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Advanced FFF of PEEK: Infill strategies and material characteristics for rapid tooling
No full textTraditional vulcanization mold manufacturing is complex, costly, and under pressure due to shorter product lifecycles and diverse variations. Additive manufacturing using Fused Filament Fabrication and high-performance polymers like PEEK offer a promising future in this industry. This study assesses the compressive strength of various infill structures (honeycomb, grid, triangle, cubic, and gyroid) when considering two distinct build directions (Z, XY) to enhance PEEK’s economic and resource efficiency in rapid tooling. A comparison with PETG samples shows the behavior of the infill strategies. Additionally, a proof of concept illustrates the application of a PEEK mold in vulcanization. A peak compressive strength of 135.6 MPa was attained in specimens that were 100% solid and subjected to thermal post-treatment. This corresponds to a 20% strength improvement in the Z direction. In terms of time and mechanical properties, the anisotropic grid and isotropic cubic infill have emerged for use in rapid tooling. Furthermore, the study highlights that reducing the layer thickness from 0.15 mm to 0.1 mm can result in a 15% strength increase. The study unveils the successful utilization of a room-temperature FFF-printed PEEK mold in vulcanization injection molding. The parameters and infill strategies identified in this research enable the resource-efficient FFF printing of PEEK without compromising its strength properties. Using PEEK in rapid tooling allows a cost reduction of up to 70% in tool production
Integration of agile development in standard labs
No full textIn addition to the technical content, modern courses at university should also teach professional skills to enhance the competencies of students towards their future work. The competency driven approach including technical as well as professional skills makes it necessary to find a suitable way for the integration into the corresponding module in a scalable and flexible manner. Agile development, for example, is essential for the development of modern systems and applications and makes use of dedicated professional skills of the team members, like structured group dynamics and communication, to enable the fast and reliable development. This paper presents an easy to integrate and flexible approach to integrate Scrum, an agile development method, into the lab of an existing module. Due to the different role models of Scrum the students have an individual learning success, gain valuable insight into modern system development and strengthen their communication and organization skills. The approach is implemented and evaluated in the module Vehicle Systems, but it can be transferred easily to other technical courses as well. The evaluation of the implementation considers feedback of all stakeholders, students, supervisor and lecturers, and monitors the observations during project lifetime
Ordnung zur Aufhebung der Prüfungsordnungen für den Masterstudiengang „Nuclear Applications“ vom 13. Februar 2004 (FH-Mitteilung Nr. 5/2004) und vom 25. Februar 2010 (FH-Mitteilung Nr. 15/2010) in den Fassungen der Bekanntmachung der Änderungsordnungen vom 6. November 2012 (FH-Mitteilung Nr. 120/2012), 18. Juni 2014 (FH- Mitteilung Nr. 72/2014) und vom 15. Juni 2015 (FH-Mitteilung Nr. 28/2015) : vom 29. November 2019
No full textAdaptive iterative learning control of an industrial robot during neuromuscular training
No full textTo prevent the reduction of muscle mass and loss of strength coming along with the human aging process, regular training with e.g. a leg press is suitable. However, the risk of training-induced injuries requires the continuous monitoring and controlling of the forces applied to the musculoskeletal system as well as the velocity along the motion trajectory and the range of motion. In this paper, an adaptive norm-optimal iterative learning control algorithm to minimize the knee joint loadings during the leg extension training with an industrial robot is proposed. The response of the algorithm is tested in simulation for patients with varus, normal and valgus alignment of the knee and compared to the results of a higher-order iterative learning control algorithm, a robust iterative learning control and a recently proposed conventional norm-optimal iterative learning control algorithm. Although significant improvements in performance are made compared to the conventional norm-optimal iterative learning control algorithm with a small learning factor, for the developed approach as well as the robust iterative learning control algorithm small steady state errors occur
Cross border adjustment mechanism: Initial data for the assessment of hydrogen-based steel production
No full textAmbitious climate targets affect the competitiveness of industries in the international market. To prevent such industries from moving to other countries in the wake of increased climate protection efforts, cost adjustments may become necessary. Their design requires knowledge of country-specific production costs. Here, we present country-specific cost figures for different production routes of steel, paying particular attention to transportation costs. The data can be used in floor price models aiming to assess the competitiveness of different steel production routes in different countries (Rübbelke, 2022)
Design of reinforced concrete enclosures infilled with clay block masonry (Part 2)
No full textIm Rahmen des europäischen Verbundprojekts INSYSME wurden von den deutschen Partnern die Systeme IMES und INODIS zur Verbesserung des seismischen Verhaltens von ausgefachten Stahlbetonrahmen entwickelt. Ziel beider Systeme ist es, Stahlbetonrahmen und Ausfachung zu entkoppeln, anstatt die Tragfähigkeit durch aufwendige und kostspielige zusätzliche Bewehrungseinlagen zu erhöhen. Erste Ergebnisse des Systems IMES für Belastungen in und senkrecht zu der Wandebene werden vorgestellt.Within the scope of the joint European project INSYSME, the German partners developed two systems - IMES and INODIS - for improving the seismic behaviour of masonry infilled reinforced concrete frames. The purpose of both systems is to decouple frame and infill instead of working to improve their load-bearing capacity by means of elaborate, expensive, supplementary reinforcing elements. Initial findings for the IMES system with regard to the loads acting in-plane and perpendicular to the wall plane (out-of-plane) are presented
Influence of prior in-plane damage on the out-of-plane response of non-load bearing unreinforced masonry walls under seismic load
No full textReinforced concrete frames with masonry infill walls are popular form of construction all over the world as well in seismic regions. While severe earthquakes can cause high level of damage of both reinforced concrete and masonry infills, earthquakes of lower to medium intensity some-times can cause significant level of damage of masonry infill walls. Especially important is the level of damage of face loaded infill masonry walls (out-of-plane direction) as out-of-plane load cannot only bring high level of damage to the wall, it can also be life-threating for the people near the wall. The response in out-of-plane direction directly depends on the prior in-plane damage, as previous investigation shown that it decreases resistance capacity of the in-fills. Behaviour of infill masonry walls with and without prior in-plane load is investigated in the experimental campaign and the results are presented in this paper. These results are later compared with analytical approaches for the out-of-plane resistance from the literature. Conclusions based on the experimental campaign on the influence of prior in-plane damage on the out-of-plane response of infill walls are compared with the conclusions from other authors who investigated the same problematic
Der KI-Chatbot ChatGPT: Eine Herausforderung für die Hochschulen
No full textEssays, Gedichte, Programmcode: ChatGPT generiert automatisch Texte auf bisher unerreicht hohem Niveau. Dieses und nachfolgende Systeme werden nicht nur die akademische Welt nachhaltig verändern
Miela : digitale Wissensvermittlung für Vorschulkinder
No full textKinder sind bei der Suche nach Antworten auf ihre Fragen in unserer medialen Gesellschaft stark mit dem digitalen Raum konfrontiert. Diese Medien können bei einer nicht kindergerechten Benutzung wichtige Entwicklungsprozesse hindern. Im Gegensatz dazu geben diese aber auch die Möglichkeit, Kindern wichtige Denkgewohnheiten beizubringen und sie besser auf die Zukunft vorzubereiten. Ziel der Arbeit ist es, eine Verbindung zwischen der analogen und digitalen Welt herzustellen und ein vielfältiges Lernen zu ermöglichen. Die App „miela“ schafft eine neue Ebene der Wissensvermittlung durch die Kombination von digitaler und analoger Welt. Das Userinterface ist altersentsprechend gestaltet und bietet unterschiedliche Themenfelder an, wobei die Wissensvermittlung und die Kreativität im Fokus stehen. Eine Zusammenarbeit mit der Toniebox als digitale Erweiterung kann weitere Themenfelder anbieten