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Viewing 1 to 30 of 3810
2010-09-28
Technical Paper
2010-32-0068
Shaiju M. Belsus, Gopi Sankar, Amol Sharma
Reliability has been a complicated domain of vehicle engineering, basically due to the quantum of the authentic data required, and variability of parameters that make real contributions to the subject. Reliability of a vehicle in very generic terms, is not only its functional worthiness and consistency, but also its probability to perform satisfactorily within the intended design life for a particular production batch, application domain, operation duty and customer use. Commercial vehicle industry is driven by returns that a vehicle gives, on the investments made, which depend on parameters like minimum turnaround time, lesser breakdowns, optimized maintenance interval and cost of operation etc. Severe operating conditions, regular customer abuse and higher expectations from products (as expected by Indian customer-base) demand a need to deliver more robust and reliable products.
2010-10-25
Technical Paper
2010-01-2135
Gregory Davis, Craig Hoff
Currently, a majority of the ‘gasoline’ sold at the pumps in the United States is a nominal blend of 90% gasoline and 10% ethanol. This mixture is commonly referred to as E10. This paper reports on a study conducted to determine the effects of E10 on the fuel system performance of vintage automobiles. The study focused on the potential degradation in performance of the carburetors and fuel pumps due to exposure to E10. Six fuel systems were selected for study including the 1948 Flathead Ford, 1958 Volkswagen Beetle, 1962 Ford Falcon, 1969 Chevrolet Bel Air and 1970 Chrysler New Yorker. The components tested were either rebuilt original equipment or new aftermarket replacement parts, depending on availability. Although the components tested were not all original equipment parts, they represent a reasonable sample of the types of parts likely to be found in vintage vehicles currently on the road. The fuel system components were tested under both dynamic and static conditions.
2010-10-25
Journal Article
2010-01-2160
Steven J. Schmieg
Unique silver/alumina (Ag-Al₂O₃) catalysts developed using high-throughput discovery techniques in collaboration with BASF Corporation were investigated at General Motors Corporation under simulated lean-burn engine exhaust feed conditions for the selective catalytic reduction of NOx using hydrocarbons (HC-SCR). Hydrocarbon mixtures were used as the reductant to model the multi-component nature of diesel fuel and gasoline. Previous work has shown promising HC-SCR results in both laboratory reactor and engine dynamometer testing. This report investigates several aspects of HC-SCR catalyst durability, including thermal durability, sulfur tolerance, and hydrocarbon deactivation.
2010-04-12
Technical Paper
2010-01-0492
YoungJin Seo
The verification of the durability for vehicle body and chassis components is a basic requirement for the vehicle development process. For this, automotive company performs durability test on the proving ground or predict the durability using CAE technology. The representative proving ground test that verifies the durability of vehicle body and chassis components are belgian(hereinafter B/G) and cross-country(hereinafter X/C) test road. The B/G test road verifies the durability of body and chassis components for periodic road load that the vehicle undergoes while travelling on a rough road with regular speed. The X/C test road is composed of squat, dive, bumping and bottoming test modes and this test verifies the durability under aperiodic road load. Because of the relatively long test load of X/C, the road load signal of X/C is too long and enormous to apply it to durability analysis.
2010-04-12
Technical Paper
2010-01-0495
Indranil Bhattacharyya, Siddharth Unadkat, Dharmendrasinh Matieda
With an increasing demand to reduce the product development time cycle from concept-to-vehicle, weight saving effort and less prototype initiative, CAE evaluation technique in the vehicle durability development must allow the computer simulation to reproduce the actual driving condition over a proving ground. This paper describes the case study to predict the durability performance of full vehicle using vehicle FE parts in ADAMS model. The objective is to carry out full vehicle simulation in actual road load condition using reduced full vehicle FE model, condensed with the ADAMS model. The measured acceleration is applied to the vehicle FE model and dynamic loads converted to equivalent static loads. The FE model solved in MSC.Nastran® with number of static load subcases converted from the measured proving ground road data. It also verifies the validity of the evaluation methodologies by simulation-to-experiment comparisons.
2011-04-12
Journal Article
2011-01-0321
Tejal Kanitkar, Dragoljub Kosanovic
This paper presents a method for reliability assessment of the electric grid with distributed generation providing support to the system. Evaluation of customer controlled distributed generation contribution is done for two cases; the first case analyses distributed generation wherein generation units export power to the grid. The second case analyses onsite generation wherein units handle loads at individual customer sites, thus relieving grid congestion. Reliability parameters for the distributed generation systems were obtained from data collected from existing systems that have been in operation for an extended period of time. Calculations are performed on the IEEE-Reliability Test System. The state duration sampling approach using Monte Carlo simulations is employed to evaluate the ability of the system to meet demand requirements. The impact of distributed generation on the utility controlled grid as well as on individual customer reliability is evaluated.
2011-04-12
Technical Paper
2011-01-0270
Leigh Berger, Lisa Fallon, Michael G. Carpenter
This study documents a method developed for dynamically measuring occupant pocketing during various low-speed rear impact, or “whiplash” sled tests. This dynamic pocketing measurement can then be related to the various test parameters used to establish the performance rating or compliance results. Consumer metric and regulatory tests discussed within this paper as potential applications of this technique include, but are not limited to, the Insurance Institute for Highway Safety (IIHS) Low Speed Rear Impact (LSRI) rating, Federal Motor Vehicle Safety Standard (FMVSS) 202a, and European New Car Assessment Program (EURO-NCAP) whiplash rating. Example metrics are also described which may be used to assist in establishing the design position of the head restraint and optimize the balance between low-speed rear impact performance and customer comfort.
2011-04-12
Technical Paper
2011-01-0464
Renee Hotton
As customer dissatisfaction with interior trim components is tracked by the JDPowers question on “surface durability”, there is a need to increase the durability of the parts that are molded in color. In particular, door trim panel lowers are susceptible to surface damage which results in an unfavorable appearance. To address this issue, an assessment of the various factors that can affect surface durability was conducted using talc filled TPO materials in order to determine the optimum set of physical properties. The team used Design for Six Sigma (DFSS) methodology. A Taguchi orthogonal experiment was used and included control system factors of material, grain, gloss, and color. Noise factors included molding process parameters, aging, and piece to piece variation. The output was a measure of the scratch resistance of the molded plaque which was defined by a Delta L calculation.
2011-04-12
Technical Paper
2011-01-0466
Mohammad R. Movahhedy, Saeed khodaygan
The process capability indices are widely used to measure the capability of the process to manufacture objects within the required tolerance. Fit quality is mainly dominated by the distribution of fit dimensions, i.e., a gap dimension. As the fit dimensions are very difficult to be measured in mass production, they are not to be considered as a direct inspection objective. The quality inspection and evaluation relative to fit quality are focused on whether the processes of assembly requirements are conformed with their specification limits respectively. Fit quality specification can be indicated by the process capability indices of mating parts. In this paper, the statistical-based process capability analysis method is presented to estimate ability of manufacturing process for considering of assembly requirements and fit quality in a mechanical assembly with asymmetric tolerances.
2010-04-12
Technical Paper
2010-01-1308
Yi Gao, Ray Long, Yong Pang, Magnus Lindenmo
With electric vehicles (EVs) and hybrid electric vehicles (HEVs) set to grow in the coming years, design optimizations of electric motors for automotive applications are receiving more attention. Under demanding duty cycles, the moving part within a motor, the rotor, may experience high and varying stresses, which may lead to fatigue failure. Therefore, engineers are facing challenges in designing efficient and durable motors, especially for interior permanent-magnet (IPM) motors, in which the rotors have embedded magnets with small "bridges" of laminated electrical steel to keep the magnets in place. Cost-effective stators and rotors are made from electrical steels, with high magnetic permeability and low power losses. However, national and international standards for electrical steels do not specify mechanical properties. Steel producers would normally state typical mechanical properties only, and no fatigue properties are available in published literature.
2010-04-12
Technical Paper
2010-01-1108
Farzin H. Montazersadgh
Valve lift is of major importance when considering engine performance, valvetrain durability and NVH. Automating valve lift design and optimization is challenging since there are numerous variables that define the profile and many kinematic and dynamic objectives have to be considered. The kinematic and dynamic objectives for engine performance, valvetrain durability and NVH are conflicting which complicates the automation of the process even more. For example, engine performance requires the valve to open and close in a short period of time which means high valve velocity and acceleration, where as valvetrain durability and NVH require lowering valve seating velocity and acceleration for better dynamic control and reduced impact noise. In this study, a tool has been developed to design and optimize valve lift profile without a starting point and based on kinematic and dynamic design constraints.
2010-04-12
Technical Paper
2010-01-0500
Abhijit Londhe, Aparajita Sen
The cylinder block for the power train has always been a classic example of concurrent engineering in which disciplines like NVH, Durability, thermal management and lubrication system layout contribute interactively for concept design. Since the concept design is based on engineering judgment and is an estimated design, the design iterations for optimization are inevitable. This paper aims at outlining a systematic approach for design of crankcase for fatigue which would eliminate design iterations for durability. This allows a larger scope for design improvement at the concept stage as the design specifications are not matured at this stage. A process of stress optimization is adopted which gives accurate dimensional input to design. The approach is illustrated with a case study where an existing crankcase was optimized for fatigue and significant weight reduction was achieved.
2010-04-12
Technical Paper
2010-01-0636
Kapila Wadumesthrige, Nicholas Johnson, Mark Winston-Galant, Eric Sattler, Noel Bezaire, Sidong Zeng, Steven Salley, Ka Yuen Ng
The feasibility of using ultra low sulfur diesel (ULSD), synthetic paraffinic kerosene (S-8), military grade jet fuel (JP-8) and commercial B20 blend (20% v biodiesel in ULSD) in a power generator equipped with a compression ignition (CI) engine was investigated according to the MIL-STD-705C military specifications for engine-driven generator sets. Several properties of these fuels such as cetane number, lubricity, viscosity, cold flow properties, heat of combustion, distillation temperatures, and flash point, were evaluated. All fuels were tested for 240 hours at a stationary load of 30 kW (60% of full load) with no alteration to the engine calibrations. The brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), frequency, and power of the generator using S-8, JP-8 and B20 were compared with the baseline fuel ULSD.
2010-04-12
Technical Paper
2010-01-0646
Marco Junglas, Ruediger Eick, Amir Kazeminia, Dirk Soeffker
During development process phases, mechatronic systems needs to be quantified to decide in early design phase which topology or hardware satisfy the safety requirements regulated by law. The regulations by law are focused especially to reliability and safety oriented aspects of safety relevant systems or components. The contribution deals with the automation of formal processes from design to the generation of reliability-oriented evaluation allowing the consideration of alternatives and appearing conflicts between several additional aspects like cost, spatial needs etc.. During design stage, when relevant system factors are determined, the system architecture is designed, and a function oriented topology tree is generated, the construction of the reliability-oriented structure (topology), which is used to consider the reliability-oriented aspects, can be made.
2010-04-12
Journal Article
2010-01-0644
Amandeep Singh, Zissimos P. Mourelatos
Reliability is an important engineering requirement for consistently delivering acceptable product performance through time. As time progresses, the product may fail due to time-dependent operating conditions and material properties, component degradation, etc. The reliability degradation with time may increase the lifecycle cost due to potential warranty costs, repairs and loss of market share. Reliability is the probability that the system will perform its intended function successfully for a specified time interval. In this work, we consider the first-passage reliability which accounts for the first time failure of non-repairable systems. Methods are available in the literature, which provide an upper bound to the true reliability which may overestimate the true value considerably. This paper proposes a methodology to calculate the cumulative probability of failure (probability of first passage or upcrossing) of a dynamic system, driven by an ergodic input random process.
2010-04-12
Journal Article
2010-01-0696
Amandeep Singh, Zissimos P. Mourelatos
The system response of many engineering systems depends on time. A random process approach is therefore, needed to quantify variation or uncertainty. The system input may consist of a combination of random variables and random processes. In this case, a time-dependent reliability analysis must be performed to calculate the probability of failure within a specified time interval. This is known as cumulative probability of failure which is in general, different from the instantaneous probability of failure. Failure occurs if the limit state function becomes negative at least at one instance within a specified time interval. Time-dependent reliability problems appear if for example, the material properties deteriorate in time or if random loading is involved which is modeled by a random process. Existing methods to calculate the cumulative probability of failure provide an upper bound which may grossly overestimate the true value.
2010-04-12
Technical Paper
2010-01-0694
Lev Klyatis
The paper demonstrates the results of the analysis of reliability, quality and durability in the industrial areas (automotive, aerospace, electronics, etc.), and shows the reasons for the negative aspects of this situation and how to eliminate them. Automotive vehicles recalls have increased dramatically over the years. In the automotive industry the companies, which have a high reputation in quality and reliability, have a much lower reliability and durability record than people think. Analysis discloses that in Europe recalls mostly affect buyers in the German market. This situation relates to vehicles for the Army too. In the electronics area the situation is not any better. The paper gives many examples of the current situation.
2010-04-12
Journal Article
2010-01-0721
Lingyang Li, Yunqing Zhang, Shiwei Wu, Liping Chen
Elastomeric bushings are widely used in the passenger cars to make the cars have an ideal vehicle Noise, Vibration and Harshness (NVH) performance. However, elastomeric bushings also influence on the vehicle handling, ride and the durability performance of each component in the vehicle suspension system. It is relatively easy and cost effective to change the compliance of the bushing components compared with other method because they are made of elastomeric materials. The design of an elastomeric bushing is really a big challenge. One of the main difficulties comes from the different target compliance is wanted according to the handling, ride and durability demand at each different orientation (indicated by X Y Z) of the bushing. In this paper the following procedure was used for optimization of suspension elastomeric bushing compliance. Firstly, a detailed multi-body model was built including the nonlinear bushing effects and lower control arm flexibility.
2011-04-12
Technical Paper
2011-01-0225
Sam Scime
For decades, the industry standard for laboratory durability simulations has been based on reproducing quantified vehicle responses. That is, build a running vehicle, measure its responses over a variety of durability road surfaces and reproduce those responses in the laboratory for durability evaluation. To bring a vehicle to market quickly, the time between tightening the last bolt on a prototype test vehicle and starting the durability evaluation test must be minimized. A method to derive 4-Post simulator displacements without measuring or predicting vehicle responses is presented.
2011-04-12
Technical Paper
2011-01-0194
Pierre Santacreu, Saghi Saedlou, Laurent FAIVRE, Antoine ACHER, Johan Leseux
One way to respect the Euro 5 depollution norm is the downsizing of the engine, which leads to more severe in-use operating conditions especially an increase of the exhaust gas temperature. Consequently, the hot part of the exhaust system, i.e., from manifold to the catalytic converter, could be subjected to maximal temperature up to 1000°C. Moreover, an improved durability and longer life guaranties are also required for such parts. In this context, a new ferritic stainless steel grade has been developed, named K44X (AISI 444, EN 1.4521), which fulfills these new specifications and that could be applied for both fabricated manifold and turbocharger shells. The K44X, with a chromium content of 19% (weight), an addition of 2% molybdenum and 0.6% of niobium, offers excellent high temperature properties like cyclic oxidation, creep and thermal fatigue resistance, a low thermal expansion coefficient.
2011-04-12
Journal Article
2011-01-0187
Hamid Ansari Ardeh, Makarand Datar, Manoj kumar Jagadeesan, Dan Negrut
This paper discusses an approach to construct a high fidelity surrogate tire model using a two-phase optimization-based algorithm that draws on data generated by off-line nonlinear ABAQUS tire simulations. It subsequently describes the process of Simulink-based interfacing of the resulting surrogate model to a full ADAMS vehicle model to enable accurate and expeditious durability studies. The two-phase surrogate model construction relies on an identification method that draws on the Instantaneous Center Manifold (ICM) theory. In the proposed method, a generally forced non-autonomous nonlinear structural system is represented as a sequence of harmonically excited autonomous nonlinear systems. The close-form solution of each of these systems is produced using the ICM theory. The first phase of the surrogate model construction uses an optimal Orthogonal Matching Pursuit (OMP) algorithm to unify all ICMs used to approximate the reaction force of the tire at its spindle.
2011-04-12
Journal Article
2011-01-0061
Tadashi Naito, Hirokazu Kobayashi, Yuta Urushiyama, Kunihiro Takahashi
A new index U* for evaluating load path dispersion is proposed, using a structural load path analysis method based on the concept of U*, which expresses the connection strength between a load point and an arbitrary point within the structure. U* enables the evaluation of the load path dispersion within the structure by statistical means such as histograms and standard deviations. Different loading conditions are applied to a body structure, and the similarity of the U* distributions is evaluated using the direction cosine and U* 2-dimensional correlation diagrams. It is shown as a result that body structures can be macroscopically grasped by using the U* distribution rather than using the stress distribution. In addition, as an example, the U* distribution of torsion loading condition is shown to comprehensively include characteristics of the U* distribution of other loading conditions.
2011-04-12
Journal Article
2011-01-0509
Megumu Oshima, Kanya Nara
This paper describes the development of a design method and process for quality variation control. Conventional approaches utilizing Taguchi method [6,7,8] can quantify the sensitivities of parts characteristics on a system characteristic from both viewpoints of nominal value and variation. But the interpretation of the sensitivities depends on engineers' judgments. At the new process, function deployment has been introduced as the tool for breaking down hierarchically vehicle performance to the level of parts characteristics. And the relation between vehicle performance and parts characteristics is formulated based on a physical model in order to interpret the sensitivities more technically. The methodology combining the formulated function deployment and Taguchi method is referred to as design response analysis and variation effect analysis. These approaches can facilitate the interpretation of the quantified sensitivities considering the mechanism.
2011-04-12
Journal Article
2011-01-0485
Marko Nagode, Michael Hack
In the last decades the development time of vehicles has been drastically reduced due to the application of advanced numerical and experimental methods. Specifications concerning durability and other functional attributes for every new model improve for every vehicle. In particular, for machines and components under variable multiaxial loading, fatigue evaluation is one of the most important steps in the design process. Appropriate material testing and simulation is the key to efficient life prediction. However, the life of automotive components, power plants and other high-temperature facilities depends mostly on thermo-mechanical fatigue (TMF). This is due to the normally variable service conditions, which contain the phases of startup, full load, partial load and shut-down.
2011-04-12
Technical Paper
2011-01-0490
Sharvin Motamedi, John Dennis, Ted T. Stawiarski, A.K. Khosrovaneh, Li L. Sun, Mohamed El-Sayed
Large hood mounted plastic trim components are subjected to complex and often extreme loading conditions. Typical loading conditions include solar and thermal cycling, as well as road and powertrain induced vibrations, aero lift and buffeting, and mechanical loads such as car wash. For the above components understanding and classifying the typical loading conditions is an essential and important step in achieving long term quality. This paper discusses different approaches to the design, analysis, development, and testing of plastic trim components. Samples of analysis and test results are presented to demonstrate how to identify and prevent the loss of the part function. Some useful guidelines and practices for addressing thermal expansion, dimensional variation, and redundancy in attachments are also discussed.
2010-04-12
Technical Paper
2010-01-1209
Rance Stehouwer
As global automotive manufacturers prepare for the introduction of HFO-1234yf as the low GWP refrigerant solution in Europe, concern over compressor durability and material compatibility still remain. This preliminary study evaluates several different compressor types on several different tests to address these concerns. Compressor performance and teardown results are shared.
2010-04-12
Technical Paper
2010-01-0852
Xian Zhang, Pierluigi Pisu, Todd J. Toops
Of the fuel cells being studied, the proton exchange membrane fuel cell (PEMFC) is viewed as the most promising for transportation. Yet until today, the commercialization of the PEMFC has not been widespread in spite of its large expectation. Poor long term performances or durability, and high production and maintenance costs account for the main reasons. For the final commercialization of fuel cell in transportation field, the durability issue must be addressed, while the costs should be further brought down. In the meantime, health-monitoring and prognosis techniques are of great significance in ensuring the normal operation of the fuel cell and preventing or predicting its likely abrupt and catastrophic failure. In this paper, an analytical formulation of a damage accumulation law for fuel cell is presented.
2013-04-08
Technical Paper
2013-01-1330
Shady Baher El Safty
Purpose - This research aimed to investigate the process of quality culture development in automotive industry in in order to identify the critical success factors. Design/methodology/approach - A review of relevant literature is used to identify potential critical success factors for quality culture development. The research had targeted quality directors, quality managers, and quality employees, and consultants working in automotive industry. Data were collected with an electronic survey which included 20 close ended questions, each measured by using five-point scale, Out of total 150 questionnaire distributed, 60 useable responses were received resulting in 40% response rate. A judgmental sampling technique had been selected. Both descriptive and inferential statistics had been used to analyze this data.
2013-04-08
Journal Article
2013-01-1165
Abhijit Londhe, Suhas Kangde
In current scenario, virtual validation is one of the important phase for any new product development process. The initial step for virtual validation for durability analysis of vehicle is to understand the loads which are transmitted to body from the roads. In current methodology standard 3g load cases are considered. These are worst load cases which show more number of high stress locations on vehicle. In actual vehicle running condition, dynamic loads are coming on vehicle structure. These dynamic loads can be obtained by measuring the loads coming on the vehicle through road load data acquisition system. The use of measured loads posed challenges due to the non-availability of representative mule in the initial phase of vehicle development. To overcome these challenges, Mahindra & Mahindra developed a new approach which enabled the direct substitution of analytically synthesized loads for measured data.
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.
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