Browse Topic: Fuselages

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The applications of Acoustic Black Holes to attenuation of Coach/Bus Frame Structure Vibrations2025-01-006505/05/2023
Abstract An acoustic black hole (ABH) is a structure whose cross-sectional thickness decreases exponentially to zero, and the phase velocity and group velocity of wave propagation in those structure acoustic black holes decrease as the thickness decreases until they are zero. ABH produce some very magical physical phenomena. For example, because the wave velocity decreases to zero, the wave can never reach the center of the ABH, so the wave propagation in the acoustic black hole has neither refraction nor reflection; that is to say the vibration wave will not go through the acoustic black hole. As a result, the wave energy is concentrated in the center of the ABH. The arrangements of those acoustic black holes in the structures could change the directions of the vibrational wave propagation in the structures at NVH engineers’ wills. These amazing phenomena could play a magical role in reducing structural vibration, structural noise radiation and structure-borne noise. Basic structures
Huang, Xianli
Rear Fuselage PackerTBMG-3759909/01/2020
Kaman UK Darwen, UK +44 1254 706000
Foldable Mechanical DevicesTBMG-3686005/01/2020
Engineers have developed new technology that builds complex mechanisms into the exterior of a structure without taking up any actual space below the surface. This new class of mechanisms, called “developable mechanisms,” get their name from developable surfaces, or materials that can take on 3D shapes from flat conformations without tearing or stretching, like a sheet of paper or metal. They reside in a curved surface and can transform or morph when deployed to serve unique functions. When not in use, they can fold back into the surface of the structure seamlessly.
Application of Extended Messinger Models to Complex Geometries2020-01-002203/10/2020
Since, ice accretion can significantly degrade the performance and the stability of an airborne vehicle, it is imperative to be able to model it accurately. While ice accretion studies have been performed on airplane wings and helicopter blades in abundance, there are few that attempt to model the process on more complex geometries such as fuselages. This paper proposes a methodology that extends an existing in-house Extended Messinger solver to complex geometries by introducing the capability to work with unstructured grids and carry out spatial surface streamwise marching. For the work presented here commercial solvers such as STAR-CCM+ and ANSYS Fluent are used for the flow field and droplet dispersed phase computations. The ice accretion is carried out using an in-house icing solver called GT-ICE. The predictions by GT-ICE are compared to available experimental data, or to predictions by other solvers such as LEWICE and STAR-CCM+. Three different cases with varying levels of
Gupta, Avani, Sankar, Lakshmi, Kreeger, Richard
Structure Deformation Calculation Program for Structural Shape MonitoringTBMG-3528910/01/2019
Researchers at NASA’s Armstrong Flight Research Center are pioneering shape-sensing technologies that seek to maximize structural integrity and efficiency. A new and versatile computer program offers critical shape-monitoring capabilities and has applications for a wide variety of structures.
Step & Repeat: Reduce Derivative Aircraft Development Risk with Design Reuse2019-01-187109/16/2019
The complex and risky process of designing derivative aircraft, especially when it comes to electrical systems, can be a daunting task at best. There are a number of design strategies that can be employed to mitigate risk and increase the overall efficiency. Quite simply, the current methods of manual processes, design and integration approaches that were optimized from mechanical approaches, are no match for today’s complexities. One method gaining significant traction is to employ a central database serving global interface definitions for the entire design process. Automation through generative design minimizes manual intervention and repetitive work. Furthermore, detecting changes through design rule checks allows system engineers to verify their designs, capturing both inadvertent and planned changes. The ability to instantly update the design content from the new definition streamlines the change management process. Employing these technologies in a digital, connected thread
Askar, Muhammad
Advanced Assembly Solutions for the Airbus RACER Joined-Wing Configuration2019-01-188409/16/2019
The Rapid And Cost Effective Rotorcraft (RACER) is being developed by Airbus Helicopters (AH) to demonstrate a new Vertical Take-Off and Landing configuration to fill the mobility gap between conventional helicopters and aeroplanes. RACER is a compound rotorcraft featuring wings and multiple rotors. The wing arrangement suggested by AH is defined as a staggered bi-plane joined configuration with an upper and a lower straight wing, either side of the fuselage, connected at their outboard extent to form a triangular structure. The ASTRAL consortium, consisting of the University of Nottingham and GE Aviation Systems, are responsible for the design, manufacture, assembly and testing of the wings. Producing an optimised strategy to assemble a joined-wing configuration for a passenger carrying rotorcraft is challenging and novel. The objective of this work concerns all aspects of assembling the joined-wing structure. The joined-wing and fuselage structures will be produced independently and
Bainbridge, David, Bacharoudis, Konstantinos, Cini, Andrea, Turner, Alison, Popov, Atanas, Ratchev, Svetan
Landing Gear Integration into Aircraft Structure in Early Design Stage2019-01-189009/16/2019
The demanded development towards various emission reduction goals set up by several institutions forces the aerospace industry to think about new technologies and alternative aircraft configurations. With these alternative aircraft concepts, the landing gear layout is also affected. Turbofan engines with very high bypass ratios could increase the diameter of the nacelles extensively. In this case, mounting the engines above the wing could be a possible arrangement to avoid an exceedingly long landing gear. Thus, the landing gear could be shortened and eventually mounted at the fuselage instead of the wings. Other technologies such as high aspect ratio wings have an influence on the landing gear integration as well. To assess the difference, especially in weight, between the conventional landing gear configuration and alternative layouts a method is developed based on preliminary structural designs of the different aircraft components, namely landing gear, wing and fuselage. Simplified
Kling, Ulrich, Hornung, Mirko
How Dual Polarization Technique May Improve Weather Radar on Commercial Aircraft2019-01-198206/10/2019
The airborne weather radar on a commercial aircraft is essential to ensure flight safety. It is able to detect severe weather, probable areas where presence of hail may be suspected, and thanks to its Doppler capability, the wind shears that may be dangerous when taking-off or landing. However, because it operates at X-band, the picture that it offers to the pilot may be seriously biased in situation of severe weather, in reason of the attenuation of the radar wave. The adoption of the dual pol technique in this weather radar would be most beneficial for the quality of the information delivered to the pilot for the following reasons: 1 Dual pol technique allows to operate a classification of the precipitation: distinguishing rain, melting layer, snow, hail, small ice particles. 2 Dual pol technique allows correcting the return signal for attenuation in rain. The paper aims reporting recent advances in the exploitation of dual pol radar data, based on the concept of normalisation of the
Testud, Jacques Victor, Moreau, Emmanuel, Le Bouar, Erwan
Predicted Ice Shape Formations on a Boundary Layer Ingesting Engine Inlet2019-01-202506/10/2019
Computational ice shapes were generated on the boundary layer ingesting engine nacelle of the D8 Double Bubble aircraft. The computations were generated using LEWICE3D, a well-known CFD icing post processor. A 50-bin global drop diameter discretization was used to capture the collection efficiency due to the direct impingement of water onto the engine nacelle. These discrete results were superposed in a weighted fashion to generate six drop size distributions that span the Appendix C and O regimes. Due to the presence of upstream geometries, i.e. the fuselage nose, the trajectories of the water drops are highly complex. Since the ice shapes are significantly correlated with the collection efficiency, the upstream fuselage nose has a significant impact on the ice accretion on the engine nacelle. These complex trajectories are caused by the ballistic nature of the particles and are thus exacerbated as particle size increases. Shadowzones are generated on the engine nacelle, and due to
Porter, Christopher
Machining Titanium Aero-FramesTBMG-3454306/01/2019
The rise of titanium for aerospace applications has been well documented in recent years. Equally, the challenges associated with the efficient, productive and high-quality machining of this popular material, have also been a topic of debate and scrutiny. Of course, every machine shop wants optimized performance from its cutters when milling titanium, but this can prove less than straightforward without the right technology and know-how in place. Today, however, thanks to a breakthrough in this area, things are beginning to change.
Machining Titanium Aero-Frames19AERP06_1106/01/2019
The rise of titanium for aerospace applications has been well documented in recent years. Equally, the challenges associated with the efficient, productive and high-quality machining of this popular material, have also been a topic of debate and scrutiny. Of course, every machine shop wants optimized performance from its cutters when milling titanium, but this can prove less than straightforward without the right technology and know-how in place. Today, however, thanks to a breakthrough in this area, things are beginning to change. The aerospace segment is expected to demonstrate impressive growth in the coming years as consumers continue to drive demand for new routes and greater flight frequency. Further drivers include global demographics and wealth creation in Asia and the Middle East. In fact, according to Airbus, air traffic is set to double from its current levels over the course of the next fifteen years.
5 Ws of Foldable Mechanical DevicesTBMG-3440205/01/2019
Manufacturers across medical, space, aviation, military, and automotive industries could use the technology to build complex machines that integrate with surfaces to be very compact, but can deploy to do complex tasks.
Numerical Analysis of Asymmetric Canard-Wing System in Detroit Flying Cars2019-01-136103/19/2019
A numerical simulation system of airflow around the Detroit Flying Cars-Wild Dream 1 (WD-1) is introduced. It involves the application of FVM, the mesh-independence system, boundary conditions and the verification of the simulation conditions to NACA airfoil data and the discussion of technological treatments corresponding to the evaluation of asymmetric wings. The present work is investigating the aerodynamic behavior of an asymmetric canard-wing system used on the Detroit Flying Cars-WD 1 model. The work involves the application of Finite Volume Method (FVM), the mesh-independence system, boundary conditions and the verification of simulation conditions to NACA airfoil data using OpenFOAM software. The Reynolds number based on free stream velocity and root chord is 5X106. Based on the Coefficient of Lift and Coefficient of Drag obtained from the analysis, the effect of canards on the wings, the distance between the canard trailing edge and the leading edge of the wings and the
Kocherla, Isaac Shanth, Yu, ChenXing
Axiomatic Design of a Reconfigurable Assembly System for Aircraft Fuselages2019-01-135903/19/2019
Modern aerospace industry develops assembly process lines for new aircraft which is produced on a single production line while shortening production times by new technologies. Production processes are developed with systems such as lightweight fixtures, reconfigurable tools, automated part positioning, automated scanning countersink control, automated riveting, robotic measurement etc. These systems provide the necessary flexibility for aircraft fuselage and wing assembly projects. Aerospace manufacturers invest in assembly lines in order to increase production rates and meet growing customer demands. Most of the investments are allocated to state-of-the-art robots for drilling and riveting, sealing, coating and painting applications, in addition to material handling, carbon fiber layup and different types of machining operations. In this study, an assembly system design methodology is developed by using axiomatic design principles in order to propose a solution to design complexity
Celek, Osman Emre, Yurdakul, Mustafa, Ic, Tansel
MOMENTUM: APRIL 201818MOMP0404/02/2018
The road to victory is not a straight line Through highs and lows and curves in the road, Milwaukee School of Engineering's Formula SAE Hybrid team kept its focus and ended up with a championship. Winging it BYU-Idaho students develop innovative wing-to-fuselage connection for SAE Aero Design competition. The SpiRIT of Baja BYU-Idaho students develop innovative wing-to-fuselage connection for SAE Aero Design competition. Kettering Baja SAE hoists the SAE Collegiate Cup Seven SAE Collegiate Design Series teams competed in an annual presentation contest hosted by the SAE Mid-Michigan Section.
The Evolution of the Composite Fuselage - A Manufacturing Perspective2017-01-215409/19/2017
A review of critical technologies and manufacturing advances that have enabled the evolution of the composite fuselage is described. The author’s perspective on several development, military, and production programs that have influenced and affected the current state of commercial fuselage production is presented. The enabling technologies and current approaches being used for wide body aircraft fuselage fabrication and the potential reasons why are addressed. Some questions about the future of composite fuselage are posed based on the lessons learned from today and yesterday.
Hiken, Alan
Drivmatic® Automatic Fastening System with Single Robot Positioner2017-01-207809/19/2017
The focus of this technical paper is a unique automatic fastening system configuration for loading, positioning & unloading pre-tacked door assemblies within a static C-Frame Drivmatic® fastening machine using an off-the-shelf, high accuracy Fanuc robot. In 2011, PMC was awarded a significant contract for supplying commercial OEM aircraft doors and recognized automation was the most feasible approach for fastening each door assembly. At the time of contract award, PMC was an established aero structure supplier with significant automation capability for machining high tolerance parts & assemblies and manual fastening resources to support many different OEM programs however PMC did not have automatic fastening experience or capability. In support of this new Tier-2 contract, PMC reached out to Gemcor to propose a collaborative robot solution for automatically fastening 5 different door assemblies that were historically fastened using a semi-automatic configuration. Demand for quality
Barton, Eric, Wolf, Rick
Automatic Tool Change System for Stringer Side Rivet and Bolt Anvils on a D-Frame or C-Frame Fuselage Fastening Machine2017-01-208009/19/2017
Manually changing stringer-side tooling on an automatic fastening machine is time consuming and can be susceptible to human error. Stringer-side tools can also be physically difficult to manage because of their weight, negatively impacting the experience and safety of the machine operator. A solution to these problems has recently been developed by Electroimpact for use with its new Fuselage Skin Splice Fastening Machine. The Automatic Tool Changer makes use of a mechanically passive gripper system capable of securely holding and maneuvering twelve tools weighing 40 pounds each inside of a space-saving enclosure. The Automatic Tool Changer is mounted directly to the stringer side fastening head, meaning the machine is capable of changing tools relatively quickly while maintaining its position on the aircraft panel with no machine operator involvement. Additionally, since the tools are all contained within an interlocked enclosure, this system reduces the required frequency of tool
Merluzzi, James, Bahr, Isaac
Automatic Drilling, Countersink and Riveting Experience. Aernnova Highlights Based on More Than 20 Million of Fasteners Installed2016-01-208909/27/2016
Aernnova experience on automatic drilling operations started in 1,999. The company signed a new contract with Embraer, to design, manufacture and assembly several structures of the model 170. It was big news for the company. But after that minute of pride, manufacturing engineering people of the company started to think about the process to assemble those big panels of the Horizontal Stabilizer, Vertical Stabilizer and Rear Fuselages in the best Quality and Cost. There were a lot of rows of rivets to install. Some ideas arisen, but the final decision was to forget the available processes at that time and think about to automate the drilling, countersink and riveting of the stringers, doublers and window frames to the panels. There were a lot of doubts, figures to do and obstacles, but the company took the decision of going ahead with that process. That step changed the state of the art at that time in the company. The investment was important, the risks were high, and the beginnings
Guerra cEng, Jose, Castillo, Miguel Angel
Robotic Installation of OSI-Bolts2015-01-251209/15/2015
Electroimpact has developed an automated solution for installing OSI-Bolts on the HStab for Boeing's 787-9 aircraft. This solution utilizes Electroimpact's existing accurate robotic system together with new hardware designed specifically for OSI-Bolts. In addition to automated drilling and fastener installation, this system performs numerous quality checks to insure the installed fastener meets engineering requirements. Before installing the fastener, the system measures actual stack thickness and the length of the fastener to ensure that the proper grip is installed. Torque and angle feedback are recorded during installation which can be used determine if the fastener was installed correctly. The system will also automatically shave the small protuberance on the fastener head left by the broken off fastener stem, which is inherent to the OSI-Bolt. Figure 1 Cell Overview
Sydenham, Mark W., Brown, Tim
Innovative Approach for Modular and Flexible Positioning Systems for Large Aircraft Assembly2015-01-250309/15/2015
This paper presents an innovative approach for modular and flexible positioning systems for large aircraft assembly, for instance the manufacturing of the fuselage sections from shell panels and floor grids, the alignment of the sections to build the fuselage, and the joining of wings and tail units to the fuselage. The positioning system features a modular, reconfigurable, and versatile solution for various aircraft dimensions and different applications. This includes the positioning units, the controls, the measurement interface and the product supports. It provides the customer with a holistic solution that considers the specific positioning task taking into account high absolute positioning accuracy, repeatability and synchronization of the motion for all manipulators that constitute the positioning system. Various tools and method which were used during the development process are introduced and the developed standardized Positioning Technology is briefly explained.
Dr. Schneider, Thomas
Passive Heat Exchange System for Aircraft Equipment Cooling Applications2015-01-241809/15/2015
Due to the increasing power density of onboard electric and electronic equipment and heat dissipation in civil and military aircraft, more efficient ways of transferring heat and new cooling techniques are necessary. A passive heat transfer prototype was developed and experimentally evaluated in laboratory and on ground and flight tests in an Embraer test aircraft. The passive heat transfer device consists of a loop-thermosyphon with two condensers and a common evaporator, using water as the heat transfer working fluid. An electric resistance and a variable power source were used to dissipate heat inside the evaporator simulating heat transfer from an onboard electronics bay. The fuselage/external air stream and the air flow inside an air conditioning system duct were used as heat sinks. Prior to flight test, laboratory tests were conducted simulating ground and flight operations. During flight test, the fuselage/external air stream was responsible for dissipating over 80% of the heat
Gandolfi, Ricardo, Ribeiro, Luiz, Oliveira, Jorge, Paiva, Kleber, Mantelli, Marcia
Wireless and Flexible Ice Detection on Aircraft2015-01-211206/15/2015
We present a wireless sensor system for temperature measurement and icing detection for the use on aircraft. The sensors are flexible (i.e. bendable), truly wireless, do not require scheduled maintenance, and can be attached easily to almost any point on the aircraft surface (e.g. wings, fuselage, rudder, elevator, etc.). With a sensor thickness of less than two millimeters at the current state of development, they hardly affect the aero dynamical behavior of the structure. In this paper, we report laboratory and field results for temperature measurement and icing detection.
Schlegl, Thomas, Moser, Michael, Zangl, Hubert
Numerical and Experimental Study of Sound Power Reduction Performance of Acoustic Black Holes in Rectangular Plates2015-01-227006/15/2015
Global attenuation of structural velocities is one of the most effective approaches in order to reduce noise emitted by shell structures such as a car roof or aircraft fuselage panels. This global reduction can be achieved by the application of passive damping treatments like constraint layer damping on large fractions of the vibrating surface. The main disadvantage of this approach arises from the fact that it leads to increasing total cost and weight of the structure. To overcome this problem, acoustic black holes can be used to create locations with high vibration amplitudes and low bending waves velocity in order to dissipate the energy of structure borne sound by very limited application of damping treatments. Acoustic black holes are funnel shaped thickness reductions that attract sound radiating bending waves and allow a global vibration reduction by an acceptable use of additional damping. This paper presents the results of a numerical and experimental study of acoustic black
Unruh, Oliver, Blech, Christopher, Monner, Hans Peter
Designed for the Environment1193402/25/2015
Boeing is designing jetliners with the environmental impact of their life span in mind. From the fuselage to the carpet, Boeing Director of Environmental Performance Jeanne Yu explains why Boeing considers how entire airplanes will be recycled before they're ever built.
Flex Track One Sided One Up Assembly2014-01-227409/16/2014
The Boeing Company is striving to improve quality and reduce defects and injuries through the implementation of lightweight “Right Sized” automated drill and fasten equipment. This has lead to the factory adopting Boeing developed and supplier built flex track drill and countersink machines for drilling fuselage circumferential joins, wing panel to spar and wing splice stringers. The natural evolution of this technology is the addition of fastener installation to enable One Up Assembly. The critical component of One Up Assembly is keeping the joint squeezed tightly together to prevent burrs and debris at the interface. Traditionally this is done by two-sided machines providing concentric clamp up around the hole while it is being drilled. It was proposed that for stiff structure, the joint could be held together by beginning adjacent to a tack fastener, and assemble the joint sequentially using the adjacent hole clamp up from the previous hole to keep the joint clamped up. This process
HansonSmith, Riley, Merkley, Alan
Next Generation Mobile Robotic Drilling and Fastening Systems2014-01-225909/16/2014
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. The mobile robot is sized so it can be shipped complete on a lowboy trailer for deliveries that can be completed by
Adams, Greg
Riveting Thin A320 Stacks2014-01-226409/16/2014
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.
Zieve, Peter B., Celek, Osman Emre, Fenty, John
Automated drilling machine takes the burr out of fuselage jointTBMG-1984302/01/2014
More than 1200 large-diameter (up to ¾-in) holes must be drilled into titanium/ carbon stacks for the side-of-body joint on a particular Boeing commercial aircraft fuselage. This is the joint between the upper shell (section 44) of the center fuselage and the lower corresponding section (section 45), which includes the wingbox and the landing gear well.
Aircraft Structure Paint Thickness and Lightning Swept Stroke Damages2013-01-213509/17/2013
During its flight an aircraft can be struck by lightning and the induced high current will require a highly conductive airframe skin structure in order for it to propagate through with minimum damage. However an aircraft skin is generally coated with paint and the airframer does not always have control on the paint thickness. Paint thickness generates heightened concerns for lightning strike on aircraft, mainly because most of coatings dedicated to that purpose are non-conductive. Using insulating material or non-conductive coating with certain thickness may contribute to or increase damage inflicted by the swept stroke lightning energy, even on metallic structures Due to its high relative permittivity, a non-conductive paint or coating on a fuselage skin surface will contribute to slow down the lightning current propagation through structure. With this comes the risk of increasing heat that will favor structural damage and possible melt through. The correlation between paint thickness
Moupfouma, Fidele
Challenges Associated with a Complex Compound Curvature Passenger Doors2013-01-221709/17/2013
This study investigates challenges associated with integrating a passenger (PAX) door on complex compound curvature (CCC) fuselages. Aerospace companies are investigating concepts that no-longer have constant cross-section (CS) fuselages. The PAX door is based on a generic semi-plug door for a long range business jet (BJ). This study investigates limitations of locating the door by varying the transition zone angle. A parametric CATIA tool, coupled with the use of finite element model (FEM) results can highlight key drivers in the design and location of PAX doors, creating a first-draft structural layout. The associated impact on the design and structural architecture for a fold down PAX door with integrated stairs is discussed. The impact of CCCs on the PAX door design is investigated with consideration to location, kinematics and function of the door. Design requirements, when coupled with stress analysis to simulate pressurization effect of the load applied to the stops, can create
Mistry, Sunil
Smart Portable Tools: The Practical Solution to Agile Assembly2013-01-229509/17/2013
Fully autonomous systems are seen as the ultimate solution to all manufacturing problems due to their consistent quality and ability to improve rates, but they also have one key disadvantage: Limited equipment versatility. This shortcoming becomes most apparent when trying to apply automation to aircraft final assembly. The variety of jobs is great and would necessitate the development of many unique solutions. Therefore a robotic system designed for one job on one aircraft version might be useless on the next version. Also there are many tight spaces and complex jobs where automation is just not practical, meaning that workers with portable tools will always have some presence in production. The modern smart portable tool as exemplified by the Novator PM Series orbital drill motor is capable of matching the quality and speed of a robotic system while still maintaining the ability to be applicable over a wide variety of jobs. Smart portable tools build on the tried and true portable
Holleman, Wesley, Whinnem, Eric, Wrede, Madeleine
Preforming of a Fuselage C-Shaped Frame Manufactured by Resin Transfer Molding2013-01-221409/17/2013
The need for efficient manufacturing approaches has emerged with the increasing usage of composites for structural components in commercial aviation. Resin Transfer Molding (RTM), a process where a fiber preform is injected with resin into a closed tool, can achieve high fiber content required for structural components as well as improved dimensional accuracy since all surfaces are controlled by a tool surface. Moreover, RTM is well suited for parts that can be standardized throughout the aircraft, such as a fuselage frames and stringers. The objective of this investigation is to develop a preforming approach for a C-Shaped Fuselage frame. Two approaches are proposed: tri-axial braiding and hand lay-up of Non-Crimp Fabrics. The fiber architecture of the basic materials as well as the complete preforms is explained. The necessary preforming operations are detailed. The quality control measurement of fiber orientation and thickness are presented. A relation between the fabric lay-up
Laberge Lebel, Louis, Trudeau, Paul
Development of Low Cost Fuselage Frames by Resin Transfer Molding2013-01-232509/17/2013
This paper presents work on the development of a low cost fuselage C-frame for aircraft primary structure using a Light Resin Transfer Molding (RTM) process. Compared to labor intensive hand layup prepreg technologies, Light RTM offers some substantial advantages by reducing infrastructure requirements such as hydraulic presses or autoclaves. Compared to Prepreg, Light RTM tooling creates two finished surfaces, which is an advantage during installation due to improved dimensional accuracy. The focus of this work was to develop means of achieving high fiber volume fraction structural frames using low cost tooling and a low volume manufacturing strategy. In this case a three piece Light RTM mold was developed using an internal mandrel. To achieve the strength requirements, a combination of crimped and non-crimped fabrics were selected for the reinforcing preform. This made it possible to reduce the number of flat patterns by more than 8 times, saving layup time compared to the prepreg
Salek, Hasan, Trudeau, Paul
5-Axis Flex Track Drilling Systems on Complex Contours: Solutions for Position Control2013-01-222409/17/2013
Previous Flex Track drilling systems move along two parallel tracks that conform to the contour of a work piece surface. Until recently, applications have been limited to relatively simple surfaces such as the cylindrical mid-body fuselage join of a commercial aircraft. Recent developments in the state of the art have introduced the 5-axis variant which is capable of precision drilling on complex contours. This paper presents solutions to two positioning challenges associated with this added functionality: the ability to align the spindle axis normal to an angled drilling surface while maintaining accuracy in tool-point position, the ability to maintain synced motion between dual drives on complex track profiles.
Malcomb, Joseph R.
Automated Positioning and Alignment Method and System for Aircraft Structures Using Robots2012-01-187609/10/2012
Automated assembly of components and parts has been largely applied in aerospace industry due to several advantages such as low cost, high flexibility, reduction of floor space and high repeatability of process. The work described herein is part of the activities being carried at the Aircraft Structure Assembly Automation Laboratory (ASAA Lab). An outcome of a partnership between the Aeronautics Institute of Technology (ITA) and the Brazilian aerospace sector, the ASAA Lab is developing an automated process for the assembly of aircraft fuselages. This process [1] is constituted of two main steps: the leveling and alignment of the fuselage barrels and the drilling and riveting procedures that join the barrels together. This paper is related to the first step, a method and a system for positioning and aligning aircraft parts one in relation to each other during the structural assembly using robots with articulated arms as positioning means assisted by large volume measurement systems.
Negroni, Daniella Yada, Trabasso, Luis, Simonetti, Marcos Leandro
Mating Aircraft Using Flexible Tooling via the Digital Thread2012-01-185109/10/2012
Tooling structures to make wing/wing, fuselage/fuselage, and wing/fuselage mates have long been rather massive tools. Not only are these tools large and expensive, but they often obstruct the very drilling and fastening work to be done in the mate tool. Furthermore, these legacy mate tools can only do one job - a mate tool cannot be used for a different airplane, or even a different part of the same airplane. A flexible, more versatile system will lower the cost of aircraft with a low quantity production run planned, and a more open design can reduce the cost of assembly on a high production aircraft. This paper will discuss the development and recent breakthroughs that allow the mating of any size aircraft sections with very high precision using only a set of specialized jacks that provide six degrees-of-freedom coupled with a non-contact measurement system. Data extracted directly from a CAD 3-D model is fed into a computer system that is then used with a closed-loop control system
Richardson, Roger C.
5-Axis Flex Track System2012-01-185909/10/2012
Flex Track Systems are seeing increased usage in aerospace applications for joining large assemblies, such as fuselage sections. Previous systems were limited to work pieces that allowed the tracks to follow a gentle radius of curvature, limiting the locations where the system could be used. This paper describes a new 5-Axis Flex Track System developed to expand the usage of the systems, allowing them to process work pieces containing complex and irregular contours. Processing complex contours is accomplished through the addition of A and B axes providing normalization in multiple directions. These new systems are configured with the latest multi-function process capabilities allowing drilling, hole quality measurement, and temporary or permanent fastener installation.
Seater, Brian
Automation for Unprecedented Production Rates2012-01-187009/10/2012
Unprecedented rates in Boeing 737 aircraft production have driven a need for an increase in capacity in fuselage manufacturing and assembly. This paper will discuss the requirements by Spirit AeroSystems to add capacity, and the new and upgraded machinery provided by Broetje Automation in response to these requirements. Production areas found to require additional capacity included galley and entry door skin fastening, as well as frame fastening in upper and lower lobes. Three new Mobile Panel Assembly Cell (MPAC) machines were installed in rapid succession for efficient and flexible production of door panels. For frame fastening of upper and lower lobes, three existing machines were taken out of production one at a time for a comprehensive upgrade resulting in process speed increases of more than 40%.
O'Rourke, Brian, Rounkles, Randy
Design and Safety Criteria for Passenger Boarding StairwaysARP836C (Current)03/28/2012
This SAE Aerospace Recommended Practice (ARP) is broken into various categories for convenience and ease of identification. It is the purpose of this document to provide certain criteria for the design and selection of stairways, for the boarding of passengers onto an aircraft. The criteria presented are limited to those factors which affect the safety of the passengers and are coordinated, where applicable, with the practices of the architectural profession, with respect to the design of stairways. The recommended practices are applicable to both mobile variable-elevation type stairways and to fixed-elevation stairways of the type built into an aircraft fuselage.
AGE-3 Aircraft Ground Support Equipment Committee
Controlling Cabin and Envelope Air Flows and Pressure Differentials to Prevent Envelope Condensation, Enable Cabin Humidification, Improve Fire Safety, and Decrease Fuel Use2011-01-268910/18/2011
The uncontrolled flow of cabin air into the aircraft envelope caused by indoor-outdoor temperature gradients and associated stack pressure differentials causes cabin air to circulate between the cabin and the envelope, producing condensation on the cold fuselage behind the insulation with a number of adverse consequences. These include an inability to practically maintain cabin humidity at normal levels, a reduction in ventilation effectiveness, microbial growth, metal corrosion and structural failures, insulation performance degradation, thermal discomfort, increased engine noise transmission, additional fuel consumption and electrical failures and fires. This paper explains the origin of these stack pressures and the air flows they create between the cabin and the envelope, and indicates means to control the flows and associated cabin-envelope pressure differentials and thereby minimize condensation and its associated problems, improve thermal comfort and fire safety, and
Walkinshaw, Douglas Stuart, Preston, Keith F.
One Piece AFP Spar Manufacture2011-01-259210/18/2011
Manufacturing C cross-sectional components with high aspect ratios out of carbon fiber reinforced composites is desirable by the aircraft industry. Modular AFP heads with short, fixed tow path have the fundamental performance characteristics required to successfully and productively automate the production of these part families. Aircraft parts in this family include wing spars, stringers, and fuselage frames.
Rudberg, Todd, Purvis, Andrew J., Faubion, Guy, Nancarrow, John
Positioning System for the Aircraft Structural Assembly2011-01-263710/18/2011
This paper presents a new conception of a positioning technology concept for aircraft structural assembly, for instance the manufacturing of the fuselage sections from shell panels and floor grids, the alignment of the sections to build the fuselage, and the joining of wings and tail units to the fuselage. The positioning system features a modular, reconfigurable, and versatile solution for various aircraft dimensions and different applications. It provides the customer with a holistic solution that considers the positioning task taking into account the operation conditions and the environmental influences within the very same control unit. The positioning system consists of three main modules that communicate over a standardized interface: A large-scale metrology system for an accurate identification of the positions and orientation of the aircraft components, a mechanical system for the handling of these components and a control system. The latter is the core module of the
Mbarek, Taoufik, Meissner, Alexander, Biyiklioglu, Nihat
A Comparison of Wing Stowing Designs Focused on Increased Continuous Payload Volume for Projectile Applications2011-01-278210/18/2011
West Virginia University's Mechanical and Aerospace Engineering Department is studying the benefits of continuous payload volume in transforming projectiles. Continuous payload volume is the single largest vacancy in a vehicle that may be utilized. Currently there is a market for transforming projectiles, which are gun launched (or tube launched) vehicles stowed in an initial configuration; which deploy wings once exiting the launcher to become small unmanned aircraft. WVU's proposed design uses a helical hinge, which allows the wing sections to be externally stowed outside the UAV's fuselage. Additionally, the design positions the vehicles wing sections sub-bore (or smaller than the guns internal diameter), and flush (smooth and planer) to the surface of the fuselage. The typical transforming winged projectile design considered, stores its wing sections along the center axis of the fuselage. This bisects the payload space and limits the continuous payload carrying potential
Minehart, Robert F., Browning, Patrick, Wilhelm, Jay, Hamburg, Shanti, Gautam, Mridul, Huebsch, Wade
Distributed Aerodynamic Sensing and Processing ToolboxTBMG-899001/01/2011
A Distributed Aerodynamic Sensing and Processing (DASP) toolbox was designed and fabricated for flight test applications with an Aerostructures Test Wing (ATW) mounted under the fuselage of an F-15B on the Flight Test Fixture (FTF). DASP monitors and processes the aerodynamics with the structural dynamics using nonintrusive, surface-mounted, hot-film sensing. This aerodynamic measurement tool benefits programs devoted to static/dynamic load alleviation, body freedom flutter suppression, buffet control, improvement of aerodynamic efficiency through cruise control, supersonic wave drag reduction through shock control, etc.
Fracture Behavior of Typical Structural Adhesive Joints Under Quasi-Static and Cyclic Loadings2010-01-096904/12/2010
Structural adhesive joints are expected to retain integrity in their entire service-life that normally involves cyclic loading concurrent with environmental exposure. Under such a severe working condition, effective determination of fatigue life at different temperatures is crucial for reliable joint design. The main goal of this work was thus defined as evaluation of fatigue performance of adhesive joints at their extreme working temperatures in order to be compared with their fracture properties under static loading. A series of standard double-cantilever-beam (DCB) specimens have been bonded by three structural 3M epoxy adhesives selected from different applications. The specimens were tested under monotonic and cyclic opening loads (mode-I) in order to evaluate the quasi-static and fatigue performances of selected adhesives at room temperature, 80°C and -40°C. The test results revealed that the fatigue damage occurred at relatively low load levels when compared to quasi-static
Eskandarian, Mojtaba, Jennings, Robert, Cote, Maxime, Arsenault, Bernard
Final Assembly Line2009-01-311811/10/2009
Manually aligning and joining completed aircraft sections is historically a time consuming and cumbersome process. Constant manual measuring is required, as well as very fine movements which are difficult to control and accomplish manually. In order to increase both the efficiency as well as the quality and safety of the section join process, BRÖTJE-Automation has developed the Automated Positioning and Alignment System. This paper describes two Positioning and Alignment Systems – one for joining fuselages and one for wing attachment. The Positioning and Alignment Systems are designed with the flexibility to join fuselage sections and wings to the fuselages for a range of different aircraft, all fully automatically through the use of a laser measurement system.
Maylaender, Holger, O'Rourke, Brian
Open (and often) communicationAEROMAR08_0403/01/2008
As aircraft companies battle for market share, uniting design and manufacturing teams remains a key challenge. The value of communication and teamwork was understood by ancient Greeks and Romans, but getting teams to work well together remains a hard-to-achieve goal even today. That communicating early in the process prevents errors when they are less expensive may seem almost ancient as Greek wisdom, but that does not mean it is easy to do. Instant communications around the globe offers the potential for great success, but the flip side remains just as ominous as when papyrus was the communications media of the day.
Costlow, Terry
Dispersion of De-Icing Chemicals to the Areas Along the Runways at Oslo Airport Gardermoen2007-01-335109/24/2007
Oslo Airport Gardermoen is located on the largest unconfined groundwater aquifer in Norway and acts upon strict governmental regulations concerning groundwater balance and contamination of groundwater and surface waters. In the cold Norwegian winter climate, de-icing of aircrafts and runway systems is necessary for safety reasons. The aircraft de-icing fluids (type 1 and type 2) are based on propylene glycol (PG). Potassium Formate (PF) is used for de-icing of runways and taxiways. Aircraft de-icing takes place on remote de-icing platforms. At each platform there is a system for drainage of excess de-icing fluid, but some is passively dispersed from the aircraft body to the area along the runways and mix with snow. During melting, release of de-icers to the ground occurs. In such events the chemicals need to be biologically degraded in the unsaturated zone to meet the governmental requirements. To avoid negative effects on the environment and to meet governmental regulations
Øvstedal, Jarl, Wejden, Bente
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