Improvement and Characterization of Direct-Ink-Write Manufactured Continuous Fiber Reinforced Photopolymer Matrix Composites

Fiber reinforced polymer (FRP) composites play a significant and continuously growing role in engineering applications that require high strength, weight optimized structural components. Additive manufacturing (AM) has proven to be an extremely powerful tool in expanding the limits of part complexity and optimization. The present work aims to combine the two by reliably and efficiently additively manufacturing continuous fiber reinforced thermoset polymer composites. Building off previous efforts, a novel 3D printer was refined that utilizes direct ink write (DIW) technology to simultaneously extrude both an in-situ cured UV resin and continuous reinforcing fiber. Improvements to the system ensured that the most common failures were significantly mitigated or eliminated. The capabilities of the printer, specifically the maximum print size, were also increased by a wide margin. The printer’s more predictable state allowed the creation of samples for material characterization. Tensile specimens showed strengths as high as 209 MPa and an average tensile modulus of 19.5 MPa. Volume fraction testing using carbonization in a nitrogen atmosphere gave an average fiber volume fraction of 8.3%. These are competitive with the results of other investigations of similar continuous fiber AM processes. The printed material was further characterized with scanning electron microscopy, showing that the bonding between matrix layers and resin impregnation within fibers were both ideal. Printed cones and honeycombs also showed that the process can produce complex geometry. Future efforts can serve to increase the fiber volume fraction and overall strength optimization of the printed material. The introduction of new materials into the process, like fiberglass or nanoparticles, could also change the properties of the products to have better curing behavior or higher strength

High Performance Real-Time Scheduling Framework for Multiprocessor Systems

Embedded systems, performing specific functions in modern devices, have become pervasive in today's technology landscape. As many of these systems are real-time systems, they necessitate operations with stringent time constraints. This is especially evident in sectors like automotive and aerospace. This thesis introduces a High Performance Real-time Scheduling (HPRTS) framework, which is designed to navigate the multifaceted challenges faced by multiprocessor real-time systems. To begin with, the research attempts to bridge the gap between system reliability and resource sharing in Mixed-Criticality Systems (MCS). In addressing this, a novel fault-tolerance solution is presented. Its main goal is to enhance fault management and reduce blocking time during fault tolerance. Following this, the thesis delves into task allocation in systems with shared resources. In this context, we introduce a distinct Resource Contention Model (RCM). Using this model as a foundation, our allocation strategy is formulated with the aim to reduce resource contention. Moreover, in light of the escalating system complexity where tasks are represented using Directed Acyclic Graph (DAG) models, the research unveils a new Response Time Analysis (RTA) for multi-DAG systems. This particular analysis has been tailored to provide a safe and more refined bound. Reflecting on the contributions made, the achievements of the thesis highlight the potency of the HPRTS framework in steering real-time embedded systems toward high performance

Stuttgarter Symposium für Produktentwicklung SSP 2017 : Stuttgart, 29. Juni 2017, Wissenschaftliche Konferenz

Veränderte Anforderungen in internationalen Märkten erfordern hohe Anstrengungen, um Prozesse in Innovation und Produktentwicklung zu optimieren. Das Stuttgarter Symposium für Produktentwicklung (SSP) ermöglicht die Diskussion der an Produktgestaltung und -entwicklung beteiligten Disziplinen aus Industrie und Wissenschaft. Das SSP zeigt, wie erfolgreiche Produkte effizient gestaltet und entwickelt werden. Neueste Forschungsergebnisse zu Methoden, Strategien und Werkzeugen werden vorgestellt, um Prozesse zu verbessern und die Digitalisierung zu unterstützen. Mit dem Ziel, nationale und internationale Fachleute unterschiedlicher Disziplinen der Produktentwicklung aus Industrie und Wissenschaft in den Dialog zu bringen, veranstaltet das Fraunhofer IAO gemeinsam mit dem Institut für Konstruktionstechnik und Technisches Design IKTD, dem Institut für Maschinenelemente IMA und dem Institut für Arbeitswissenschaft und Technologiemanagement IAT der Universität Stuttgart das Stuttgarter Symposium für Produktentwicklung SSP. Am 28. und 29. Juni 2017 fand das SSP bereits zum vierten Mal im Zentrum für Virtuelles Engineering des Fraunhofer IAO statt, nachdem die Symposien 2011, 2013 und 2015 mit jeweils über 200 Besuchern aus Wissenschaft und Wirtschaft großen Zuspruch gefunden hatten. Am Forumstag stand wie immer die Industrie im Fokus, am zweiten Tag die wissenschaftliche Konferenz. Die Konferenz bietet Wissenschaftlern eine Plattform zur Präsentation und Diskussion ihrer neuesten Forschungsergebnisse im Bereich der Produktentwicklung und fördert so den interdisziplinären Wissenstransfer. Aufgerufen waren in der SSP 2017 Beiträge aus folgenden Kategorien: • Wissensmanagement in der Produktentwicklung • Nachhaltige Produktentwicklung • Altersgerechte Produktentwicklung • Zuverlässige Produktentwicklung • Industrie 4.0/Cyber-Physical Products • Konstruktionsmethodiken • Leichtbau in der Produktentwicklung • Nutzerzentriertes Design • Innovations- und Technologiemanagement • Digital Engineering • Lean Development. Eingereicht wurden Beiträge zu Methoden, Strategien und Verfahren, die es ermöglichen, Produktentwicklungsprozesse zu vernetzen, digitale Werkzeuge zu integrieren und die Potenziale neuer Technologien und Werkstoffe optimal auszuschöpfen

Digital Product and Process Development Systems: IFIP TC 5 International Conference, NEW PROLAMAT 2013, Dresden, Germany, October 10-11, 2013

International audienceBook Front Matter of AICT 41

Digital Product and Process Development SystemsIFIP TC 5 International Conference, NEW PROLAMAT 2013, Dresden, Germany, October 10-11, 2013. Proceedings /

XVI, 428 p. 290 illus.online resource