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Technical Paper

Development Of Multi-Material Overhead Stowage Systems For Commercial Aircrafts By Using New Design and Production Methods

2019-09-16
2019-01-1858
The relevance of innovative and functional lightweight components for aircrafts has risen significantly during the recent years. In this context, modern lightweight materials as well as cost-efficient and time-saving manufacturing technologies are required for a future aircraft production. The so called Hybrid SMC Technology and the SMC-Foam-Sandwich Technology are promising approaches for the cost-efficient and time-saving manufacturing of lightweight, geometrically complex and functional aircraft components. Both technologies have been used for the development of a new generation overhead stowage system. It is realized by sidewalls made out of enhanced SMC technologies with directly implemented metallic load introduction elements and regular sandwich structures that can be assembled by a quick-assembly principle.
Technical Paper

Local Weakening of Honeycomb Core for Improved Surface Quality and Bonding in Co-cured Sandwich Panels

2019-09-16
2019-01-1859
Sandwich panels made of NOMEX honeycomb core and fiber reinforced face sheets are a major component of aircraft interior parts. A common way to locally increase the strength of such panels, e.g. for load introduction, is the local thickening of the face sheets with additional prepreg layers. Curing of such strengthened panels without further processing of the core leads to higher flatness tolerances due to the added thickness as well as residual stresses. Machining of the core in the strengthened areas is possible, but expensive due to high machine costs and additional cleaning processes. In this paper a new automated process for the reduction of the residual stresses in strengthened areas is presented. The process is based on a local reduction of the compressive strength in the surface area of the honeycomb core, which allows for a plastic deformation in thickened areas at curing pressure.
Technical Paper

Design Approach for Secure Networks to introduce Data Analytics within the Aircraft Cabin

2019-09-16
2019-01-1853
In the past, aircraft network design did not demand for information security considerations. The aircraft systems were simple, obscure, proprietary and, most importantly for security, the systems have been either physically isolated or they have been connected by directed communication links. The union of the aircraft systems thus formed a federated network. These properties are in sharp contrast with today’s system designs, which rest upon platform-based solutions with shared resources being interconnected by a massively meshed and shared communication network. The resulting connectivity and the high number of interfaces require an in-depth security analysis as the systems also provide functions that are required for the safe operation of the aircraft. This network design evolution, however, resulted in an iterative and continuous adaption of existing network solutions as these have not been developed from scratch.
Technical Paper

Self-affinity of an Aircraft Pilot's Gaze Direction as a Marker of Visual Tunneling

2019-09-16
2019-01-1852
For the last few years, a great deal of interest has been paid to crew monitoring systems in order to address potential safety problems during a flight. They aim at detecting any degraded physiological and/or cognitive state of an aircraft pilot or crew, such as visual tunneling, also called inattentional blindness. Indeed, they might have a negative impact on the performance to pursue the mission with adequate flight safety levels. One of the usual approaches consists in using sensors to collect physiological signals which are then analyzed. Two main families exist to process the signals. The first one combines feature extraction and machine learning whereas the second is based on deep-learning approaches which require a large amount of labeled data. In this work, we focused on the first family.
Technical Paper

Advanced Exergy Analysis of an Air Craft Gas Turbine Engine at Different Power Loading Operations.

2019-09-16
2019-01-1863
The innovations in aircraft propulsion have been identified as the key parameter towards the progress in transportation. Continuous advancement in the performance and efficiency of propulsion has enabled aircraft to travel over larger distances with higher speed. Aviation is also responsible for approximately 2% of total greenhouse gases emission and is expected to grow around 3% by 2050. The present study aims to use the exergetic analysis of a turboprop engine which should be helpful in designing of such engines and also helps these engine users to regulate and select the operation modes. A gas turbine with film air cooling of turbine blades has been proposed to be the turboprop engine. The engine is analyzed on exergy point of view at different power loading operation modes and the performance is studied.
Technical Paper

Optimisation of assembly processes for Adhesive bonded Brackets onto the airframe structure

2019-09-16
2019-01-1855
Aircraft manufacturers use adhesive bonded brackets (ABB) to support wire harnesses, looms and sensors. Using ABBs eliminates the necessity to drill holes in the airframe and significantly reduces the assembly time. Such brackets are installed manually on the airframes in numerous locations using high strength epoxy based adhesives. In addition, the application of adhesive onto bracket is carried out manually. Thus it's time consuming and quality relies on operator’s skill sets to apply a certain quantity of adhesive using a predefined pattern, both of which are commonly not controlled. On the other hand, removing the damaged brackets by manual operations tend to cause dents and scratches in metallic airframes and delamination in composites. Prior research indicates that the brackets can be removed by heating them. But, they are not recommendable to aerospace manufacturers due to the longer process times.
Technical Paper

A model to forecast non-routine work for the wide body base maintenance

2019-09-16
2019-01-1869
In this paper we investigate how WBBM Unit can improve the accuracy of non-routine tasks man-hours forecasts for the Wide-Body C-checks, per specific check visit and maintenance organization. Following a contingent approach, a database was set-up and three econometric forecasting methods are compared with the judgmental method currently used by the unit: linear regression analysis, artificial neural network and nearest neighbour analysis. Higher accuracy was obtained from the econometric methods when cross-validated, which proves that it is indeed possible to have a model to forecast non-routine maintenance work more accurately than judgmental methods
Technical Paper

Service-based modelling approach to ease the certification of multi-core COTS processors

2019-09-16
2019-01-1851
PHYLOG is a four years DGAC (French Civil Aviation) project (2016-2020) that aims at offering a model-based and software-aided certification framework for aeronautics systems based on multi/many-core architectures. Among the objectives of the position paper MCP-CRI/CAST 32A, two types of analysis are required: interference analysis. and safety analysis. Because of the large size of the multi-core platforms and their complexity, those analyses can lead to combinatorial explosion and some misinterpretation. To simplify those analyses, we explore and classify multi-core platform properties in order to represent a platform as a set of services
Technical Paper

The Research on Validation and Verification Method of Configuration Data for IMA Resources Allocation

2019-09-16
2019-01-1850
Integrated Modular Avionics (IMA) system comprises IMA platform and hosted applications. The IMA platform provides the hosted applications with shared resources, e.g. computing, memory, communication, health monitoring resources. As a bridge between them, the IMA configuration data specifies how these shared resources are allocated to each hosted application. The IMA configuration data, which is different from real hardware and software code, should be validated and verified as an important portion of IMA system. After a brief introduction of IMA system, development processes, and general means of compliance for certification, this paper proposed a Architecture Analysis and Design Language (AADL) model of IMA configuration based on a case study of airborne datalink system. Based on the model, the IMA configuration data is abstracted and categorized into several types, with the correspondent means of compliance identified for each type.
Technical Paper

ORBITAL DRILLING OPTIMIZATION IN HIGH SPEED MACHINING AND FATIGUE LIFE ENHANCEMENT BY ORBITAL ROLLER BURNISHING: APPLICATION TO AN ALUMINUM ALLOY

2019-09-16
2019-01-1861
Orbital drilling has proved to be advantageous to achieve aeronautical-level quality drilling (surface roughness, geometry control…) fully adapted for complex assemblies in a single operation. However, compared to conventional drilling method, this process leads to a drastic change in structure's fatigue life probably due to a non-optimised level of residual stress. The control of the mechanical behaviour of parts obtained by orbital drilling is the goal of the European-CleanSky collaborative R&D project RODEO (Robotized Orbital Drilling Equipment and Optimized Residual Stresses, GA no.738219). In this work, an orbital drilling unit (ORBIBOT) allowing high-speed-machining conditions was developed by PRECISE France, that can be integrated on a lightweight industrial robot. Cutting parameters were determined through an original Tool-Material Couple optimization strategy dedicated to orbital drilling, developed with MITIS Engineering and carried out on aluminium alloy 2024-T351.
Technical Paper

Compensating the Effects of Ice Crystal Icing on the Engine Performance by Control Methods

2019-09-16
2019-01-1862
Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted.
Technical Paper

Numerical investigation of Electrostatic Spray Painting Transfer Processes for vehicle Coating

2019-09-16
2019-01-1856
In this study we examined numerically the electrostatic spray transfer processes in the rotary bell spray applicator, which is this case implemented in a full 3D representation. The algorithm implemented and developed for this simulation includes airflow, spray dynamics, tracking of paint droplets and an electrostatic modularized solver to present atomization and in-flight spray phenomena for the spray forming procedure. The algorithm is implemented using the OpenFOAM package. The shaping airflow is simulated via an unsteady 3D compressible Navier-Stokes method. Solver for particle trajectory was developed to illustrate the process of spray transport and also the interaction of airflow and particle that is solved by momentum coupling. As the numerical results in this paper indicates dominant operating parameter voltage setting, further the charge to mass ratio and air-paint flow rate deeply effect the spray shape and the transfer efficiency (TE).
Technical Paper

MANAGEMENT OF MANUFACTURING AND ASSEMBLY PROCESSES RISCS BASED ON MODIFIED FMEA

2019-09-16
2019-01-1870
The quality of production is defined by the actual deviations from the requirements stated in design and technological documentation including drawings. In this article the problem of ensuring steady decrease in quantity of deviations from these requirements by production is considered. Carrying out preventive actions, in combination with control of time and costs of correction of discrepancies of such decrease it is possible to achieve. For the solution of an objective the method of the modified FMEA using parameters and levels of ranging as elements of operation of technological process where at a design stage of a product are set structure, is offered and are adjusted on the basis of feedback of production and operation. Such statement of a problem demands automation of collecting and data processing which can be used for creation of the knowledge base necessary for management of productions.
Technical Paper

Hypersonic flow simulation towards space propulsion geometries

2019-09-16
2019-01-1873
With the actual tendency of space exploration, hypersonic flight have gain a significant relevance, taking the attention of many researchers over the world. This work aims to present a numerical tool to solve hypersonic gas dynamic flows for space propulsion geometries. This will be done by validating the code using two well-known hypersonic test cases, the double cone and the hollow cylinder flare. These test cases are part of NATO Research and Technology Organization Working Group 10 validation of hypersonic flight for laminar viscous-inviscid interactions. During the validation process several important flow features of hypersonic flow are captured and compared with available CFD and numerical data. Special attention is taken to the phenomenon of vibrational excitation of the molecules. Different vibrational non-equilibrium models are used and compared with the available data. The pressure and the heat flux along the surfaces are also analyzed.
Technical Paper

Identifying Virtuous Cycles of Using Real-Time Process Data in Portable Semi-Automated Electric Drilling

2019-09-16
2019-01-1875
Purpose: Thanks to the long lifetimes of aerospace platforms, manufacturers face opportunities for improving the manufacturing processes of legacy products. However, the potential benefits of process innovations must be carefully balanced with the costs. One such opportunity is offered through portable semi-automated electric drilling. The purpose of this paper is to identify critical elements in building a business case for incorporating portable semi-automated electric drills on aerospace products and processes. Design/methodology/approach: Drawing on institutional knowledge, we distinguish three entities in hole-generation tasks: hole types, hole-cutting tools, and hole-cutting assets (e.g. portable drills). We identify the specific needs, requirements and constraints in hole generation by focusing on each entity and the relationships between them. We then examine the implications of introducing sensor-equipped portable electric drills that allow real-time process data collection.
Technical Paper

Forces vibration assistance for TA6V/CFRP drilling

2019-09-16
2019-01-1874
For aircraft structures, mechanical assembly using fasteners remains the most common technology. The setting of the numerous fasteners requires a large number of drilling operations. In the case of CFRP/TA6V stacks, the drilling still remains a technological challenge. Indeed the high-quality requirements by the aeronautic standards are limited by the fast damaging drilling tool phenomena. For TA6V, the forced assisted drilling provides a breakthrough technology. An axial forced oscillating displacement on the feed direction of the tool allows the creation of segmented chips. Those small chips are then easily evacuated from the cutting area using a vacuum device. This allows the improvement of the hole’s roughness and mastering the burr creation at the exit of the hole. The lubrication process is also enhanced during the exit sequence of the tool. For the CFRP/TA6V configuration, the segmented geometry of the chip avoids the roughness degradation on the composite part of the stack.
Technical Paper

Line Side Equipment

2019-09-16
2019-01-1879
The aircraft production rate is now increasing and requires to keep the production tools as close as possible from the assembly work area. As production sites cannot be extended as much as the rate increases, this has created the need for developing innovative & efficient line side equipment, which fulfils storage capacity, ergonomical accessibility, easy handling & quick load unload performance for all aircraft part assemblies. This paper will focus on the development and the integration into the production on our innovative solutions on Line Side Equipment . The Line Side Equipment is custom designed and built for manual or semi-automated assembly lines. It offers a wide range of solutions such as dedicated storage areas, trolleys, easy acces, tool kits & smart cabinets.
Technical Paper

C919 Trailing Edge Assembly Interchangeable Tooling

2019-09-16
2019-01-1880
Traditional Trailing Edge (TE) assembly that utilise fixtures for accurate positioning of aircraft (a/c) parts do not allow for removal of specific tooling from the fixtures to travel with the TE, post assembly. Instead, the tooling that positions all the primary a/c assembly datums generally utilise precision pins of various sizes that index and clamp the a/c ribs. Often it is difficult to remove the pins post assembly before the spar can be taken out of the fixture. Use of hammers is common place to hit pins out of holes which is less than ideal considering the a/c parts can be fragile and the tooling is precision set. Also, the Main Assembly Fixture (MAJ) that will receive the TE will inevitably need to relocate some if not all the primary a/c ribs and therefore will most likely be subject to some amount of persuasion.
Technical Paper

Reconfigurable Jig Tooling and In-Process Metrology for High Accuracy Prototype Compound Helicopter Wing Assembly

2019-09-16
2019-01-1877
This paper documents the potential use of reconfigurable reusable jig tooling based on the box-joint system for use in the assembly of a prototype compound helicopter wing. Due to the aircraft configuration the wing design is pinned at both ends and therefore requires a higher degree of accuracy (typically 0.2mm), over the 4m length, than conventional wings. In this paper the cost benefit of reusable tooling in a low volume prototype scenario is examined followed by the design of the jig and location features to enable accurate build and metrology documentation. A prototype 4m test jig comprising of commercially available components and bespoke machined ‘pick-ups’ is presented here. Hardware and measurement process cost modelling is documented along with results for the positional and hinge-line concentricity setting accuracy that was achieved using a laser tracking system.
Technical Paper

Optimization of automated airframe assembly process on example of A350 S19 splice joint

2019-09-16
2019-01-1882
The paper presents the numerical approach to simulation and optimization of A350 S19 splice assembly process. The main goal is to reduce the number of installed temporary fasteners while preventing the gap between parts from opening during drilling stage. The numerical approach includes computation of residual gaps between parts, optimization of fastener pattern and validation of obtained solution on input data generated on the base of available measurements. The problem is solved with ASRP (Assembly Simulation of Riveting Process) software. The described methodology is applied to the optimization of the robotized assembly process for A350 S19 section.
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