Criteria

Text:
Display:

Results

Viewing 1 to 30 of 13851
Training / Education
2015-06-02
Surface texture is one of the most important topics in today's world of design, development and performance. As tolerances are shrinking and performance demands are increasing, surface texture is rapidly becoming one of the most important aspects of engine and vehicle performance. Every moving component on a vehicle or engine is influenced by surface texture in one or more of the following ways: vibration, sealing, adhesion, traction, emissions, safety, durability, wear/failure analysis. Many of the industry's top warranty issues (leaks, noise, vibration, etc.) are a direct result of surface texture implications.
Training / Education
2014-12-17
There is a potential for metal fatigue in any situation where a component is subjected to cyclic loads. Fatigue failures of various types are a key concern in increasing the reliability of products. Problems involving fatigue have become more severe with the demand for lighter weight structures and components. The effective use of fatigue analysis and predictive tools is critical for reducing the development time of new products. Two methods of metal fatigue analysis will be covered. The first is the stress-life approach. This method is used for high cycle or very long life fatigue problems where loads have fairly constant amplitude.
Training / Education
2014-12-15
This seminar introduces participants to all aspects of threaded fasteners including nomenclature, geometric considerations, metallurgy, material properties, applied stresses, and considerations for fatigue, corrosion, brittle fracture and temperature. Methods are developed for the analysis and design of bolted joints under axial and shear loads. Other topics include assembly practice and methods to control preload.
Training / Education
2014-11-10
After more than 40 years of promise, the next decade will see an explosion in the use of composite materials. Aerospace and general aviation have been using the technology for years and automotive and alternative energy markets are now on the cusp of broader implementation. Car manufacturers are already implementing and launching carbon fiber composite development programs and working with both domestic and foreign producers of carbon fibers and composites. With the significant weight savings associated with composites, it is essential for automotive engineers to become knowledgeable about this technology which may revolutionize the way carbon fiber is used in automobiles and ultimately be instrumental in meeting government mandates for fuel economy.
Technical Paper
2014-10-13
Vicente Macian, Bernardo Tormos, Santiago Ruiz, Guillermo Miró, Tomás Pérez
Abstract Due to the increasingly stringent emissions standards in the world and, on the other hand, the foreseen shortage of fossil fuels, the application of low viscosity engine oils (LVO) is considered one of the most interesting options for counter these threats. In parallel to a fuel consumption fleet test, the aim of this study was to assess the performance of commercial low viscosity oils regarding their degradation and engine wear, since the use of LVO could imply an increase in wear rate. Potential higher engine wear could result in a reduction in the expected engine life cycle, obviously is a non-desired effect. In addition, currently limited data are available regarding “real-world” performance of LVO in a real service fleet. On this test, 39 urban buses were monitored using a detailed and extensive oil analysis program, comprising two engine technologies (Diesel and CNG) and four different lubricants, two of them LVO and other two considered as a reference baseline, during an oil drain period of 30000 km.
Training / Education
2014-10-09
The transportation industry, including motor vehicles, aircraft, rail, marine, commercial, off-road and defense vehicles, as well as infrastructures, energy sectors, raw materials, manufacturing, health and food industries all experience significant issues with corrosion which results in billions of dollars of loss each year. Corrosion education and prevention is essential to improve and increase the service life of parts and components which may have a significant impact on the economy of various industries and nations. The focus of this course will be on the fundamentals of corrosion engineering and corrosion prevention of metallic and alloy structures as well as on non-metallic composites and hybrid materials.
Training / Education
2014-10-02
The purpose of this course is to provide an overview of the factors in the cylinder kit assembly of natural gas, gasoline, and diesel engines that affect oil consumption, ring and cylinder bore wear, and blow-by. This course includes background and the evolution of designs and materials currently employed in modern engines as well as providing an overview of computer models, designs, and material systems that can be utilized to optimize the performance of new engines. An overview of the trends in materials and designs employed in U.S., European and Japanese engines will be presented.
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
Zhigang Wei, Yunfei Qu, Yanping Zhang, Fulun Yang, Matthew Yule, Kay Ellinghaus, Markus Pieszkalla, Figen Lacin
Thermo-mechanical fatigue (TMF) resistance characterization and life assessment are extremely important in the durability/reliability design and validation of vehicle exhaust components/systems, which are subjected to combined thermal and mechanical loadings during operation. The current thermal-fatigue related design and validation for exhaust products are essentially based on testing and the interpretation of test results. However, thermal-fatigue testing are costly and time consuming, therefore, computer aided engineering (CAE) based virtual thermal-fatigue life assessment tools with predictive powers are strongly desired. Many thermal-fatigue methods have been developed and eventually implemented into the CAE tools; however, most of them are based on deterministic life assessment approach, which cannot provide satisfactory explanation for the observed uncertainties introduced in thermal-fatigue failure data. In this paper, a probabilistic thermal-fatigue life assessment procedure is developed.
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
Fatih Kosar, Mehmet Burak Yegin, Okan Dogru, Cüneyt Akarsu
Abstract Nowadays, a lightweight component design plays a significant role in both cost of a vehicle and fuel economy in competitive heavy duty truck industry. This paper describes the optimization study of an Anti-Roll Bar (ARB) bracket used in a heavy duty truck. ARB system is used to avoid rolling of a vehicle. In order to measure real forces acting on ARB links, calibration study is performed in laboratory conditions. According to this study, measured strains are correlated with theoretical strain-force curve. After the correlation study, fatigue based topology optimization is made on ARB cast iron bracket according to correlated Road Load Data (RLD) which is performed at Proving Ground. Most of the optimization studies in the literature depend on maximum static loading condition. However, many components or structures in the industry subjected to fluctuating loads when they are in service condition. Small loads in a fluctuating load domain may cause potential danger in the design because there will be damage accumulation on the part when those loads are repeated.
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
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
2014-09-28
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.
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
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
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
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
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
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
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
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.
Standard
2014-09-25
Form: This specification covers an aluminum alloy in the form of an extrusion. Application: This product has been used in aerospace applications requiring a combination of high strength and compressive properties and with good corrosion resistance, but usage is not limited to such applications.
WIP Standard
2014-09-24
This specification has been declared "CANCELLED " by the Aerospace Materials Division, SAE, as of January 2009. By this action, this document will remain listed in the Numerical Section of the Index of Aerospace Material Specifications indicating that it has been "CANCELLED ".
WIP Standard
2014-09-24
This specification has been declared "CANCELLED " by the Aerospace Materials Division, SAE, as of January 2009. By this action, this document will remain listed in the Numerical Section of the Index of Aerospace Material Specifications indicating that it has been "CANCELLED ".
WIP Standard
2014-09-24
This specification has been declared “NONCURRENT” by the Aerospace Materials Division, SAE, as of August 2009. It is recommended, therefore, that this specification not be specified for new designs. “NONCURRENT” refers to those specifications which have previously been widely used and which may be required for production or processing of existing designs in the future. The Aerospace Materials Division, however, does not recommend these specifications for future use in new designs. “NONCURRENT” specifications are available from SAE upon request.
WIP Standard
2014-09-23
This specification establishes the requirements for chromate conversion coatings on magnesium alloys. This process has been used typically to improve corrosion resistance and adherence of organic finishes but usage is not limited to such applications. The dichromate treatment may not be suitable for alloys with high manganese content. The chrome pickle treatment has been used as touch-up for previously dichromate-treated surfaces and for improving corrosion protection temporarily, but usages are not limited to such applications.
WIP Standard
2014-09-23
This specification establishes the requirements for a hard aluminum oxide coating, impregnated or codeposited with polytetrafluoroethylene (PTFE) on aluminum alloys.
Viewing 1 to 30 of 13851

Filter

  • Range:
    to:
  • Year: