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Viewing 1 to 30 of 4368
2016-09-27
Technical Paper
2016-01-8053
Adime Kofi Bonsi, Marius-Dorin Surcel
The objective of this project was to provide pertinent information on the performance of refrigerated and heated van semitrailers to help fleets make decisions that will improve efficiency and increase productivity. To achieve this objective, tests were designed to benchmark fuel consumption of reefers and heating units and measure the impact of trailer characteristics on fuel consumption of the unit for various temperature settings. The project compared older- to newer-design refrigerated van semitrailers to determine what potential fuel savings could be obtained while maintaining temperature control. The outcome of this project is a summary of the impact of trailer characteristics on fuel consumption. Additionally, a literature survey was conducted and best practices were identified.
2016-09-27
Technical Paper
2016-01-8049
Keith Friedman, Khanh Bui, John Hutchinson, Matthew Stephens, Francisco Gonzalez
Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. The frame technology opens opportunities that are likely to improve crash compatibility, fuel economy, fuel storage system protection. While examples of integrated front, side and rear underride protection systems enabled with this frame design technology, in this study, the effect of incorporating the fuel storage system within the available curved frame rails was evaluated using virtual testing. Fuel system storage for diesel and compressed natural gas (CNG) were evaluated under impact conditions. The impact performance was evaluated under a range of horizontal impacts and rollover conditions.
2016-09-27
Technical Paper
2016-01-8050
Chihua Lu, Wenxin Yang, Hao Zheng, Jingqiang Liang, Guang Fu
In this paper, we proposed a method of dynamic simulation and analysis based on superelement modeling to increase the efficiency of dynamic simulation for vehicle body structure. Using this method, a certain MPV body structure was divided into several subsystems, and the modal parameters and frequency response functions of which were obtained through superelement condensation, residual structure solution, and superelement data restoration. The study shows that compared to the traditional modeling method, the computational time for vehicle body modal analysis can be reduced by 6.9% without reducing accuracy; for the purpose of structural optimization, the computational time can be reduced by 87.7% for frequency response analyses of optimizations; consistency between simulation and testing can be achieved on peak frequency points and general trends for the vibration frequency responses of interior front row floors under accelerating conditions.
2016-09-27
Technical Paper
2016-01-2133
Carl Landau
Aircraft manufacturers are seeking automated systems capable of positioning large structural components with a positional accuracy of 0.25mm. Previous attempts at using coordinated arm robots for such applications have suffered from the use of low accuracy robots and minimal systems integration. Electroimpact have designed a system that leverages our patented Accurate Robot technology to create an extensively automated and comprehensively integrated process driven by the native airplane component geometry. The predominantly auto-generated programs are executed on a single Siemens CNC that controls two Electroimpact-enhanced Kuka 6 axis robots. This paper documents the system design including the specification, applicable technologies, descriptions of system components, and the comprehensive system integration. The first use of this system will be the accurate assembly of production empennage panels for the Boeing 777X, 787 and 777 airplanes.
2016-09-27
Technical Paper
2016-01-2105
Thomas G. Jefferson, Richard Crossley, Anthony Smith, Svetan Ratchev
This paper presents a novel reconfigurable assembly cell which can assemble multiple fuselage and wing variants. Most aerostructure assembly systems are designed to produce one variant only. For multiple variants, each assembly typically has a dedicated assembly cell, despite most assemblies requiring a process of drilling and fastening to similar tolerances. Assembly systems that produce more than one variant do exist but have long changeover or involve extensive retrofitting. Quick assembly of multiple products using one assembly system offers significant cost savings from reductions in NRC and lead time. Recent trends advocate Reconfigurable Assembly Systems (RAS) as a solution designed to have exactly the functionality necessary to produce a group of similar components. Components with similar geometries and processes are grouped into part families by iterating between design and manufacturing.
2016-09-27
Technical Paper
2016-01-2095
Agata Suwala, Lucy Agyepong, Andrew Silcox
Reduction of overall drag to improve aircraft performance has always been one of the goals for aircraft manufacturers. One of the key contributors to decreasing drag is achieving laminar flow on a large proportion of the wing. Laminar flow requires parts to be manufactured and assembled within tighter tolerance bands than current build processes allow. Drilling of aircraft wings to the tolerances demanded by laminar flow requires machines with the stiffness and accuracy of a CNC machine while having the flexibility and envelope of an articulated arm. This paper describes the development and evaluation of high accuracy automated processes to enable the assembly of a one-off innovative laminar flow wing concept. This project is a continuation of a previously published SAE paper related to the development of advanced thermally stable and lightweight assembly fixture required to maintain laminar flow tolerances.
2016-09-27
Technical Paper
2016-01-2130
Enkhsaikhan Boldsaikhan, Shintaro fukada, Mitsuo Fujimoto, Kenichi Kamimuki, Hideki Okada, Brent Duncan, Phuonghanh Bui, Michael Yeshiambel, Brian Brown, Alan Handyside
The Refill Friction Spot Joining (RFSJ) is an emerging solid-state spot welding technology that creates a molecular-level bond between the work-pieces through a thermo-mechanical processing. The RFSJ process does not consume any filler or foreign materials so that no additional weight is introduced to the assembly. As the solid-to-liquid phase transition is not involved in RFSJ in general, there is no fusion lack or material deterioration caused by liquefaction and solidification. Unlike the conventional friction stir spot welding, RFSJ produces a spot joint with a perfectly flush surface finish without a key or exit hole. Currently, the aerospace industry employs solid rivets for fastening the primary structures as they meet the baseline requirements and have well-established standards and specifications.
2016-09-27
Technical Paper
2016-01-2124
Sara Nilsson, Jonas Jensen, Mats Björkman, Erik Sundin
For the aerospace industry carbon fiber reinforced plastics (CFRP) is one of the fastest developing materials right now. The material has a strength-to-weight ratio that is several times higher than aluminium and steel, which makes it a great fit for applications where a low weight is crucial while maintaining strength and stiffness. It is specifically CFRP in pre-impregnated form, so called pre-preg, which has made its way into the aircrafts. Pre-preg is an anisotropic material that lets the designer control its properties to a high level of detail. Analogously to the material becoming used more widely in the aerospace industry the costs have decreased as the manufacturing methods have developed to follow the demands. However, how material and manufacturing method change the requirements and affect a product's design and performance can be hard to determine.
2016-09-27
Journal Article
2016-01-2112
Hilmar Apmann
As a new material FML made by aluminum foils and Glasfibre-Prepreg is a real alternative to common materials for fuselages of aircrafts. Since experiences within A380 this material has some really good advantages and becomes status as alternative to Aluminum and composite structures. Main goal for an industrial application for a higher production rates of aircrafts (like for single aisle) is the automation of production processes inside the process chain for FML-parts like skins and panels for fuselages. To reach these goals for high production rates first steps of automation inside this process chain have been developed in the last two years. Main steps is the automated lay-up of metallic foils and Glasfibre-Prepreg and also for integration of the bond film. Over this there are some more steps within positioning of i.e. stringers and doublers by automatic integration and shorter process chain to reduce process cost significantly.
2016-09-27
Journal Article
2016-01-2139
Hendrik Susemihl, Christian Moeller, Simon Kothe, Hans Christian Schmidt, Nihar Shah, Christoph Brillinger, Jörg Wollnack, Wolfgang Hintze
Highly growing production rates and the demand for efficient large-scale machining tools in aerospace industry have led to an increasing request for more flexible and productive manufacturing solutions. Robots are a promising solution, although there are some major disadvantages regarding the poor absolute accuracy, low structural stiffness, gear elasticity and limited workspace. Industry and research have shown a high ambition in optimizing industrial robots. Primary aircraft structures are commonly machined by portal, gantry or movable column machines of large dimensions. Due to high investment and time-consuming referencing processes, cost-effectiveness of these machines is often non-satisfying. With mobile robot-based solutions machining can be executed simultaneously which increases the productivity significantly. In this publication a mobile robotic machining system with enhanced absolute accuracy will be presented.
2016-09-27
Journal Article
2016-01-2120
David Judt, Kevin Forster, Helen Lockett, Craig Lawson, Philip Webb
In the civil aircraft industry there is a continuous drive to increase the aircraft production rate, particularly for single aisle aircraft where there is a large backlog of orders. One of the bottlenecks is the wing assembly process which is largely manual due to the complexity of the task and the limited accessibility. The presented work describes a general wing build approach for both structure and systems equipping operations. A modified build philosophy is then proposed, concerned with large component pre-equipping, such as skins, spars or ribs. The approach benefits from an offloading of the systems equipping phase and allowing for higher flexibility to organize the pre-equipping stations as separate entities from the overall production line. Its application is presented in the context of an industrial project focused on selecting feasible system candidates for a fixed wing design, based on assembly consideration risks for tooling, interference and access.
2016-09-27
Technical Paper
2016-01-2089
Jose Guerra cEng, Miguel Angel Castillo
During the year 2003 Aernnova decided to invest in automated machines procuring and installing a Broetje automatic machine (known in Aernnova as CIMPA) in Aernnova Berantevilla facility in order to perform operations such as drilling, countersinking or riveting in aircraft structures during its assembly. Due to the high load of work at that time in Aernnova mainly due to work packages from Embraer and Sikorsky, a solution was needed in order to assemble all the products required by our customer and deliver them on properly in terms of time and good quality. Several ideas came to our engineering team always having in mind the idea of reducing time being more competitive specially in repetitive operations and at the same time keeping good quality. Finally after a depth search, the option selected was an automated machine from Broetje that after some adjustments and customizations regarding our purposes could provide us the best solution.
2016-09-27
Technical Paper
2016-01-8138
Pranav Shinde, K Ravi, Nandhini Nehru, Sushant Pawar, Balaji Balakrishnan, Vinit Nair
Body in white forms a major structure in any automobile. It is responsible in providing structural rigidity to vehicle, safety, frame and a skeleton to support all body parts of vehicle. When it comes to judge the performance of vehicle, BIW is analyzed not only for its strength and shape but also weight. Light weight BIW structures have seen to be developed rapidly in order to fulfill requirement of best vehicle performance in dynamic conditions. Since then lot of efforts have been put into CAE, materials research, advanced manufacturing process and joining methods, each plays a critical role in BIW functionality. Constructional designing, development of light materials with improved strength and special manufacturing practices for BIW are few research areas with never ending questions. This paper attempts to review various factors studied for weight reduction and solutions provided so far. Some of the major findings are briefly discussed and suggestions are made for future research.
2016-09-27
Technical Paper
2016-01-8155
Devaraj Dasarathan, Jonathan Jilesen, David Croteau, Ray Ayala
Side window clarity and its effect on side mirror visibility plays major role in the driver comfort. Driving in inclement weather conditions such as rain can be stressful. Having optimal visibility under these conditions is ideal. However, extreme conditions can overwhelm exterior water management devices, resulting in rivulets of water flowing over the a-pillar and onto the vehicle’s side glass. Once on the side glass, these rivulets and the pooling of water they feed can significantly impair the driver’s ability to see the side mirror or to see outwardly when in situations such as changing lanes. Designing exterior water management features of a vehicle is a challenging exercise as traditionally, physical testing methods first require a full-scale vehicle for evaluations to be possible. Additionally, common water management devices such as grooves and channels often have undesirable aesthetic, drag, and wind noise implications.
2016-09-27
Technical Paper
2016-01-2103
Eric Barton
This technical paper details an optimized Drivmatic machine design delivered to a Tier 1 aero structure supplier to automate drilling and installation of rivets, hi-loks, lockbolts & swage collars for individual fuselage panel assemblies with high throughput & strict quality requirements. While certain robot solutions continue to be explored for specific applications at many Tier 1 aero structure suppliers, robot payload capacity has limitations beyond certain criteria, which often times point towards an alternative machine design as in this case study. A typical approach for adding more automation is to allocate shop floor space based on the solution's foot print, however contrary to most approaches this solution had to be designed to fit within a pre-determined factory footprint over a geographic location with a high water table that would not permit a foundation.
2016-09-27
Technical Paper
2016-01-2090
Sergey Lupuleac, Margarita Petukhova, Julia Shinder, Alexander Smirnov, Mariia Stefanova, Nadezhda Zaitseva, Tatiana Pogarskaia, Elodie Bonhomme
Perspective way of solving the problem of aircraft assembly optimization is global simulation of junction process using efficient numerical algorithms. Specialized software complex [1] was developed within the framework of cooperation between Airbus SAS and Saint Petersburg Polytechnic University. This tool allows engineers to simulate the aircraft assembly process and solve the number of tasks: • Calculation of resulting gap under given initial disposition of riveted parts and distribution of fastening elements; • Determination of fastening element pattern that provides sufficient quality of assembly; • Shimming prediction; • Evaluation of stresses caused by assembly. The tool is based on special approach that necessitates solving contact problem arising when aircraft parts are being joined. This problem can be described by several simplifying assumptions such as ommiting tangential displacements and friction from consideration and creating substructure for junction area.
2016-09-27
Technical Paper
2016-01-8123
Lei Peng, Zhuo Wang, Jiantao Gu
Abstract Body structure design needs to meet multi-attributes requirements such as global bend stiffness/modal, torsion stiffness/modal, Noise and velocity transfer functions (NTF/VTF), and others. Computer-aided engineering (CAE) is a significant way to enhance the accuracy of design results. However, it also brings computation burden for optimization. In order to improve the performance and reduce the weight of automobile body structure, this paper presents a novel process of body CAE multi-attributes optimization. Four significant phases are described: 1) Sensitivity analysis for each body CAE performance, 2) MDO process, 3) Non-sensitive gauges reducing, and 4) Slightly optimization. Considering the mixed variables in the MDO process including continuous geometry shapes and discrete gauges, the developed continuous relaxation method was employed to deal with such situation.
2016-09-20
Technical Paper
2016-01-2019
Richard P. Johnston
Abstract An advanced composite Blended Wing Body (BWB) air frame previously used as a study aircraft to transport a 75-ton military cargo halfway around the world and back unrefueled has been modified and evaluated as a 150-ton heavy lifter. The modifications include enlarging the forward trim canard, reducing fuel load by 151,850 lbs, increasing the high-mach NASA-type counter-rotating propellers from 12 feet to 13 feet diameter, extending the propeller support pylons' height by 6 inches and modifying cruise flight and prop control strategies. Due to structural and propulsion system changes, the air frame Operational Empty Weight (OEW) was increased by 1,850 lbs. but the maximum Take Off Gross Weight (TOGW) was held to 800,000 lbs. Brief descriptions of the major propulsion system components are provided. In addition, a comparison of three different counter-rotating propeller systems is presented. The first is a Standard configuration.
2016-09-20
Technical Paper
2016-01-1979
William D. Bertelsen
Abstract Technology to create a VTOL for general aviation that is fast, efficient, easy to fly, and affordable, has proven elusive. Bertelsen Design LLC has built a large research model to investigate the potential of the arc wing VTOL to fulfill these attributes. The aircraft that is the subject of this paper weighs approximately 145 kg (320 lbs) and features coaxial, dual-rotating propellers, diameter 1.91 m (75 inches). Power is from an MZ 202 two-cycle, two-cylinder engine. Wingspan is 1.82 m (72 inches). The arc wing differentiates this aircraft from previous deflected-slipstream prototypes, which suffered from pitch-trim issues during transition. This paper will present configuration details of the Bertelsen model, showing how it is possible to generate high lift from a short-span wing system. The Bertelsen model can hover out of ground effect using just two arc-wing elements: a main wing and a “slat”.
2016-09-20
Journal Article
2016-01-2013
Evgeni Ganev, Chiyuan Chiang, Leroy Fizer, Ed Johnson
Abstract This paper addresses the implementation of electric taxiing without the use of main engines by using electric propulsion of the landing gears. Substantial progress in this area has been achieved by Honeywell Aerospace and Safran in a joint initiative for developing an electric green taxiing system (eTaxi). Considerable analysis, design, fabrication, and testing have already been completed, which culminated in a demonstration at the Paris Air Show (PAS) in 2013. The eTaxi system has been installed on an A320 airplane that uses the auxiliary power unit (APU) to generate electric power to provide propulsion to two wheels of the main landing gear. The main advantages of such a system are reduction of fuel consumption and audio noise, reduction of CO2 , carbon and nitrous emissions, reduced engine foreign object damage (FOD) exposure and fast-turn time savings by elimination of the ground tractor for pushback operation.
2016-09-20
Technical Paper
2016-01-2055
Koji Muraoka, Daisuke Hirabayashi, Masayuki Sato, Yoshihisa Aoki
Abstract JAXA (Japan Aerospace Exploration Agency) has been conducting a research on a future commercial tilt wing VTOL (Vertical TakeOff and Landing) transport under JAXA's "Sky Frontier" Program aiming to develop technologies for aircraft innovation. The research focuses on QTW (Quad Tilt Wing) civil VTOL transport, which features tandem tilt wings with propellers mounted at the mid-span of each wing. The goals of the research in the present phase are to propose a concept of a QTW business VTOL transport system and to pursue the essential technologies development such as OEI (One-Engine-Inoperative) safe recovery, transition flight control and cruise efficient aerodynamic design. Nine passengers business QTW concept was designed and trade-off analysis of the propulsion system architecture for OEI safety was conducted.
2016-09-20
Technical Paper
2016-01-2046
Neno Novakovic
Abstract A Landing Gear Control and Actuation System (LGCAS) is one of the most complex aircraft systems. Due to the large landing gear masses and high performance requirements, aircraft hydraulic power with multiple hydraulic actuators and valves is used to provide system dynamic. LGCAS also requires a electrical source of energy for the electro-mechanical components, sensors and electronic control unit. For many years, correct fault isolation in a complex kinematic system, such as an aircraft landing gear actuation system, has been a great challenge with limited success. The fault isolation design challenge rests on the fact that landing gear control and actuation system has many so called “passive” components, whose basic function cannot be continuously monitored without additional sensors, transducers, and designated health monitoring equipment.
2016-06-15
Technical Paper
2016-01-1806
Sumon Sinha, Farokh Kavarana, Dan Williams, Kazuya Asao
Abstract A high performance rigid airfoil profile sunroof wind deflector has been developed for high speed freeway driving with the sunroof open. This deflector is clearly superior to the conventional bar type deflector and less expensive compared to tall flexible fabric mesh deflectors applied on high end vehicles today. It provides superior speech intelligibility under high speed driving with sunroof open. The criterion for designing this deflector was to get the highest airspeed possible to span the sunroof opening under all conditions. The customized shape also utilizes flow unsteadiness, including those at the onset of buffeting, in order to condition the shear layer. The airfoil profiled deflector yielded superior mid and high frequency acoustic performance with acceptable low frequency performance. A shorter airfoil deflector was sufficient to keep the external airflow from entering the forward tilted sunroof opening on a mid-size SUV under test.
2016-06-15
Technical Paper
2016-01-1803
Hannes Frank, Claus-Dieter Munz
Avoiding narrowband components in the acoustic spectrum is one of the most critical objectives in the automotive aeroacoustic optimization process. The underlying physical mechanisms are not completely understood. In a preceding numerical and experimental investigation, we performed large eddy simulations of an early-development stage realistic side-view mirror, where tonal noise was captured and the principle mechanisms were identified. In this contribution, we present simulations on a simplified two-dimensional geometry that is based on these findings. It is shown that the basic flow topology relevant for tonal noise generation on the original side-view mirror as well as the tonal noise source is reproduced in the 2D case. Furthermore, we present comparisons with measurements and the necessity and influence of a splitter plate downstream of the 2D body to avoid large scale vortex shedding.
2016-06-15
Technical Paper
2016-01-1849
Arnaud Caillet, Luca Alimonti, Anton Golota
Abstract The need for the industry to simulate and optimize the acoustic trim parts has increased during the last decade. There are many approaches to integrate the effect of an acoustic trim in a finite element model. These approaches can be very simple and empirical like the classical non-structural mass (NSM) combined to a high acoustic damping value in the receiver cavity to much more detailed and complex approach like the Poro-Elastic Materials (PEM) method using the Biot parameters. The objective of this paper is to identify which approach is the most appropriate in given situations. This article will first make a review of the theory behind the different methods (NSM, Impedances, Transfer Matrix Method, PEM). Each of them will be investigated for the different typical trim families used in the automotive industry: absorber, spring/mass, spring/mass/absorber.
2016-06-15
Technical Paper
2016-01-1830
Denis Blanchet, Luca Alimonti, Anton Golota
Abstract This paper presents new advances in predicting wind noise contribution to interior SPL in the framework of the Wind Noise German Working Group composed of Audi, Daimler, Porsche and VW. In particular, a new approach was developed that allows to fully describe the wind noise source using CFD generated surface pressure distribution and its cross-correlation function and apply this source on an SEA side glass. This new method removes the need to use a diffuse acoustic field or several plane waves with various incidence angle to approximate the correct acoustics source character to apply on the SEA side glass. This new approach results are compared with results previously published which use more deterministic methods to represent the side glass and the interior of a vehicle.
2016-06-15
Journal Article
2016-01-1795
Charly Faure, Charles Pezerat, Frédéric Ablitzer, Jérôme Antoni
In this paper, a local method of structure-borne noise source characterization is presented. It is based on measurements of transverse displacement and local structural operator knowledge and allows to localize and quantify sources without any need of boundary condition information. To fix the instability caused by measurement noise, the regularization step inherent to inverse problem is realized with a probabilistic approach, within the Bayesian framework. When a priori distributions about noise and sources are considered as Gaussian, the Bayesian regularization is equivalent to the well-known Tikhonov regularization. The optimization of the regularization is then performed by the Gibbs Sampling (GS) algorithm, which is part of Markov Chain Monte Carlo (MCMC) techniques. The whole probability of the regularized solution is inferred, providing access to confidence intervals.
2016-06-15
Journal Article
2016-01-1801
Jonathan Vaudelle, Florian Godard, Florian Odelot, Anne Sanon
Abstract Acoustic comfort inside the vehicle is required whenever a wiper system is in function: front wiper motor noise is of great influence on the global comfort and its perception inside the car is 100% due to transmission of vibrations through wiper system fixation points on the vehicle. As any active source, both car manufacturer and system supplier need to be involved, at early stages of project development, in order to master the vibroacoustic integration of the system into the vehicle. This paper presents an experimental methodology dedicated to the front wiper system that offers the possibility to estimate the acoustic comfort inside the vehicle during project deployment phase, when modifications can still be proposed. Based on the XP-R-19701 standard, the procedure allows to measure, on a bench, the dynamic forces transmitted via the fixation points and details how to transpose them to the vehicle, taking into account the different specificities of the wiper system.
2016-06-15
Journal Article
2016-01-1825
Jung-Han Woo, Da-Young Kim, Jeong-Guon Ih
Abstract To hear the powerful and spectrally rich sound in a car is costly, because the usual car audio system adopts small loudspeakers. Also, the available positions of the loudspeakers are limited, that may cause the reactive effect from the backing cavity and the sound distortion. In this work, a part of the roof panel of a passenger car is controlled by array actuators to convert the specified large area to be a woofer. An analogous concept of the acoustic holography is employed to be projected as the basic concept of an inverse rendering for achieving a desired vibration field. The vibration of the radiating zone is controlled to be in a uniform phase, and the other parts outside it are to be made a no-change zone in vibration. The latter becomes a baffle for the woofer, and the backing cavity is virtually infinite if the sound radiation into the passenger cabin is only of concern.
2016-06-15
Journal Article
2016-01-1809
Alexander Schell, Vincent Cotoni
Abstract Prediction of flow induced noise in the interior of a passenger car requires accurate representations of both fluctuating surface pressures across the exterior of the vehicle and efficient models of the vibro-acoustic transmission of these surface pressures to the driver’s ear. In this paper, aeroacoustic and vibro-acoustic methods are combined in order to perform an aero-vibro-acoustic analysis of a Mercedes-Benz A-class. The exterior aero-acoustic method consists of a time domain incompressible Detached Eddy Simulation (DES) and an acoustic wave equation. The method is extended in this paper to account for convection effects when modelling the exterior sound propagation. The interior vibro-acoustic model consists of a frequency domain Finite Element (FE) model of the side glass combined with a generalized Statistical Energy Analysis (SEA) model of the interior cabin.
Viewing 1 to 30 of 4368