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Viewing 1 to 30 of 14326
Technical Paper
2014-11-11
Simone Vezzù, Carlo Cavallini, Silvano Rech, Enrico Vedelago, Alessandro Giorgetti
The deposition of thick, pore-free and high performances copper alloy matrix composite coatings is a topic of interest for several industrial applications such as friction materials, high mechanical resistance electrical contacts, and welding electrodes. This study investigates the opportunity to use cold spray for the deposition of CuCrZr/Al2O3 cermet coatings on 6060 aluminium alloys. The project’s aim is to investigate the feasibility of producing integral coolers on mechanical parts. This will make it possible to the design of high performance hybrid motorcycles more compact. Fused and crushed alumina and gas-atomized CuCrZr powder blends have been used as initial feedstocks, with compositional weight ratio of 65/35 and 80/20 (ceramic/metal). The deposition process and coating growth have been studied as a function of carrier gas temperature, exploring the range between 200°C and 750°C. Pure CuCrZr alloy coatings have been also deposited for comparison. The coatings have been characterized in terms of microstructure and morphology, coating microindentation hardness, adhesion to the Al alloy substrate, and cohesion.
Technical Paper
2014-11-11
Akiko Tanaka, Ikue Sato
Southeast Asian Nations are large scale markets for motorcycles and the market size is still growing. Moreover, the volume of plastic parts used for those motorcycles is increasing with growing popularity of scooter-type motorcycles. Accordingly, decorative features applied for plastic coverings are increasingly important to enhance the attractiveness of exterior designs of those motorcycles. Under these circumstances, we had adopted the magnetically-formed decorative painting and applied to a mass-production motorcycle model sold in Thailand in 2008. The magnetically-formed decorative painting is the method in which the designed patterns are formed by painting the material that contains flakes movable along with the magnetic lines of force, while applying an auxiliary attachment to the backside of the parts for generating magnetic fields, such as magnetic sheet trimmed to fit the shape of ornamenting designs. The magnetically-formed decorative painting offers three-dimensional appearance even though its actual surface has no protuberances or dents.
Technical Paper
2014-09-30
Zhigang Wei, Shengbin Lin, Limin Luo, Litang Gao
Road vibrations cause fatigue failures in vehicle components and systems. Therefore, reliable and accurate damage and life assessment is crucial to the durability and reliability performances of vehicles, especially at early design stages. However, durability and reliability assessment is difficult not only because of the unknown underlying damage mechanisms, such as crack initiation and crack growth, but also due to the large uncertainties introduced by many factors during operation. How to effectively and accurately assess the damage status and quantitatively measure the uncertainties in a damage evolution process is an important but still unsolved task in engineering probabilistic analysis. In this paper, a new procedure is developed to assess the durability and reliability performance, and characterize the uncertainties of damage evolution of components under constant amplitude loadings. The linear and two nonlinear probabilistic damage accumulation models are briefly described first.
Technical Paper
2014-09-30
Nishant Mohan, Mayank Sharma, Ramesh Singh, Naveen Kumar
Abstract The economics of operating internal combustion engines in cars, buses and other automotive equipment is heavily affected by friction and wear losses caused by abrasive contaminants. As such, dust is a universal pollutant of lubricating oils. Road dust consists of depositions from vehicular and industrial exhausts, tire and brake wear, dust from paved roads or potholes, and from construction sites. Present research investigates the influence of dust powder of size 5 μm-100 μm as contaminant in SAE 20W-40 lubricant on the relative motion of a plane surface over the other having circular surface in contact. A pin-on-disk setup as per ASTM G99 has been used to conduct the experiments, firstly at increasing rpm keeping constant load of 118 N, and secondly by increasing loads, keeping rpm constant at 1000. The contaminated lubricant has been used to study its influence on friction and wear rate at the interface of pin of 12 mm diameter and disk at track diameter of 98 mm. Based on the experiments at constant load, the coefficient of friction decreased with increase in rpm and the wear rate first increased and then decreased.
Technical Paper
2014-09-30
Balakrishnan Natesan
Abstract Phosphorous is an important alloying element in powder metallurgy applications. It is used in Powder metal parts for effective Sintering, dimensional stability, improved machinability, corrosion resistance etc. However it does have some negative effects on properties of Powder metal parts. The purpose of the paper is to study the effect of phosphorous on Powder metal gear of Mix A and Mix B having identical composition differing only in phosphorous content. The samples were detailed on each stage, viz. sintering & Heat treatment. In addition two defective samples were studied to observe the extent to which phosphorous may deteriorate the Powder metal Gear.
Technical Paper
2014-09-30
Steffen Hoppe, Troy Kantola
Abstract The fundamental drivers in the development of commercial vehicle engines are improved fuel efficiency and the need to meet more stringent exhaust emissions legislation. This strategy presents significant challenges in the development of engine components, particularly piston rings. Within the power cylinder, piston rings are significant contributors to friction losses, with the ring pack contributing up to 25 percent of the total mechanical engine friction loss, and a corresponding fuel consumption of up to four percent. The challenge lies in reducing friction power loss, without compromising oil consumption, while also mastering the increasing thermo-mechanical and tribological demands that piston rings must endure due to increased power density, smoother cylinder bores, reduced lubrication, and the use of alternative fuels. In this context, the robustness of the piston ring running face, as characterized by wear resistance and scuff resistance in particular, plays an increasing role.
Technical Paper
2014-09-30
Hongyu Zheng, Linlin Wang
Abstract A brake pad wear control algorithm used under non-emergency braking conditions is proposed to reduce the difference in brake pad wear between the front and rear axles caused by the difference in brakes and braking force. According to the adhesion state of the pad wear, the control algorithm adjusted the braking force distribution ratio of front and rear wheel that balanced adhesion pad wear value. Computer co-simulations of braking with Trucksim and Matlab/Simulink using vehicle models with equal brake pad wear, greater wear on the front axle and greater wear on the rear axle respectively is performed. The computation simulation results show that meet the brake force distribution system regulatory requirements and total vehicle braking force unchanged.
Technical Paper
2014-09-30
Marco Carriglio, Alberto Clarich, Rosario Russo, Enrico Nobile, Paola Ranut
Abstract The main purpose of this study is the development of an innovative methodology for Heat Exchangers (HE) design to replace the conventional design procedures. The new procedure is based on the definition of a software package managed by modeFRONTIER, a multi-objective optimization software produced by ESTECO, able to create HE virtual models by targeting several objectives, like HE performance, optimal use of material, HE minimal weight and size and optimal manufacturability. The proposed methodology consists first in the definition of a workflow for the automatic CFD simulation of a parametric model of a periodic HE cellular element. This is followed by the definition of a Response Surface (meta-model) covering all the possible range of parameters' combination, the definition of a “bridge”, e.g. low-fidelity - standard or macroscopic - models to extend the behavior of the liquid and air HE cellular elements to a real scale HE, and an optimization process to obtain the optimal HE design for any proposed application and requirements.
Technical Paper
2014-09-30
Jon Dickson, Matthew Ellis, Tony Rousseau, Jeff Smith
Abstract Fuel efficiency for tractor/trailer combinations continues to be a key area of focus for manufacturers and suppliers in the commercial vehicle industry. Improved fuel economy of vehicles in transit can be achieved through reductions in aerodynamic drag, tire rolling resistance, and driveline losses. Fuel economy can also be increased by improving the efficiency of the thermal to mechanical energy conversion of the engine. One specific approach to improving the thermal efficiency of the engine is to implement a waste heat recovery (WHR) system that captures engine exhaust heat and converts this heat into useful mechanical power through use of a power fluid turbine expander. Several heat exchangers are required for this Rankine-based WHR system to collect and reject the waste heat before and after the turbine expander. The WHR condenser, which is the heat rejection component of this system, can be an additional part of the front-end cooling module. Packaging this WHR condenser as part of the front-end cooling module can be an engineering challenge given the tight underhood environment where the current powertrain cooling components are already near system-capable thermal limits.
Technical Paper
2014-09-30
C Venkatesan, V Faustino, S Arun, S Ravi Shankar
Abstract The automotive industry needs sustainable seating products which offer good climate performance and superior seating comfort. The safety requirement is always a concern for current seating systems. The life of the present seating system is low and absorbs moisture over a period of time which affects seat performance (cushioning effect). Recycling is one of the major concerns as far as polyurethane (PU) is concerned. This paper presents the development of an alternative material which is eco-friendly and light in weight. Thermoplastic Polyolefin (PO) materials were tried in place PU for many good reasons. It is closed cell foam which has better tear and abrasion resistance. It doesn't absorb water and has excellent weathering resistance. Also it has a better cushioning effect and available in various colours. Because of superior tear resistance, it is possible to eliminate upholstery and would reduce system level cost. The development involves testing and characterization of the materials, making of prototypes and validations.
Technical Paper
2014-09-30
Abhishake Goyal, Nadeem Yamin, Naveen Kumar
Abstract Fuel cells are a promising energy source on account of their high efficiency and low emissions. Proton exchange membrane fuel cells (PEMFC) are clean and environmental-friendly power sources, which can become future energy solutions especially for transport vehicles. They exhibit good energy efficiency and high power density per volume. Working at low temperatures (<90°C), hydrogen fuelled proton exchange membrane fuel cells (PEMFCs) are identified as promising alternatives for powering autos, houses and electronics. At the middle of the proton exchange membrane (PEM) fuel cell is the membrane electrode assembly (MEA). The MEA consists of a proton exchange membrane, catalyst layers, and gas diffusion layers (GDL). However, most of the researchers have already mentioned that PEMFC are not competitive enough to rechargeable lithium ion battery with respect to price because of the rare metal used such as platinum in it. Presence of platinum in PEM fuel cells is one of the reasons why fuel cells are excluded from commercialization.
Technical Paper
2014-09-30
Vinod Kumar Mannaru, Sunil M Makhe, Lori Stephens, Dinesh Kumar, Shivaprasad Goud
Abstract Vapor management system is critical to manage fuel tank capacity, evaporative emissions and pressure control for hybrid applications. Due to stringent emission norms and other regulations there has been lot of advancements in design and application of vapor control valves that are used in automotive fuel tanks. Continuous exposure of these valves to fuel vapor or fuel in some instances led to swelling of assemblies and poses serious threat to product functionality and maintaining required tolerances. Swelling of plastics in fuel is ideally a case of multi physics, which involves modeling of complex mass transfer phenomena. In this study a simple thermal analogous approach has been used to model swelling behavior by characterizing the basic plastic-fuel soaking through coefficient of hygroscopic swelling. Extensive testing has been performed with multiple plastic-fuel combinations with different shapes at different temperatures. Periodic measurements helped to extract coefficients in different directions, which have been used to predict swelling induced strains and stresses in the specimens through finite element analysis.
Technical Paper
2014-09-30
Francis J. Walker
Abstract According to the International Energy Agency (IEA), the United States consumes 20 million barrels of crude oil per day (840,000,000 gallons)1. More than half of this quantity is imported. It is expected that by 2025 this quantity is expected to rise to 26 million barrels per day with an estimated sixty percent of the consumed quantity being imported. With the prices of oil to continue to be above $90/barrel, the expected annual expenditures on imported oil is estimated to be >$250 billion. With the cost of fossil fuel continuing to increase as its quantity is depleted, there is a strong driver for continued investment in renewable fuel sources. One such approach is the use of plant-based feedstock to augment conventional fossil fuel for diesel applications. Use of such feedstock has given rise to the biodiesel fuel industry (BD). Studies have documented fuel-oil dilution issues in diesel applications. The presence of BD in the engine oil reduces the life of the oil as well as its effectiveness2.
Technical Paper
2014-09-28
Veronika Mayer, Brian Richards
Abstract Fierce competition demands more and more consideration for raw materials that are price competitive without the sacrifice of technical results. High and very often fluctuating raw material costs and availability challenge and complicate the calculation for brake pads raw materials. Therefore there is a strong demand for raw materials with high technical performance at stable predictable costs. For these reasons micaceous Iron Oxide (MIO) is evaluated. A case study describes the substitution of two well-established materials Zirconium Silicate and Potassium Titanate by micaceous iron oxide MIO in disk brake pads. MIO is a naturally occurring mineral with lamellar particle shape. The study compares the addition of 3 wt-% and 6 wt-% of Zirconium Silicate, Potassium Titanate and of MIO in a low-metallic formulation for disk brake pads. Regarding technical performance several properties are evaluated. Tests for friction coefficients are carried out according to the AK-Master SAE J2522.
Technical Paper
2014-09-28
Axel Stenkamp, Michael Schorn
Abstract Starting in the late '90s, a new and innovative brake disk technology entered the high performance passenger car market. Approx. 2 years later, small volume production of carbon-ceramic brake disks started. In the past ten years the number of cars equipped with the new generation of ceramic matrix composite (CMC) brake disks has continuously increased, with main usage in low volume, high horse power applications. The goal of this paper is to give an overview of the system specific boundary conditions as well as today's and tomorrow's targets and aspects of friction material development used in CMC-disk based brake systems. Starting with a description of the system component properties, a comparison of typical CMC vs. standard gray cast iron disk (GCI) applications will be made. The impact of the component properties, especially the disk as friction counterpart to the pad, will be shown by comparing industry standard test scenarios. One described system boundary will be the thermal load to the brake pad.
Technical Paper
2014-09-28
SeongJoo Lee, JooSeong Jeong, ShinWook Kim, ShinWan Kim, Seong Rhee
A previous investigation showed that minor variations in alloying elements in gray cast iron disc contributed to measurable differences in friction and disc wear. This investigation was undertaken to find out if and how the increased friction and disc wear might affect brake squeal. The SAE J2522 and J2521 dynamometer procedures as well as an OEM noise dynamometer procedure and a chassis dynamometer noise procedure were used to find out if a correlation between disc wear and brake squeal could be discovered. In all cases, as the wear rate of a disc increases under a given set of test conditions, disc material transfer to the pad surface increases, which results in increased friction and brake squeal. Also a good method to detect disc variability (disc to disc, within a disc) is discussed.
Technical Paper
2014-09-28
Lars Wilkening, Hans-Guenther Paul, Georg Peter Ostermeyer
Abstract Friction materials for automotive brakes are known to exhibit a time-dependent tribological behavior. When examining these dynamic effects special demands are made on the measurement device: The influences of the brake system should be minimized and parameters like velocity, contact pressure and temperature should be controlled closely and independently. Furthermore, special test procedures need to be designed. This can ideally be achieved using a scaled tribometer like the High-Load-Tribometer at the Institute of Dynamics and Vibrations in Braunschweig. Former investigations [1] have shown that a kind of memory effect can occur for a low-met brake pad rubbing on a cast iron disk. A variation of the initial disk temperatures has revealed that a temporary increase of the coefficient of friction can occur at slightly elevated temperatures. This effect is memorized by the material as a certain procedure needs to be performed in order to achieve a regeneration. The scope of the current work is to extend this examination with respect to different materials and also include different load cases.
Technical Paper
2014-09-28
Johannes Schneider
The brake discs and brake drums used on motor vehicles are, in 90% of applications, made from grey cast iron. Although other designs such as composite systems comprising of a grey iron braking band and a light weight mounting bell made from aluminum, Al-MMC or entire ceramic brake discs have been developed, cast iron will continue to play a major role as a work piece material for brakes. Cast iron offers advantages in material characteristics such as good thermal conductivity, high compressive strength and damping capacity. In addition it shows a superior casting behavior and also an unbeatable competitive price per part, when compared to other brake materials or designs. Ongoing research in material and casting science are leading to new types of alloyed CI materials, fulfilling the increasing demands in terms of performance but also increasing the demands for a reliable and economical production. As a product of high volume production the economics and productive manufacturing of the brake discs is a fundamental issue to ensure the competitiveness of the manufacturers.
Technical Paper
2014-09-28
Abdulwahab A. Alnaqi, Suman Shrestha, David C. Barton, Peter C. Brooks
Abstract Aluminium alloys have been used extensively in the automotive industry to reduce the weight of a vehicle and improve fuel consumption which in turn leads to a reduction in engine emissions. The main aim of the current study is to replace the conventional cast iron rotor material with a lightweight alternative such as coated aluminium alloy. The main challenge has been to meet both the cost and functional demands of modern mass-produced automotive braking systems. A sensitivity analysis based on the Taguchi approach was carried out to investigate the effect of various parameters on the thermal performance of a typical candidate disc brake. Wrought aluminium disc brake rotors coated with alumina on the rubbing surfaces were determined to have the best potential for replacing the conventional cast iron rotor at reasonable cost. Optimisation of the structure was subsequently carried out using a genetic algorithm on the selected coated aluminium disc brake rotor. This determines the optimum thickness of the coating and the composition of the substrate based on selected criteria.
Technical Paper
2014-09-28
Yannick Desplanques
Abstract The ratio of two forces acting respectively perpendicular and normal to a contact surface of two bodies, the coefficient of friction, is widely used in engineering and science depicting the friction resistance of materials sliding over one another. Ruled by the so-called Amontons-Coulomb friction laws (independence from the load, the contact area and the sliding speed), this dimensionless quantity appears to be convenient for engineering and relatively easy to determine. Nevertheless, the use of tabulated friction coefficients becomes somewhat an issue to predict friction behavior of mechanical systems. The system dependence of friction is sometimes ignored, leading to misapplication. Moreover, the fundamental origins of sliding resistance are not as clear and care should be taken when attributing a fundamental significance to the friction coefficient. This paper aims to clarify findings on friction Charles Augustin Coulomb did and that have been used for hundred of years. At the demand of the French Académie Royale des Sciences calling for rules and accurate data to design machines, Coulomb developed an experimental study of friction of woods and metals used for rubbing parts in machinery.
Technical Paper
2014-09-28
Adarsh Venkata Padmanabhan, Hariram Ravichandran, Lokendra Pavan Kumar Pappala, Shreyas Shenoy
This paper comprises obtaining friction coefficient (μ) measure by extracting surface and texture information using sensors during brake interventions. A primary estimate of friction coefficient has been obtained using wheel and vehicle signals. The estimates have been compared and combined to obtain a more accurate measure of friction coefficient. Finally, a suitable interpolation technique is used to obtain a μ-grid around the vehicle. The grid is graphically realized with the aid of visualization techniques using vehicle traces. This type of surface characterization usually enables brake distance optimization and effective countermeasures pertaining to a standard ESP system.
Technical Paper
2014-09-28
Prashant Mahale, Aziz Bohari, Raajha M P
Abstract Brake noise is an emerging concern in Indian Auto-industry; with brake squeal being the most evident form of brake NVH. Squeal noise generation attributes to many parameters including kinematics of braking parts during pressure application, structural dynamic behavior which in turn depends on coupling at resonant frequencies of different parts of a brake assembly, material of brake parts, operating clearances in the mating parts etc. The genesis of brake squeal lies in the generation of unstable frictional forces during braking event. These frictional forces induce uncontrolled amplification of brake parts vibration, which in turn tend to produce perceivable sound or noise. The magnitude this vibration induced squeal depends on co-efficient of friction, braking pressure, speed and temperature of friction material. It is known from typical squeal evaluations on dynamometer that at different temperatures of friction, the ability/ occurrence, of squeal is different, typically in the range of 50°C to 200°C.
Technical Paper
2014-09-28
Toshikazu Okamura
Abstract There are various processes for finishing the friction surfaces of a brake disc, which affect the braking effectiveness of a vehicle in the early stages of use in some cases. To examine the interaction between the disc surface texture, rotational direction, and friction material, a series of experiments on a tribotester using small-scale specimens was conducted. In a previous paper (2013-01-2056), the results from the first series of experiments, which involved of thirty disc surface textures and a less aggressive non-asbestos organic (NAO) friction material in on-brake-drag conditions combining constant speed and normal-load, was reported. Disc surfaces were finished by the following finishing processes in two rotational directions: turning under four cutting conditions, roller burnishing after turning, turning with a wiper insert, and grinding with two stones. Contact-pressure dependency of friction and wear was confirmed. Roller-burnished and wiper-turned discs exhibited different friction and wear at a certain contact pressure between rotational directions in the turning process.
Technical Paper
2014-09-28
Qiang Wang, Gang Qi, Guangrong Zhang, Xinyu Pu
Abstract A brake durability experimental method is proposed to simulate a brake durability vehicle road test. Brake judder and noise often occur in brake durability road testing. Brake judder is difficult to address because of its many potential causes, such as assembly run out, component stiffness, lining characteristics, thermal coning/hot spot/thermal instability and corrosion. There are currently several test procedures to predict brake thermal roughness and pad cleaning corrosion performance for preventing brake judder. Brake durability vehicle road testing is performed to check brake NVH and wear; examples include the Mojacar test in Spain and the Huangshan test in China. Brake energy intensity and road vibration are the significant factors that cause brake rotor thickness variation, which generates brake judder in public road testing. This study is focused on brake pad wear depending on brake energy intensity and brake rotor temperature to simulate brake durability road testing and brake rotor thickness variation (RTV) generation induced by wear.
Technical Paper
2014-09-28
Diego Masotti, Ney Ferreira, Patric Neis, Ademir Menetrier, Luciano Matozo, Paulo Varante
Abstract Creep groan is a low-frequency (20-300Hz) self-excited brake vibration caused by stick-slip phenomena at the friction interface observed at very low vehicle speed. The creep groan propensity of friction materials is closely related with the difference (Δμ) between the static (μs) and the kinetic (μk) coefficients of friction. In this study, a NAO brake pad material was used as a base formulation and the abrasives tested were commercial grade of black iron oxide, chromite, zirconium oxide, magnesium oxide and aluminum oxide. Experimental results were obtained by testing seven different friction material formulations, in which the type of abrasives or its hardness or its particle size was changed in order to explore the impact of these variables on the stick-slip occurrence. A laboratory-scale tribometer was used to investigate the influence of different types of abrasives and their physical properties in the stick-slip. The results showed that abrasive particle size and hardness significantly affect the propensity of stick slip.
Technical Paper
2014-09-28
Tomasz Grabiec
Abstract Wear and friction behavior of disc brakes are important properties of disc brake systems and are mainly addressed by appropriate selection and tuning of friction material. Disc material composition is often considered as “given”. The most common material used for brake discs is grey cast iron which can have carbon content between 2.5 to 4.2 percent. It is difficult to find in literature investigations related to the influence of cast iron material in combination with modern low-met friction material on wear and friction performance of disc brakes. In this work, the author will try to analyze impact of brake disc material properties on wear and friction performance.
Technical Paper
2014-09-28
Meechai Sriwiboon, Nipon Tiempan, Kritsana Kaewlob, Seong Kwan Rhee
The influence of processing conditions on Low-Copper NAO disc pads were investigated as part of an effort to develop Low-Copper disc pad formulations as this kind of information is not readily available in open literature. Processing conditions as well as formulation modifications are found to influence friction, pad wear, disc wear and brake squeal. Low-Copper disc pads for pick-up trucks, equivalent to an OE pad, are developed. It is also found that brake squeal measured during the SAE J2522 (AK Master) Performance testing is related to the combined total wear rate of the disc plus the inner/outer pads or the disc wear rate alone, and that there is a threshold wear rate, above which brake squeal increases rapidly.
Technical Paper
2014-09-28
Werner Oesterle, Andrey I. Dmitriev
Abstract Third bodies, also termed friction layers, tribofilms or secondary contact patches, are layers of more or less compacted wear debris between pads and rotor of a disc brake. Our approach of assessing the sliding behavior and friction properties induced by third bodies has been: i) structural characterization after AK-master test procedure, ii) sliding simulation of model structures similar to the observed ones but with simpler and well defined compositions, and iii) verification of simulation results by pin-on-disc tests with artificial third bodies showing the same microstructures and compositions as the model structures. The idea was to simulate structure formation during real braking conditions by high energy ball milling of appropriate powder blends. The final outcome of numerous parameter studies was that a third body containing 15 vol% soft ingredients and 0-20 vol % hard ingredients, both distributed homogeneously in a nanocrystalline iron oxide matrix, should be most desirable for braking.
Technical Paper
2014-09-28
David B. Antanaitis, Heewook Lee
Abstract An area of brake system design that has remained continually resistant to objective, computer model based predictive design and has instead continued to rely on empirical methods and prior history, is that of sizing the brake pads to insure satisfactory service life of the friction material. Despite advances in CAE tools and methods, the ever-intensifying pressures of shortened vehicle development cycles, and the loss of prototype vehicle properties, there is still considerable effort devoted to vehicle-level testing on public roads using “customer-based” driving cycles to validate brake pad service life. Furthermore, there does not appear to be a firm, objective means of designing the required pad volume into the calipers early on - there is still much reliance on prior experience. This paper builds upon previous work by GM [1], where short duration, objective vehicle and dyno tests were combined with a computer model to allow for accurate pad service life prediction without vehicle tests, and expands it into a methodology combining CAE (CFD), computer modeling, objective friction material characterization data, to enable confident sizing of the brake pads very early in the vehicle development process.
Technical Paper
2014-09-28
Kazuho Mizuta, Yukio Nishizawa, Koji Sugimoto, Katsuya Okayama, Alan Hase
Abstract Brake pads are composite materials made from dozens of ingredients intended to simultaneously satisfy various performances such as brake effectiveness, wear, noise and vibrations. For this reason, the friction phenomena that occur during braking are complicated. It is important to clarify the friction phenomena, but that is not easy because the associated complexities as mentioned above. We looked to acoustic emission (AE) as an online evaluation method of friction phenomena. AE is a non-destructive testing method that measures elastic stress waves caused by the deformation and fracturing of materials. In fact, it has been reported that the difference between abrasive wear and adhesive wear of a metal can be identified from the change in the frequency spectrum of AE signals. In this study, we verify whether differences in the friction phenomena of brake pads are detectable by the AE method. Three kinds of brake pads were used in the experiments. One of the specimens included an abrasive ingredient, one included an adhesive ingredient, and another included neither.
Viewing 1 to 30 of 14326