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[EN] The Cluster of Excellence Integrative Computational Design and Construction for Architecture at the University of Stuttgart brings together various disciplines to jointly develop amongst other things a better understanding of processes in the manufacturing and construction domain. One of the cluster’s aims is to create new solutions for the construction of lightweight fibrous structures using coreless winding of lightweight fiber composite systems. For this purpose, a precise geometry and an understanding of the fibers’ behavior during the production process are of major importance. The fibers’ production process is monitored by repeatedly scanning the fibers during different stages of the process using a terrestrial laser scanner. In order to determine the geometry of the fibers’ axes as well as their cross-sections, two different strategies are used. The first strategy focuses on the segmentation of several straight lines between two intersection points. For the comparison of the individual fabrication steps, the positions of the intersection points are contrasted. For the cross-sectional areas of the fibers, orthogonal planes of intersection are then defined and all points within a predefined area are projected onto this plane. Then the area is calculated using a convex hull. In the second strategy, the fibers‘ main axes are represented by best-fitting B-spline curves. The borders of the cross-sections of interest are also approximated by best-fitting B-spline curves, forming the basis for the final determination of the cross-sectional areas. In this case study two epochs are analyzed with a deformation of the size of around 1cm. For both epochs the cross-sections are calculated in cm steps., The research published in this article is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2120/1 – 390831618. The authors cordially thank the DFG. A part of the research was realized within a one-month research stay of the second author at the University of Stuttgart within the IntCDC incoming programme.

Accepting the ecological necessity of a drastic reduction of resource consumption and greenhouse gas emissions in the building industry, the Institute for Lightweight Structures and Conceptual Design (ILEK) at the University of Stuttgart is developing graded concrete components with integrated concrete hollow spheres. These components weigh a fraction of usual conventional components while exhibiting the same performance. Throughout the production process of a component, the positions of the hollow spheres and the level of the fresh concrete have to be monitored with high accuracy and in close to real-time, so that the quality and structural performance of the component can be guaranteed. In this contribution, effective solutions of multiple sphere detection and concrete surface modeling based on the technology of terrestrial laser scanning (TLS) during the casting process are proposed and realized by the Institute of Engineering Geodesy (IIGS). A complete monitoring concept is presented to acquire the point cloud data fast and with high-quality. The data processing method for multiple sphere segmentation based on the efficient combination of region growing and random sample consensus (RANSAC) exhibits great performance on computational efficiency and robustness. The feasibility and reliability of the proposed methods are verified and evaluated by an experiment monitoring the production of an exemplary graded concrete component. Some suggestions to improve the monitoring performance and relevant future work are given as well.

Durch die globale Erwärmung in Folge des Klimawandels kommt es zu einer Abnahme des Landeises in Grönland und der Antarktis. Dies führt zu einer globalen Änderung des Meeresspiegels. Die Variation des Meeresspiegels wird außer von der Variation der abnehmenden Eislast und der zunehmenden Wasserlast auch von der Änderung der Gravitationsanziehung beeinflusst. Um die durch die Meeresspiegeländerungen betroffenen Gebiete rechtzeitig erkennen zu können, ist eine Berechnung der Entwicklung des Meeresspiegels von großem Interesse. Hierfür wurden zwei pseudospektrale Algorithmen implementiert, welche die Berechnung der Meeresspiegeländerung für eine kugelförmige, elastische, nicht rotierende Erde durchführen. Dabei wurden je zwei Varianten implementiert. Eine Variante fixierte Küstenlinien als Berechnungsgrundlage, während die andere eine Variation der Küstenlinien zulässt. Als Eingangsmodelle wurden für den Test der implementierten Algorithmen das postglaziale ICE5G-Modell und das Modell der gravimetrischen Massenbilanz der Technischen Universität Dresden verwendet. Eine mögliche Erweiterung der Algorithmen wäre die Berücksichtigung weiterer Effekte wie beispielsweise der Erdrotation sowie die Verwendung eines visko-elastischen Erdmodells, um realistischere Ergebnisse zu erhalten.