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Viewing 1 to 30 of 1009
2014-11-11
Technical Paper
2014-32-0113
Vipin Sukumaran T., Sumith Joseph, Kamal kant, Vipin P, Mohan D Umate
Abstract In recent past, the two stroke vehicle manufacturers are continuously motivated to develop extreme low emission vehicle for meeting the requirements of emissions regulations. To achieve this emission compliance, manufacturers have developed engines with better induction system, improved ignition timings, increased compression ratio (C.R) and larger after-treatment devices. As an effect of above changes, engine operating temperatures are quite high which reduces the block-piston life. Even though, typical two stroke engines are forced cooled engines, there is a lot of potential for optimizing block cooling to reduce maximum liner temperature and block gradient for enhancing block-piston durability. This paper presents an experimental study of various measures to reduce liner temperature for a two stroke, single cylinder 70 c.c. engine used for two wheeler application.
2014-10-13
Technical Paper
2014-01-2707
Brian C. Kaul, Benjamin J. Lawler, Charles E.A. Finney, Michelle L. Edwards, Robert M. Wagner
Abstract Advances in engine controls and sensor technology are making advanced, direct, high-speed control of engine combustion more feasible. Control of combustion rate and phasing in low-temperature combustion regimes and active control of cyclic variability in dilute SI combustion are being pursued in laboratory environments with high-quality data acquisition systems, using metrics calculated from in-cylinder pressure. In order to implement these advanced combustion controls in production, lower-quality data will need to be tolerated even if indicated pressure sensors become available. This paper examines the effects of several data quality issues, including phase shifting (incorrect TDC location), reduced data resolution, pressure pegging errors, and random noise on calculated combustion metrics that are used for control feedback.
2014-09-30
Technical Paper
2014-01-2430
Rajendra Vivekananda Hosamath, Muralidhar Nagarkatte
Abstract All top ranking automobile companies in the world believe in single word “Quality” and maintaining quality standards is a philosophy, a belief in which we live, a task which cannot be put aside for another day. To achieve the world class quality standards Divgi-Warner meticulously follows a highly effective tool known as Quality System Basics (QSB).QSB helps Divgi-Warner to preserve integrity of commitment to achieve manufacturing excellence. This case study covers the Quality System Basics implementation experience of Divgi-Warner Pvt. Ltd. (DWPL) India, a BorgWarner's plants located at Pune and Sirsi in India.
2014-09-30
Journal Article
2014-01-2308
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.
2014-09-30
Journal Article
2014-01-2307
Zhigang Wei, Limin Luo, Shengbin Lin
This paper reviews the correlation concepts and tools available, with the emphasis on their historical origins, mathematical properties and applications. Two of the most commonly used statistical correlation indicators, i.e., modal assurance criterion (MAC) for structural deformation pattern identification/correlation and the coefficient of determination (R2) for data correlation are investigated. The mathematical structure of R2 is critically examined, and the physical meanings and their implications are discussed. Based on the insights gained from these analyses, a data scatter measure and a dependency measure are proposed. The applications of the measures for both linear and nonlinear data are also discussed. Finally, several worked examples in vehicle dynamics analysis and statistical data analyses are provided to demonstrate the effectiveness of these concepts.
2014-09-30
Technical Paper
2014-01-2306
Mathialagan Balaji, Hemant Bhatkar, Jeya Kumar Ranjith Kumar, Ananthan Anbazhagan, Pramod Palkar
Abstract Rear axles are subjected to bending and torsion loads out of which Bending loads are predominant. In case of Off road vehicles Bi Axial- combination of Bending and torsion loads were predominant, because of axle construction and vehicle usage pattern. Defined test procedures are available for bending durability and torsional durability evaluation of axles. In this experiment, new test methodology was developed for Bi Axial durability evaluation of Off road vehicle rear axle with single servo hydraulic linear actuator. For creating Bi Axial load condition, we may need multiple actuators and complicated fixtures. Axle wheel end is constrained at an angle with suitable fixtures for creating the bending and torsional forces together in the axle. Servo hydraulic linear actuator with suitable loading arm is used for applying the test torque in the axle input flange.
2014-09-30
Technical Paper
2014-01-2312
Venkatesan Chokkalingam, Mohan Rao
Abstract The durability of the components in a vehicle plays one of the major roles in its life cycle cost. The powertrain mount is one such component since its rubber characteristics have significant impact on the vehicle's NVH and fatigue life. This paper presents the enhanced durability benefits obtained by changing the polymer composition, manufacturing methods and design optimization of a powertrain mount for an off-road commercial vehicle. The methodology involved characterization[2] of the existing mount, arriving a new compound formulation, making of prototypes, experimental validation for durability[3] and repeatability in the laboratory combined with rigorous on field vehicle trials. NVH measurements were also carried out on the improved mounts. The above exhaustive exercise resulted in the development of a comprehensively far better mount than an existing mount with improved durability without compromise on NVH properties.
2014-09-30
Technical Paper
2014-01-2297
Mehmet Bakir, Murat Siktas, Serter Atamer
Abstract In today's world, there are a prominent number of weight and cost reduction projects within the vehicle engineering development activities. Regarding this phenomenon, a complete optimization study is applied to a leaf spring assembly, which has 4 leaves and which is used in heavy duty trucks, by reducing the number of leaves down to 3 together with weight and cost reductions. At the first step of the project, the stiffness of the leaf spring is calculated with in-house software based on mathematical calculations using the thickness profile of the leaves. Then the results of these calculations are compared with non-linear elastic leaf spring calculations which are conducted with FEA. This elastic leaf spring finite element model is transferred into Multi-Body-Simulation (MBS) model in order to determine the forces acting on the leaf spring.
2014-09-16
Journal Article
2014-01-2144
Marco Amrhein, Jason Wells, Eric Walters, Seana McNeal, Brett Jordan, Peter Lamm
Abstract Transient operating conditions in electrical systems not only have significant impact on the operating behavior of individual components but indirectly affect system and component reliability and life. Specifically, transient loads can cause additional loss in the electrical conduction path consisting of windings, power electronic devices, distribution wires, etc., particularly when loads introduce high peak vs. average power ratios. The additional loss increases the operating temperatures and thermal cycling in the components, which is known to reduce their life and reliability. Further, mechanical stress caused by dynamic loading, which includes load torque cycling and high peak torque loading, increases material fatigue and thus reduces expected service life, particularly on rotating components (shaft, bearings).
2014-09-16
Technical Paper
2014-01-2262
Rostislav Sirotkin, Galina Susova, Gennadii Shcherbakov
Abstract Within the Russian aviation industry the necessary level of reliability risks related to the failures of aircraft mechanical parts and systems vital to the safety of flight is assured via the system of activities aimed at influencing the parameters of critical parts (CP). The goal of the system is to provide a relationship between activities aimed at prevention of dangerous failures at all phases of airplane life cycle. The system operation is regulated by the normative documents and by controlling their observance. Normative documents containing requirements and recommendations were developed about 15 years ago based on the industry experience and traditions and taking into account the requirements of AS9100 series of international standards [2] wherever possible. The documents were developed taking into account typical safety management errors outlined in [1].
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
2014-01-0863
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
2014-01-0887
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
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
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
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
2014-01-0718
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.
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
2014-01-0722
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
Technical Paper
2014-01-0749
Ram Kiran Tholeti, Shyamsundar Kumbhar, Nainish Kumar B, R Govindarajan
Abstract Scooter segment growth is tremendously increasing in India. The increased competition challenges automotive manufacturers to deliver the high quality and high reliable product to the market. Higher reliability involves increased durability testing which involves time and cost. Stress testing a part of durability is initially conducted on prototype vehicles for structural design validation and then later on production units to ensure its structural integrity. The obtained data from the tests can be used for future structural design improvements. Scooters with small tires, suspension limitations transfers more loads to structure, challenges engineers to design robust structure without compromising on weight much. It is necessary to look at Real World Usage Pattern (RWUP) and to create a stress life cycle block for simulation of accelerated testing, thereby optimizing the testing time and the development costs.
2014-04-01
Technical Paper
2014-01-0774
Zhigang Wei, Limin Luo, Shengbin Lin, Dmitri Konson
Abstract A modern definition of quality control and improvement is the reduction of variability in processes and products. The reduced variability can be directly translated into lower costs, better functions and fewer repairs. However, the final quality of processes and products is sometimes derived from other measured variables through some implicit or explicit functional relationships. Sometimes, a tiny uncertainty in a variable can produce a huge uncertainty in a derived quantity. Therefore, the propagation of uncertainty needs to be understood and the individual variables need to be well controlled. More importantly, the critical factors that affect quality the most should be identified and thoroughly investigated. Design of experiments and statistical control plays central roles in finding root cause of failure, reduction of variability and quality improvement.
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.
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.
2013-04-08
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
2013-01-0195
Joseph G. D'Ambrosio, Rami Debouk
ASIL decomposition is a method described in the ISO 26262 standard for the assignment of ASILs to redundant requirements. Although ASIL decomposition appears to have similar intent to the hardware fault tolerance concept of IEC 61508-2, ASIL decomposition is not intended to reduce ASIL assignments to hardware elements for random hardware failures, but instead focuses on functions and requirements in the context of systematic failures. Based on our participation in the development of the standard, the method has been applied in different ways in practice, not all of which are fully consistent with the intent of the standard. Two potential reasons that may result in the use of “modified” ASIL algebra include the need of OEMs to partition a system and specify subsystem requirements to suppliers and the need for designers to construct systems bottom up.
2013-04-08
Technical Paper
2013-01-0854
Tao Ye
A Design for Six Sigma (DFSS) statistical approach is presented in this report to correlate a CFD cabin model with test results. The target is the volume-averaged hot-soak terminal temperature. The objective is to develop an effective correlation process for a simplified CFD cabin model so it can be used in practical design process. It is, however, not the objective in this report to develop the most accurate CFD cabin model that would be too expensive computationally at present to be used in routine design analysis. A 3-D CFD model of a vehicle cabin is the central part of the computer modeling in the development of automotive HVAC systems. Hot-soak terminal temperature is a thermal phenomenon in the cabin of a parked vehicle under the Sun when the overall heat transfer reaches equilibrium. It is often part of the simulation of HVAC system operation.
2013-04-08
Technical Paper
2013-01-0153
Lev Gorelik
A powerful methodology of reliability testing is described. This technique is based on the application of dimensional analysis. The whole process of determination of reliability consists of the choosing the relevant physical quantities, calculation the corresponding complete set of dimensionless variables, obtaining the Model Law, and the determination of the limited condition of reliability for the product (prototype). The application of the presented methodology is demonstrated on the example of the determination of reliability of revolving disc.
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.
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