14 research outputs found
Analyse luftfahrtrelevanter Fertigungsverfahren von Faser-Kunststoff-Verbunden und Ableitung eines abstrahierten Prozessmodells
With regard to the current transformation processes of the manufacturing industry towards âIndustry 4.0â, universal data models are required, that can flexibly be adapted to new production variants and their variations and thus can be applied in multidisciplinary projects. On this account the present thesis introduces a modelling approach that is applicable for the visualization of manufacturing processes of fiber plastic composites, which are relevant for the aircraft industry.
For this purpose, selected manufacturing technologies are analyzed, which can be mapped, among other things, by the large-scale research facilities at the Stader site of the âCentre for Lightweight Production Technologies â(ZLP Âź), a sub-institute of the âGerman Center for Aerospace Technology â. Based on the process analysis, an abstract process model is then generated. This is followed by an initial approach to delineate the considered manufacturing processes regarding design-relevant requirements and restrictions
Towards Robustness Assessment in Virtual Testing - Manufacturing Influences by Simulation-based Methods in the Virtual Product House
The result of a virtual design process is an ideal structure, the virtual product in the "as-designed" state. While it is possible to perform probabilistic analyses in the design phase to explore the stability of the solution, there usually is one final "as-designed" configuration. This and the digital twin serve as images of the nominal state and the real manufactured structure. While there is only a single "as-designed" dataset of the virtual product, there is an individual digital twin for each physical instance whose data and properties may vary due to influencing factors. Within physical testing it is not possible to consider all these different variations, especially on higher levels of the building-block-approach.
To reduce the development risk and gain earlier insights in the effects of the manufacturing on the structural performance simulation-based manufacturing methods are integrated in the end-to-end process, from virtual design to virtual testing, developed in the Virtual Product House (VPH). These enable the process to give a quantifiable estimation of these uncertainties in early development or can assess whether certain manufacturing scenarios are even valid options due to their effect on the virtual product.
In this text, approaches are presented to determine the scatter of the use case in the VPH start-up project, a multifunctional multi-spar composite moveable, from expected manufacturing uncertainties. A manufacturing scenario consisting of an automated fibre placement (AFP) for the creation of the preforms, the infusion and the subsequent curing is considered.
After these steps, the virtual product information for the "as-built" state is readily available for the chosen manufacturing process parameters. With the "as-built" configuration it is possible to use the following virtual testing methods with a more realistic representation of the structure or to return the effects from manufacturing on the "as-designed" state of the virtual product back to the design phase. Both aspects contribute to an improved understanding of the virtual product and increase confidence with regard to production and certification
Schneller geht's im Team: Effiziente Fertigung von FlĂŒgelschalen
Beside the further development of existing
production technologies of large carbon fibre
reinforced (CFR) structures, completely new
man-ufacturing strategies have to be modeled
and tested to counteract the striven
production rate of 60AC/month. Within the
LuFo V-1 funded project âEfficient Wing Cover
Manufacturingâ (EWiMa), therefore the
fibre layup of a wing cover with two manufacturing
units working simultaneously will
be tested and demonstrated for the first time
using the GroFiÂź plant of the ZLP in Stade.
Due to a simulated process, a time saving of
38% is expected.
In addition the use of a segmentally heatable
curing tool is investigated. By the use of
a thermal camera system, mounted in the
research autoclave of the ZLP in Stade, the
triggering of the heatable tool is completely
done by the autoclave control system. Beside
an improvement of the manufacturing
quality, a time saving of the energy-intensive
autoclave process and thus a reduction of
the manufacturing cost is expected with this
approach
Entwicklung eines Modellansatzes zur Beschreibung des Tack-Verhaltens im Dry Fiber Placement
In dieser Arbeit wird ein semi-empirischer Modellansatz entwickelt, der zur Beschreibung des Tack-Verhaltens in AbhĂ€ngigkeit der Anpresskraft, Vorschubgeschwindigkeit und Verbindungstemperatur im Automated Dry Fiber Placement dient. Zur Messung des Tacks zwischen zwei abgelegten Slit-Tapes mit thermoplastischen Binder wird ein SchĂ€lprĂŒfstand konstruiert und aufgebaut. Die drei Prozessparameter werden nach einem dreistufigen Versuchsplan durch 15 Versuche untersucht, die insgesamt viermal durchgefĂŒhrt werden. Anstatt der Heizleistung der InfrarotLampen wird die resultierende Temperatur innerhalb der Verbindungszone beschrieben. Der Tack wird durch die SchĂ€lprĂŒfung verlĂ€sslich bestimmt. FĂŒr alle Faktoren werden hochsignifikante Effekte und Wechselwirkungseffekte auf die Erhöhung des Tacks berechnet. Durch die nichtlineare Regression werden zwei Modellgleichungen an die Ergebnisse angepasst, die auf physikalischen ZusammenhĂ€ngen basieren. Hieraus wird ein Modellansatz entwickelt, welcher die Ergebnisse mit einer hohen AnpassungsgĂŒte beschreibt und mit der nichtparametrischen Regression ĂŒbereinstimmt. Die Untersuchung der Residuen bestĂ€tigt, dass der entwickelte semi-empirische Modellansatz korrekt spezifiziert und konsistent mit den Ergebnissen ist
Efficient CFRP-manufacturing using multiple industrial robots
To increase the competitiveness and efficiency of next generation transportation systems, the production costs and the time of production of large structures made of carbon fiber reinforced plastics (CFRP) need to be reduced. This can be achieved by using highly industrialized layup technologies as well as improved layup strategies.
For this purpose, within the project GroFi, the German Aerospace Center (DLR) in Stade developed an innovative plant concept for a fully automated fiberplacement (AFP) process using multiple robot units working simultaneously on one or more parts. Within the scope of the project "Efficient Wing Cover Manufacturing" (EWiMa) the functional capability of the research platform GroFi could be demonstrated by realizing the first mulithead AFP-process worldwide. For the demonstration a generic wing cover with a span of 8 m was manufactured using two layup units working simultaneously. In addition, efficiency improvements of a fiber placement process using multiple industrial robots were investigated.
Within the scope of the presentation the multihead approach and the results of the EWiMa project will be demonstrated
Entwicklung eines Materialmodells zur Vorhersage von SchÀden an Faserhalbzeugen wÀhrend
Bei der Fertigung groĂflĂ€chiger faserverstĂ€rkter Kunststoffbauteile ĂŒberwiegt der Einsatz automatisierter Ablegeprozesse wie Automated Fiber Placement oder Automated Tape Laying. AbhĂ€ngig von gewĂ€hlten Prozessparametern und der verwendeten Halbzeugbreite kann es beim Ablegevorgang zu SchĂ€den am abgelegten Material kommen. Diese werden in bestehenden Simulationsprozessen bisher nicht vollumfĂ€nglich erfasst. Als wesentliche Mechanismen zur Entstehung von SchĂ€den werden in dieser Arbeit Kontaktverlust und StabilitĂ€tsverlust wĂ€hrend der Ablage identifiziert. FĂŒr beide Mechanismen werden ein Materialmodell und entsprechende Versagenskriterien entwickelt. Dabei wird ein in der Literatur bestehender Ansatz so weiterentwickelt, dass er auch auf allgemeine dreidimensionale Geometrien anwendbar ist. DarĂŒber hinaus werden erforderliche EinflussgröĂen identifiziert und Möglichkeiten zu ihrer Ermittlung aufgezeigt. Basierend darauf werden Versuche zur Validierung des entwickelten Modells definiert und durchgefĂŒhrt
AFP Crawlers - Automated Fiber Placement without limiting Kinematics
Die automatisierte Fertigung groĂflĂ€chiger Faserverbundstrukturen, wie beispielsweise der FlĂŒgelschalen moderner Verkehrsflugzeuge, erfolgt aktuell mit groĂen Portalanlagen oder Knickarmroboter gestĂŒtzten Fertigungsanlagen. Diese Anlagen sind meist auf ein oder wenige Bauteile zugeschnitten und wenig flexibel hinsichtlich einer Variation der BauteilgröĂe oder der Bauteilgeometrie.
Der Forschungsansatz FlappyBot des Deutschen Zentrums fĂŒr Luft- und Raumfahrt löst sich von bauteilspezifischen Fertigungsanlagen und hebt die bisherige Wechselwirkung âgröĂeres Bauteil â gröĂere Anlageâ auf. Der Ansatz verfolgt die Idee von autonomen, mobilen Robotereinheiten, welche sich ohne starre FĂŒhrungskinematik auf dem formgebenden Werkzeug selbst bewegen. Mit diesem Konzept kann flexibler auf Skalierung, Geometrie- und DesignĂ€nderung der Bauteilstruktur reagiert werden. Der Verzicht auf verstĂ€rkte Fundamente ermöglicht zudem eine Verwendung in bestehender Halleninfrastruktur und Anpassung. VerĂ€nderte Bedarfe und EngpĂ€sse können ohne hohe Zusatzinvestitionen abgefangen werden.
Im vorliegenden Vortrag wird das grundlegende Konzept des Forschungsansatzes, das Einsatzpotential sowie der aktuelle Entwicklungsstand vorgestellt
First Ply Tack of an Automated Fibre Placement Process: Influence of heatable mould surface, release films and process parameters
During an automated manufacturing process of fibre reinforced plastics parts, material is laid up on a mould surface with Automated Fiber Placement technology. For this a sufficient tack between first ply and mould surface is important, especially for layups on vertical positioned moulds.
With the aim of providing the highest possible tack, the influence of different parameters on the first ply tack was investigated.
The influence of a heated mould surface on the tack was analysed by increasing the surface temperature in several steps up to 75°C. Both, a temporarily, as well as a permanently heated mould surface during the layup was investigated. In addition to that the tack between fibre material and six different release films were compared. Thereby, layup speed and power of an infrared heater were varied.
These experiments provide important insights for the development of a reliable method for a layup process on a mould in vertical position. The selection of the release films showed an influence on the tack. Furthermore, an increase of tack could be determined, if the mould surface was heated. But also without a heated mould surface and for all tested release films, the tack was high enough for a reliable layup
Modular, mobile, multiple robotics poised to change the AFP/ATL paradigm
New approach to keep AFP/ATL cost competitive in the future:
1. multiple robots cooperate based on intelligent job scheduling algorithms
2. smart arrangement of hardware for a more efficient process, redundancy within the system and fewer downtimes
3. use of autonomous, mobile robotic units to reduce amount of required infrastructur