As a solution to mid-air haptic actuation with strong and continuous tactile force, Magnetic Rendering is presented as an intuitive haptic display method applying an electromagnet array to produce a magnetic field in mid-air where the force field can be felt as magnetic repulsive force exerted on the hand through the attached magnet discs. The magnetic field is generated by a specifically designed electromagnet array driven by direct current. By attaching small magnet discs on the hand, the tactile sensation can be perceived by the user. This method can provide a strong tactile force on multiple points covering user’s hand and avoid cumbersome attachments with wires, thus it is suitable for a co-located visual and haptic display. In my work, the detailed design of the electromagnet array for haptic rendering purposes is introduced, which is modelled and tested using Finite Element Method simulations. The model is characterized mathematically, and three methods for controlling the magnetic field are applied accordingly: direct control, system identification and adaptive control. The performance of the simulated model is evaluated in terms of magnetic field distribution, force strength, operation distance and force stiffness. The control algorithms are implemented and tested on a 3-by-3 and a 15-by-15 model, respectively. Simulations are performed on a 15-by-15 model to generate a haptic human face, which results in a smooth force field and accurate force exertion on the control points.

This thesis is focused on measuring the shape of loaded tire and finding dependencies between inner tire pressure, load and the influence of these parameters on the resulting shape of the tire. Data for these dependencies were obtained by using a constructed measuring stand and 3D optical technology. Found dependencies describe the change in shape of the tire in specific mathematical functions, and served the creation of a parametric model of the tire. The main finding of this thesis is that the tire is actually behaves according to dependencies described by varying degrees of polynomial function.

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Planing hull is one solution to break the speed barrier of conventional hull, but as the boat reaches a high speed, massive whisker spray will be developed and attached to the hull, which causes a notable resistance increase. A Swedish company Peterstep invented an innovative spray deflector that can deflect the spray backwards and harvest kinetic energy from the spray.In the 2019 spray deflector project, many tests were done in Davison Laboratory Towing Tank, and there is a trim angle difference between plated and non-plated hulls. To investigate possible reasons, more tests are implemented in this project. According to the test results, the reason is determined as the different roughness of the hull and bottom due to differences in materials. Also, the tape for sealing the seam between hull and bottom plate affects the sharpness of the hard chine, thereby hindering the flow separation.The model used in previous experiments is no longer suitable for the further investigation. The modular design caused the different running position of plated and non-plated hull. In addition, the hull is too slender for the wave test. Therefore, a new model is needed to satisfy the new objectives of experiments. In this paper, the detailed design is surrounded by design aims and restrictions, such as increase spray resistance and avoid porpoising.There are few researches on HSC free running model test. To investigate the performance of the spray deflector in the test environment more similar to reality, a free running model with propulsion and steering system is necessary. The preliminary design, component selection and testing plan are outlined in this paper. / Planande skrov är en lösning för att bryta hastighetsbarriären hos ett konventionellt skrov, men när båten når hög hastighet kommer omfattande whisker spray att utvecklas på skrovet, vilket orsakar en anmärkningsvärd ökning av motståndet. Ett svenskt företag Peterstep har utvecklat en innovativ sprutdeflektor som kan avleda sprayen bakåt och skörda kinetisk energi från sprayen.Under sprutdeflektorprojektet 2019 gjordes många tester i Davison Laboratorys släpränna och det noterades en oönskad trimvinkelskillnad mellan modeller där skrovet byggts i en del eller med ett steg som fyllts igen med en bottenplatta. För att undersöka möjliga skäl till detta implementeras nya tester i detta projekt. Enligt testresultaten bestäms orsaken som skrovets och bottenplattans olika jämnhet på grund av materialskillnader. Även tejpen för tätning av sömmen mellan skrov och bottenplatta påverkar skärpan i slaget och hindrar därmed flödets avlösning.Modellen som använts i tidigare experiment är inte lämplig för fortsatt utredningen. Den modulära designen orsakade olika gångläge beroende på hur skroven hade byggts upp. Dessutom är skrovet för smalt för vågproven. Det behövs därför en ny modell för att uppfylla målen med experimenten.I det här arbetet har designen ytterligare designmål och begränsningar, som att mäta sprutmotståndet och att undvika porpoising.Det finns få undersökningar om HSC-test med frigående modeller. För att undersöka sprutdeflektorers prestanda i testmiljö som liknar verkligheten är det nödvändigt med en frigående modell med eget framdrivnings- och styrsystem. Den preliminära designen, komponentvalet och testplanen beskrivs i detta dokument.

Several reinforced concrete bent caps (deep beams) in Texas have developed significant diagonal cracks in service. The cracking in two bent caps was so extensive that costly retrofits were implemented to strengthen the structures. Strut-and-tie modeling is currently recommended in most U.S. design specifications for the design of reinforced concrete bent caps and deep beams. Designers have expressed concerns with the lack of clarity and serviceability-related considerations in strut-and-tie model design provisions. Due to concerns with strut-and-tie modeling design provisions and field problems of in-service bent caps, TxDOT Project 5253 was funded. Several tasks conducted within Project 5253 are addressed in this dissertation. The effects of minimum web reinforcement and member depth on the strength and serviceability behavior of deep beams are presented. The transition between deep beam shear capacity and sectional shear capacity near a shear-span-to-depth (a/d) ratio of 2 is addressed. A service-load shear check to limit diagonal cracking in service is outlined. Lastly, a simple chart that correlates the maximum width of diagonal cracks in a deep beam to its residual capacity is developed. To accomplish the objectives of Project 5253, thirty-seven tests were conducted on reinforced concrete beams with the following cross-sectional dimensions: 21”x23”, 21”x42”, 21”x44”, 21”x75”, and 36”x48.” The specimens were loaded with a/d ratios of 1.2, 1.85, and 2.5. The test specimens are among the largest reinforced concrete deep beams in the literature. To supplement the findings of the experimental program, a database of deep beam test results was compiled. Entries in the database that lacked sufficient information and that did not meet established cross-sectional size or web reinforcement criteria were filtered from the database. The use of the database in conjunction with the experimental program enabled each objective to be addressed from both broad and specific viewpoints. Several recommendations for improving the strength and serviceability design of deep beams are presented including a minimum web reinforcement requirement, provisions to ease the transition between calculated deep beam and sectional shear capacity, and a design check to limit diagonal cracking in service. / text

The performance of product development processes is important to the commercial success of new products. The improvement of these processes is thus a strategic imperative for many engineering companies - the aero-engine is one example of a complex product for which market pressures necessitate ever-shorter development times. This thesis argues that process modelling and simulation can support the improvement of complex product development processes. A literature review identified that design process modelling is a well-establishedresearch area encompassing a diverse range of approaches. However, most existing tools and methods are not widely applied in industry. An extended case study was therefore conducted to explore the pragmatic utility of process modelling and simulation. It is argued that iteration is a key driver of design process behaviour which cannot be fully reflected in a mechanistic model. Understanding iteration can help select an appropriate representation for a given process domain and modelling objective. A model-based approach to improve the management of iterative design processes was developed. This approach shows that design process simulation models can support practice despite their limited fidelity. The modelling and simulation framework resulting from this work was enhanced for application to a wider range of process improvement activities. A robust and extensible software platform was also developed. The framework and software tool have made significant contribution to research projects investigating process redesign, process robustness and process optimisation. These projects are discussed to validate the framework and tool and to highlight their applicability beyond the original approach. The research results were disseminated in academia and industry - 72 copies of the software were distributed following requests in the first three months of its release.

Dieser Beitrag stellt ein neues, hybrides Modell für die Entwicklung mechanischer und mechatronischer Systeme vor. Ziel ist es, die derzeitig bestehende Lücke zwischen abstrakten Funktionsmodellen und sehr konkreten, geometrieorientierten 3D-CAD-Modellen zu überbrücken. Das hier vorgestellte SkiPo-Modell beschreibt die Interaktionen zwischen den Komponenten eines Systems basierend auf den zugehörigen Material-, Energie- und Signalflüssen. Ergänzt wird diese abstrakte Darstellung mit Skizzen, die wichtige Konstruktionsentscheidungen in einer strukturierten, semistandardisierten Weise dokumentieren. Das Ziel dieser hybriden Modellierung ist es, die unvermeidbaren Iterationen zwischen abstrakten und sehr detaillierten Betrachtungen von mechanischen und mechatronischen Systemen in der frühen Phase der Produktentstehung zu unterstützen. In Erprobungen mit Studentengruppen zeigte sich, dass dieser Modellierungsansatz das Verständnis und die Kommunikation im Team fördern kann.

Aus der Einleitung: "Produktentwicklung und Fertigungsplanung innovativer komplexer technischer Produkte sind heute ohne massiven Rechnereinsatz gar nicht mehr möglich: Produkteigenschaften wie Funktion, Fertigung, Montage, Bedienbarkeit, dynamisches Verhalten, Reaktion auf Störgrößen, Ästhetik, Instandhaltung bis Recycling sollten möglichst früh im Entwicklungsprozess durch virtuelle Prototypen technischer Produkte und Verfahren beschrieben und abgesichert werden (Höhne 2009)."

La prise de décision dans les phases amont de conception est autant cruciale que difficile. Les besoins des parties prenantes et leurs perceptions sont difficiles à prédire et à partager au sein de l’équipe de conception. Il est ensuite difficile de comprendre quels concepts sont à plus forte valeur ajoutée.Cette thèse s’inspire des méthodes de conception orientées valeur et développe une méthodologie en trois étapes pour aider à la prise de décision dans les phases amont de conception.La méthodologie a été testée et validée sur plusieurs cas industriels. / Decision making in early design stages is crucial as well as difficult. Stakeholders’ needs and perceptions are difficult to predict and share among the design team. It is then difficult to understand which design concepts are the most valuable to explore.This thesis builds upon value-oriented design methodologies and develops a three-step methodology to maximize value creation in early design stages.The methodology was tested and validated on several industrial use cases.

Die Dissertation von Lars Mackel befasst sich mit der Gestaltung Service-Dominanter Geschäftsmodelle in der Frühphase von Startups. Untersucht wird, welche Veränderungen Startup-Unternehmer an ihren Geschäftsmodellen vornehmen und welche Faktoren diese beeinflussen. Als Bezugsrahmen dient die Service-Dominant Logic (SD-Logic) von Vargo & Lusch, die den Fokus auf Service als generische Form des Austauschs und den Cocreation-Prozess der Akteure legt. Nach einer Einführung in die Grundlagen des Entrepreneurship und der verschiedenen Definitionen und Elemente von Geschäftsmodellen, wird die SD-Logic erläutert. Es wird gezeigt, wie Geschäftsmodelle als Basis für die Beziehungen zwischen Akteuren dienen, die gemeinsam Wert schaffen. Die Dissertation verwendet einen qualitativen Forschungsansatz, um die Anpassungen von Geschäftsmodellen in der Frühphase und insbesondere in der Erprobungsphase eines Startups zu untersuchen. Die empirischen Ergebnisse zeigen, dass die Cocreation-Prozesse mit den ersten Kunden nicht nur entscheidend für die Weiterentwicklung der Geschäftsmodelle sind, sondern darüber hinaus die Ausrichtung des Designs der jeweiligen Geschäftsmodelle an der SD-Logic dazu beiträgt, dass die betrachteten Startups besser gerüstet sind, die Erprobungsphase und das sogenannte ‚Valley of Death‘ zu überstehen. Die Arbeit schließt mit Empfehlungen für die Praxis und einem Ausblick auf zukünftige Forschungsfelder.:1 Einleitung 2 Grundlagen im Kontext Entrepreneurship 3 Entwicklung von Geschäftsmodellen 4 Geschäftsmodelle im Kontext der Service-Dominant Logic 5 Entwicklung des Untersuchungsrahmens und methodisches Vorgehen 6 Ergebnisse der empirischen Untersuchung 7 Schlussbetrachtungen