Search

In-situ thermoplastic automated fiber placement (TP-AFP) is a lean additive manufacturing process without further vacuum bagging and autoclave cycling. Heated by laser and subsequently compacted with a consolidation roller, the tapes are consolidated on the fly. This makes TP-AFP a single stage manufacturing process. For this highly transient process inline quality assurance (QA) is vital. The inline QA sensor is situated about 100 mm behind the consolidation roller and measures height profiles via laser triangulation. The evaluation routine identifies gaps and overlaps between tows and tracks as well as early/late cut at the beginning and end of each track. Processing the profile data includes outlier removal, thresholding, bitwise operations, the Sobel operator, erode and dilate operations and contour finding. We present the data evaluation of a full-scale fuselage skin of a test shell which was produced with a multitow laying head that processes three ½” carbon fiber tapes. The primary focus is the detection of gaps and overlaps. A 3D spatial plot will give an overview where the production process has to be revised.

Künstliche Intelligenz und Analytics halten immer mehr Einzug in den Wissenschaftsalltag. Gerade der Umgang mit Daten aus komplexen multi-Schritt Experimenten stellt heute noch eine Herausforderung dar. Das am DLR entwickelte integrierte Datenmanagementsystem "shepard" [1] vereinfacht den Einstieg und die Verarbeitung dieser Daten. Im Folgenden wird kurz auf die Motivation hinter Experimentaldatenmanagement eingegangen. Danach wird die Basisarchitektur der Einzelkomponenten von shepard dargestellt. Am Beispiel von thermoplastischem AFP wird die kontextualisierte Datenerfassung verdeutlicht und abschließend ein Ausblick auf Weiterentwicklungsperspektiven gegeben.

During the last decade the DLR Center of Lightweigth Production Technology (ZLP) in Augsburg investigated the potential of the autonomous production of composite parts by means of pick and place executed by industrial robots. Starting from conventional teaching the research focus was extended to the development of technology bricks for computer vision based gripping, automated derivation of grip- and drop coordinates from CAD data, digital process description and workflow, autonomous cut-piece transfer by means of collision free path planning and a multi-robot synchronization and execution layer. The technology bricks are enriched by a process data acquisition system and controlled by a manufacturing execution system embedded into a high-level process control system. In this work we give an overview of the developed technologies and achievements based upon several use cases from the field of composite production.

Automated Dry Fibre Placement (DFP) is considered a viable technology for preform production of advanced composites. In this process, the heat source crucially determines the achievable lay-down rates and thus ultimately the effective productivity. Therefore high energy density heat sources are desirable. In this context, flashlamp heating is a promising technology especially for large part production. In this study, the Heraeus humm3 flashlamp system is benchmarked to infrared (IR) radiators in terms of peel strength and heat distribution at various lay-down speeds. For this purpose a parameter study is conducted to identify suitable processing parameters for binder activation. A significant increase to lay-down speeds of 30 m/min compared to 6 m/min with infrared heaters is accomplished with enhanced controllability of the process regarding the energy transfer into the material. The temperature profiles measured indicate more uniform distribution along the tracks. Subsequently the opportunities and limitations of applying a flashlamp heat source in a DFP process are discussed.

INTRODUCTION: Stress is one of the greatest burdens of our society and often implies impairments in cognitive and emotional functions. Here, we hypothesise that changes in the brain's dopamine (DA)-based mesocorticolimbic projec-tions in patients with work-related stress (adjustment disorder) will manifest themselves as altered glucose metabolism in relation to neural activity, and as altered DA radiotracer binding potentials at the relevant receptors.METHODS: Subjects and healthy controls undergo neuropsychiatric tests and PET/MRI with three tracers: 18F-fluorodeoxyglucose to measure glucose metabolism as a marker of neural activity, 11C-raclopride to explore binding potentials in the striatum, and 11C-FLB 457 to study possibly impaired mesocortical dopaminergic transmission in the cortex. To demonstrate differences of glucose metabolism, more than 2 × 41 patients/controls are needed. We expect to find that symptoms of cognitive and motivational reward deficits are attributable to changes in the frontal lobe and striatal glucose metabolism in the majority of patients, and that changes of D2-receptor availability and impaired dopaminergic transmission in the striatum and prefrontal cortex are contributing factors.CONCLUSIONS: This project is designed to generate entirely new and objective evidence of stress-induced cerebral illness, and to provide a basis for in-depth research and for a more rational management of this strenuous disorder.FUNDING: Private, industrial and public funds.TRIAL REGISTRATION: Clinicaltrails.gov/NCT03334045.