TY - THES A1 - Jaouadi, Zouhour T1 - Pareto and Reliability-Oriented Aeroelastic Shape Optimization of Bridge Decks N2 - Due to the development of new technologies and materials, optimized bridge design has recently gained more attention. The aim is to reduce the bridge components materials and the CO2 emission from the cement manufacturing process. Thus, most long-span bridges are designed to be with high flexibility, low structural damping, and longer and slender spans. Such designs lead, however, to aeroelastic challenges. Moreover, the consideration of both the structural and aeroelastic behavior in bridges leads to contradictory solutions as the structural constraints lead to deck prototypes with high depth which provide high inertia to material volume ratios. On the other hand, considering solely the aerodynamic requirements, slender airfoil-shaped bridge box girders are recommended since they prevent vortex shedding and exhibit minimum drag. Within this framework comes this study which provides approaches to find optimal bridge deck cross-sections while considering the aerodynamic effects. Shape optimization of deck cross-section is usually formulated to minimize the amount of material by finding adequate parameters such as the depth, the height, and the thickness and while ensuring the overall stability of the structure by the application of some constraints. Codes and studies have been implemented to analyze the wind phenomena and the structural responses towards bridge deck cross-sections where simplifications have been adopted due to the complexity and the uniqueness of such components besides the difficulty of obtaining a final model of the aerodynamic behavior. In this thesis, two main perspectives have been studied; the first is fully deterministic and presents a novel framework on generating optimal aerodynamic shapes for streamlined and trapezoidal cross-sections based on the meta-modeling approach. Single and multi-objective optimizations were both carried out and a Pareto Front is generated. The performance of the optimal designs is checked afterwards. In the second part, a new strategy based on Reliability-Based Design Optimization (RBDO) to mitigate the vortex-induced vibration (VIV) on the Trans-Tokyo Bay bridge is proposed. Small changes in the leading and trailing edges are presented and uncertainties are considered in the structural system. Probabilistic constraints based on polynomial regression are evaluated and the problem is solved while applying the Reliability Index Approach (RIA) and the Performance Measure Approach (PMA). The results obtained in the first part showed that the aspect ratio has a significant effect on the aerodynamic behavior where deeper cross-sections have lower resistance against flutter and should be avoided. In the second part, the adopted RBDO approach succeeded to mitigate the VIV, and it is proven that designs with narrow or prolonged bottom-base length and featuring an abrupt surface change in the leading and trailing edges can lead to high vertical vibration amplitude. It is expected that this research will help engineers with the selections of the adequate deck cross-section layout, and encourage researchers to apply concepts of optimization regarding this field and develop the presented approaches for further studies. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2022,10 KW - Gestaltoptimierung KW - Vibration KW - Deck cross-sections KW - Reliability-based design optimization KW - Shape optimization KW - Pareto Front KW - Vortex-induced vibration Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230303-49352 ER - TY - JFULL A1 - Ainio, Anna A1 - Bartetzky, Arnold A1 - Győrffy, Rachel A1 - Islam, Naslima A1 - Khvadagiani, Irakli A1 - Kibel, Jochen A1 - Landau-Donnelly, Friederike A1 - Leko, Kristina A1 - Lenz, Patricia A1 - Onuoha, Nnenna A1 - Rathjen, Lukas A1 - Reinsch, Natalie A1 - Rykov, Anatol A1 - Tajeri, Niloufar A1 - Ullmanová, Klára ED - Dinççağ Kahveci, Ayşegül ED - Hajdu, Marcell ED - Höhne, Wolfram ED - Jesse, Darja ED - Karpf, Michael ED - Torres Ruiz, Marta T1 - Censored? Conflicted Concepts of Cultural Heritage N2 - Those who ask how social entities relate to the past, enter a field defined by competing interpretations and contested practices of a collectively shared heritage. Dissent and conflict among heritage communities represent productive moments in the negotiation of these varying constructs of the past, identities, and heritage. At the same time, they lead to omissions, the overwriting and amendment of existing constructs. A closer look at all that is suppressed, excluded or rejected opens up new perspectives: It reveals how social groups are formed through public disputes upon the material foundations of heritage constructs. Taking the concept of censorship, the volume engages with the exclusionary and inclusionary mechanisms that underlie the construction of heritage and thus social identities. Censorship is understood here as a discursive strategy in public debates. In current debates, allegations of censorship surface primarily in cases where the handling of a certain heritage constructs is subjected to critical evaluation, or on the contrary, needs to be protected from criticism or even destruction. The authors trace the connection between heritage and identity and show that identity constructs are not only manifested within heritage but are actively negotiated through it. T3 - Schriftenreihe des DFG-Graduiertenkollegs 2227 "Identität und Erbe" - 4 KW - Kulturerbe KW - Denkmalpflege KW - Architektur KW - Zensur KW - Heritage Studies KW - Cancel Culture KW - Censorship KW - Kulturgeschichte Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230213-49276 SN - 978-3-95773-304-7 PB - Bauhaus-Universitätsverlag CY - Weimar ER - TY - CHAP A1 - Völlmecke, Lars A1 - Schwendner, Sascha A1 - Ho, Ai Phien A1 - Fischer, Jens A1 - Seim, Werner T1 - Assessment of nailed connections in existing structures N2 - This paper presents the development of an assessment scheme for a visual qualitative evaluation of nailed connections in existing structures, such as board trusses. In terms of further use and preservation, a quick visual inspection will help to evaluate the quality of a structure regarding its load-bearing capacity and deformation behaviour. Tests of old and new nailed joints in combination with a rating scheme point out the correlation between the load-bearing capacity and condition of a joint. Old joints of comparatively good condition tend to exhibit better results than those of poor condition. Moreover, aged joints are generally more load-bearing than newly assembled ones. KW - Holzbau KW - Träger KW - nailed trusses KW - nailed constructions KW - Corrosion KW - Preservation KW - Re-use Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230609-63615 ER -