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Viewing 241 to 270 of 1648
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.
2013-05-13
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
2013-01-1330
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.
2013-04-08
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
2013-01-0153
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
2013-01-0152
Lev Klyatis
This paper will discuss the first two standards in the six-part series of SAE International reliability testing documents that are being developed by the SAE G11 Reliability Committee. These two documents attempt to standardize the glossary and strategy associated with reliability testing technology. A new Glossary standard has been drafted that defines the most commonly used words and terms associated with reliability (accelerated reliability/durability) testing. It is intended to serve as a basis for reliability testing definitions and to reduce the possibility of conflicts, duplications, and incorrect interpretations either expressed or implied elsewhere in the technical literature. Terms and definitions included in this standard are important in the acquisition of weapon systems (where there is a need for precise and unambiguous technical definitions), and are expressed clearly (and without mathematical symbols whenever possible).
2013-04-08
Technical Paper
2013-01-0151
Lev Klyatis
There are no standards that directly consider practical reliability testing technology (methods and equipment). This void needs to be filled. The SAE G-11 division has approved the development of six new standards to fill this void. This paper discusses these six standards: 1) Reliability Test-Glossary; 2) Reliability Testing-Strategy; 3) Reliability Testing-Procedures; 4) Reliability Testing-Equipment; 5) Reliability Testing-Statistical Criteria for Comparison of Reliability Testing Results and Field Results; 6) Reliability Testing-Collection, Calculation, and Statistical Analysis of Reliability Testing Data, Development Recommendations for Improvement of Test Subject Reliability, Durability, and Maintainability.
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.
2013-04-08
Technical Paper
2013-01-0708
Ibrahim A. Badiru, Michael W. Neal
This paper presents subjective and objective methods for evaluating transient vehicle dynamics characteristics in four sections: (1) Definition of transient behavior in terms of four traits-agility, stability, precision, and roll support; (2) Description of subjective evaluation methods; (3) Implementation of Design for Six Sigma principles to the development of a steering robot controlled objective test for transient performance; (4) The final section of this paper uses data from simulation and road tests to demonstrate how chassis design parameters can affect transient handling performance.
2013-04-08
Journal Article
2013-01-0606
Vijitashwa Pandey, Zissimos Mourelatos
The classical definition of reliability may not be readily applicable for repairable systems. Commonly used concepts such as the Mean Time Between Failures (MTBF) and availability can be misleading because they only report limited information about the system functionality. In this paper, we discuss a set of metrics that can help with the design of repairable systems. Based on a set of desirable properties for these metrics, we select a minimal set of metrics (MSOM) which provides the most information about a system, with the smallest number of metrics. The metric of Minimum Failure Free Period (MFFP) with a given probability generalizes MTBF because the latter is simply the MFFP with a 0.5 probability. It also generalizes availability because coupled with repair times it provides a clearer picture of the length of the expected uninterrupted service. Two forms of MFFP are used: transient and steady state.
2013-04-08
Technical Paper
2013-01-0513
Aaron Williams, Jonathan Burton, Robert L. McCormick, Todd Toops, Andrew A. Wereszczak, Ethan E. Fox, Michael J. Lance, Giovanni Cavataio, Douglas Dobson, Jim Warner, Rasto Brezny, K. Nguyen, D. William Brookshear
Alkali and alkaline earth metal impurities found in diesel fuels are potential poisons for diesel exhaust catalysts. Using an accelerated aging procedure, a set of production exhaust systems from a 2011 Ford F250 equipped with a 6.7L diesel engine have been aged to an equivalent of 150,000 miles of thermal aging and metal exposure. These exhaust systems included a diesel oxidation catalyst (DOC), selective catalytic reduction (SCR) catalyst, and diesel particulate filter (DPF). Four separate exhaust systems were aged, each with a different fuel: ULSD containing no measureable metals, B20 containing sodium, B20 containing potassium and B20 containing calcium. Metals levels were selected to simulate the maximum allowable levels in B100 according to the ASTM D6751 standard.
2013-04-08
Journal Article
2013-01-1686
Yong-Yuan Ku, Ko Wei Lin, Ya-Lun Chen, Ching-Fu Liao
Due to the increasing price of crude oil, biofuel as an alternative of fossil fuels is sought to be a global-wide solution to reduce the emission of greenhouse gas. In order to compare the influence on engine which meet euro IV emission standard by using pure fossil diesel, 2% and 5% biodiesel. A long-term operation with blended 2% and 5% biodiesel by standard engine test had been evaluated in this study. The results could be referred to the consideration of marketing promotion strategy as well as government policy in Taiwan. Both B2-B5 diesel fuel (2 and 5 vol% biodiesel) and diesel fuel were employed to the same engines for testing purpose to compare the influence. The engines were equipped with an electronically controlled common-rail fuel injection system. After 500 hours full load durability operation, the key components of the engines were analyzed and characterized by a series of inspections to identify the degree of decay and wear behavior.
2013-04-08
Technical Paper
2013-01-1725
Eduardo Nocera, Rafael Antonio Bruno, Davi Silva, Jason Bieneman
Modern engine manufacturers are under pressure to continuously improve the performance of diesel engines. Government requirements and customer demands drive significant changes to power cylinder designs. Great efforts are being made to reduce emission levels and increase operating efficiencies. The power cell unit (PCU) environment is becoming more aggressive at the same time that peak cylinder pressures are increasing. Engines are expected to perform at this high level throughout their operating life with little to no degradation in performance. Besides that, greater emphasis is also being placed on fuel efficiency of the engine. In order to meet these challenges the design of a modern ring pack should consider the utilization of high wear resistance coatings aligned with new geometries to enhance oil film control and reduce friction.
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
2013-01-0511
Matthew Leustek, Sylvain Charbonnel, Jared Parsons, Hind Abi-Akar
This paper features an application study on the impact of different blend levels of commercially-supplied biodiesel on engine and aftertreatment systems' durability and reliability as well as the impact on owning and operating factors: service intervals and fuel economy. The study was conducted on a bus application with a 2007 on highway emissions equipped engine running biodiesel blends of B5, B20, and B99 for a total period approaching 4500 hours. Biodiesel of waste cooking grease feedstock was used for the majority of the testing, including B5 and B20 blends. Biodiesel of soybean feedstock was used for testing on B99 blend. No negative impacts on engine and aftertreatment performance and durability or indication of future potential issues were found when using B5 and B20. For B99 measurable impacts on engine and aftertreatment performance and owning and operating cost were observed.
2013-04-08
Journal Article
2013-01-1007
Liang Wang, Robert Burger, Yung-Li Lee, Keyu Li
In this paper, the development of random vibration testing schedules for durability design verification of engine mounted products is presented, based on the equivalent fatigue damage concept and the 95th-percentile customer engine usage data for 150,000 miles. Development of the 95th-percentile customer usage profile is first discussed. Following that, the field engine excitation and engine duty cycle definition is introduced. By using a simplified transfer function of a single degree-of-freedom (SDOF) system subjected to a base excitation, the response acceleration and stress PSDs are related to the input excitation in PSD, which is the equivalent fatigue damage concept. Also, the narrow-band fatigue damage spectrum (FDS) is calculated in terms of the input excitation PSD based on the Miner linear damage rule, the Rayleigh statistical distribution for stress amplitude, a material's S-N curve, and the Miles approximate solution.
2013-04-08
Journal Article
2013-01-1437
Dae-Un Sung, Eun-Joo Kim, June-Yeop Kim, Chun Woo Shin, Won Wook Jung
As a new vehicle is based on common vehicle platform, the durability problems of chassis components in development stage are decreasing. However a vehicle body structure is changed by exterior design and a chassis and a suspension are tuned by vehicle performance targets. The main issue on developing a new vehicle is to satisfy the durability target of a body structure and tuned suspension components. The accuracy of durability Computer Aided Engineering analysis is mainly depending on the accuracy of input loads and boundary conditions on suspension system. The input loads should be estimated accurately. These could be changed by vehicle specifications such as vehicle weight, wheel base and so on. It is also affected by the change of suspension types and tuning parameters. This paper presents the experimental parametric study results using road load data analysis techniques.
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
Journal Article
2013-01-0947
Vijitashwa Pandey, Zissimos Mourelatos
Our recent work has shown that representation of systems using a reliability block diagram can be used as a decision making tool. In decision making, we called these block diagrams decision topologies. In this paper, we generalize the results and show that decision topologies can be used to make many engineering decisions and can in fact replace decision analysis for most decisions. We also provide a meta-proof that the proposed method using decision topologies is entirely consistent with decision analysis at the limit. The main advantages of the method are that (1) it provides a visual representation of a decision situation, (2) it can easily model tradeoffs, (3) it can incorporate binary attributes, (4) it can model preferences with limited information, and (5) it can be used in a low-fidelity sense to quickly make a decision.
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
2013-01-1291
Yinhua Zheng
The majority of vehicle AC system warranty costs are a result of compressor replacement caused by excessive wear and seizure-related failures. In today's environment, compressor manufacturers can control manufacturing process well and maintain a stable product quality. Thus, compressor durability heavily relies on a durable AC system design. Both vehicle compressor suppliers have a variety of procedures and test methods to evaluate AC system and compressor durability. Often times, we still see very different compressor warranty return rates (one higher, the other lower) for the same compressor from the same production line in similar vehicle AC systems. In many cases, both AC systems passed vehicle and component durability tests. In addition, compressor manufacturing process quality was controlled well. The question remains why is there such different compressor warranty return rates?
2013-04-08
Technical Paper
2013-01-0510
Amir Ghasemi, Ming Dong, Lakshmikanth Meda, Martin Romzek
In order to have a robust exhaust system design a comprehensive durability analysis is required. This durability analysis should include thermal loads, engine vibration loading, and proving ground road loads. The dynamic performance evaluation in exhaust system development is a valuable tool to identify the best design alternative. The finite element analysis (FEA) applications in the design of automotive exhaust system have become an indispensable tool. Both the cost and cycle of the product development benefit from its usages. This paper presents a robust design procedure for the dynamic performance of exhaust system in a passenger vehicle. For dynamic analyses it is essential that the complete exhaust assembly is modeled, including manifold, a representation of the engine, and a flex decouple model. This is because dynamic excitation is predominantly comprised of unbalanced forces within the engine, which is transmitted to the exhaust system through the flex decoupling element.
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
2013-01-0837
Hidemasa Iwata, Athanasios Konstandopoulos, Kazuki Nakamura, Takafumi Kasuga, Kazutake Ogyu, Kazushige Ohno
ABSTRUCT This paper describes the durability of the filtration layer integrated into Diesel Particulate Filters (DPFs) that we have developed to ensure low pressure loss and high filtration efficiency performances which also meet emission regulations. DPF samples were evaluated in regards to their performance deterioration which is brought about by ash loading and uncontrolled regeneration cycles, respectively. Ash was synthesized by using a diesel fuel/lubrication oil mixture and was trapped up to a level which corresponded to a 240,000km run, into the DPFs both with and without the filtration layer. Afterwards, aged-DPFs were measured with respect to their permeability, pressure loss, filtration efficiency, as well as soot oxidation speed using suitable analytical methods. Consequently, it has been confirmed that there was no noteworthy deterioration of the performances in the DPF with the filtration layer.
2013-04-08
Technical Paper
2013-01-0841
Kentaro Iwasaki, Takumi Shibuta
Diesel Particulate Filter (DPF) requires higher capacity of ash materials, incombustible particulate matters derived from lubricant oil, engine wear, etc., for usage of long lifetime. Conventional DPF such as SiC-DPF has been developed by optimizing cell geometry as of octagonal inlet shapes and square outlet shapes, called as “Octosquare”. Thus-obtained SiC-DPF could improve the lifetime to previous type with square cell design. However, under ash/soot-loading, pressure drop between upstream and downstream DPF, involving in the fuel penalty for the vehicle itself, makes higher. On the other hand, it was previously proposed that aluminum titanate (AT) with hexagonal cell design shows lower pressure drop and higher endurance performance. The characteristic of the filter design consists of higher open frontal area, relating to higher ash capacity, and higher filtration area, enabling lower pressure drop with soot loading.
2013-04-08
Technical Paper
2013-01-1367
Yuki Takao, Kazuki Takeno
Bonded piston seals (BPSs) which consist of metal ring and rubber lips are used as hydraulic pistons for Automatic Transmission (AT) or Continuously Variable Transmission (CVT). While engaging clutches, BPSs preserve the hydraulic pressure, therefore it is necessary to endure number of cyclic pressure through the life. This paper describes a reliable design method of BPSs with taking account of the influence of residual stress on the fatigue limit of the metal ring. A new plastic-elastic analysis model considering Bauschinger effect is applied in order to estimate the residual stress, which generates due to metal forming process. Validation for calculated residual stress is done by X-ray diffract meter. A proofed BPS design calculated with this new FEM model shows longer fatigue life than conventional design.
2013-04-08
Journal Article
2013-01-1384
Zhen Jiang, Wei Chen, Yan Fu, Ren-Jye Yang
Reliability-based design optimization (RBDO) has been widely used to obtain a reliable design via an existing CAE model considering the variations of input variables. However, most RBDO approaches do not consider the CAE model bias and uncertainty, which may largely affect the reliability assessment of the final design and result in risky design decisions. In this paper, the Gaussian Process Modeling (GPM) approach is applied to statistically correct the model discrepancy which is represented as a bias function, and to quantify model uncertainty based on collected data from either real tests or high-fidelity CAE simulations. After the corrected model is validated by extra sets of test data, it is integrated into the RBDO formulation to obtain a reliable solution that meets the overall reliability targets while considering both model and parameter uncertainties.
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.
Viewing 241 to 270 of 1648