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Viewing 211 to 240 of 1640
2014-04-01
Journal Article
2014-01-0233
James G. McLeish, Russell Haeberle
Quality, Reliability, Durability (QRD) and Safety of vehicular Electrical/Electronics (E/E) systems traditionally have resulted from arduous rounds of Design-Built-Test-Fix (DBTF) Reliability and Durability Growth Testing. Such tests have historically required 12-16 or more weeks of Accelerated Life Testing (ALT), for each round of validation in a new product development program. Challenges have arisen from: The increasing number of E/E modules in today's vehicle places a high burden on supplier's test labs and budgets. The large size and mass of electric vehicle power modules results in a lower test acceleration factors which can extend each round of ALT to 5-6 months. Durability failures tend to occur late in life testing, resulting in the need to: perform a root cause investigation, fix the problem, build new prototype parts and then repeat the test to verify problem resolutions, which severely stress program budgets and schedules.
2014-04-01
Journal Article
2014-01-0046
Takehito Shiraishi, Yasuo Shimizu
In the automobile industries, weight reduction has been investigated to improve fuel efficiency together with reduction of CO2 emission. In such circumstance, it becomes necessity to make an electric power steering (EPS) more compact and lightweight. In this study, we aimed to have a smaller and lighter EPS gear size by focusing on an impact load caused at steering end. In order to increase the shock absorption energy without increase of stopper bush size, we propose new theory of impact energy absorption by not only spring function but also friction, and a new stopper bush was designed on the basis of the theory. The profile of the new stopper bush is cylinder form with wedge-shaped grooves, and when the new stopper bush is compressed by the end of rack and the gear housing at steering end, it enables to expand the external diameter and produce friction. In this study, we considered the durability in the proposed profile.
2014-04-01
Journal Article
2014-01-0916
John George, Bharat Joshi, H.R. Shih, Yin Chen
A variety of parameters influence the durability of a converter to pipe joint of an automotive exhaust system. Some of the parameters are design variables and some factors are related to manufacturing. The design parameters include the thickness of the components, diameter of the pipe, sleeve length of the cone etc. While the variables like the weld penetration and the fit-up of the joint are related to manufacturing. Traditional durability simulations utilizing computer aided engineering (CAE) methods are conducted using nominal values of the design and manufacturing variables. In reality scatter and randomness in parameters are present due to the tolerance in components and limitations of the manufacturing process. In this paper a CAE based stochastic approach to determine the life distribution for a converter joint of an automotive exhaust system is presented.
2014-04-01
Journal Article
2014-01-0229
David E. Verbitsky
Failure analysis (FA) management is insufficiently described by current standards and literature. Previously proposed three-step systemic FA methodology provides effective and efficient alternative to sporadic FA. Organization, methods and results of the first step of the systemic FA, failure mode analysis (FMA), during product/project life cycle, is described. FMA promptly address ∼80% of all problems and justify/supports further actions using conventional ready techniques and resources. Original subject matter tools (three FMA levels, joint FMA-FMECA-F5 technique, and P5 failure classification) substantiate, facilitate and illustrate FMA. Multiple examples demonstrate FMA strengths and limitations with uniquely broad range of products and applications. Particular attention is paid to rare combination of high quality, reliability and profitability.
2014-04-01
Journal Article
2014-01-0717
Igor Baseski, Dorin Drignei, Zissimos Mourelatos, Monica Majcher
We propose a new metamodeling method to characterize the output (response) random process of a dynamic system with random parameters, excited by input random processes. The metamodel can be then used to efficiently estimate the time-dependent reliability of a dynamic system using analytical or simulation-based methods. The metamodel is constructed by decomposing the input random processes using principal components or wavelets and then using a few simulations to estimate the distributions of the decomposition coefficients. A similar decomposition is also performed on the output random process. A kriging model is then established between the input and output decomposition coefficients and subsequently used to quantify the output random process corresponding to a realization of the input random parameters and random processes. What distinguishes our approach from others in metamodeling is that the system input is not deterministic but random.
2014-04-01
Technical Paper
2014-01-0070
Ralph S. Shoberg, Jeff Drumheller
Abstract Reliable wheel attachment must start with proper tightening of the lug nuts in order to achieve the clamping force necessary to hold the vehicle's wheels securely for all operating conditions. It is the purpose of this paper to provide a complete overview of the theory and practice of using torque-angle signature analysis methods to examine the installation and audits of wheel lug nuts. An accurate estimate of clamp load can be determined without actually measuring the clamp load. The torque-angle signature analysis, known as “M-Alpha”, performed on tightening and loosening curves provides a powerful tool to understand the integrity of a bolted joint when clamp load data is not available. This analysis technique gives insight into the frictional effects, material properties, and geometric factors that can affect the clamp load attained during the installation process.
2014-04-01
Journal Article
2014-01-0884
Hong Su
Durability of a product is related to three major factors, the load, structure and material. The durability performance of an automotive product is, therefore, not only depended on the structure configuration, but also on the road load dynamic characteristics (profiles and frequency spectrum), and the material fatigue properties as well. Due to the dynamic nature of vehicle loads, one of the major technical challenges, to the durability design optimization of automotive products, is how to define a set of representative road loads, for fidelity and efficiency, based on the measured proving ground durability data of huge size. This paper presents a procedure of processing the proving ground road loads, for vehicle durability design and optimization of automotive products, based on the statistical characteristics evaluation and fatigue damage equivalency techniques.
2013-11-27
Technical Paper
2013-01-2788
Sathish Kumar P, Manikandan M, Mahendra N
The objective of this work is to find cumulative fatigue damage of the truck cabin caused by proving ground data. Stresses in the cabin are derived by finite element analysis using inertia relief method. Multi body simulation software ADAMS was used to obtain the load history at cabin attachment points using measured proving ground data as input. The fatigue damage of the truck cabin was estimated by linear super position method with static results and load history. The calculated numerical fatigue damage results were compared with physical test results and correlated.
2013-11-27
Technical Paper
2013-01-2848
V. Sivakumar
Spring seat plays major role in bogie suspension; which is guiding and controlling the leaf spring for better suspension and also to withstand the compressive load from leafs. Currently used spring seats are failing frequently in medium and heavy duty vehicles, which lead to customer concerns by higher idle time and part replacement cost. Thickness of the spring seat can't be increased by large extent due to packaging constraints in the vehicle. Stress levels identified by FEA method are found higher than the current material capacity. With these constraints, the spring seat has been re-designed with improved strength and ductility of material by modern technology - Austempered Ductile Iron (ADI). The parts have been developed and assembled in various tipper applications and performance was studied. The developed spring seat shows five times superior durability compare to existing design.
2013-10-15
Technical Paper
2013-32-9055
Shin-Hui Lin, Chao-Lung Chen
Since the exhaust emissions of an in-use motorcycle usually increases along its age, the Taiwan Environmental Protection Administration (TEPA) started to adopt useful life and deterioration factors requirements for the emission type approval certification in 1991. Considering the actual travel mileages for most motorcycles in Taiwan, it is necessary to extend the useful life period and mileage requirements for the future emission standards. This change of requirement will increase certification time and costs of new models for manufacturers. To evaluate the feasibility of shortening the accumulated useful life mileage for the regulatory durability test requirement; this study surveyed 105 sets of durability test results to explore the effects of deterioration factors on durability test result calculations.
2013-10-15
Journal Article
2013-32-9033
Gianluigi Zoli, May Turner, Cliff Newman
As a result of extremely competitive market environment and severe emission legislation, motorcycle manufacturers are giving increased focus to the lubricant as a potential tool to improve engine performance reducing at same time tailpipe emissions and fuel consumption. However, due to very specific hardware constraints, application of highly efficient low viscosity oils to modern motorcycle requires careful formulation approach and thorough testing procedure. Previous work carried out by Castrol and described in SAE paper # 2011-32-0513 indicated that optimized, low viscosity motorcycle engine oils, formulated with dedicated technology to combine optimum clutch compatibility with engine and gearbox protection, can bring significant increase in engine power and acceleration in comparison with commercially available lubricants.
2013-10-14
Journal Article
2013-01-2591
Joonwoo Kim, Eunseok Kim, JaeUk Han, Hyun Sik Han
Compressed natural gas (CNG) has been regarded as an alternative fuel for current fossil fuels such as gasoline and diesel. Recently the increasing interest in shale gas is drawing more attention to CNG vehicles of which number is expected to increase. Exhaust gas from CNG engines with lean combustion contains relatively low nitrogen oxides and particulate matters compared to conventional fossil fuel based engines. However, high amount of unburned methane, which has much higher greenhouse warming potential than CO2, limits the wide use of CNG for many applications. Even though Pd-based catalysts have been popularly studied in order to convert methane, their activity and durability have not been sufficient for practical applications to aftertreatment of lean burn CNG engines and the formation of a new Pd containing.
2013-10-07
Technical Paper
2013-36-0622
Celso Eduardo Fávero, Leandro Barcellos de Souza, Fabiane Pacheco, Mário Celso Duarte Pereira
For lifetime verification in automotive components it is necessary to simulate their operation in test benches that reproduce the conditions of vehicular application, according to the boundary conditions defined in the project. In durability tests of electric fuel pumps for Otto cycle engines, test benches are often used comprised of fuel tanks made of stainless steel provided with a fuel temperature control system. They also have a hydraulic system that allows simulating the fuel circulation loop of the vehicle consisting of fuel filter and fuel pressure regulator. Moreover, they are also equipped with flow meters and fuel pressure for monitoring the test. It has been observed in test bench durabilities that fuel pumps of Flex Fuel type are likely to present high levels of corrosion on their outer housing, even higher than expected after this kind of test.
2013-10-07
Technical Paper
2013-36-0256
Taboada Gonzalo
This paper is to for determine, using a simulation model (equation) and graphic, each of the faults that may occur in a systems, mechanical / electrical / hydraulic / pneumatic. In this case I have taken the rear axle of a truck as a component to analyze. Was sampled over 34,000 units in warranty, from 2004 to 2012 The next steps for the project are: Search specific data (manufacturers, companies, dealers) on the different types of failures and their respective analysis, in order to model and interpret correctly my analysis and simulation. Take a drive current park representative to mount the rear axle and are within one standard warranty period for a truck plant (1 to 2 years or 100,000 km. 200,000 km. respectively). Analyze data obtained in point 2 (number of faults, fractures) to have a database, with respect to reliability, unreliability and hazard rate.
2013-09-24
Technical Paper
2013-01-2377
Sivashankar S, Sudarsanam S, N. Saravanan
Based on customer application and loading condition, each Commercial Vehicle model has an entirely different usage pattern. To perform accurate durability validation, each vehicle model prototype should run on actual customer usage locations and loading conditions for the durability target kilometers. But it is time consuming and not practical. So a statistical approach is followed to generate the accelerated durability test sequence and target on in-house Proving Ground tracks to match the real customer usage for the durability target kilometers. Again a single durability test sequence and target cannot be followed for all vehicle models due to the variability in customer usage. For that, specific durability test sequence and target need to be established for every class of commercial vehicle. This paper summarizes the methodology to develop Durability test sequence and target for commercial vehicle based on the work carried out on variants of medium and heavy duty trucks.
2013-09-24
Technical Paper
2013-01-2378
Manimaran Krishnamoorthy, Mathew Sam Paul Albert
In this work, durability of the bus structure is evaluated with a Virtual Test Model (VTM).Full vehicle Multi Body Dynamics (MBD) model of the bus is built, with inclusion of flexibility of the bus structure to capture structural modes. Component mode synthesis method is used for creation of flexible model for use in MBD. Load extraction is done by performing MBD analysis with measured wheel inputs. Modal Superposition Method (MSM) is employed in FE along with these extracted loads for calculation of modal transient dynamic stress response of the structure. e-N based fatigue life is estimated. The estimated fatigue life from the modal superposition method show good correlation with the physical test results done in 6-poster test rig.
2013-09-24
Journal Article
2013-01-2379
Zhigang Wei, Shengbin Lin, Limin Luo, Fulun Yang, Dmitri Konson, Bala Gurusamy
Durability/reliability design of products, such as auto exhaust systems, is essentially based on the observation of test data and the accurate interpretation of these data. Therefore, test planning and related data analysis are critical to successful engineering designs. To facilitate engineering applications, testing and data analysis methods have been standardized over the last decades by several standard bodies such as the American Society for Testing and Materials (ASTM). However, over the last few years, several effective testing and data analysis methods have been developed, and the existing standard procedures need to be updated to incorporate the new observations, knowledge, and consensus. In this paper, the common practices and the standard test planning and data analysis procedures are reviewed first. Subsequently, the recent development in accelerated testing, equilibrium based data fitting, design curve construction, and Bayesian statistical data analysis is presented.
2013-09-24
Technical Paper
2013-01-2380
Anandan Sivakumar, Sachin Wagh, G. Raghavendra, Chaitanya Govind Kulkarni, Hemant Malekar
Success of the vehicle in the market depends on comfort provided while usage, which also includes noise, vibration and harshness (NVH). In order to achieve comfort level, the NVH levels have to be as low as possible. Powertrain is the main source of NVH, in which internal combustion engine consists of crank shaft and balancer shaft. Crank shaft gear is connected and driven by crank shaft and balanced by integral eccentric mass coupled with gear. Balancer shaft is used for additional balancing of rotating masses. Pair of crank shaft and balancer shaft gears generates noise and vibration when unbalance in the system and backlash in the gears increase while usage. The practice of interposing a vibration isolator on the surface of gear has been so far resorted for preventing transmission of vibration, therefore reduction in noise. In the work presented, balancer gear was made with sandwich design to reduce noise. Sandwich design comprises of Inner hub and outer ring with lug projections.
2013-09-20
Journal Article
2013-01-9041
Shawki Abouel-Seoud, Mohamed Khalil, Sameh Metwalley, Essam Allam, Hany Assad
Reliability has always been an important aspect in the assessment of industrial products and/or equipments. Good product design is of course essential for products with high reliability. However, no matter how good the product design is, products deteriorate over time since they are operating under certain stress or load in the real environment, often involving randomness. Maintenance has, thus, been introduced as an efficient way to assure a satisfactory level of reliability during the useful life of a physical asset. The earliest maintenance technique is basically breakdown maintenance (also called unplanned maintenance, or run-to-failure maintenance), which takes place only at breakdowns. A later maintenance technique is time-based preventive maintenance (also called planned maintenance), which sets a periodic interval to perform preventive maintenance regardless of the health status of a physical asset. The vehicle component is judged to be safe depending on its reliability.
2013-09-17
Technical Paper
2013-01-2173
Ali Aidibe, S. Antoine Tahan, Jean-Francois Lalonde
Nowadays, optimization of manufacturing and assembly operations requires taking into account the inherent processes variations. Geometric and dimensional metrology of mechanical parts is very crucial for the aerospace industry and contributes greatly to its. In a free-state condition, non-rigid parts (or compliant parts) may have a significant different shape than their nominal geometry (CAD model) due to gravity loads and residual stress. Typically, the quality control of such parts requires a special approach where expensive and specialized fixtures are needed to constrain dedicated and follow the component during the inspection. Inspecting these parts without jig will have significant economic impacts for aerospace industries, reducing delays and the cost of product quality inspection. The Iterative Displacement Inspection (IDI) algorithm has been developed to deal with this problem.
2013-09-17
Technical Paper
2013-01-2121
Zdzislaw H. Klim, Adam Skorek
The safe operation of technical systems is a mandatory basic requirement for the entire industry. However, there are specific industries where the safety of operation is critical and is considered as a required characteristic. These types of industries include the aerospace, military, civil aviation, nuclear power, as well as chemical and automotive industries. Safety is everyone's responsibility but engineering plays the most important role in the course of achieving a safe product operation. There are two specific phases of the product life cycle where the safety characteristics should be addressed by engineering activities: the design and development and operation phases. Modern engineering education is oriented to provide future engineers with a sufficient background to be able to Conceive-Design-Implement-Operate.
2013-09-17
Journal Article
2013-01-2198
Maryam Aramesh, Xavier Rimpault, Zdzislaw H. Klim, Marek Balazinski
Metal matrix composites (MMCs) exhibit superior characteristics such as low weight, high stiffness, and high mechanical and physical properties. Inheriting such an outstanding combination of specifications, they are nowadays considered as the promising materials in the aerospace and biomedical industries. However, the presence of high abrasive reinforcing particles in MMCs leads to severe manufacturing issues. Due to the tool-particle interactions which occur during the machining of MMCs, high tool wear and poor surface finish are induced and those elements are considered as the main drawbacks of cutting MMCs. In this study, dry turning experiments were conducted for two different inserts and coated carbide on a bar of titanium metal matrix composite (Ti-MMC). Semi-finishing machining is operated with cutting parameters based on the tool supplier's recommendations which were not fully optimized. The maximum flank wear length (VBBmax) was selected as the tool wear criteria.
2013-09-17
Journal Article
2013-01-2201
Joshua Benhabib
Manufacturing operations introduce unreliability into hardware that is not ordinarily accounted for by reliability design engineering efforts. Inspections and test procedures normally interwoven into fabrication processes are imperfect, and allow defects to escape which later result in field failures. Therefore, if the reliability that is designed and developed into an equipment/system is to be achieved, efforts must be applied during production to insure that reliability is built into the hardware. There are various ways to improve the reliability of a product. These include: Simplification Stress reduction/strength enhancement Design Improvement Using higher quality components Environmental Stress Screening before shipment Process Improvements, etc. This paper concentrates on ‘Manufacturing Process Improvement’ effort through the use of design of experiments, (DOE). Hence, improved levels of reliability can be achieved.
2013-09-17
Journal Article
2013-01-2232
Zdzislaw H. Klim, Martin Zeppetelli, Michel Saad
The hydraulic actuators are used to power flight control surfaces of the aircraft and to ensure surface movement. A system of two or three actuators is usually designed depending on the surface and intuitively these actuators are considered as a redundant architecture from a reliability and functionality point of view. The proper reliability modeling of the system of actuators must consider the system's functionality and design constraints for the remaining available actuator hinge-moment in the event of a partial or total actuator failure. As a result, this will affect the reliability assessment of that design. Furthermore, this system of actuators is also designed to provide a second function involving an assurance of the surface stiffness and damping. Generally, this second function does not require necessarily the same number of available actuators in order to be fully provided.
2013-05-13
Technical Paper
2013-01-1923
Chitrabala Subramanian, Vijay Tirumala, Bill Williams, David Reynolds
Transfinity® elastomer composites are a new class of material that drastically improves the durability of elastomer parts. Vehicle engineers can take advantage of improved elastomer endurance to design longer lasting engine mounts and suspension bushings without compromising vibration isolation performance. This is particularly important in NVH component design, which requires management of trade-offs in fatigue life, vibration and noise suppression. Transfinity products are composites made by direct mixing of elastomer latex and reinforcing particles, such as carbon black. The products are produced in a novel liquid-phase mixing process that revolutionizes elastomer compound mixing, replacing the traditional solid-state mixing process for the incorporation of reinforcing agents like carbon black into rubber.
2013-04-08
Technical Paper
2013-01-0450
Akindeji Ojetola, Landon Onyebueke
Long periods of sitting occur during our day to day life. It has been estimated that up to 80% of our active non-sleeping time is spent in some sort of sitting position during work, recreation, entertainment, commuting, resting, and exercising. As a result, several health effects like numbness, nerve/circulation occlusions, pressure sore, low back pain, and vein thrombosis have been associated with protracted sitting. Numerous researches have been conducted in the area of seat comfort that depended on conventional methods of testing physical prototype of seat model for comfort. The implementation of the seat comfort results are implemented in the next cycle of the design which may take up to three years. Recent advances in new technology, available after the prototype seat comfort testing, may not be incorporated in the next new seat design. This research work is geared towards developing a technique, tool and metric for seat comfort prediction.
2013-04-08
Technical Paper
2013-01-1376
Christian-Andreas Schumann, Egon MUELLER, Dieter Gerlach, Claudia Tittmann, Martin-Andreas Schumann
Achieving and sustaining high levels of quality is an essential prerequisite for successful and sustainable development. The requirement for the description of the existing quality levels are measurement parameters and comparative values for defining the state of the art. The quality of products is defined by measurements determining information for comparing with the planned parameters. The measurement results are used to determine absolutely and relatively the achieved quality. Products change shape and form within the whole product lifecycle. The more accurate and safe the measurement of form and shape become, the better the product quality can be defined. The methods of 3D-measurement are divided into contact (mechanical) and non-contact (optical) using CMMs, 3D scanners and 3D cameras. Advanced methods exploit e.g. the stereo photography. Therefore, a scanner technology has been developed based on 3D surface stereo photography.
2013-04-08
Technical Paper
2013-01-0596
Bo Zhang, Charles Beyer, Jack Pelkey, Glenn Whitehead, Alexandre Opeiko
Brake judder is a brake induced vibration that a vehicle driver experiences in the steering wheel or floor panel at highway speeds during vehicle deceleration. The primary cause of this disturbance phenomenon is the brake torque variation (BTV). Virtual CAE tools from both kinematics and compliance standpoints have been applied in analyzing sensitivities of the vehicle systems to BTV. This paper presents a recently developed analytical approach that identifies parameters of steering and suspension systems for achieving optimal settings that desensitize the vehicle response to BTV. The analytical steps of this integrated approach started with creating a lumped mass noise-vibration-harshness (NVH) control model and a separate multi-body dynamics (MBD) suspension model. Then, both models were linked to run in a sequence through optimization software so the results from the MBD model were used as quasi-static inputs to the lumped mass NVH model.
2013-04-08
Technical Paper
2013-01-0194
Rasmus Adler
A safety concept describes a plan for implementing safety. A bad safety concept compromises the achievement of safety or leads to unnecessarily high costs for implementing and proving safety. However, safety standards and research approaches do not provide any means for developing a good safety concept or for assessing the quality of a safety concept. Consequently, real-world safety concepts often lack information or have low quality. To overcome this practical problem, we systematically derive which fundamental information should be contained in a safety concept and introduce quality attributes for a safety concept. We also evaluate state-of-the-art approaches for developing a safety concept.
2013-04-08
Technical Paper
2013-01-0150
Marcella Turano, Fulvio Civera, Guilherme Figueiredo, Marco Margaria, Andre Smith Pereira
Fatigue tests on exhaust system usually require long time to be performed on the proving ground. Road simulation bench test reduces the time needed to execute the entire fatigue test on the proving ground and does not involve the operator presence for long time as proving ground test requires. In order to put on evidence the potentiality of performing the fatigue test with the RSB in substitution of the fatigue test on proving ground, a correlation between virtual analysis, the proving ground test and RSB test are illustrated. A specific component of the exhaust system is studied and specifically the bracket connecting the flexible pipe to the vehicle under body. During the proving ground test several failures occurred on the bracket connecting the exhaust system and the gear box. A virtual FE calculation and a fatigue test on the Road Simulation Bench were required to investigate the failure.
Viewing 211 to 240 of 1640