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Viewing 1 to 30 of 1480
2011-04-12
Technical Paper
2011-01-0244
Mark A. Smith, David Okonski
Current manufacture of alternative energy sources for automobiles, such as fuel cells and lithium-ion batteries, uses repeating energy modules to achieve targeted balances of power and weight for varying types of vehicles. Specifically for lithium-ion batteries, tens to hundreds of identical plastic parts are assembled in a repeating fashion; this assembly of parts requires complex dimensional planning and high degrees of quality control. This paper will address the aspects of dimensional quality for repeated, injection molded thermoplastic battery components and will include the following: First, dimensional variation associated with thermoplastic components is considered. Sources of variation include the injection molding process, tooling or mold, lot-to-lot material differences, and varying types of environmental exposure. Second, mold tuning and cavity matching between molds for multi-cavity production will be analyzed.
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.
2004-09-21
Technical Paper
2004-01-2816
Holly J. Thomas, Alex M. Rubin
Many questions have been directed in recent years to aircraft structural repair communities concerning bonded repairs. Areas of concern have primarily focused on surface preparation issues with the various types of composite and metallic structure, cure profiles, and quality assurance requirements. These questions have come from a variety of sources – within the OEM, from outside suppliers and from customers, both military and commercial. Some questions are asked in an effort to reduce the “down time” on an aircraft associated with these repairs. Others because of frequent “re-repairs” due to poor bond quality from a previous repair. Future design concepts are focusing on more “one-piece” types of structure that will rely on structural, durable repairs that can be performed with a minimal amount of facilities required.
2011-04-12
Journal Article
2011-01-1268
Ioan F. Campean, Edwin Henshall, David Brunson, Andrew Day, Rod McLellan, Joseph Hartley
Function analysis provides the backbone of systems engineering design and underpins the use of Design for Six Sigma and Failure Mode Avoidance tools. Identification and management of interfaces is a key task in systems engineering design, in ensuring that the system achieves its functions in a robust and reliable way. The aim of the work presented in this paper was to develop and implement a structured approach for function analysis of a complex system, which focuses on the identification and characterization of interfaces. The proposed approach is based on the principle of separation of the functional and physical domains and development of function decomposition through iteration between functional and physical domains. This is achieved by integrating some existing / known engineering tools such as Boundary Diagram, State Flow Diagram, Function Tree and an enhanced interface analysis within a coherent flow of information.
2011-04-12
Technical Paper
2011-01-1270
Shady Baher El Safty
Purpose - This research aimed to investigate the process of six-sigma implementation in automotive industry in Egypt in order to identify the critical success factors. Research design and methodology - A review of relevant literature is used to identify potential critical success factors for six-sigma implementations. The research had targeted six-sigma management, practitioners, process users, and consultants working in automotive industry in Egypt. Data were collected with an electronic survey which included 20 close ended questions, each measured by using five-point scale, Out of total 600 questionnaire distributed, 240 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.
2011-04-12
Technical Paper
2011-01-1272
Balakrishna Chinta
Great work has been done already in developing robust engineering techniques to improve ideal functions for systems and sub systems. Characterizing an ideal function as a dynamic response type is most preferred way to build quality into a product over a range of input signal values. However, when it is difficult to measure ideal functions, symptomatic outputs such as oil leaks, vibrations, and squeaks, are selected and treated as “Smaller-the-Better” response in non-dynamic response manner. A better approach is to reduce the symptomatic responses over the entire usage range. In order to accomplish this goal, engineers often switch output response and signal axes and apply dynamic response formulation for making the design robust. In this paper, a new and better formulation is proposed and compared with the other formulation. These two formulations were applied on a real automotive case study of decklid bobble and inaccuracies associated with the other formulation were discussed.
2011-04-12
Technical Paper
2011-01-1273
Ed Henshall, Ioan Campean, David Brunson
The quality of the output generated by a team is directly influenced by how well the team works together. Despite the complexity of the team system, within a typical Design for Six Sigma (DFSS) project the consideration given to the team process is often disproportionately small in comparison to that paid to the technical aspects of the project. This paper presents an efficient approach to teamwork within an engineering design context such as a DFSS project, in which team skills are modelled on DFSS technical processes allowing team members to learn both technical and teamwork skills within the common context of the technical process. DFSS engineering tools used within the framework of Failure Mode Avoidance are used to identify key potential failure modes in the team process and their effects and causes. A series of effective and efficient countermeasures to the team process failure modes are introduced as straight forward and easy to use interlinking teamwork tools.
2011-04-12
Technical Paper
2011-01-1274
Srinivasa Mandadapu, Balakrishna Chinta, Brian Jutila, Maria Schoenefeld
Roof racks are designed for carrying luggage during customers' travels. These rails need to be strong enough to be able to carry the luggage weight as well as be able to withstand aerodynamic loads that are generated when the vehicle is travelling at high speeds on highways. Traditionally, roof rail gage thickness is increased to account for these load cases (since these are manufactured by extrusion), but doing so leads to increased mass which adversely affects fuel efficiency. The current study focuses on providing the guidelines for strategically placing lightening holes and optimizing gage thickness so that the final design is robust to noise parameters and saves the most mass without adversely impacting wind noise performance while minimizing stress. The project applied Design for Six Sigma (DFSS) techniques to optimize roof rail parameters in order to improve the load carrying capacity while minimizing mass.
2011-04-12
Technical Paper
2011-01-0242
Sankar Rao Nallapati, Jason Miller, Srinivasa Mandadapu, Balakrishna Chinta
Engineering has continuously strived to improve the vehicle development process to achieve high quality designs and quick to launch products. The design process has to have the tools and capabilities to help ensure both quick to the market product and a flawless launch. To achieve high fidelity and robust design, mistakes and other quality issues must be addressed early in the engineering process. One way to detect problems early is to use the math based modeling and simulation techniques of the analysis group. The correlation of the actual vehicle performance to the predictive model is crucial to obtain. Without high correlation, the change management process begins to get complicated and costs start to increase exponentially. It is critical to reduce and eliminate the risk in a design up front before tooling begins to kick off. The push to help achieve a high rate of correlation has been initiated by engineering management, seeing this as an asset to the business.
1999-10-06
Technical Paper
1999-01-3450
Blake Stancik, Carter Boad
This paper details the Electroimpact Cartridge Feed Auto Select (CFAS) System, the Electroimpact Cartridge Filling Station (CFS) and the implementation of these systems on today&’s factory floors. Problems inherent in handling tens of thousands of fasteners per workpiece have traditionally been an Achilles Heel to many aerospace-manufacturing cells. The CFAS system moves the job of sorting through bulk fasteners to the stand alone offline CFS. With the bulk feeding process offline, problems such as contaminated fastener lots get taken care of before they ever get to a fastening machine. Modular briefcase sized coiled tube magazines store and distribute fasteners to automated riveting and bolting equipment via the CFAS rack. Cartridges captively hold 500 to 3,000 fasteners from 1/8” to 3/8” diameters and are length independent which allow a small number of cartridges to work with a large array of overall fasteners.
1938-01-01
Technical Paper
380119
Kent R. Van Horn, Howard J. Heath
ARTICLES of a wide variety of sizes and shapes can be produced easily by the sand-casting process. The advantage of simplicity and low cost offered by the sand-casting process for small numbers of identical parts is offset by certain inherent limitations which must be recognized clearly if it is to yield optimum results. The various methods of inspecting and controlling structural variations that affect the strength and serviceability of aircraft castings are described. It is recognized that the user of castings must rely to a considerable extent on the foundryman for careful inspection. Several direct tests worthy of consideration as final acceptance tests of quality, such as the proof test, radiography (X-ray examination), and the static breakdown test, are described. However, this discussion leads to the conclusion that there is not yet available a satisfactory direct method of predicting the normal life of an aircraft casting.
1959-01-01
Technical Paper
590172
C. W. HARRIS
1959-01-01
Technical Paper
590173
ERROL J. LANCASTER
1954-01-01
Technical Paper
540206
PAUL E. ALLEN
1954-01-01
Technical Paper
540201
T. R. SMITH
2007-09-17
Technical Paper
2007-01-3813
Brian J. Martinek
Increased emphasis on standardizing processes and controlling variability in production operations includes validating perishable tools used in daily operations. Even though dealing with reputable manufacturers, many factors including communication, custom specifications and personnel turnover can lead to the perpetuation of mistakes if errors are not discovered and corrective action implemented. However, inspection is costly and inspection costs far outweigh many item costs unless considering product defects. A beneficial balance may be obtained by employing statistical sampling techniques similar to ISO 2859 [1] to verify the quality of incoming tools.
2007-09-17
Technical Paper
2007-01-3841
Trevor H. Stansbury
On the whole, strategic sourcing and supplier rationalization have been successful Original Equipment Manufacturer (OEM) strategies. Often ignored however, are some of the longer-term ramifications of strategic sourcing and supplier rationalization that are less favorable, particularly if, in the process of embarking upon these strategies, an OEM looses visibility into and/or relinquishes control over, the finished part bill of material (BOM). Finished part BOM is defined as all of the material “inputs” that go into a manufactured part materials such as bar, sheet, tube, wire, fasteners, etc. This negative consequence of outsourcing, the loss of BOM visibility and control, can dilute and even undermine the very strategy that spawned it.
2009-11-10
Technical Paper
2009-01-3130
Brett L. Hopkins, Peter J. Dickin
The main challenge for aerospace manufacturers today is to develop the ability to produce high-quality products on a consistent basis as quickly as possible and at the lowest-possible cost. At the same time, rising material prices are making the cost of scrap higher than ever so making it more important to minimise waste. Proper inspection and quality control methods are no longer a luxury; they are an essential part of every manufacturing operation that wants to grow and be successful. However, simply bolting on some quality control procedures to the existing manufacturing processes is not enough. Inspection must be fully-integrated with manufacturing for the investment to really produce significant improvements.
2009-11-10
Technical Paper
2009-01-3153
Diana Giorgini
Torino Piemonte Aerospace project (TPA) implemented a scientific, strategic planning method that simultaneously supports selected aerospace Piemonte Region (located in North-Western Italy) SMEs in their internationalisation process and offers the world aerospace community a competitive Supply Chain for professional procurement and for world-class partners and suppliers identification. Strategic Planning Framework adopted by TPA is a disciplinary tool which measured the competitive strength of the Piemonte aerospace cluster (TPA companies) and analyzed the external environment (market trends, business models, strategic assets). Within the limits of Competitive Positioning analysis, TPA Team performed the selection of the 66 top class aerospace and defence companies able to match buyers' needs and interact with international markets.
2009-11-10
Technical Paper
2009-01-3139
Itzhak Ben-Levy
- THE RATIONALE When analyzing the reasons for delays in product development programs, we typically discover the underlying reasons are linked directly to requirements. Additionally, not being aware of the value to the customer, misunderstanding customer needs and priorities, waiting for requirements, looking for information and so on, also contribute to delays, (Figure 1). This causes many redesign cycles that create delays in the product development process. This paper will illustrate how implementing QFD practices during the development process, leads to a reduction in development cycle time.
2008-08-19
Technical Paper
2008-01-2271
Francesco Gargiulo, Gianpaolo Romano, Alessandro Busco
The purpose of this work is to increase the effectiveness and the efficiency of the operations carried out during the activities in the aeronautical maintenance and transformation processes. In particular, we examine the Non-Routine Card Resolution Process. An NRC is document issued when a fault, not expected, detected during the maintenance/transformation operations, is found. Typically to describe a defect we need of the aircraft zone (MajorZone, Sub-MajorZone, Zone, etc.) and/or the system (ATA system) and/or the coordinates, the component (sometimes with the sub-component) and the kind of the defect with its attributes. We name this set of information Non-Routine Card. The costs and the efforts of the NRC management are of the same order of magnitude of the planned activity management (Job Card - JC). The process requires that corrective actions come from applicable technical documentation.
2008-09-16
Technical Paper
2008-01-2313
Bobby J. Marsh
The patented (US 7,277,811 B1) Position Bar provides precise measurement, machining and drilling data for large Engineering and Tooling structure. The Position Bar also supports end item verification seamlessly in the same machining control code. Position Bar measurements are fast, accurate, and repeatable. The true centerline of the machine tool's spindle bearings are being measured to within .002 in a 20 foot cubic volume (20×20×20). True “I”, “J”, & “K” machine tool spindle positions are also precisely measured. Any Gantry or Post Mill Tool can be converted to a Coordinate Measurement Machine (CMM) with this laser tracker controlled Position Bar. Determinant Assembly (D.A.) holes, for fuselage and wing structures are drilled and then measured to within .006 in X, Y, & Z, over a 40 foot distance. Average laser tracker measurement time, per hole, is 2 seconds.
2008-10-07
Technical Paper
2008-36-0092
Angelo José Castro Alves Ferreira Filho, Valério Antonio Pamplona Salomon, Fernando Augusto Silva Marins
This paper presents a proposal of a model to measure the efficiency of outsourced companies in the aeronautical industry applying the methods DEA and AHP. It also proposes an evaluation in the relation between the variables of the process and the value obtained for the effiiency. The criteria of Quality, Time and Cost were considered the outputs of the process, and those criteria were quantified by AHP for DEA matrix.The number of technical documents received by those outsorced companies were considered the input of the process. The other purpose is to separate the companies in groups considered able to receive an investment to improve their process. RESUMO Este artigo apresenta uma proposta de um modelo para medir a eficiência de empresas terceirizadas na indústria aeronáutica aplicando-se os métodos DEA e AHP. Também propõe uma avaliação na relação entre as variáveis do processo e os valores de eficiência obtidos.
2008-10-07
Technical Paper
2008-36-0200
Janaina Fracaro de Souza, André Marcon Zanatta, Jefferson de Oliveira Gomes
This work aims to study the drilling dry process in the aircraft structures. In the first stage were used helical speed steel drills with different geometries. This was used various combinations of cutting parameters. The power cut was monitored by sensors connected to the machine tool. The burr were measured and evaluated in accordance with the terms of cut. The structure deformation and the roundness of the holes were evaluated. Based on preliminary results, there is a need to replace the process of drilling using drills by helical interpolation milling. The second stage was used the same method of evaluation.
2008-03-30
Technical Paper
2008-36-0557
Márcio Henrique de Avelar Gomes, Paulo Roberto de Oliveira Bonifácio, Caio Merlini Giuliani, Franciso Manoel Correa Dias, José Ilton Gomes
The present work describes an alternative way (to ultrasound) to check the existence of superficial flaws in sandwich panels used in the aerospace industry, based in a technique inspired in the well known "tap test". In this case, however, a non-impulsive excitation is provided by a especial transducer and the acoustic response is captured with a microphone. Correlation and Deconvolution techniques are used in order to assess the system's vibroacoustic impulse response and generate a "failure" map after post-processing the results. Results and aspects in regard to its implementation and automation are described in the paper.
2008-06-29
Technical Paper
2008-01-2125
John T. James
NASA has unique requirements for the development and application of air quality standards for human space flight. Such standards must take into account the continuous nature of exposures, the possibility of increased susceptibility of crewmembers to the adverse effects of air pollutants because of the stresses of space flight, and the recognition that rescue options may be severely limited in remote habitats. NASA has worked with the National Research Council Committee on Toxicology (NRCCOT) since the early 1990s to set and document appropriate standards. The process has evolved through 2 rounds. The first was to set standards for the space station era, and the second was to set standards for longer stays in space and update the original space station standards. The update was to be driven by new toxicological data and by new methods of risk assessment for predicting safe levels from available data. The last phase of this effort has been completed.
2008-06-29
Technical Paper
2008-01-2103
H. Charles Dischinger, Damon B. Stambolian, Darcy H. Miller
The National Aeronautics and Space Administration has long applied standards-derived human engineering requirements to the development of hardware and software for use by astronauts while in flight. The most important source of these requirements has been NASA-STD-3000. While there have been several ground systems human engineering requirements documents, none has been applicable to the flight system as handled at NASA's launch facility at Kennedy Space Center. At the time of the development of previous human launch systems, there were other considerations that were deemed more important than developing worksites for ground crews; e.g., hardware development schedule and vehicle performance. However, experience with these systems has shown that failure to design for ground tasks has resulted in launch schedule delays, ground operations that are more costly than they might be, and threats to flight safety.
2008-06-29
Technical Paper
2008-01-2196
J. Torin McCoy, John T. James
Water quality standards have been completed for space vehicles and habitats for ingestion periods from 1 day to 1000 days. These standards are called spacecraft water exposure guidelines (SWEGs). The National Research Council Committee on Toxicology has worked with the Toxicology Group at the National Aeronautics and Space Administration (NASA) to set and document these standards. Prior to SWEG development, the practice of NASA was to apply the United States Environmental Protection Agency (USEPA) maximum contaminant levels (MCLs) in the interpretation of any potential health effects from water pollutants. This practice had the potential to result in erroneous conclusions because MCLs are intended for lifetime exposures and are set to protect a much more diverse population than is present in the astronaut corps. However, for certain pollutants it was recognized that the stresses of spaceflight may make astronauts more susceptible to adverse effects.
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