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Viewing 211 to 240 of 1655
2014-04-01
Technical Paper
2014-01-0747
Youji Hiraoka, Katsunari Yamamoto, Tamotsu Murakami, Yoshiyuki Furukawa, Hiroyuki Sawada
Abstract The authors propose computerized support for Fault Tree Analysis (FTA) based on new knowledge management in product design. FTA is a method of analyzing and visualizing the causes of a fault event by Fault Tree diagram (FT diagram) that has a tree structure with logical step. Many methods of support for FTA are studied, but they are not effective for our FTA. We have developed the system of Computer-Aided FTA (FTAid) for design engineers by the collaborative research group (JATCO Ltd, The University of Tokyo and National Institute of Advanced Industrial Science and Technology). We reported this system in SAE2012 World Congress. After that, the knowledge management for FTA and new functions of this system have been studied continuously. In this paper we report that FT diagrams used FTAid improved to be useful for design engineers are analyzed based on individual qualification and skill of FTA, we study improvement of FTAid and the FTA education system.
2014-04-01
Technical Paper
2014-01-0724
Derek R. Braden, David M. Harvey
Abstract There is a continual growth of test and validation in high reliability product applications such as automotive, military and avionics. Principally this is driven by the increased use and complexity of electronic systems deployed in vehicles, in addition to end user reliability expectations. Higher reliability expectations consequently driving increased test durations. Furthermore product development cycles continue to reduce, resulting in less available time to perform accelerated life tests. The challenge for automotive electronic suppliers is performing life tests in a shorter period of time whilst reducing the overall associated costs of validation testing. In this paper, the application of prognostic and health monitoring techniques are examined and a novel approach to the validation and testing of automotive electronics proposed which it is suggested may be more cost effective and efficient than traditional testing.
2014-04-01
Journal Article
2014-01-0722
Andre Kleyner
This paper discusses the effect of the field stress variance on the value of demonstrated reliability in the automotive testing. In many cases the acceleration factor for a reliability demonstration test is calculated based on a high percentile automotive stress level, typically corresponding to severe user or environmental conditions. In those cases the actual field (‘true’) reliability for the population will be higher than that demonstrated by a validation test. This paper presents an analytical approach to estimating ‘true’ field reliability based on the acceleration model and stress variable distribution over the vehicle population. The method is illustrated by an example of automotive electronics reliability demonstration testing.
2014-04-01
Journal Article
2014-01-0731
Zhenfei Zhan, Yan Fu, Ren-Jye Yang
In vehicle design, response surface model (RSM) is commonly used as a surrogate of the high fidelity Finite Element (FE) model to reduce the computational time and improve the efficiency of design process. However, RSM introduces additional sources of uncertainty, such as model bias, which largely affect the reliability and robustness of the prediction results. The bias of RSM need to be addressed before the model is ready for extrapolation and design optimization. This paper further investigates the Bayesian inference based model extrapolation method which is previously proposed by the authors, and provides a systematic and integrated stochastic bias corrected model extrapolation and robustness design process under uncertainty. A real world vehicle design example is used to demonstrate the validity of the proposed method.
2014-04-01
Technical Paper
2014-01-0723
Valerie Earlene Bumbaca
Abstract Virtually every major automaker has announced intentions of producing an electric vehicle (EV). Hyundai Motor Group has also announced plans to sell an electric vehicle in the next several years. There is strong and increasing support for electric vehicles in the USA due to an interest in protecting the environment, limiting dependence on oil, and reducing the associated cost of petroleum-based transportation. From a durability perspective, battery performance and longevity are significant concerns. In order to better prepare for upcoming electric vehicles, Hyundai-Kia America Technical Center, Inc (HATCI) Vehicle Evaluation group is developing an EV durability test and battery lifecycle laboratory test based on real world EV customer usage. Since there is limited availability of real world customer information for electric vehicles, a program has been started to collect EV customer usage data. This will be correlated with test inputs for both road and lab testing.
2014-04-01
Journal Article
2014-01-0729
Alaa El-Sharkawy, Asif Salahuddin, Brian Komarisky
In this paper a design methodology for automotive heat exchangers has been applied which brings robustness into the design process and helps to optimize the design goals: as to maintain an optimal coolant temperature and to limit the vehicle underhood air temperature within a tolerable limit. The most influential design factors for the heat exchangers which affect the goals have been identified with that process. The paper summarizes the optimization steps necessary to meet the optimal functional goals for the vehicle as mentioned above. Taguchi's [1] Design for Six Sigma (DFSS) methods have been employed to conduct this analysis in a robust way.
2014-04-01
Technical Paper
2014-01-0746
Lev Klyatis
Abstract This paper will discuss how accurate simulation of the real world conditions and ART/ADT (accelerated reliability/durability testing) technology is influencing accurate efficiency predicting as a final goal of product/process design, manufacturing, and development. The paper begins with the overview of current approaches of predicting the efficiency for a complete product and its components with an examples of life cycle costs (LCC), empirical reliability, physics-based reliability, their benefits and risks. It includes also the history of reliability prediction. As a result of the overview, it will be conclude that one cannot ensure that predicting results will not be misinterpreted or misapplied, even though all assumptions and rationale have been meticulously documented and clearly stated.
2014-04-01
Technical Paper
2014-01-1027
Daisuke Taniguchi, Wataru Tokuhara, Yuichi Miyake
Abstract The enhancement of material durability is a key development theme for automakers since customers own cars longer. Research is being carried out to extend the lifetime of current thermoplastic polyurethane (TPU) materials by enhancing hydrolysis resistance while maintaining excellent low-temperature properties and scratch resistance. This development of enhanced hydrolysis resistance without degrading the melting properties of the material was achieved by introducing a new resin structure that is resistant to the invasion of water, acid, alkalis, and other substances causing hydrolysis.
2014-04-01
Technical Paper
2014-01-0921
Barry (Baizhong) Lin, Mike Gundle, Mike Rowley, Alan Aloe, Frederick Zweng, Eric Blackburn, Chandra Thandhayuthapani, Chandra Thonta, Edward Law, Kah Wah Long, Mike Temkin, Zachary Calkins
Abstract Fuel Tank Straps very often get different durability fatigue test results from different types of durability testing such as shaker table vibration, road test simulator (RTS) vehicle testing and proving ground vehicle durability testing. One test produces good durability results and other may indicate some durability risk. A special study was conducted to address this inconsistency. It was found that fuel level in the tank plays a big role in fuel tank strap durability. Higher fuel levels in a tank produce higher loads in straps and lower fatigue life. This paper will use a CAE fuel tank strap model and acquired proving ground strap load data to study fuel level influence in fuel tank strap durability. The fuel level study includes a full tank of fuel, 3 quarters tank of fuel, a half tank of fuel and one quarter tank of fuel.
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
Technical Paper
2014-01-0863
Takamasa Shimodaira
Abstract The aim discussed in this paper is to show a technique to predict loads input to the wheels, essential to determining input conditions for evaluation of suspension durability, by means of full vehicle simulations using multi body analysis software Adams/Car. In this process, model environments were built to enable reproduction of driving modes, and a method of reproducing the set-up conditions of a durability test vehicle was developed. As the result of verification of the accuracy of the simulations in the target driving modes, good correlation for waveforms can be confirmed. And also confirm a good correlation in relation to changes of input load due to changes in suspension specifications.
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.
2014-04-01
Journal Article
2014-01-0887
Weiguo Zhang, Rakesh Khurana, Mark Likich, Mac Lynch
Taguchi method is a technology to prevent quality problems at early stages of product development and product design. Parameter design method is an important part in Taguchi method which selects the best control factor level combination for the optimization of the robustness of product function against noise factors. The air induction system (AIS) provides clean air to the engine for combustion. The noise radiated from the inlet of the AIS can be of significant importance in reducing vehicle interior noise and tuning the interior sound quality. The porous duct has been introduced into the AIS to reduce the snorkel noise. It helps with both the system layout and isolation by reducing transmitted vibration. A CAE simulation procedure has been developed and validated to predict the snorkel noise of the porous ducted AIS. In this paper, Taguchi's parameter design method was utilized to optimize a porous duct design in an AIS to achieve the best snorkel noise performance.
2014-04-01
Technical Paper
2014-01-0880
Christian Scheiblegger, Nantu Roy, Orlando Silva Parez, Andrew Hillis, Peter Pfeffer, Jos Darling
Abstract Cab mounts and suspension bushings are crucial for ride and handling characteristics and must be durable under highly variable loading. Such elastomeric bushings exhibit non-linear behavior, depending on excitation frequency, amplitude and the level of preload. To calculate realistic loads for durability analysis of cars and trucks multi-body simulation (MBS) software is used, but standard bushing models for MBS neglect the amplitude dependent characteristics of elastomers and therefore lead to a trade-off in simulation accuracy. On the other hand, some non-linear model approaches lack an easy to use parameter identification process or need too much input data from experiments. Others exhibit severe drawbacks in computing time, accuracy or even numerical stability under realistic transient or superimposed sinusoidal excitation.
2014-04-01
Technical Paper
2014-01-0715
Jin Woo Lee, Efstratios Nikolaidis
Abstract Inflatable space structures can have lower launching cost and larger habitat volume than their conventional rigid counterparts. These structures are made of composite laminates, and they are flexible when folded and partially inflated. They contain light-activated resins, and can be cured with the sun light after being inflated in space. A spacecraft can burst due to cracks caused by meteor showers or debris. Therefore, it is critical to identify the important fracture failure modes, and assess their probability. This information will help a designer minimize the risk of failure and keep the mass and cost low. This paper presents a probabilistic approach for finding the required thickness of an inflatable habitat shell for a prescribed reliability level, and demonstrates the superiority of probabilistic design to its deterministic counterpart.
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
2014-01-1437
Melanie Zielenski, Peter Downes, Darren Jelbert
Abstract Heavy duty diesel engine development has always faced high customer durability requirements, short development timelines and increasingly stringent emissions legislations. However, more frequently heavy duty engines are being used in multiple vehicle platforms across the globe with increasingly stringent quality demands in emerging markets. In order to meet engine life requirements, Delphi Diesel Systems has adapted accepted validation procedures to evaluate their system performance for the global market. In addition to durability and structural testing Delphi Diesel Systems has introduced specialized tests to validate their product at extremes of environmental conditions and fuel properties and has increased OEM collaboration. This paper details some of the adjustments made to the validation test suite to meet the specific challenges of the Heavy Duty market.
2014-04-01
Technical Paper
2014-01-1636
Narinder Kumar, Amit Gautam, Vineet Gupta
Abstract Front end accessory drive (FEAD) system explained in this paper is a sub-system of an engine. In FEAD system, a poly-v belt is used to drive the alternator and water pump by transmitting power from crankshaft pulley. In a new vehicle development program, durability targets of FEAD system are based on required life of poly-v belt, its static tension readjustment interval and replacement frequency. To meet these durability targets following methodology is applied in design stage:- 1 Simulation of FEAD system to calculate the theoretical life of belt2 Part level testing of belt as per SAE J2432 These methods give sufficient information on belt durability. However in actual usage, certain failures are prone to happen and enormous difference is always observed between theoretical and actual life of belt. This paper describes the traditional stair-case approach followed to optimize the FEAD system based on the outcome of durability tests.
2014-04-01
Technical Paper
2014-01-0399
Mohamed Sithik, Rama Vallurupalli, Barry (Baizhong) Lin, Subash Sudalaimuthu
Abstract In recent trend, there is a huge demand for lightweight chassis frame, which improves fuel efficiency and reduces cost of the vehicle. Stiffness based optimization process is simple and straightforward while durability (life) based optimizations are relatively complex, time consuming due to a two-step (Stress then life) virtual engineering process and complicated loading history. However, durability performances are critical in chassis design, so a process of optimization with simplified approach has been developed. This study talks about the process of chassis frame weight optimization without affecting current durability performance where complex durability load cases are converted to equivalent static loadcases and life targets are cascaded down to simple stress target. Sheet metal gauges and lightening holes are the parameters for optimization studies. The optimization design space is constrained to chassis unique parts.
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
2014-01-0233
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
Technical Paper
2014-01-0718
Venkatesh Agaram
Abstract Cars and trucks today are getting fitted with a large number of sensors in an effort to improve safety, comfort, fuel economy and emissions. The revenue from the automotive sensors market, driven by intense global competition and regulation, is expected to double over the next decade, while the size of the automotive sensors market, over the same period, is expected to triple. The field of sensor-fusion is highly multi-disciplinary, making use of technics from artificial intelligence, pattern recognition, digital signal processing, control theory, and statistical estimation. Sensor-fusion strategies based on probability theory, evidence theory, fuzzy theory, and possibility theory are being explored in different industries, e.g., defense, robotics, automotive, etc. The majority of sensor-fusion operators are based on optimistic assumptions about reliability of the information generated by the sensors.
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.
2013-11-27
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.
2013-10-15
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.
2013-10-15
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.
2013-10-14
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
2013-01-2378
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.
Viewing 211 to 240 of 1655