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Viewing 151 to 180 of 21493
2017-09-19
Journal Article
2017-01-2165
Christian Moeller, Hans Christian Schmidt, Philip Koch, Christian Boehlmann, Simon Kothe, Jörg Wollnack, Wolfgang Hintze
Abstract The high demand of efficient large scale machining operations by concurrently decreasing operating time and costs has led to an increasing usage of industrial robots in contrast to large scaled machining centers. The main disadvantage of industrial robots used for machining processes is their poor absolute accuracy, caused by the serial construction, resilience of gearings and sensitivity for temperature changes. Additionally high process forces that occur during machining of CFRP structures in aerospace industry lead to significant path errors due to low structural stiffness of the robot kinematic. These errors cannot be detected by means of motor encoders. That is why calibration processes and internal control laws have no effect on errors caused by elastic deformation. In this research paper an approach for increasing the absolute accuracy of an industrial milling robot with help of a Laser Tracker system during machining tasks will be presented.
2017-09-19
Technical Paper
2017-01-2075
Burton Bigoney, Nicholas Huddleston
Abstract Electroimpact and Lockheed Martin have developed an automated drilling and fastening system for C-130J aft fuselage panels. Numerous design and manufacturing challenges were addressed to incorporate the system into Lockheed Martin’s existing manufacturing paradigm and to adapt Electroimpact’s existing line of riveting machines for manufacture of these legacy aircraft parts. Challenges to automation included design of a very long yet sufficiently rigid and lightweight offset riveting anvil for fastening around deep circumferential frames, automated feeding of very short, “square” rivets in which the length is similar to the head diameter, creation of part programs and simulation models for legacy parts with no existing 3d manufacturing data, and crash protection for the aircraft part from machine collisions, given the uncertainties inherent in the model and the unique geometry of the aircraft parts.
2017-09-19
Technical Paper
2017-01-2072
Yilian Zhang, Qingzhen Bi, Nuodi Huang, Long Yu, Yuhan Wang
Abstract Interference-fit riveting is a critical fastening technique in the field of aerospace assembly. The fatigue and sealing performance of the rivet joint are determined by the interference-fit level of the rivet joint. As a result, it is of great importance to measure the interference-fit level accurately and effectively. Conventional interference-fit level measurement methods can be divided into direct measurement (destructive test on test-piece) and indirect measurement (off-line dimensional measurement of upset rivet head). Both methods cannot be utilized in automatic riveting. In this paper, an on-line non-destructive measurement method is developed to measure the interference-fit level. By taking full advantage of servo-driving riveting integrated with force measurement, the force-deformation data of the deformed rivet can be obtained in real time. The recognized feature points from the force-deformation data can reflect the height of the upset rivet head.
2017-09-19
Technical Paper
2017-01-2073
Rick Calawa, Gavin Smith
Abstract The decision to replace a successful automated production system at the heart of a high volume aircraft factory does not come easily. A point is reached when upgrades and retrofits are insufficient to meet increasing capacity demands and additional floor space is simply unavailable. The goals of this project were to increase production volume, reduce floor space usage, improve the build process, and smooth factory flow without disrupting today’s manufacturing. Two decades of lessons learned were leveraged along with advancements in the aircraft assembly industry, modern machine control technologies, and maturing safety standards to justify the risk and expense of a ground-up redesign. This paper will describe how an automated wing spar fastening system that has performed well for 20 years is analyzed and ultimately replaced without disturbing the high manufacturing rate of a single aisle commercial aircraft program.
2017-09-19
Technical Paper
2017-01-2086
Justin Lo
Abstract The fast growth of air traffic and the need for lighter and more fuel efficient aircraft is driving the ramp-up of important new aircraft programs. These increases in production rates are driving manufacturers to seek out robust and reliable installation systems. They must also adapt to the unique requirements of composite materials that now have an increasingly important place in the aerospace industry. Moreover, environmental constraints continue to evolve and drive new regulations, such as REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) in Europe. As an example, this regulation is leading to the adoption of non-chromate surface treatments and paints for most applications. The legacy generation of fasteners does not comply with all of these new requirements.
2017-09-19
Technical Paper
2017-01-2085
Sergey Lupuleac, Nadezhda Zaitseva, Margarita Petukhova, Julia Shinder, Sergey Berezin, Valeriia Khashba, Elodie Bonhomme
Abstract The paper is devoted to the simulation of A320 wing assembly on the base of numerical experiments carried out with the help of ASRP software. The main goal is to find fasteners’ configuration with minimal number of fastening elements that provides closing of admissible initial gaps. However, for considered junction type initial gap field is not known a priori though it should be provided as input data for computations. In order to resolve this problem the methodology of random initial gap generation based on available results of gap measurements is developed along with algorithms for optimization of fasteners' configuration on generated initial gaps. Presented paper illustrates how this methodology allows optimizing assembly process for A320 wing.
2017-09-19
Technical Paper
2017-01-2088
Long Yu, Qingzhen Bi PhD, Yilian Zhang, Yuhan Wang
Abstract A novel normal measurement device for robotic drilling and countersinking has been developed. This device is mainly composed of three contact displacement sensors and a spherically compliant clamp pad. The compliance of the clamp pad allows it to be perpendicular to the part when the Multi-Function End Effector (MFEE) drives it to clamp the part surface prior to drilling, while the displacement sensors are used to measure the movement of the clamp pad relative to the MFEE. Once the sensors’ position is calibrated, the rotation angle of the clamp pad can be calculated by the displacement of the sensors. Then, the normal adjustment of MFEE is obtained, and the adjustment process can be achieved by the Rotation Tool Center Point (RTCP) function of robot. Thus, an innovative method based on laser tracker to identify the position of sensors is proposed.
2017-09-19
Technical Paper
2017-01-2087
Peter Mueller-Hummel, Alex Hjorten
Abstract This article characterizes the special features of machining composite in comparison to machining metal. Simplified theoretic models will demonstrate how CFRP should be machined without delamination, burn marks and cutting tool breakages. Different strategies can be chosen depending on the material removal rate. The paper will present, based on this analytical approach, how milling cutters should be designed for optimal trimming, and how a drill should be designed in order to avoid the entrance, inner and exit delamination. While entrance and exit delamination is well understood, the paper will focus more to the delamination inside the bore. The appearance and the avoidance of the so called "Volcano Effect" and the reason why holes in composite becomes smaller after a couple of days will be explained. The comparison between 4 different cutting tool technologies will prove and give a better understanding how to use this theoretical approach.
2017-09-19
Technical Paper
2017-01-2078
Eric Barton, Rick Wolf
Abstract 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.
2017-09-19
Technical Paper
2017-01-2092
Ryan Mir, Russell DeVlieg
Abstract Fabrication and assembly of the majority of control surfaces for Boeing’s 777X airplane is completed at the Boeing Defense, Space and Security (BDS) site in St. Louis, Missouri. The former 777 airplane has been revamped to compete with affordability goals and contentious markets requiring cost-effective production technologies with high maturity and reliability. With tens of thousands of fasteners per shipset, the tasks of drilling, countersinking, hole inspection, and temporary fastener installation are automated. Additionally and wherever possible, blueprint fasteners are automatically installed. Initial production is supported by four (4) Electroimpact robotic systems embedded into a pulse-line production system requiring strategic processing and safeguarding solutions to manage several key layout, build and product flow constraints.
2017-09-19
Technical Paper
2017-01-2094
Tyler Everhart
Abstract Electroimpact, in collaboration with Boeing, has developed an advanced robotic assembly cell, dubbed “The Quadbots.” Using Electroimpact’s patented Accurate Robot technology and multi-function end effector (MFEE), each robot can drill, countersink, inspect hole quality, apply sealant, and insert fasteners into the part. The cell consists of 4 identical machines simultaneously working on a single section of the Boeing 787 fuselage, two on the left, and two on the right. These machines employ “collision avoidance” a new feature in their software to help them work more synchronously. The collision avoidance software uses positional feedback from external safety rated encoders mounted to the motors on the robot. From this feedback, safe spaces, in the form of virtual boundaries can be created. Such that a robot will stop and wait if the adjacent robot is in, or going to move into its programmed work envelope.
2017-09-19
Technical Paper
2017-01-2098
Didier Friot, Loic Meiffre, Christophe Vandaele
Abstract With air traffic demand constantly increasing and several years of aircraft production in their backlog, major aircraft manufacturers are now shifting their focus toward improving assembly process efficiency. One of the most promising solutions, known as “One Side Assembly”, aims to perform the whole assembly sequence from one side of the structure (drilling, temporary fastener installation and removal, blind fastener installation, assembly control) and with a high level of integrated automation. A one-sided, or blind fastener that is capable of matching the performance of current two-sided structural fasteners while meeting volume and cost objectives can be a major driver for assembly process efficiency improvements. To achieve a blind fastener assembly capable of both fully automated and manual installations while providing robust cycle times and assembly cost reductions is full of challenges.
2017-09-19
Technical Paper
2017-01-2150
Joshua Cemenska, Todd Rudberg, Michael Henscheid, Andrew Lauletta, Bradley Davis
Abstract In AFP manufacturing systems, manually inspection of parts consumes a large portion of total production time and is susceptible to missing defects. The aerospace industry is responding to this inefficiency by focusing on the development of automated inspection systems. The first generation of automated inspection systems is now entering production. This paper reviews the performance of the first generation system and discusses reasonable expectations. Estimates of automated inspection time will be made, and it will be shown that the automated solution enables a detailed statistical analysis of manufactured part quality and provides the data necessary for statistical process control. Data collection allows for a reduction in rework because not all errors need to be corrected. Expectations will be set for the accuracy for both ply boundary and overlap/gap measurements. The time and resource cost of development and integration will also be discussed.
2017-09-19
Journal Article
2017-01-2154
Alan Hiken
Abstract 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.
2017-09-19
Technical Paper
2017-01-2149
Cameron S. Gillespie
Abstract As carbon fiber reinforced plastics (CFRP) become more integrated into the design of large single piece aircraft structures, aircraft manufacturers are demanding higher speed and efficiency in Automated Fiber Placement (AFP) deposition systems. To facilitate the manufacturing of large surface area and low contour parts (wing skins, in this case) at a high production rate, Electroimpact has developed a new AFP head consisting of 20 1.5 inch wide pre-impregnated carbon tows. The new head design has been named the ‘OH20’, short for ‘One and a Half Inch, 20 Tows’. This AFP head format creates a deposition swath over 30 inches wide when all 20 tows are active. A total of four of these AFP heads have been integrated with a quick change robotic tool changer on two high speed, high acceleration, and high accuracy moving beam gantries.
2017-09-19
Technical Paper
2017-01-2074
Thorsten Dillhoefer, Fatih Erdinc
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specifications. The result is the new flexible C-Frame Panel Assembly Cell (CPAC) Bulkhead riveting System. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the CPAC.
CURRENT
2017-09-19
Standard
J2710_201709
This SAE Recommended Practice describes test methods for measuring and identifying the lower order natural frequencies of an inflated radial tire with a fixed rim while expending modest effort and employing a minimum of test equipment. The methods apply to any size of radial tire so long as the test equipment is properly scaled to conduct the measurements for the intended test tire. Two types of boundary conditions are considered for the tire: unloaded and loaded against a flat surface. The test involves the performance and measurement of an input vibratory force (excitation) to the tire and the corresponding vibratory output (response). The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development. NOTES: The focus of this standard is identification and reporting of the lower order natural frequencies of the tire using a simple test procedure.
CURRENT
2017-09-18
Standard
AMS5333G
This specification covers a low-alloy steel in the form of investment castings.
CURRENT
2017-09-18
Standard
AMS4981H
This specification covers a titanium alloy in the form of bars, wire, and forgings up through 4.000 inches (101.60 mm), inclusive, in diameter or least distance between parallel sides and forging stock of any size (see 8.6).
2017-09-17
WIP Standard
J1257
This recommended practice applies to mobile construction type cranes with cantilevered, telescopic booms when used in lifting crane service.
2017-09-17
Technical Paper
2017-01-2504
Scott Lambert
Abstract As the brake industry moves completely into globalization, a standardized method to define and validate the dimensions of backing plates, in a way that is both clear and feasible, is of critical importance for manufacturers at all tiers. The plate drawing not only defines the component as it fits into a brake assembly; it is also what the plate supplier relies on to define the plate for manufacture. If a drawing does not define every dimensional aspect of the product with perfect clarity, in ways that are easily measured, loss of time and resources will result from questions and/or mistakes. This paper proposes an SAE standard for defining the dimensional requirements of backing plates on the drawings themselves, and defining the measuring procedures used to validate those dimensions.
2017-09-17
Technical Paper
2017-01-2507
Matthias Hoch, Michal Kaczmarek, Markus Ahr
Abstract The demand for zinc-nickel coatings continuously increases in the automotive industry due to their high corrosion protection as well as superior wear and heat resistance compared to pure zinc platings. The state-of-the-art plating systems in the brake caliper industry are acid zinc-nickel electrolytes, as only they allow for direct plating on cast iron. Cast iron is the most common base material for the production of automotive brake components due to excellent mechanical and thermal properties. Well suited coatings will preserve the functional properties and provide additional advantages like improved corrosion protection and homogeneous and long lasting appearance. Consistently increasing quality demands, extended warranty periods and cost pressure lead to further developments and force the industry to look for new solutions.
2017-09-15
WIP Standard
D17AA
This specification covers the specific requirements for 2017 aluminum alloy bar, rod and wire produced by rolling, drawing or cold finishing supplied in the annealed (O temper) condition (see 8.4). When specified, product shall be supplied in the “as fabricated” (F) temper.
CURRENT
2017-09-14
Standard
AMS5337E
This specification covers an alloy steel in the form of investment castings.
CURRENT
2017-09-14
Standard
AMS5338H
This specification covers a low-alloy steel in the form of investment castings.
CURRENT
2017-09-13
Standard
AMS4466A
This specification covers an aluminum alloy in the form of alclad sheet and plate 0.020 to 0.500 inch (0.508 to 12.70 mm) inclusive, in thickness, supplied in the -T361 temper (see 8.5).
CURRENT
2017-09-13
Standard
AMS5336J
This specification covers a low-alloy steel in the form of investment castings.
CURRENT
2017-09-13
Standard
AMS4163F
This specification covers an aluminum alloy in the form of extruded bars, rods, wire, profiles, and tubing up to 2.999 inches, incl (76.17 mm, incl) in thickness, nominal diameter or wall thickness with cross-sectional area 25 in2 (161 cm2) and under (see 8.5).
CURRENT
2017-09-13
Standard
J2597_201709
This SAE Recommended Practice defines a procedure for the use of computer generated saturation curves to determine peening intensity. Calculation of intensity within a tolerance band for each data set in Table 1 one is required for compliance with this practice.
CURRENT
2017-09-11
Standard
AMS4251B
This specification covers an aluminum alloy in the form of sheet 0.040 to 0.249 inch (1.02 to 6.32 mm) in thickness (see 8.6).
Viewing 151 to 180 of 21493

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