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Viewing 121 to 150 of 19755
2014-09-23
Standard
AS3535B
Scope is unavailable.
2014-09-23
WIP Standard
AMS2481K
This specification covers the requirements for a manganese phosphate coating on ferrous alloys.
2014-09-23
WIP Standard
AMS2475H
This specification establishes the requirements for chromate conversion coatings on magnesium alloys. This process has been used typically to improve corrosion resistance and adherence of organic finishes but usage is not limited to such applications. The dichromate treatment may not be suitable for alloys with high manganese content. The chrome pickle treatment has been used as touch-up for previously dichromate-treated surfaces and for improving corrosion protection temporarily, but usages are not limited to such applications.
2014-09-23
WIP Standard
AMS2482E
This specification establishes the requirements for a hard aluminum oxide coating, impregnated or codeposited with polytetrafluoroethylene (PTFE) on aluminum alloys.
2014-09-20
WIP Standard
AMS2467A
No Scope Available
2014-09-19
Standard
AMS4162E
This specification covers an aluminum alloy in the form of extruded bars, rods, wire, profiles, and tubing under 3.00 inches (76.2 mm) in diameter, least thickness, or wall thickness and 25 in 2 (161 cm 2 ) or less in cross-sectional area.
2014-09-16
Technical Paper
2014-01-2127
Karl Strauss
Abstract “Today's electronic components rely on principles of physics and science with no manufacturing precedence and little data on long term stability and reliability.” [1] Yet many are counting on their reliable performance years if not decades into the future, sometimes after being literally abandoned in barns or stored neatly in tightly sealed bags. What makes sense? To toss everything away, or use it as is and hope for the best? Surely there must be a middle ground! With an unprecedented number of missions in its future and an ever-tightening budget, NASA faces the daunting task of doing more with less. One proven way for a project to save money is to use already screened and qualified devices from the spares of its predecessors. But what is the risk in doing so? How can a project reliably count on the value of spare devices if the risk of using them is not, in itself, defined?
2014-09-16
Technical Paper
2014-01-2138
Ron Wang, Michelle Bash, Steven D. Pekarek
Abstract In this research, excitation strategies for a salient-pole wound rotor synchronous machine are explored using a magnetic equivalent circuit model that includes core loss. It is shown that the excitation obtained is considerably different than would be obtained using traditional qd-based models. However, through evaluation of the resulting ‘optimal’ excitation, a relatively straightforward field-oriented type control is developed that is consistent with a desire for efficiency yet control simplicity. Validation is achieved through hardware experiment. The usefulness/applicability of the simplified control to variable speed applications is then considered.
2014-09-16
Journal Article
2014-01-2230
Ruiqiang Lu
Abstract With the development of many new technologies in aircraft manufacturing area and the increasing competition of the global market, aircraft manufacturing enterprises have to reduce their production time and increase the cost-efficiency, with the consideration of high speed response to the changes inside enterprises or in the environment. Production scheduling is a significant process in manufacturing, especially for complicated part or component processing. This paper proposes an agent based multi-objective optimization approach for production scheduling based on Genetic Algorithms. It aims to minimize the total production cost and simultaneously reducing the emission released during production, and the delivery time and equipment constraints are satisfied as well. The new approach is tested in a virtual plant for turbine blade manufacturing.
2014-09-16
Journal Article
2014-01-2240
Joshua Norman, Cesar Moreno, Zhiyu Wang, James Mann, Christopher Saldana
Abstract The beneficial effects of contact disruption in modulation-assisted machining of aerospace alloys have been well documented, but sources for such improvements are not well understood. This study explores the underlying nature of differences that occur in energy dissipation during conventional and modulation-assisted machining by characterizing the relationship between controllable process parameters and their effects on chip formation. Simultaneous in situ force and tool position measurements are used to show that the forces in modulation-assisted machining can be described by empirical force models in conventional machining conditions. These models are found to accurately describe plastic dissipation over a range of modulation conditions and configurations, including in cases where energy expenditure decreases with the application of modulation.
2014-09-16
Technical Paper
2014-01-2238
Richard Kingston
Abstract Industrial robots are extremely good at repetitive tasks. They exhibit excellent repeatability, making them ideal candidates for many tasks. However, increasing use of CAD based offline programming highlights the fact that industrial robots are generally not accurate devices. Several approaches have been used to compensate for this deficiency. Robot calibration is well established and factory calibrated robots are available from most industrial robot manufacturers. This can improve the spatial accuracy of robots to figures better than 1mm which is adequate for most robot processes in use today. Improvements in accuracy beyond this point can be achieved if the working range of the robot is constrained in some way. For example, limiting a robot to working in a single plane or restricting the robot to a reduced work volume can contribute to significant improvements in accuracy.
2014-09-16
Journal Article
2014-01-2242
Samuel Baha II
Hybrid (bolted/bonded) joining is becoming one of the innovative joining processes for light weight structures in the transport industry, especially in the aerospace industry where weight reduction and high joining requirements are permanent challenges. Combining the adhesive bonding with the mechanical joining -riveting for instance- can lead to an enhancement of the properties of the joint compared to the wide established riveting, as a result of a synergistic load bearing interaction between the fastener and the adhesive bondline. The influence of the rivet installation process on a hybrid joint regarding the joint stress state, the change of the bondline thickness as well as its effects on the joint performance and load transfer are some of the factors that drive the users to a better understanding of the hybrid joining process.
2014-09-16
Journal Article
2014-01-2241
Jamie Skovron, Laine Mears, Durul Ulutan, Duane Detwiler, Daniel Paolini, Boris Baeumler, Laurence Claus
Abstract A state of the art proprietary method for aluminum-to-aluminum joining in the automotive industry is Resistance Spot Welding. However, with spot welding (1) structural performance of the joint may be degraded through heat-affected zones created by the high temperature thermal joining process, (2) achieving the double-sided access necessary for the spot welding electrodes may limit design flexibility, and (3) variability with welds leads to production inconsistencies. Self-piercing rivets have been used before; however they require different rivet/die combinations depending on the material being joined, which adds to process complexity. In recent years the introductions of screw products that combine the technologies of friction drilling and thread forming have entered the market. These types of screw products do not have these access limitations as through-part connections are formed by one-sided access using a thermo-mechanical flow screwdriving process with minimal heat.
2014-09-16
Journal Article
2014-01-2234
Nelson W. Sorbo, Jason J. Dionne
Abstract The use of composite materials and composite stackups (CO-Ti or CO-Al) in aerospace and automotive applications has been and will continue to grow at a very high rate due to the high strength and low weight of the materials. One key problem manufacturers have using this material is the ability to efficiently drill holes through the layers to install fasteners and other components. This is especially true in stackups of CFRP and titanium due to the desire of drilling dry for the CFRP layer and the need for cooling when drilling the high strength Ti layer. By using CO2 through tool cooling, it is possible to protect both layers. Through work supported by the National Science Foundation (NSF) and Department of Energy (DOE) it is shown that CO2 through tool cooling productivity can be significantly increased while maintaining required hole tolerances in both the composite and Ti layers.
2014-09-16
Journal Article
2014-01-2236
Julian Lonfier, Côme De Castelbajac
Abstract As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied.
2014-09-16
Technical Paper
2014-01-2237
Rainer Mueller, Matthias Vette, Andreas Ginschel, Ortwin Mailahn
Abstract The global competition challenges aircraft manufacturers in high wage countries. The assembly of large components happens manually in fixed position assembly. Especially the completion of the inner fuselage structure is done 100% manually. The shells have to be joined with rivets and several hundred clips have to be assembled to connect the shell to the frames. The poise of the worker is not ergonomic so a lot of physical stress is added to the worker and minimizes the working ability. Aircraft manufacturers need a lot of different production resources and qualified persons for the production, which provokes higher costs. Due to these high costs there is a demand for automated reconfigurable assembly systems, which offer a high flexibility and lower manufacturing costs. The research project “IProGro” deals with this challenge and develops innovative production systems for large parts.
2014-09-16
Journal Article
2014-01-2252
Lucas Irving, Svetan Ratchev, Atanas Popov, Marcus Rafla
Abstract The replacement for the current single-aisle aircraft will need to be manufactured at a rate significantly higher that of current production. One way that production rate can be increased is by reducing the processing time for assembly operations. This paper presents research that was applied to the build philosophy of the leading edge of a laminar flow European wing demonstrator. The paper describes the implementation of determinate assembly for the rib to bracket assembly interface. By optimising the diametric and the positional tolerances of the holes on the two bracket types and ribs, determinate assembly was successfully implemented. The bracket to rib interface is now secured with no tooling or post processes other than inserting and tightening the fastener. This will reduce the tooling costs and eliminates the need for local drilling, de-burring and re-assembly of the bracket to rib interface, reducing the cycle time of the operation.
2014-09-16
Journal Article
2014-01-2253
Ralf Schomaker, Richard Pedwell, Björn Knickrehm
Abstract As a result of the increasing use of fibre reinforced plastic (FRP) components in a modern commercial aircraft, manufacturers are facing new challenges - especially with regards to the realisation of significant build rates. One challenge is the larger variation of the thickness of FRP components compared with metal parts that can normally be manufactured within a very narrow thickness tolerance bandwidth. The larger thickness variation of composite structures has an impact on the shape of the component and especially on the surfaces intended to be joined together with other components. As a result, gaps between the components to be assembled could be encountered. However, from a structural point of view, gaps can only be accepted to a certain extent in order to maintain the structural integrity of the joint. Today's state of the art technologies to close gaps between FRP structures comprise shimming methods using liquid and solid shims.
2014-09-16
Journal Article
2014-01-2256
Roger Holden, Paul Lightowler, Simon Andreou
Abstract The 30 month COMET project aims to overcome the challenges facing European manufacturing industries by developing innovative machining systems that are flexible, reliable and predictable with an average of 30% cost efficiency savings in comparison to machine tools. From a conceptual point of view, industrial robot technology could provide an excellent base for machining being both flexible and cost efficient. However, industrial robots lack absolute positioning accuracy, are unable to reject disturbances in terms of process forces and lack reliable programming and simulation tools to ensure right first time machining, once production commences. These three critical limitations currently prevent the use of robots in typical machining applications. The COMET project is co-funded by the European Commission as part of the European Economic Recovery Plan (EERP) adopted in 2008.
2014-09-16
Journal Article
2014-01-2255
Joseph R. Malcomb
Abstract Automated countersink measurement methods which require contact with the workpiece are susceptible to a loss of accuracy due to cutting debris and lube build-up. This paper demonstrates a non-contact method for countersink diameter measurement on CFRP which eliminates the need for periodic cleaning. Holes are scanned in process using a laser profilometer. Coordinates for points along the countersink edge are processed with a unique filtering algorithm providing a highly repeatable estimate for major and minor diameter.
2014-09-16
Technical Paper
2014-01-2246
Yanbin Yao
Abstract Drilling plays a significant process in the aircraft manufacturing. This paper develops a robot automatic drilling system for processing the titanium alloy, aluminum alloy and laminated composites component of aircraft. The accurate robot drilling system is comprised of ABB IRB6640-235 robot, drilling end-effector, end-effctor control system and vision system. Experimental results show that the system absolute location precision is within 0.3mm, and the drilling efficiency can be up to four holes per minute. The drilling efficiency and quality of the aircraft component can be increased immensely by the developed robot automatic drilling system.
2014-09-16
Journal Article
2014-01-2248
Santiago Droll
In contemporary industries the demand for very accurate robots is continuously growing. Yet, robot vendors are limited in the achievable accuracy of their robots, as they have no means to provide a direct end-effector feedback. Therefore, most approaches aim to identify an accurate model of the robotic system, thus providing compensation factors to correct the deflections. Models, however, are unable to represent the real physical system in a sufficient manner for path correction. The non-linearities in robotic systems are difficult to model and the dynamics cannot be neglected. A better approach is, therefore, to use direct end-effector position and orientation feedback from an external sensor as, e.g. a Leica laser tracker. The measured data can directly be compared to the nominal data from the path interpolator. Hence, the data are independent of the kinematic robot model.
2014-09-16
Journal Article
2014-01-2249
Thomas G. Jefferson, Svetan Ratchev, Richard Crossley
Abstract Aerospace assembly systems comprise a vast array of interrelated elements interacting in a myriad of ways. Consequently, aerospace assembly system design is a deeply complex process that requires a multi-disciplined team of engineers. Recent trends to improve manufacturing agility suggest reconfigurability as a solution to the increasing demand for improved flexibility, time-to-market and overall reduction in non-recurring costs. Yet, adding reconfigurability to assembly systems further increases operational complexity and design complexity. Despite the increase in complexity for reconfigurable assembly, few formal methodologies or frameworks exist specifically to support the design of Reconfigurable Assembly Systems (RAS). This paper presents a novel reconfigurable assembly system design framework (RASDF) that can be applied to wing structure assembly as well as many other RAS design problems.
2014-09-16
Journal Article
2014-01-2250
Nicholas Lum, Qun Luo
Abstract Electroimpact has designed and manufactured a flexible tooling system for the E7000-ARJ horizontal panel riveter. This tooling design accommodates panel sizes from 3.5m to 10m long, with a variety of straight and tapered curvatures. The tooling is re-configured manually and utilizes removable index plates that can be adapted to accommodate new panel types. This type of tooling is ideal for value-conscious applications where a single machine must process a large range of panel styles. Electroimpact is currently using this system to tool 17 different styles of pre-tacked panels on a single E7000-ARJ machine. This flexible system does not require large removable form boards or custom frames that index one type of panel. Instead it uses 4 form boards that are permanently mounted to the picture frame by linear rails, allowing them to index anywhere along the 10m working envelope.
2014-09-16
Journal Article
2014-01-2257
Roger Holden, Paul Lightowler, Simon Andreou
Abstract The 30 month COMET project aims to overcome the challenges facing European manufacturing industries by developing innovative machining systems that are flexible, reliable and predictable with an average of 30% cost efficiency savings in comparison to machine tools. From a conceptual point of view, industrial robot technology could provide an excellent base for machining being both flexible and cost efficient. However, industrial robots lack absolute positioning accuracy, are unable to reject disturbances in terms of process forces and lack reliable programming and simulation tools to ensure right first time machining, once production commences. These three critical limitations currently prevent the use of robots in typical machining applications. The COMET project is co-funded by the European Commission as part of the European Economic Recovery Plan (EERP) adopted in 2008.
2014-09-16
Technical Paper
2014-01-2263
Eric Barton, Dan Hasley, Joey Jackson
Abstract The following is a unique case study expounding on automatic fastening technology designed and engineered to ramp up a Tier 2 supplier that had no experience with automatic fastening, to efficiently produce a large volume of fuselage panel assemblies with demanding process requirements in a very short amount of time. The automation technology integrated for the skin to stringer & skin to window frame fastening were two GEMCOR G12 five-axis CNC All-Electric fastening systems coupled with a Cenit offline part programming system. This joint solution served as a launch vehicle for Center Industries to efficiently supply the full rate of fuselage panel assemblies for a large volume commercial aircraft program without having any automatic riveting experience.
2014-09-16
Technical Paper
2014-01-2264
Peter B. Zieve, Osman Emre Celek, John Fenty
Abstract The E7000 riveting machine installs NAS1097KE5-5.5 rivets into A320 Section 18 fuselage side panels. For the thinnest stacks where the panel skin is under 2mm (2024) and the stringer is under 2mm (7075), the normal process of riveting will cause deformation of the panel or dimpling. The authors found a solution to this problem by forming the rivet with the upper pressure foot extended, and it has been tested and approved for production.
2014-09-16
Journal Article
2014-01-2265
Lutz Neugebauer
The demand of fulfilling increasing Prime Customer requirements forces Tier 1 suppliers to continually improve their system solutions. Typically, this will involve integration of “state of the art” tools to afford the Tier 1 supplier a throughput and cost advantage. The subject “Production Optimization Approach” addresses the machine and process optimization of automated fastening machines in operation at customer factories. The paper will describe and focus on the main aspects of production optimization of existing machines to meet and exceed the required customer production and reporting criteria. Furthermore, the paper will present existing examples based on use of the established diagnostic tools
2014-09-16
Journal Article
2014-01-2258
Sylvain Laporte, Etienne Gueydon, Alain Auffret, Cosme De Castelbajac
Abstract In today's aircraft assembly process several new features make drilling operations very challenging according to production requirements. Parts are made of thin or thick multi-material stacks with a large scope to cover and complex assembly sequences. In addition, the current ramp-up in aircraft programs involves to improve productivity while keeping process quality and reliability. In this context robotic solution meets perfectly all these requirements as it is flexible, reconfigurable, fast and agile. Among the possible end-effectors, the Barrel Multi-Function End Effector (BMFEE) appears to be the most flexible solution to allow many different process configurations. The latest developments have been focused on the drilling equipment of this BMFEE. In fact the drilling process efficiency can be constantly improved especially in terms of reliability, quality and productivity. Therefore vibration-assisted drilling system has been integrated into the BMFEE drilling module.
2014-09-16
Technical Paper
2014-01-2259
Greg Adams
Abstract Electroimpact has developed a second generation of mobile robots with several improvements over the first generation. The frame has been revised from a welded steel tube to a welded steel plate structure, making the dynamic response of the structure stiffer and reducing load deflections while maintaining the same weight. The deflections of the frame have been optimized to simplify position compensation. The caster mechanism is very compact, offers greater mounting flexibility, and improved maneuverability. The mechanism uses a pneumatic airbag for both lifting and suspension. The robot sled has been improved to offer greater rigidity for the same weight, and dual secondary feedback scales on the vertical axis further improve the rigidity of the overall system. Maintenance access has been improved by rerouting the cable and hose trays, and lowering the electrical cabinet.
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