Automatisierte Herstellung funktional gradierter Betonbauteile

Die Gradierung von Beton ermöglicht eine funktionale Adaption der inneren Struktur respektive der Eigenschaften eines Bauteils an das vorherrschende statische und bauphysikalische Belastungsprofil. In diesem Kontext stellt die Automatisierung der Herstellungsverfahren insbesondere zur reproduzierbaren Herstellung von gradierten Betonbauteilen einen zentralen Aspekt dar. Dabei muss der gesamte Prozess, vom Entwurf des Bauteils über die Übernahme des CAD-Modells, der anforderungsabhängigen Mischung, Dosierung und Förderung des Betons bis hin zum Materialauftrag in eine Prozesssteuerung und Regelung integriert werden. Die Konzeption, Auslegung und anschließende Umsetzung der automatisierten Prozesskette in einem Prototypen der Herstellungsplattform sowie die Entwicklung des Steuerungs- und Regelungskonzeptes bilden die Eckpunkte des ISYS im Rahmen des Kooperations-Forschungsvorhabens Optimalstrukturen aus funktional gradierten Betonbauteilen – Entwurf, Berechnung und automatisierte Herstellung

Modelling of a rope-free passenger transportation system for active cabin vibration damping

Conventional vertical passenger transportation is performed by lifts. Conventional traction-drive electrical lifts use ropes to transfer the rotational motion of an electrical motor into a vertical motion of the cabin. The vertical passenger transportation system discussed in this paper does not use any ropes, the motor directly provides a driving force, which moves the cabin. This new propulsion is realized through an electrical linear motor. The use of the linear motor requires a new design of the passenger transportation system (PTS), which includes reducing the weight of the car through lightweight construction. The reduced stiffness of the lightweight design renders the construction more vulnerable to vibrations. In order to improve ride quality of the transportation system it is necessary to develop new concepts to damp the vibrations. One way to increase stiffness characteristics of the system is to introduce active damping components to be used alongside passive damping components. It is essential to derive a dynamic model of the system in order to design and also later control these damping components in the best possible way. This paper describes the fundamental steps undertaken to derive a dynamic model for designing and controlling active damping components for the new type of vertical PTS. The model is derived as a Multi-Body System (MBS), where the connections between the bodies are modelled as spring damper elements. The derivation of the MBS is demonstrated on a transportation system, consisting of three main components: a sledge, holding the rotor of the linear motor; a mounting frame, which is used to provide support for the cabin; and the actual cabin. The modelling of the propulsion system, thus the electrical part of the PTS, will not be the focus of this work

Effiziente automatisierte Herstellung multifunktional gradierter Bauteile mit mineralischen Hohlkörpern

Das Bauwesen steht in den kommenden Jahren vor der Herausforderung, für eine steigende Weltbevölkerung Habitate und Infrastruktursysteme zu errichten – unter Berücksichtigung abnehmenden Ressourcenvorkommens. Dies erfordert die Erforschung und Entwicklung neuer, innovativer Leichtbautechnologien für die Baubranche, die auf ein möglichst leichtes Bauen, die Minimierung des Verbrauchs an fossil erzeugter Energie sowie eine recyclinggerechte Bauweise abzielen [1]. Eine Möglichkeit im Bereich des Bauens mit Beton ist die von Werner Sobek entwickelte Technologie des Gradientenbetons. Dieser technologische Ansatz befasst sich erstmalig mit der Optimierung des Bauteilinnenraums und verfolgt das Ziel, die im Bauteil vorherrschenden Spannungsfelder durch die gezielte Platzierung von Hohlräumen zu homogenisieren. Dies ermöglicht die Herstellung von gewichtsminimalen, sortenrein rezyklierbaren und multifunktionalen Bauteilen aus Beton. [Aus: Einführung und Zielsetzung]For years to come, the construction industry will be faced with the challenge of building habitats and infrastructure systems for an increasing world population – with regard to dwindling resources. This requires the research and development of new, innovative lightweight-construction technologies for the building sector that aim at constructions that are as light as possible, minimize the consumption of fossil-based energy and are designed for recycling [1]. One possibility to meet these requirements in the field of concrete construction is the technology of graded concrete which was invented by Werner Sobek. This technological approach focuses for the first time on the optimisation of the component’s interior and pursues the goal of homogenizing the stress fields prevailing in the component through the targeted placement of cavities. This enables the production of minimal-weight, mono-material and multifunctional components. [Off: Introduction and objectives

Pneumatic cylinders: modelling and feedback force-control

In this paper, we model, analyse, and control an experimental set-up of a servo pneumatic cylinder. The dynamic behaviour of pneumatic actuator systems is dominant by non-linear functions. First, a mathematical model for the pneumatic system is derived. Secondly, we investigate the mathematical properties of this model and show boundedness and positiveness of certain variables. Thirdly, we prove that a proportional output feedback controller with saturation achieves practical tracking a wide class of reference trajectories. We verify the theoretical results and the effectiveness of the control by experiments

Energy-optimal control of adaptive structures

Adaptive structures are equipped with sensors and actuators to actively counteract external loads such as wind. This can significantly reduce resource consumption and emissions during the life cycle compared to conventional structures. A common approach is to derive a port-Hamiltonian model and to employ linear quadratic control. However, the quadratic control penalization lacks physical interpretation and merely serves as a regularization term. Rather, we propose a controller, which achieves the goal of vibration damping while acting energy optimal. Exploiting the port-Hamiltonian structure, we show that the optimal control is uniquely determined, even on singular arcs. Further, we prove a stable long-time behavior of optimal trajectories in the sense of a turnpike property. Last, the proposed controller's efficiency is evaluated by means of a numerical study.Comment: 14 pages, 4 figure

Active vibration control of a double-curved shell structure using the example of stuttgart smartshell

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