TY - CHAP A1 - Wu, Ziyi A1 - Kemper, Hans T1 - The optimal 48 V – battery pack for a specific load profile of a heavy duty vehicle T2 - 8. Internationale Fachtagung Kraftwerk Batterie : 26. – 27. April 2016, Münster, Deutschland Y1 - 2016 ER - TY - CHAP A1 - Weber, Tobias A1 - Tellis, Jane J. A1 - Duhovic, Miro T1 - Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation T2 - ECCM 17, 17th European Conference on Composite Materials, München, DE, Jun 26-30, 2016 Y1 - 2016 SN - 978-3-00-053387-7 SP - 1 EP - 7 ER - TY - JOUR A1 - Weber, Tobias A1 - Arent, Jan-Christoph A1 - Münch, Lukas A1 - Duhovic, Miro A1 - Balvers, Johannes M. T1 - A fast method for the generation of boundary conditions for thermal autoclave simulation JF - Composites Part A N2 - Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.compositesa.2016.05.036 SN - 1359-835X VL - 88 SP - 216 EP - 225 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schüller, K. A1 - Kowalski, Julia A1 - Raback, P. T1 - Curvilinear melting – A preliminary experimental and numerical study JF - International Journal of Heat and Mass Transfer N2 - When exploring glacier ice it is often necessary to take samples or implement sensors at a certain depth underneath the glacier surface. One way of doing this is by using heated melting probes. In their common form these devices experience a straight one-dimensional downwards motion and can be modeled by standard close-contact melting theory. A recently developed melting probe however, the IceMole, achieves maneuverability by simultaneously applying a surface temperature gradient to induce a change in melting direction and controlling the effective contact-force by means of an ice screw to stabilize its change in attitude. A modeling framework for forced curvilinear melting does not exist so far and will be the content of this paper. At first, we will extend the existing theory for quasi-stationary close-contact melting to curved trajectories. We do this by introducing a rotational mode. This additional unknown in the system implies yet the need for another model closure. Within this new framework we will focus on the effect of a variable contact-force as well as different surface temperature profiles. In order to solve for melting velocity and curvature of the melting path we present both an inverse solution strategy for the analytical model, and a more general finite element framework implemented into the open source software package ELMER. Model results are discussed and compared to experimental data conducted in laboratory tests. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.ijheatmasstransfer.2015.09.046 SN - 0017-9310 IS - 92 SP - 884 EP - 892 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Schleupen, Josef A1 - Engemann, Heiko A1 - Bagheri, Mohsen A1 - Kallweit, Stephan T1 - The potential of SMART climbing robot combined with a weatherproof cabin for rotor blade maintenance T2 - 17th European Conference on Composite Materials – ECCM, Munich, Germany Y1 - 2016 N1 - ECCM 17 SP - 1 EP - 8 ER - TY - CHAP A1 - Rupp, Matthias A1 - Kuperjans, Isabel A1 - Schulze, Sven ED - Berns, Karsten T1 - Energetische und ökologische Bewertung hybrider Antriebe im städtischen Busverkehr T2 - Commercial vehicle technology 2016 : proceedings of the 4th Commercial Vehicle Technology Symposium (CVT 2016), March 8-10, 2016, University of Kaiserslautern, Kaiserslautern, Germany N2 - In Anbetracht weltweit zunehmend strengerer klimapolitischer Ziele steigt auch der Druck für Nutzfahrzeughersteller, effizientere und umweltfreundlichere Technologien zu entwickeln. Den Blick bei der Bewertung dieser ausschließlich auf die Fahrzeugnutzung zu richten, ist längst nicht mehr zufriedenstellend. Im Rahmen dieser Analyse wird ein gegenwärtig auf dem Markt erwerblicher und in deutschen Städten bereits seit Jahren betriebener Hybridbus energetisch und ökologisch mit einem konventionell angetriebenen, nahezu baugleichen Modell entlang des Lebensweges bewertet. Nach Definition von Ziel und Untersuchungsrahmen wird ein Überblick auf bereits durchgeführte Lebenszyklusanalysen zu Hybridbussen im Stadtverkehr gegeben und Schlussfolgerungen für die anschließende Analyse abgeleitet. Diese wird im Rahmen einer energetischen und ökologischen Bewertung beider Produktsysteme anhand der Parameter "Primärenergieeinsatz" und "CO2äq Emissionen" praktiziert. Der Fahrzeugrumpf beider Fahrzeuge des gleichen Modells wird dabei als einheitlich angenommen, sodass bei dem Vergleich der Herstellung vereinfacht nur die sich unterscheidenden Komponenten des Antriebstranges berücksichtigt werden. Die Resultate der Wirkungsabschätzung werden als Differenz des Hybridbusses gegenüber dem Referenzfahrzeug über die einzelnen Lebenszyklusphasen dargestellt. Schließlich werden Prognosen getroffen, ab welcher Strecke die bei der Herstellung erzeugten höheren CO2äq Emissionen des Hybridantriebstranges gegenüber dem Referenzmodell ausgeglichen werden. Y1 - 2016 SP - 227 EP - 237 PB - Shaker CY - Aachen ER - TY - JOUR A1 - Peloni, Alessandro A1 - Ceriotti, Matteo A1 - Dachwald, Bernd T1 - Solar-sail trajectory design for a multiple near-earth-asteroid rendezvous mission JF - Journal of Guidance, Control, and Dynamics N2 - The scientific interest for near-Earth asteroids as well as the interest in potentially hazardous asteroids from the perspective of planetary defense led the space community to focus on near-Earth asteroid mission studies. A multiple near-Earth asteroid rendezvous mission with close-up observations of several objects can help to improve the characterization of these asteroids. This work explores the design of a solar-sail spacecraft for such a mission, focusing on the search of possible sequences of encounters and the trajectory optimization. This is done in two sequential steps: a sequence search by means of a simplified trajectory model and a set of heuristic rules based on astrodynamics, and a subsequent optimization phase. A shape-based approach for solar sailing has been developed and is used for the first phase. The effectiveness of the proposed approach is demonstrated through a fully optimized multiple near-Earth asteroid rendezvous mission. The results show that it is possible to visit five near-Earth asteroids within 10 years with near-term solar-sail technology. Y1 - 2016 U6 - http://dx.doi.org/10.2514/1.G000470 SN - 0731-5090 VL - 39 IS - 12 SP - 2712 EP - 2724 PB - AIAA CY - Reston, Va. ER - TY - CHAP A1 - Otten, D. A1 - Schmidt, M. A1 - Weber, Tobias T1 - Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations T2 - SAMPE Europe Conference 16 Liege Y1 - 2016 SN - 978-1-5108-3800-0 SP - 570 EP - 577 ER - TY - JOUR A1 - Neu, Eugen A1 - Janser, Frank A1 - Khatibi, Akbar A. A1 - Orifici, Adrian C. T1 - Automated modal parameter-based anomaly detection under varying wind excitation JF - Structural Health Monitoring N2 - Wind-induced operational variability is one of the major challenges for structural health monitoring of slender engineering structures like aircraft wings or wind turbine blades. Damage sensitive features often show an even bigger sensitivity to operational variability. In this study a composite cantilever was subjected to multiple mass configurations, velocities and angles of attack in a controlled wind tunnel environment. A small-scale impact damage was introduced to the specimen and the structural response measurements were repeated. The proposed damage detection methodology is based on automated operational modal analysis. A novel baseline preparation procedure is described that reduces the amount of user interaction to the provision of a single consistency threshold. The procedure starts with an indeterminate number of operational modal analysis identifications from a large number of datasets and returns a complete baseline matrix of natural frequencies and damping ratios that is suitable for subsequent anomaly detection. Mahalanobis distance-based anomaly detection is then applied to successfully detect the damage under varying severities of operational variability and with various degrees of knowledge about the present operational conditions. The damage detection capabilities of the proposed methodology were found to be excellent under varying velocities and angles of attack. Damage detection was less successful under joint mass and wind variability but could be significantly improved through the provision of the currently encountered operational conditions. Y1 - 2016 U6 - http://dx.doi.org/10.1177/1475921716665803 SN - 1475-9217 VL - 15 IS - 6 SP - 1 EP - 20 PB - Sage CY - London ER - TY - CHAP A1 - Neu, Eugen A1 - Janser, Frank A1 - Khatibi, Akbar A. A1 - Orifici, Adrian C. T1 - In-flight vibration-based structural health monitoring of aircraft wings T2 - 30th Congress of the internatonal council of the aeronautical sciences : 25.-30. September 2016, Daejeon, Korea N2 - This work presents a methodology for automated damage-sensitive feature extraction and anomaly detection under multivariate operational variability for in-flight assessment of wings. The method uses a passive excitation approach, i. e. without the need for artificial actuation. The modal system properties (natural frequencies and damping ratios) are used as damage-sensitive features. Special emphasis is placed on the use of Fiber Bragg Grating (FBG) sensing technology and the consideration of Operational and Environmental Variability (OEV). Measurements from a wind tunnel investigation with a composite cantilever equipped with FBG and piezoelectric sensors are used to successfully detect an impact damage. In addition, the feasibility of damage localisation and severity estimation is evaluated based on the coupling found between damageand OEV-induced feature changes. Y1 - 2016 ER -