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Viewing 31 to 60 of 20082
2015-09-15
Technical Paper
2015-01-2609
Pinar Acar, Avinkrishnan A. Vijayachandran, Veera Sundararaghavan, Anthony Waas, Mostafa Rassaian
With the development of automated manufacturing processes for orthotropic laminates, it has become much easier to tailor the properties of laminates as per design considerations. Minimizing the stress concentrations around cutouts in a plate is often a design problem, especially in the Aerospace industry, one quick example being cutouts in a fuselage. A problem of optimizing spatially varying fiber paths in a symmetric, linear orthotropic composite laminate with a cutout, so as to achieve minimum stress concentration under remote unidirectional tensile loading is of interest in this study. A finite element model is developed to this extent, which constraints the fiber angles while optimizing the fiber paths, proving essential in manufacturing processes.
2015-09-15
Technical Paper
2015-01-2610
Patrick Land, Richard Crossley, David Branson, Svetan Ratchev
There is a growing demand for composites to be utilized in the production of large-scale components within the aerospace industry where the size and rate of production rules out traditional manual methods. Therefore, a high speed automated solution is required to produce these parts. Unfortunately, there are a limited number of effective options to achieve this; the complex geometries of structural components often cannot be achieved at the lay-up stage with existing automated equipment; and currently secondary forming processes are required to complete parts. This paper will review automated forming processes, their limitations and variables which affect performance to achieve production of large scale components. In particular the paper will focus on the application of force and heat within secondary forming processes. It will then review the effects of these variables against the structure of the required composite component and identify viability of the technology.
2015-09-15
Technical Paper
2015-01-2611
Samuel Baha II
The use of composite materials in aircraft manufactures increases more and more with the need of light weight and efficient airplanes. Combining composite materials with an appropriate joining method is one of the primordial ways of exploiting its light weight potential. Since the widely-established mechanical fastening, which originally, was developed for metallic materials, is not a suitable joining method for composite materials because of its low bearing strength, the adhesively bonding technology might be an appropriate alternative. However, adhesively bonding in the aircraft manufacturing, especially for joining of primary structures is liable to certification requirements, such as testing of every bond up to limit load before the operation begins or non-destructive testing of every bond before the operation begins as proof of the joint characteristics, which cannot be fulfilled with the current state of the art.
2015-09-15
Technical Paper
2015-01-2616
Richard Lindqvist, Tobias Jansson
The scope and purpose of this paper is to give input and propose solutions to the creation of an efficient and productive geometrical measurement planning process. The case study outline what is important and how to identify and determine the preconditions and input data which is required to start the preparation and planning activities of geometrical measurements. That is why the following three main research and development questions should be answered: Firstly; What is the need and why does an efficient and productive geometrical measurement planning process contribute to decrease cost upstream as well as downstream in terms of reduced lead times in measurement planning process work? Secondly; Why are reduced uncertainties related to geometrical; functionality, specification and verification, important? And how are they linked to each other and how can they be theoretically modeled and defined in terms of uncertainties?
2015-09-15
Technical Paper
2015-01-2617
Raimund Loser, Michael Kleinkes
Real-Time Robot Positioning based on Measurement Feedback Control Abstract: Industrial robots are well introduced into automated production processes. Their mechanical design is dominated by some major key factors like required flexibility, different payload demands, working range, working speed, combination with different working tools and robot costs. The final achieved position accuracy of the robot tool centre point (TCP) is based on the combination of these key factors. In general, the smallest movement steps and the repeatability of robots are much lower than the absolute achievable accuracy. The positioning results and especially the programmed paths of the TCP show relatively large differences between the programmed nominal paths related to the final achieved movements in reality. These differences can be detected using the Absolute Tracker with its very high dynamic performance, especially if the 6DoF capability is included.
2015-09-15
Technical Paper
2015-01-2491
Paul Haworth, Donald Peterson, Curtis Hayes
A new high speed forming process for fatigue rated index head rivets used in wing panel assembly using ball-screw based servo squeeze actuation has been developed. The new process is achieved using a combination of force and position control and is capable of forming to 40,000 lbs at rates of up to 200,000 lbs/second whilst holding the part location to within +/- 10 thousandths of an inch. Multi-axis riveting machines often have positioning axes that are also used for fastener upset. It is often the case that while a CNC is used for positioning control, another secondary controller is used to perform the fastener upset. In the new process, it has been possible to wrap the control of the upset process into the machine CNC and thus eliminating any separate controllers. The fastener upset force profile is controlled throughout the forming of the rivet by using a closed loop force control system that has a load cell mounted directly behind the stringer side forming tool.
2015-09-15
Technical Paper
2015-01-2494
Benjamen D. Hempstead, Scott Smith
Aircraft assembly systems which require tooling or machinery to pulse or move between multiple positions within a factory can be positioned with high repeatability without high performance foundations or sweeping out large areas of floorspace. An example shows a system of large left and right-hand frames which are positioned at 3 sequential manufacturing steps and then recirculated to the start of production via a central return aisle. The frames are 41 ton actual weight and are 72’ long, similar to a rail car. The system achieves rectangular motion for the recirculation path. The supporting and moving system incorporates low-cost rail in a floor with minimal preparation and simple to use controls. The system is also easily reconfigured if the manufacturing system needs to be altered to meet rate or flow requirements.
2015-09-15
Technical Paper
2015-01-2608
Joshua Cemenska, Todd Rudberg, Michael Henscheid
In many existing AFP cells manual inspection of composite plies accounts for a large percentage of production time. Next generation AFP cells can require an even greater inspection burden. The industry is rapidly developing technologies to reduce inspection time and to replace manual inspection with automated solutions. Electroimpact is delivering a solution that integrates multiple technologies to combat inspection challenges. The approach integrates laser projectors, cameras, and laser profilometers in a comprehensive user interface that greatly reduces the burden on inspectors and decreases overall run time. This paper discusses the implementation of each technology and the user interface that ties the data together and presents it to the inspector.
2015-09-15
Technical Paper
2015-01-2498
AbdulRahman El-Nounu, Svetan Ratchev, Richard Crossley, Kevin Forster
Design for Assembly is the concept of carrying out critical thought early in the design stage to create assembly easement at the production stage. In the aerospace industry products have very long lives, frequently being optimised rather than introducing new products. This has meant that older products that are stable cash cows have not benefited from new Design for Assembly Methods and manufacturing equipment and tooling suffer from obsolescence. It has been established that approximately 80% of overall product cost is determined at the design stage and thus existing products suffer from preloaded costs. This paper takes existing Design for Assembly methodologies and analyses them with respect to the unique challenges involved in legacy product redesign. The methodology developed is both a quantitative solution coupled with thought channelling processes. An existing case study looking at optimising the installation of small butterfly brackets is used to test this methodology.
2015-09-15
Technical Paper
2015-01-2490
Sylvain Guerin, Sylvain da Costa
The quality requirement for drilling operation in aerospace industry associated to the different material layers of the recent aircraft design is one of the most challenging issues for manufacturing engineers who want to design system for one-shot drilling operation. We have developed and validated in production a handheld electrical tool which is able to accurately monitor the drilling parameter and to adjust the drilling conditions to specific material in the stack-up. This “Smart Driller” achieves quality and performances equivalent to those obtained by the most advanced heavy automated drilling systems at a small portion of weight and cost.
2015-09-15
Technical Paper
2015-01-2492
Michael Assadi, Samuel Dobbs, Brian Stewart, Sean Hollowell, Joseph Elsholz
Abstract Developing the most advanced wing panel assembly line for very high production rates required an innovative and integrated solution, relying on the latest technologies in the industry. Looking back at over five decades of commercial aircraft assembly, a clear and singular vision of a fully integrated solution was defined for the new panel production line. The execution was to be focused on co-developing the automation, tooling, material handling and facilities while limiting the number of parties involved. Using the latest technologies in all these areas also required a development plan, which included pre-qualification at all stages of the system development. Planning this large scale project included goals not only for the final solution but for the development and implementation stages as well. The results: Design/build philosophy reduced project time and the number of teams involved.
2015-09-15
Technical Paper
2015-01-2493
Dan Vaughan, David Branson, Otto Jan Bakker, Svetan Ratchev
Abstract The aim of this work was to develop a new assembly process in conjunction with an adaptive fixturing system to improve the assembly process capability of specific aircraft wing assembly processes. The inherently complex aerospace industry requires a step change in its capability to achieve the production ramp up required to meet the global demand. This paper evaluates the capability of adaptive fixtures to identify their suitability for implementation into aircraft wing manufacturing and assembly. To understand the potential benefits of these fixtures, an examination of the current academic practices and an evaluation of the existing industrial solutions is highlighted. The proposed adaptive assembly process was developed to account for the manufacturing induced dimensional variation that causes significant issues in aircraft wing assembly.
2015-09-15
Technical Paper
2015-01-2488
Derek L. Mickelson
Abstract In the aircraft design process there are the occasional bolted joints with opposing surfaces that are not parallel to each other. This can necessitate manufacturing to machine a spot face into the structural surfaces for the bolt head and nut to seat on. Typically this process is done manually by two workers with all process verification being done visually. Additionally, the nature of airplane structure often requires one worker to be inside a confined space to monitor the process. With this in mind, a tool was requested to reduce the number of workers required, remove workers from confined spaces and ensure a robust method for process validation. The critical technology that would have to be developed was a device that could fix itself into an existing hole, measure the surface of which the hole exited and then machine a spot face into that surface to a specific calculated depth.
2015-09-15
Technical Paper
2015-01-2495
N.D. Jayaweera, L.U. Subasinghe, H.G.A.R. Gajanayaka
Abstract Modern aerospace industry is continuously seeking new technologies due to potential increase in demand for new aircrafts which are to be produced on a single production line while reducing model changeover time and improving quality of the assembly process. In mass volume production, this can be achieved by fixing a large number of similar components using special-purpose jigs and fixtures. This type of jigs and fixtures can be largely found in Aerospace industry. In low volume production, improvement of re-configurable fixturing systems becomes a favourable way to reduce the cost of production per unit. A re-configurable fixturing system consists of standard components that can be used to satisfy different fixturing requirements. These fixtures are reusable and this enhances their flexibility and reduces the time and cost of development. It also offers the benefit of eliminating the need for dedicated tooling, dedicated fixturing, associated storage and floor space.
2015-09-15
Technical Paper
2015-01-2497
George Nicholas Bullen
Abstract The introduction of composite materials onto air vehicles has complicated the traditional hole/countersink assessment criteria due its finished-part thickness variability; softer and dissimilar properties than the metallic substructure where it is mounted and attached; and the increased attention to other acceptance criteria such as fiber tear, fiber pull, and moisture propagation in the hole that degrades fastener capability. The addition of composite materials further complicates the assembly process by adding a boundary layer of liquid shim or sealant between the composite piece (usually a skin) and the substructure. Current hole inspection systems are absent the ability to assess the interior condition of the composite hole such as fiber tear, damage to the liquid shim, and debris or burrs between the multiple stacks of dissimilar material.
2015-09-15
Technical Paper
2015-01-2496
Lucy Agyepong, Marcus Rafla, David Tomlinson, Karl-Otto Strömberg, Alan Howarth
Abstract There is the need to strive towards more advanced aircraft with the use of materials such as composites, and a desire to improve efficiency by achieving and maintaining laminar flow over a large proportion of the aircraft wing. Due to the high tolerances required to achieve laminar flow, the manufacturing processes and tooling will have to be revaluated to enable successful manufacture in a production environment. A major influence in achieving the key characteristics and tolerances is the assembly fixture. This paper details the design and manufacture of a carbon fibre based assembly fixture, required for a one-off build of an innovative leading edge wing concept. The fixture has been designed and optimised in order to make it adaptable, reconfigurable, and suitable for lifting as well as being thermally stable whilst maintaining laminar flow tolerances.
2015-09-15
Technical Paper
2015-01-2499
Perla Maiolino, Richard A. J. Woolley, Atanas Popov, Svetan Ratchev
Assembly and manufacture of aerospace structures, in particularly legacy products, relies heavily on the skill or rather craftsmanship of the human operator. Compounded by low volume rates the implementation of a fully automated production facility may not be cost effective. A more efficient solution is a mixture of both manual and automated operations but herein lays an issue of human error when stepping through the build from manual operation to an automated one. Some inline quality checking must take place, machine vision is an obvious choice yet it can be plagued with problems in shop floor environments. Here we demonstrate a robust solution using a low cost 3D scanner comprising of IR enabled adaptive depth detection. The system checks the quality of manually assembled sub components before automated robot controlled operations are undertaken.
2015-09-15
Technical Paper
2015-01-2500
Brigitte Vasques
Authors: Brigitte Vasques (a), A. Mendes (a) a) ApexToolGroup S.N.C. 25, avenue Maurice Chevalier-Z. I. 77330 Ozoir-la-Ferrière (France) brigitte.vasques@apextoolgroup.com Abstract: The drilling of multilayers composite stacks remains a common process in aerospace industry. Research of productive solutions such as one shot and dry drilling operations to avoid reaming and lubrication are contemplated by aerospace customers on titanium multilayers composite applications. Those solutions permit to reduce the number of finishing operation and drilling time. Special ADEs (advanced drilling equipment’s) machines are used to drill aircraft components in limited access areas. Parameters such as cutters, ADE machines, rigidity fixation, drill cutting conditions, chip fragmentation and extraction are related and influence the hole quality. Titanium (TA6V) thickness and cutting configuration influence the cutter wear development.
2015-09-15
Technical Paper
2015-01-2501
Cosme de Castelbajac, Sylvain Laporte, Julian Lonfier, Emmanuel Puviland
Over the last few years, a number of aircraft production lines have seen their production rate increase. In some cases, to avoid bottlenecks in the assembly lines, the productivity of processes needs to be improved while keeping existing machine-tools. In this context, the case of drilling machine-tools tends to require particular attention, especially when multi-material parts are drilled. In such instances, the Vibration Assisted Drilling (V.A.D.) process can be a way to improve productivity and reliability while controlling quality standards. This article presents a case of a drilling/countersinking process for stainless steel and titanium stack parts. Firstly, the article assesses the feasibility and benefits of using Vibration Assisted Drilling and Countersinking with the current cutting-tools.
2015-09-15
Technical Paper
2015-01-2502
Jeremy Jallageas, Matthieu Ayfre, Mehdi Cherif, Jean-Yves K'nevez, Olivier Cahuc
This study investigates the self-adjusted cutting parameters technique to improve drilling multi-stacked material. The technique consists in changing automatically the cutting strategy accordingly to the material machined. The success of this technique relies on an accurate signal analysis regardless to process setting. Motor current or thrust force are mostly used as incoming signals. Today analyzes are based on thresholding method. It consists in assigning lower and upper limits for each type of material. The material is then identified when the signal level is stabilized in between one of the thresholds. Good results are observed as long as signal steps are significantly distinct. It is the case during drilling TA6V-CFRP stacks. However, thrust force standard remains roughly unchanged for AA7175-CFRP stacks, leading to overlapping thresholds. Moreover, these boundaries limits may change with tool geometry, wear condition, cutting parameters, etc.
2015-09-15
Technical Paper
2015-01-2503
Thomas Dr. Schneider
Accurate positioning of aircraft components constitutes a key task in the structural assembly of aircraft. Due to the fact that the precise alignment of the pre-built parts can reduce aerodynamic resistance and thereby reduce fuel consumption having the latest techniques and technologies for the alignment is crucial. Also having the opportunity to align the pre-built parts with a best fit operation to countervail component tolerances makes the production process even more effective. One of the main challenges is to keep the advanced technology affordable for the customer and keep the maintenance and spare part cost to a minimum. Furthermore the operation of the equipment must be less complex so it can be done by a normal worker. To meet these requirements and to fulfil the individual customer needs a modular product strategy based on standardized function groups is what you need. This includes the positioning units, the controls, the measurement interface and the product supports.
2015-09-15
Technical Paper
2015-01-2507
Rainer Mueller, Aaron Geenen, Matthias Vette
The automation of assembly processes in aircraft production is, due to technical and organizational boundary conditions, very difficult and is subject to technical and economic risks. Part of the technical risks are mainly the large product dimensions as well as the high number of variants of parts. At the same time, the aircrafts are usually produced in small quantities. An automation is often inapplicable because of the high complexity due to the component variants. For an economical automation a production system is needed that can be adjusted to various aircraft components to ensure a high utilization of the production equipment. The aim of the presented approach is the development of a new process solution to enable flexible and requirement-oriented automation by the example of selected processes (surface activation, sealant application, drilling, riveting processes, etc.). The human-robot-cooperation is an approach for a requirement-oriented and temporary automation.
2015-09-15
Technical Paper
2015-01-2508
Jason Rediger, Kyle Fitzpatrick, Rob McDonald, Daniel Uebele
An improved aircraft assembly line incorporates fully automated robotic tool change. Ten machine tools, each with two onboard 6-axis robots, drill and fasten airplane structural components. The robots change 100% of the process tooling (drill bits, bolt anvils, hole probes, and nosepieces) to allow seamless transition across the entire range of hole and fastener sizes (3/16”-7/16”). To support required rate, total tool change time (including automatic calibration) is less than 80 seconds. This paper describes the robots and their end effector hardware, reliability testing, and simulations for both mechanical clearance and cycle time estimation.
2015-09-15
Technical Paper
2015-01-2510
Ryan Haldimann
Measurement of Countersinks to high degree of accuracy has always been a challenge. The Countersink is defined relative to the panel surface which includes some degree of curvature. This curvature thus makes accurate measurements very difficult using both contact and 2D non-contact measurements. By utilizing structured light 3D Vision technologies, the ability to very accurately measure a countersink to small tolerances can be achieved. By knowing the pose of the camera and projector, triangulation can be used to calculate the distance to thousands of points on the panel and countersink surface. The plane of the panel is then calculated using Random Sample Consensus (RANSAC) method from the dataset of points which can be adjusted to account for panel curvatures. The countersink is then found using a similar RANSAC method.
2015-09-15
Technical Paper
2015-01-2509
Eric Reid
The Boeing Company has recently developed a mobile robotic drilling and fastening system, in support of its commitment to lean manufacturing techniques. The robotic system, referred to as Lower Panel Drilling and Fastening System (LPDFS), was initially developed as a way to minimize facilities costs by not requiring costly foundation work. It is designed to operate with a high level of autonomy, minimizing operator intervention, including that required for machine setup and tool changes. System design enables positioning the work piece at a lower ergonomic height for concurrent manual processes. In all aspects of design, the system will maintain maximum flexibility for accommodating future manufacturing changes and increases in production rate, while meeting the strict accuracy requirements characteristic of aircraft manufacturing.
2015-08-04
Standard
AMS5040N
This specification covers a carbon steel in the form of sheet and strip.
2015-08-03
Standard
AMS5890F
This specification covers thoria-dispersion-strengthened nickel powder metallurgy product in the form of bars, forgings,extrusions, and stock for forging or extruding.
2015-08-02
WIP Standard
AMS4871H
This specification covers an aluminum bronze alloy in the form of centrifugal and chill castings.
2015-07-30
Standard
AIR1273B
This SAE Aerospace Information Report (AIR) establishes a positive identification of the functions and, if applicable, the hazards and direction of flow of pipe, hose, tube, or electrical conduit lines.
2015-07-28
Standard
AMS5656F
This specification covers a corrosion-resistant steel in the form of bars, wire, forgings, extrusions, flash welded rings, and stock for forging, extruding, or flash welded rings.
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