutch are solved using a CFD model and then passed along to a transient structural model to determine the torque capacity of the lockup clutch. Bulk property assumptions regarding the friction material, deformation of the clutch plate and deflection of supporting structures were made to simplify the model setup, run time and solution convergence. Telemetry pressure measurements acquired in an operating torque converter under similar operating conditions on a
Beldar, Aniket, Robinette, Darrell, Blough, Jason
The Numerical Analysis of Brake Pad Related to The Properties of Composite Brake Pad Friction Material.2022-01-036503/29/2022
This project outlines the effect of changing Young’s modulus, Poisson’s ratio, and shear modulus on the natural frequencies of brake pads. It aims to improve the understanding of the influence of friction material properties on the natural frequencies and observe how the natural frequency changes with the changes in the properties of the composite brake pad friction material. In addition, two different brake pad models (Pad-A and Pad-B) were designed using CATIA V5 software to study whether different pad aspect ratios can affect the influence of friction material properties on the natural frequencies. The finite element analysis (FEA) was utilized to derive the natural frequencies and mode shapes using ABAQUS software. In addition, an experimental modal analysis (EMA) was performed on Pad-A to evaluate the accuracy of the FEA. Furthermore, the factorial analysis was applied on the obtained natural frequencies for each pad to find out the material properties that have the main effect on
Ravanbod, Mohammad
Brake Lining Quality Test ProcedureJ661_202110 (Current)10/26/2021
The purpose of this SAE Recommended Practice is to establish a uniform laboratory procedure for securing and reporting the friction and wear characteristics of brake linings. The performance data obtained can be used for in-plant quality control by brake lining manufacturers and for the quality assessment of incoming shipments by the purchasers of brake linings.
Brake Linings Standards Committee
Sensor-controlled Friction Materials based on Liquid Friction Compounds, Chip-in-Pad Concept2021-01-129610/11/2021
In this paper, the concept of integrating thin-film piezo transducers into friction pads by using a liquid friction material compound (LIQFRIC® HP), which is capable of completely embedding the sensor surface and allowing for the force transfer due to a direct contact between sensor and friction material, is explained. The low thickness of the sensor allows for an excellent ratio of sensor volume / friction volume in the pad. The piezo transducer, besides being able to detect positive and negative pressure changes, can also be used via its EMI capability to allow measurements of changes in the shape (and therefore thickness) of the pad during and after testing. Measuring the pressure distribution, the wear and possible defect situations of the pad potentially opens up new means of friction pad- and brake operations or developments.
Milczarek, Roman Paul
Chemistry of the Brake Emissions: Influence of the Test Cycle2021-01-130010/11/2021
The reliable chemical characterization of non-exhaust emissions generated by brakes is of fundamental importance in order to provide correct information for source apportionment studies as well as for their toxicological and environmental assessment. Nowadays, the best option to obtain samples of PM10 emissions composed only by material worn from the tribological interface, i.e. the braking disc (BD) and the friction material (FM) rubbing surfaces, is to sample them on suitable collection filters at a dedicated dyno-bench, during a standard braking test cycle. In particular, the use of enclosed dyno-bench is necessary for excluding other spurious contributions from the environment, while defined test cycles are necessary to simulate standard driving conditions. Nevertheless, different braking cycles are usually characterized by different overall temperature profiles or energy parameters, which in the end have significant influence on the wear and the oxidation of the materials involved
Mancini, Alessandro, Tsyupa, Bozhena, Pin, Sonia, Bandiera, Marco, Bertasi, Federico, Federici, Matteo, Bonfanti, Andrea, Perricone, Guido, Gigli, Lara, Bolzacchini, Ezio
Divergence of Thickness Losses and Weight Losses of Disc Pads for Passenger Cars: High-Copper NAOs and Copper-Free Low Mets2021-01-129010/11/2021
The current investigation was undertaken to find out if lighter-weight passenger car disc pads would exhibit wear behaviors similar to pickup truck pads and commercial heavy truck drum linings in terms of the permanent volume expansion of the friction material contact surface region. 2 high-copper NonAsbestos Organic formulations and 3 copper-free LowMet formulations were tested according to the SAE J2522 test procedure. In all cases, the measured pad thickness loss was found to be less than the thickness loss calculated from the weight loss, indicating pad volume expansion in the pad surface region, in full agreement with the results from the pickup truck and heavy trucks. The heataffected swollen/expanded layer ranges from 0.27 to 0.61 mm in thickness depending on the formula and test conditions. Due to the expansion, pad durability projections made from test results based on high temperature city traffic tests can result in underestimating the actual durability. Also, one needs to
Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra, Rhee, Seong Kwan
A Molecular Dynamics Study of Tribological Properties of Silicon Carbide as a Metal-Free Friction Material2021-01-128410/11/2021
Friction materials containing metal ingredients used in the automotive industry can cause unfavorable environmental impacts. Existing laws and regulations require heavy metals in brake pads to be phased out of production. Substitutions for metals in friction materials, however, may introduce operational safety issue and other unforeseen problems. In the current study, a molecular dynamics model based on LAMMPS has been developed to study the effect of material composition, density, and geometric configurations on the tribological, mechanical, and thermal properties of silicon carbide under various contact conditions at the atomic level. Simulations which incorporate interfacial contact between surface asperities were performed to predict the elastic modulus, thermal conductivity, wear rate, and coefficient of friction. The resulting predicted properties may help enhance the performance of engineered metal-free friction materials against thermal-mechanical failures. The following
Zhang, Yizhan, LeNeave, Cortney, Yi, Yun-Bo
Effect of Material Anisotropy on Thermal-Mechanical Instabilities in Metal-Free Friction Materials2021-01-128910/11/2021
An anisotropic ceramic matrix composite (CMC), which consists of a silicon carbide (SiC) based ceramic matrix reinforced with carbon (C) fibers, is considered as a metal-free friction material replacement in brake and clutch applications. The fibers are assumed to have a circular cross-section, arranged unidirectionally and packed in a rectangular array without the presence of voids. The rule of mixture showed the C-SiC composite to be transversely isotropic with the circumferential plane as the plane of isotropy. A set of parametric studies have been performed to computationally investigate the dominant parameters that affect thermal-mechanical instabilities. It is found that the chance of thermal buckling in the friction disc can be minimized by reducing the elastic moduli in the radial and circumferential directions, or by reducing the coefficient of thermal expansion in the same directions. Meanwhile, the material properties in the axial direction do not have a significant effect
Shaahu, Joseph-shaahu, Koranteng, Kingsford, Yi, Yun-Bo
Thermomechanical Instabilities in Metal-Free Friction Materials Using a Nonlinear Transient Simulation Approach2021-01-128610/11/2021
The invention of metal-free friction materials is gaining popularity in the manufacturing of brake pads and clutch friction discs because of the negative factors associated with metals such as copper. To gain more insight into the failure mechanism of the recent invention during brake or clutch applications, a nonlinear transient thermomechanical model is established using Finite Element Code. The model is based on a two-dimensional configuration for an investigation on the onset of TMI (Thermo-Mechanical Instability) during sliding contact in such material. The model is validated by comparing the transient simulation results for a full-contact regime to the result from the existing eigenvalue method. A parametric study is carried out to examine how the thermal conductivities and the elastic moduli influence TMI. The simulation results show that the thermal conductivities in the transverse direction and elastic moduli in the longitudinal direction can stabilize the system. Conversely
Koranteng, Kingsford, Shaahu, Joseph-shaahu, Yi, Yun-Bo
Investigation of the Rational Area of Friction Surfaces in Contact of Friction Linings for Disc Brakes of Passenger Cars2021-01-129510/11/2021
It is important for assessing the service life of the braking mechanisms of passenger cars that are in operation is the establishment of the speed and the value of the permissible wear of the friction surfaces, which ensures the durability of the brake. The purpose of the study is to assess effect of area friction surfaces on resource of vehicle braking mechanisms. This will extend the service life of the disc brakes on cars. In the work, the regularities of wear of mating parts of disc brakes were established depending on the change in the geometric parameters of the friction surfaces and operating modes during their operation. It was found that the service life of disc brakes can be increased by 1.16 times with an increase in the area of frictional contact by 15 %, for passenger cars DAEWOO LANOS and LADA PRIORA. A comparative assessment of the wear of the new DAEWOO LANOS and LADA PRIORA brake pads, which perform cyclic emergency braking, is provided. Recommendations have been
Nazarov, Aleksandr, Krivoshapov, Sergey, Misyura, Nikolay, Belov, Valentin, Zuiev, Vladimir, Nazarov, Ivan, Sergienko, Nikolay
Investigation on brake disc deformation under asymmetric mechanical loads2021-01-129110/11/2021
The mechanism of automobile brake hot spots is unclear, which is a problem in the brake industry. Complex coupling between friction, heat, contact, and structural is the main difficulty in revealing the mechanism of brake hot spots. This paper proposes a new way to study the mechanism of hot spots by analyzing the deformation behavior of brake discs under asymmetric mechanical load. The actual brake is simplified into a brake disc and friction lining system, and a transient dynamic finite element model under asymmetric mechanical loads is established to analyze the deformation characteristics of brake disc. It is found that the normal deformation of the brake disc under asymmetric mechanical loads consists of two parts: low-frequency bending deformation and high-frequency waviness deformation, which are caused by the squeezing effect of the asymmetric brake pressure on the brake disc and the constraint modal vibration of the brake disc. The influence of rotation speed, the magnitude
Meng, Dejian, Tong, Yongsheng, Zhang, Lijun
A Unique Methodology to Evaluate the Metallic noise concern of a Dual-Mass Flywheel Under Real-World Usage Conditions2021-28-024910/01/2021
Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMFs are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the robustness of the DMF. In the present work, a new methodology is developed to evaluate the robustness of a DMF capturing the RWUP conditions fitted in a Sports utility vehicle (SUV) with front-wheel drive architecture. During engagement of clutch system, enormous amount of energy is dissipated. To sustain the operating temperature of the clutch system, generated energy is dissipated through conduction & convection. If the temperature of the clutch friction material is not retained, clutch burning & burst failures happens. Ventilation holes are provided on clutch housing to improve convective heat transfer. During rainy season in
S, Kesavprasad, M, Sudhan, Vijayarangan, Deepak, Rai, Vikas
An experimental approach to monitor the clutch thermal condition to increase the clutch life2021-28-028110/01/2021
One of the top problems that every Indian automobile manufacturer struggles to manage is the clutch early failure less than 30000 Km. This is mainly due to the extreme heating of the friction lining due to the real-world user profile in the Indian market and users inappropriate driving behaviors like Overloading the goods more than the manufacturer’s recommendation, Non recommended attachments and increased wheel size, Thick traffic leading to high level of clutch modulation and Clutch riding while running and launching the vehicle at higher gears. Although many simulation and testing are done during the development phase, above listed real world user profile and customer driving habits are inevitable by any automobile manufacturer. Hence the prime goal of this experimental research is to indicate or alert the user on the clutch thermal condition due to the driving habit and to encourage the user on right driving habits. This objective is met through an stand alone electronic system
M, Sudhan, B, Vasanthan
Brake Groan Noise Investigation and Optimization Strategy for Passenger Vehicles2021-26-030109/22/2021
Groan is a low frequency noise generated when moderate brake pressure is applied between the surfaces of the brake disc and the brake pad at a low-speed condition. Brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components are excited by the brake system and result in a violent event that can be heard and felt during brake application. The cause of noise is friction variation of stick-slip phenomenon between friction material and disc. This paper discusses the approach for prediction and mitigation of brake groan noise for passenger vehicles having disc brakes. To identify the brake groan noise frequency, vehicle testing with operating condition for reproducing the groan noise is carried out and also impact frequency response analysis is performed to identify natural frequency of each chassis component like brake, suspension stud, lower control arm, knuckle etc. The finite element corner
Doundkar, Vikas, Iqbal, Shoaib
Slip energy evaluation for a conventional friction clutch2021-26-048009/22/2021
The importance of clutch in a vehicle’s performance is not new to the automotive, commercial or agricultural sectors. So is the importance of the clutch life when it comes to the durability of a vehicle. In process of making the machines more and more efficient, one can observe a steady reduction in the overall mass of the vehicle and the parts in it. While the parts were heavier, and the friction lining surfaces were more than adequate, the life of clutch has been the best. But with reduction of the overall masses, the energy has lesser amount of sink to dissipate and is being liberated in the form of heat, rising the overall temperatures. This leads to an early wear or even a burn in the clutch. In such scenario, it is necessary to estimate accurately the energy dissipation through a defined cycle to understand the clutch performance. Although different methods exist to evaluate energy, most cases include obtaining a high amount of sophisticated data. This paper discusses a simpler
Alavilli, Satya Pavan, KADHAR MAIDEEN, SALIM MALIK
Customized and market specific thermal robust clutch system solution2021-01-123909/21/2021
The goal of reducing fuel consumption and CO2-Emission is leading to turbo-charged combustion engines that deliver high torque at low speeds (down speeding). To meet NVH requirements damper technologies such as DMF (Dual Mass Flywheel) are established, leading to reduced space for the clutch system. Specific measures need to be considered if switching over from SMF (Single Mass Flywheel) to DMF. It has an impact on thermal behavior of the clutch system for example due to reduced and different distribution of thermal masses and heat transfer to surroundings. Taking these trends into account, clutch systems within vehicle power-trains are facing challenges to meet requirements e.g. clutch life, cost targets and space limitation. Clutch development process must ensure to deliver a clutch system that meets requirements taking boundary conditions such as load cycles and driver behavior into account. Relevant load cycles are derived based on feedback & an analysis of driver behavior under
Kapse, Ravi Ramesh, Lakshminarayanan, Saravanan, Németh, Ákos, Thakare, Ankit, Bernhardt, Johannes
Test Method for Catalytic Carbon Brake Disk OxidationAIR5567A (Current)09/16/2020
The scope of the test method is to provide stakeholders including fluid manufacturers, airport operators, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This simple test is only designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions. It is not possible to set a general acceptance threshold oxidation limit based on this test method because carbon brake stack oxidation is a function of heat sink design and the operating environment.
A-5A Wheels, Brakes and Skid Controls Committee
Truck and Bus Grade Parking Performance Test ProcedureJ360_202008 (Current)08/19/2020
This SAE Recommended Practice establishes methods to determine grade parking performance with respect to: a. Ability of the parking brake system to lock the braked wheels. b. The vehicle holding or sliding on the grade, fully loaded or unloaded. c. Applied manual effort. d. Unburnished or burnished brake lining friction conditions. e. Down and up grade directions.
Truck and Bus Brake Systems Committee
On Prediction of Automotive Clutch Torsional Vibrations2020-01-150806/03/2020
Automotive clutches are prone to rigid body torsional vibrations during engagement, a phenomenon referred to as take-up judder. This is also accompanied by fore and aft vehicle motions. Aside from driver behaviour in sudden release of clutch pedal (resulting in loss of clamp load), and type and state of friction lining material, the interfacial slip speed and contact temperature can significantly affect the propensity of clutch to judder. The ability to accurately predict the judder phenomenon relies significantly on the determination of operational frictional characteristics of the clutch lining material. This is dependent upon contact pressure, temperature and interfacial slip speed. The current study investigates the ability to predict clutch judder vibration with the degree of complexity of the torsional dynamics model. For this purpose, the results from a four and nine degrees of freedom dynamics models are compared and discussed. Subsequently, the predictions are compared with
Gkinis PhD, Theofilos, Rahmani, Ramin, Rahnejat, Homer
Model-Based Brake Disc Temperature Prediction on High Speed Testing Mode and Circuit2020-01-021404/14/2020
A brake is a mechanical device that inhibits the motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by friction energy. Commonly, most brakes use friction between two surfaces pressed together to convert the kinetic energy of the moving object into heat, though other methods of energy conversion may be employed. If braking is repeated or sustained in high load or high-speed conditions, the motion will be unstable and can lead to a loss of stopping power because the disc capability for braking is not enough. These phenomena are generally defined as brake fading. Brake fade is caused by an overheating brake system. This paper describes the thermal modeling and process to predict the disk temperature under a condition which causes the fade characteristics. Also, the model of disc temperature prediction developed with consideration of acceleration and deceleration from the
Jeong, PilYoung, Lee, Jaekil, Oswald, Mario, Kellner, Stefan
Optimized Wet Clutch Design2019-32-055301/24/2020
Multi-plate wet clutches used in motorbikes transmit the torque by friction under pressure between driving and driven Plates. The life & performance of the clutch for the friction material used, depends on amount of energy generated during clutch slip, amount & uniformity of heat dissipation amongst the plates and surface texture of mating surfaces. Above parameters if not properly considered during design stage may lead to higher temperature of rubbing surfaces. Higher temperature further reduces the friction coefficient and increases the wear rate of friction material leading ultimately to lower torque capacity of clutch. The temperature rise in a wet clutch is the balance between amount of heat generated and the amount of heat dissipated by oil flowing through clutch. The maximum amount of oil is limited by the requirement of clutch drag torque, Which decides the quality of neutral finding and gear shift feel on vehicle. Further, if roughness of rubbing surfaces is not controlled in
Bhone, Nitin, Thakare, Sachin, Jahagirdar, Ashutosh
Independent Aftermarket (IAM) and the Three Dimensions of Friction Material Evaluation2019-36-000601/13/2020
It is well known the difference between development levels and engineering investment applied to passenger car brake pads when compared to Original Equipment Manufacturer (OEM) and items sold in the Independent Aftermarket (IAM). Based on these differences, the objective of this paper is to propose a simple evaluation for the IAM that can provide at least some level of the understanding of frictional material behavior. Based on a tripod of variables, or three Dimensions Development, described in this work as Performance, Comfort (NVH) and Durability; and using internationally and established testing procedures to measure these dimensions in order to meet the IAM demands for the cost-benefit engineering investment. An important part of the proposed tool is to position friction material against competition for market known issues, and, more importantly, to ensure end product safety and reliability.
Oliveira, Pedro, Rodrigues, Henrique, Ferro, Eduardo
Prediction of Friction Durability in Off-Road Applications Based on Mechanistic Understanding of the Effects of Fluids and Surfaces on Clutch Friction2019-01-233912/19/2019
After new transmission lubricants are developed there is an extensive validation program where friction durability testing is performed on multiple clutch materials. Each durability test can run for long terms and the entire validation program can take much longer terms. A well designed lubricant and friction material will deliver the necessary friction control for construction equipment to operate at optimum level. A mechanistic construct has been evaluated to calculate friction durability in clutch systems based on fluid and surface tribological properties. Fluid properties include both boundary frictional and rheological effects. Surface properties include elastic modulus, surface roughness, asperity density and asperity tip radius. Using this mechanistic construct friction durability has been predicted. In the past, researchers in the field have often associated lubricant induced glazing of the friction material surface as the cause of the loss of friction control in clutch systems
Devlin, Mark, Adhvaryu, Atanu, Cameron, Timothy, Kariwa, Shinpei, Abekawa, Toshiharu
Road Vehicles - Friction Materials - Finished Brake Pad Normalized Elastic Constant of Friction MaterialJ3175_201911 (Current)11/20/2019
This SAE standard specifies a method for testing and measuring a normalized elastic constant of brake pad assemblies using ultrasound. This document applies to disc brake pad assemblies and its coupons or segments used in road vehicles.
Brake Linings Standards Committee
Exploration of Dry Sliding Wear Behaviour of Sisal Fiber Reinforced Cashew Nut Shell Liquid and Epoxy Polymer Matrix Composite as an Alternative Friction Material in Automobiles2019-28-017310/11/2019
The brake pad is one of the foremost imperative parts of the vehicle. Due to the environmental requirement, natural materials were the alternate source for products manufacturing. The product composite made by using hot press techniques with mixing ingredients such as natural fiber (treated sisal), cashew nut filler, graphite and alumina with resin (cashew nut shell liquid - CNSL and epoxy). Two formulas and four samples of each set were composed by varying the resin type of CNSL and epoxy and prepared the test samples with attaining better hardness. The main intern of this proposed effort is to appraise the wear in dry sliding and performance of friction of the prepared composites. The composites are taken for tribo test by varying the load of 10,20,30,40 N and sliding distance of 1000, 2000 m respectively. Experiments were performed at stated process parametric conditions to record the responses. The result shows that the CNSL resin composites specific wear resistance and frictional
Ranganathan, Soundararajan, Gopal, Shanthosh, Magudeeswaran, Tharunkumar, Rangasamy, Ramamoorthi
Aging Effect on Disc Pad Properties2019-01-210809/15/2019
One low-copper formulation and one copper-free formulation were made into disc pads, and both of them were cured under 4 different conditions. These pads had no backing layer and no scorched layer. Pad thickness, dynamic modulus and natural frequencies were continuously monitored over a period of 12 months. After 12 months at room temperature, pad thickness, dynamic modulus and natural frequencies all increased to higher values. The low-copper formulation increased relatively rapidly during the first 60 days and the copper-free formulation increased relatively rapidly for the first 90 days, and then slowly thereafter. Two competing processes are found to be taking place simultaneously; internal stress relief leading to pad expansion and cross-linking of the resin leading to pad shrinkage. As the pad properties are changing continuously, the timing of property measurement becomes an important issue for quality assurance. Implications of these changing properties are discussed for
Sriwiboon, Meechai, Rhee, Seong K., Kaewlob, Kritsana, Tiempan, Nipon
Divergence of Thickness Loss vs. Weight Loss, Friction and Wear Behavior of Heavy Truck Brake Blocks: Development of a New Test Procedure for the Chase Tester2019-01-210709/15/2019
Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.
Rathee, Aman, Sharma, Devendra Kumar, Singh, Shivraj, Rhee, Seong Kwan
Objective Method for Crack Detection in Brake Friction Material2019-01-211309/15/2019
Friction material manufacturing is a complex process where numerous raw materials are mixed, pressed, and cured to make brake pads. It is important to have a consistent manufacturing process that can produce a brake pad that satisfies the vehicle braking requirements. A basic and critical requirement for any brake pad is structural integrity with no internal cracks. In this work a series of processing changes were made to intentionally produce internal cracks in the friction material. Various pad crack detection methods were studied, and their advantages and disadvantages are discussed in detail. One of the crack detection methods used an ultrasonic measuring instrument which gives objective data in the form of calculated modulus of elasticity and signal loss. The details of the machine and how the measurements are obtained are discussed. The modulus calculation is also described. Additionally, random pads with and without cracks were selected and checked using subjective and objective
Divakaruni, Saikiran, Yuhas, Donald, Vorres, Carol, Kaatz, Richard
The Improvement Brake’s Qualities of Vehicle by Developing the Method of the Choosing Frictional Pairs of the Brakes Mechanisms2019-01-214509/15/2019
One of the reasons for the large number of road accidents on highways in Ukraine [1] is the instability of the braking properties due to the unstable characteristics of the brake mechanisms’ friction pairs. The manufacturer produces new automobiles with installed brake pairs (brake pads and their counter bodies), which have passed long-term tests for the stability of the friction coefficient and braking forces distribution of between the axles. This ensures the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. During operation, instead of worn-out brake pads, brake discs and drums, drivers can purchase new ones, manufactured as spare parts. However, in the well-known literature there are no methods that allow to check the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. In the article a method for choosing a set of
Podrigalo, Mikhail, Klets, Dmytro, Kholodov, Mykhailo, Bogomolov, Viktor, Turenko, Anatoliy, Molodan, Andrii, Rudzinskyi, Volodymyr, Tarasov, Yurii, Mykolai, Aloksa, Hatsko, Vasyl
Influence of Amount of Phenolic Resin on the Tribological Performance of Environment-Friendly Friction Materials2019-01-210509/15/2019
The binder in friction materials (FMs) plays a very crucial role which binds all the ingredients firmly so that they can function the way they were supposed to do. The type and amount of binder, both are very critical for manipulating the desired performance properties, which mainly include friction and its sensitivity towards operating parameters, wear resistance, counter-face friendliness, noise, vibration etc. Although a lot is reported on the influence of types of resins on tribo-performance of FMs, hardly any paper pertains to paint this on a bigger canvas with more detailed understanding of the amount of resin in FMs on the performance properties. The present study addresses these aspects by developing brake-pads with identical composition but varying in amount (wt. %) of straight phenolic resins (6, 8, 10 and 12) by compensating the difference with barite, a space filler. The ingredients did not contain asbestos, Copper, Zinc, etc. and hence were environment friendly
Kalel, Navnath, Bijwe, Jayashree, Darpe, Ashish
Brake Rotor Corrosion and Friction Cleaning Effect on Vehicle Judder Performance2019-01-211509/15/2019
Brake disc corrosion has emerged as an important field of study within the automotive industry due to the wide range of lining materials that are currently used worldwide, and their inherent rust-cleaning properties. The presence of oxide layers irregularly deposited on the cast iron disc surfaces usually leads to a forced, braking-induced vibration that can reach the driver’s position as a pronounced annoyance. Hence, the friction material composition directly impacts on the judder performance during the early corrosion-removal stage. This study incorporates both dynamometer and vehicle tests into the definition of a predictive methodology that allows corrosion-induced vibrations to be investigated at both system and vehicle levels. The oxide film is artificially generated by means of a salt spray chamber under steady-state climate conditions in order to guarantee a repetitive and robust procedure. The vibration response of the system is objectively evaluated in the form of caliper
Molina Montasell, Narcís, Ferrer, Bernat
A Study on the Optimum Reduction of Required Brake Fluid Level for Improvement of the High Speed Continuous Brake Distance2019-01-212109/15/2019
The high speed continuous braking distance assessment is the worst condition for thermal fades. This study was conducted to investigate the relationship between fade characteristic and friction materials & brake fluid amount for improving braking distance. So, we used the dynamometer to measure the friction coefficient, braking distance and required brake fluid amount. Through the measurements, the research was carried out as follows. First of all, we studied the influence of friction coefficient about different shapes (chamfer shape, area of the friction material, number of slots) on the same friction material. Secondly, we knew the effects of braking distance by the shape of the friction material. Through these two studies, the shape of the friction material favorable to the fade characteristics was derived. Finally, we measured the amount of required brake fluid in caliper after 10 consecutive braking cycles through Dynamometer. And then, we measured the amount of compression
Kim, Junggyu, Kim, Kwang Yun, So, Eue-sub
Squeal Noise Improvement by High Damping & High Stiffness under Layer Material2019-01-211109/15/2019
The purpose of this research is to clarify how damping characteristics of Under Layer (hereafter “UL”) material in the brake pads (hereafter “PAD”) influences brake squeal noise performance. In this study, UL material structure and dynamic viscoelasticity, for two different types of UL formulations are investigated. In addition, PAD damping ratio and squeal noise performance for multiple UL formulations are verified. As a result, the raw material orientation is determined based on manufacturing method, and it causes the UL material’s anisotropic properties. Dynamic viscoelasticity are dependent on the direction in which they are measured. In particular, the loss modulus, which is the damping element of dynamic viscoelasticity, is higher in the direction of the raw material orientation for the high damping and high stiffness UL formulation. In addition, it was confirmed that this loss modulus in the direction of the raw material orientation is effective for bending vibration. In the
Nishioka, Masato, Johnson, Leanne, Rosalez, Sean, Suzuki, Shusuke
Ceramic Bound Materials: A Suitable Solution for Light Brakes2019-01-210909/15/2019
A ceramic bound matrix has been investigated to be used as a friction material. The materials were produced by means of ceramic technology using frits containing silicates, and ceramic friction modifiers such as tin oxide, zircon, iron oxide, magnesium oxide. Four formulations were tested by means of a tribometer (pin-on-disc tester) using a gray cast iron counterpart. Test section included speeds between 1 and 12 ms-1, and loads between 25 and 400 N. The coefficient of friction of the tested specimens were between 0.7 and 0.4, and exhibited sensitivity to speed at low loads (25 N), while they are quite stables at high loads (400N). The characterization of the tribolayers was carried out by means of scanning electron microscopy. The four developed materials were named A, B, C, and D. They exhibited different wear rates and coefficients of friction. All the materials exhibited sensitivity to speed, while showed a lower sensitivity to load. The coefficient of friction level seems to be
Dante, Roberto C., Cotilli, Edoardo, Conforti, Michael, Cotilli, Mario, Serrano-Posada, José Carlos, Schramm, Tobias, Ostermeyer, Georg-Peter, Dastrù, Marco
Squeal Noise Improvement by High Damping & High Stiffness under Layer Material2019-01-2111.109/15/2019
This research focused on damping characteristics of Under Layer (UL) material to improve squeal noise performance. The study clarified that the raw material orientation causes anisotropy in dynamic viscoelasticity, especially with high damping and high stiffness UL material. Also, the loss modulus value, which is the damping element of dynamic viscoelasticity, corresponds with the raw material orientation and it is effective for damping for bending vibration. As a result, by using high damping and high rigidity UL material, the pad damping ratio was increased which leads to improved squeal noise.
A Study of the Disc Scoring Generation Principle and Reduction(III)2019-01-211209/15/2019
In the latest works [12], we presented the guideline for reducing Metal pick up(MPU, the main component of disc scoring) by controlling the location of the roughness of disc, the brake pad friction coefficients and the disc slot's size. In this study, the previously studied iron transfer theory to 'Cu free' brake pad and the disc surface roughness controlling methods which are based on the mass production manufacturing process are applied. It is possible to suggest the ways to improve the scoring-free disc without reducing friction coefficient between the disc and pad, and any demerit such as increased wear and airplane noise like conventional slot discs [11].
Jeong, ByeongUk, Ryu, Hyoung Tae, Jung, Kwang Ki, Kim, Chang Jin, Lee, Hyunkyoung
Inspection of Bulk Material with Trilinear Line-Scan and Prism CamerasTBMG-3476607/01/2019
Traditionally, prism-based cameras are often selected over trilinear cameras when it comes to bulk material scanning, as the inherent line-shift of a trilinear camera can only be corrected when the object scan velocity is known. In this article it is demonstrated that the traditional approach is not always necessary if the right trilinear sensor is selected and operated in binning mode to average multiple pixels.
Brake Block Effectiveness RatingJ1802_201906 (Current)06/06/2019
This SAE Recommended Practice provides the test procedure and methods to calculate the effectiveness of brake blocks, using an inertia dynamometer. To minimize testing variability, and to optimize standardization and correlation, a single, high volume size of brake block is specified (FMSI No. 4515E) and evaluated in a reference S-cam brake assembly of 419 mm x 178 mm (16.5 in x 7.0 in) size, using a specified brake drum.
Truck and Bus Foundation Brake Committee
Improved Test Method for Tribological Evaluation of High Performance Plastics2019-01-018304/02/2019
Engineering plastics are widely used in many tribological applications due to their inherent advantages such as reduced weight, ease of manufacturing, improved chemical compatibility, and damping characteristics. However, the process of selecting an appropriate polymeric material system for a specific application involves significant experimentation. Although, standardized methods of evaluating tribological performance of engineered plastics exist, their ability to be indicative of part performance in the end application is rather poor, primarily because of (a) the typically low pressure-velocity combinations used in these tests, (b) their inability to properly differentiate between various failure modes (wear vs creep vs melting of the plastic in case of thermoplastic polymers) and (c) the large number of variables that exist in a tribological system including pressure, relative speeds, thermomechanical properties of mating components, surface roughness/hardness parameters, type of
Sundararaman, Saikrishna
Development of Empirical Asperity Contact Model for Wet Friction Material2019-01-034604/02/2019
A wet clutch couples or decouples gear elements to alter torque paths in an automatic transmission system. During the gear shifting event, the clutch torque is directly transmitted to the output shaft. Hence, clutch torque heavily influences the dynamics of the transmission. In order to evaluate the behavior of the transmission early and efficiently, the development process increasingly relies on high-fidelity transmission system simulations with added complexity. However, a wet clutch continues to be modeled using Coulomb’s friction in a typical shift simulation. Its linear framework does not physically represent non-linear hydrodynamic effects due to the presence of oil layer during clutch engagement. To make up the lack of physics, Coulomb’s clutch model often requires extensive tuning to match actual shift behaviors. Alternatively, a squeeze film based clutch model, coupled with an asperity contact model, can be employed to represent hydrodynamic behaviors and enable the broader
Haria, Hiral, Fujii, Yuji, Pietron, Gregory M., Miyagawa, Masatoshi, Tsuchiya, Takahiro, Nakamura, Shinji, Wendel, Matthew, Miyoshi, Hiroya, Hou, Shiyang, Wang, Pengchuan, Katopodes, Nikolaos
High-Preload Deflection and Compressibility Test Procedures for Friction MaterialsJ2468_201811 (Current)11/12/2018
This standard specifies a method for testing and measuring the deflection of friction materials assemblies and compressibility of friction materials. This standard applies to disc brake pad assemblies and its coupons or segments, brake shoe lining and its coupons or segments, and brake blocks segments used in road vehicles. This SAE test method is consistent in intent with the ISO 6310 and the JIS 4413.
Brake Linings Standards Committee
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