@unpublished{KavrakovArgentiniOmarinietal., author = {Kavrakov, Igor and Argentini, Tommaso and Omarini, Simone and Rocchi, Daniele and Morgenthal, Guido}, title = {Determination of complex aerodynamic admittance of bridge decks under deterministic gusts using the Vortex Particle Method}, doi = {10.25643/bauhaus-universitaet.4088}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200206-40883}, abstract = {Long-span bridges are prone to wind-induced vibrations. Therefore, a reliable representation of the aerodynamic forces acting on a bridge deck is of a major significance for the design of such structures. This paper presents a systematic study of the two-dimensional (2D) fluid-structure interaction of a bridge deck under smooth and turbulent wind conditions. Aerodynamic forces are modeled by two approaches: a computational fluid dynamics (CFD) model and six semi-analytical models. The vortex particle method is utilized for the CFD model and the free-stream turbulence is introduced by seeding vortex particles upstream of the deck with prescribed spectral characteristics. The employed semi-analytical models are based on the quasi-steady and linear unsteady assumptions and aerodynamic coefficients obtained from CFD analyses. The underlying assumptions of the semi-analytical aerodynamic models are used to interpret the results of buffeting forces and aeroelastic response due to a free-stream turbulence in comparison with the CFD model. Extensive discussions are provided to analyze the effect of linear fluid memory and quasi-steady nonlinearity from a CFD perspective. The outcome of the analyses indicates that the fluid memory is a governing effect in the buffeting forces and aeroelastic response, while the effect of the nonlinearity is overestimated by the quasi-steady models. Finally, flutter analyses are performed and the obtained critical velocities are further compared with wind tunnel results, followed by a brief examination of the post-flutter behavior. The results of this study provide a deeper understanding of the extent of which the applied models are able to replicate the physical processes for fluid-structure interaction phenomena in bridge aerodynamics and aeroelasticity.}, subject = {Bridge}, language = {en} } @phdthesis{Elrasoul, author = {Elrasoul, Riham}, title = {Designing Urban National Memory}, doi = {10.25643/bauhaus-universitaet.4048}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191212-40489}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {The study of memory, architecture, and urban space has been the interest ‎of ‎researchers ‎from the diverse fields around the world due to, the significance of dealing ‎with ‎memories ‎especially after the tragedy of the Second World War. Nations in Europe has chosen ‎not to ‎neglect ‎their past, moreover, overcoming it by strengthening the national identity. An ‎approach was clear in ‎the literature, art, further in the way of rebuilding their cities; that mainly ‎has reflected on the ‎value of urban spaces and their role in narrating the country's national ‎memory. Thanks to this ‎approach, which has supported the post-war European nations to invite ‎to an act of ‎ forgiveness rather than to forget. ‎ On the contrary, memory, in relation to architecture is a form of knowledge has been ‎neglected in Egypt, especially during the previous decades after the declaration of independence ‎from the colonial power, and since 1952 revolution. Recently, a rising debate about Egypt ‎national history and the need to renationalize the Egyptian historical consciousness has rapidly ‎grown up, due to the political transformation has occurred because of the 25th uprising, 2011, ‎which unveiled the power of public spaces in constituting the nation thoughts, especially Tahrir ‎square.‎ At the same time, this has unveiled the results of neglecting the past instead of overcoming it; unveiled a present carries the danger of conflict and repeating previous mistakes. Researchers, historians, politicians, governmental organization, have ‎worked in the purpose of revisiting the historical information, and have tried to document the ‎current transformation of the 25th uprising. There was a public demand for redesigning Tahrir square to reflect the ‎memory of the uprising as a symbol of the power of the public. However, after eight years, those ‎memories have faded as if the 25th uprising has never happened. ‎ Those circumstances are very relevant to the gap between urban design and the art of ‎memory-work, in the scientific field. Few studies in Egypt conducted the concept of memory in ‎relation to urban spaces, however, the matter requires more attention, to associate the need for renationalizing Egypt ‎memory, with viewing urban space as a mean of narrating the country's national memory and ‎reflecting the citizens' current thoughts, as a try of nearing the distances between ‎competing ‎narratives. Therefore, the research aims at developing a methodological framework that should ‎contribute to renationalizing memory through urban space. Further, benefiting from the German experience by investigating lessons to learn. That is based on the hypothesis that, although there is no fixed formula for all countries to renationalize the historical ‎consciousness of memory through urban spaces, lessons to be learned from Germany experience ‎could be a driving dimension when designing Egyptian urban spaces with a concept of memory ‎as an essential factor. To guide the validity of the study's hypothesis, a set of research questions are thus ‎formulated: Starting from why memory is an essential factor when designing urban spaces? ‎Regarding Egypt national memory, how it was constituted through history and how to read its ‎representation on urban spaces? Also, the study quests the means of nationalizing memory ‎through urban spaces? And What are the learned lessons from the German experience?‎ The study tries to answer those questions. Via an inductive ‎analytical ‎methodology ‎which ‎moves from the gap of knowledge and from a particular situation ‎in Egypt, to study the German ‎experience in renationalizing the concept of memory through urban spaces.‎ ‎ Within the scope of the study, exploring Egypt prevailing narratives and the inherited ‎concepts which influenced the national memory is essential. Moreover, the research develops ‎analytical political psychosocial model that could help reading memories in urban spaces, ‎memory's actors, and memory influences. To validate this model, case studies are analysed in ‎light of the concluded aspects. Consequently, the expected result is to infer broad general ‎learned ‎lessons for the Egyptian case. ‎ Research findings and conclusions answer the research questions, interpret literature ‎review, recommend some guide points to three target groups: first, practice field; to encourage ‎designers to value the national and collective memories when designing urban spaces. Second, to ‎ask policymakers to take the public participation into consideration, when taking decisions related to urban ‎development. Third, the thesis recommends future researches of urban memory that connect ‎theoretical information with the practice field. ‎ Finally, enhancing the memory-work in relation to the national narrative, conveying a meaningful message, when ‎designing urban spaces could encourage citizens to learn, to interact, and to dissolve boundaries ‎between the competing narratives in post-conflict societies.‎}, subject = {Erinnerung}, language = {en} } @article{Vollmer, author = {Vollmer, Lisa}, title = {Der Gentrifizierungsbegriff in wohnungspolitischen Protesten. Kommentar zu Neil Smiths „F{\"u}r eine Theorie der Gentrifizierung: ‚Zur{\"u}ck in die Stadt' als Bewegung des Kapitals, nicht der Menschen" (2019 [1979])}, series = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, volume = {2019}, journal = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, number = {Band 7, Heft 3}, doi = {10.36900/suburban.v7i3.493}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200122-40643}, pages = {113 -- 118}, abstract = {Seit 50 Jahren wird {\"u}ber Erkl{\"a}rungsans{\"a}tze f{\"u}r Gentrifizierung gestritten. Sehr viel l{\"a}nger schon wandert anlagesuchendes Kapital von einem Ort zum anderen und hinterl{\"a}sst dabei Investitionsruinen einerseits und Menschen, die durch Verdr{\"a}ngung ihr Zuhause verlieren, andererseits. Sehr viel k{\"u}rzer erst wird der Begriff Gentrifizierung hier und da von sozialen Bewegungen aufgegriffen, die sich mit letzterem Ph{\"a}nomen auseinandersetzen. In diesem Beitrag soll es nicht um die wissenschaftliche Debatte um Erkl{\"a}rungsans{\"a}tze f{\"u}r Gentrifizierung und auch nicht um die wissenschaftliche Relevanz des Begriffes gehen, sondern um seine Rolle und Funktion in sozialen Bewegungen.}, subject = {Soziale Bewegung}, language = {de} } @masterthesis{Hutfless, type = {Bachelor Thesis}, author = {Hutfless, Cornelius}, title = {Der Einfluss kommunaler Planung auf die Gestaltung von Neubauvorhaben am Beispiel der Weimarer Innenstadt}, doi = {10.25643/bauhaus-universitaet.4063}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200116-40639}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {186}, abstract = {Die massive Neubaut{\"a}tigkeit in Deutschland hat die Diskussion um Baukultur wieder verst{\"a}rkt angestoßen. Dabei wird der Einfluss der kommunalen Planung auf die Baugestaltung sowohl in der {\"O}ffentlichkeit als auch der Fachliteratur nur unzureichend thematisiert. Die vorliegende Arbeit von Cornelius Hutfless untersucht die Thematik am konkreten Beispiel der Weimarer Innenstadt. Hierzu wurden die neun formellen und informellen Instrumente analysiert und bewertet, mit denen die kommunale Planung in Weimar seit dem Jahr 1990 unmittelbaren Einfluss auf die Baugestaltung von Neubauprojekten genommen hat: Bebauungspl{\"a}ne, der Denkmalschutz, Sanierungssatzungen, Gestaltungssatzungen, Wettbewerbe, der Gestaltungsbeirat, die Bauberatung, Fachkonzepte und die {\"O}ffentlichkeitsbeteiligung. Methodisch kamen die Quellenanalyse, die Fallanalyse und die St{\"a}rken-Schw{\"a}chen-Analyse zum Einsatz. Die Recherchearbeit wurde durch sechs leitfadengest{\"u}tzte Expert*inneninterviews mit Schl{\"u}sselpersonen der Weimarer Baugestaltung erg{\"a}nzt. Dieser Forschungsansatz veranschaulicht den Einfluss kommunaler Planung auf die Gestaltung von Neubauvorhaben erstmalig am Fallbeispiel einer einzelnen deutschen Stadt, indem alle angewendeten Instrumente analysiert wurden. F{\"u}r Forscher*innen erm{\"o}glicht der Bezug auf ein konkretes Untersuchungsgebiet einen praxisnahen Zugang zum Thema Baugestaltung. Stadtplaner*innen veranschaulicht das Beispiel Weimar außerdem, wie umfangreich und restriktiv die kommunalen M{\"o}glichkeiten sind, auf die Baugestaltung einzuwirken. Vorbildlich im Sinne einer konsequenten Strategie der Baugestaltung sind in Weimar zum einen die strengen Festsetzungen in den Bebauungspl{\"a}nen des Untersuchungsgebietes, deren Umsetzung durch die Einsetzung von Baubeir{\"a}ten gesichert wird. Zum anderen ist der kommunalpolitische R{\"u}ckhalt ein grundlegender Erfolgsfaktor, der u. a. den Empfehlungen des Gestaltungsbeirates Nachdruck verleiht. Zudem verf{\"u}gt Weimar {\"u}ber eine umfangreiche Denkmalausweisung. Durch die umfassende Nutzung und Kombination der Instrumente, hat die kommunale Planung in Weimar erfolgreich einen Rahmen geschaffen, der baugestalterische Standards gew{\"a}hrleistet. Der Charakter der Weimarer Innenstadt konnte erhalten werden, obwohl moderne Neubauentwicklungen zugelassen wurden. Das Beispiel Weimar zeigt also, dass Baugestaltungsqualit{\"a}t wesentlich von dem klaren Anspruch einer Kommune nach Prozess- und Verfahrensqualit{\"a}t abh{\"a}ngt. Verbesserungsw{\"u}rdig ist in Weimar hingegen die {\"O}ffentlichkeitsbeteiligung bei Gestaltungsfragen. Schon vor der Schaffung planungsrechtlicher Tatsachen sollte zuk{\"u}nftig die {\"O}ffentlichkeit umfangreicher in Baugestaltungsprozesse eingebunden und daf{\"u}r die M{\"o}glichkeiten erg{\"a}nzender, informeller Verfahren ausgesch{\"o}pft werden. Nur dann ist eine restriktive Stadtgestaltungspolitik, im Sinne der Wahrung {\"o}ffentlicher Interessen ganzheitlich positiv zu bewerten. Ausgezeichnet mit dem Hochschulpreis der Bauhaus-Universit{\"a}t Weimar 2018}, subject = {Weimar}, language = {de} } @phdthesis{ZHANG2018, author = {ZHANG, CHAO}, title = {Crack Identification using Dynamic Extended Finite Element Method and Thermal Conductivity Engineering for Nanomaterials}, doi = {10.25643/bauhaus-universitaet.3847}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190119-38478}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2018}, abstract = {Identification of flaws in structures is a critical element in the management of maintenance and quality assurance processes in engineering. Nondestructive testing (NDT) techniques based on a wide range of physical principles have been developed and are used in common practice for structural health monitoring. However, basic NDT techniques are usually limited in their ability to provide the accurate information on locations, dimensions and shapes of flaws. One alternative to extract additional information from the results of NDT is to append it with a computational model that provides detailed analysis of the physical process involved and enables the accurate identification of the flaw parameters. The aim here is to develop the strategies to uniquely identify cracks in two-dimensional 2D) structures under dynamic loadings. A local NDT technique combined eXtended Finite Element Method (XFEM) with dynamic loading in order to identify the cracks in the structures quickly and accurately is developed in this dissertation. The Newmark-b time integration method with Rayleigh damping is used for the time integration. We apply Nelder-Mead (NM)and Quasi-Newton (QN) methods for identifying the crack tip in plate. The inverse problem is solved iteratively, in which XFEM is used for solving the forward problem in each iteration. For a timeharmonic excitation with a single frequency and a short-duration signal measured along part of the external boundary, the crack is detected through the solution of an inverse time-dependent problem. Compared to the static load, we show that the dynamic loads are more effective for crack detection problems. Moreover, we tested different dynamic loads and find that NM method works more efficient under the harmonic load than the pounding load while the QN method achieves almost the same results for both load types. A global strategy, Multilevel Coordinate Search (MCS) with XFEM (XFEM-MCS) methodology under the dynamic electric load, to detect multiple cracks in 2D piezoelectric plates is proposed in this dissertation. The Newmark-b method is employed for the time integration and in each iteration the forward problem is solved by XFEM for various cracks. The objective functional is minimized by using a global search algorithm MCS. The test problems show that the XFEM-MCS algorithm under the dynamic electric load can be effectively employed for multiple cracks detection in piezoelectric materials, and it proves to be robust in identifying defects in piezoelectric structures. Fiber-reinforced composites (FRCs) are extensively applied in practical engineering since they have high stiffness and strength. Experiments reveal a so-called interphase zone, i.e. the space between the outside interface of the fiber and the inside interface of the matrix. The interphase strength between the fiber and the matrix strongly affects the mechanical properties as a result of the large ratio of interface/volume. For the purpose of understanding the mechanical properties of FRCs with functionally graded interphase (FGI), a closed-form expression of the interface strength between a fiber and a matrix is obtained in this dissertation using a continuum modeling approach according to the ver derWaals (vdW) forces. Based on the interatomic potential, we develop a new modified nonlinear cohesive law, which is applied to study the interface delamination of FRCs with FGI under different loadings. The analytical solutions show that the delamination behavior strongly depends on the interphase thickness, the fiber radius, the Young's moduli and Poisson's ratios of the fiber and the matrix. Thermal conductivity is the property of a material to conduct heat. With the development and deep research of 2D materials, especially graphene and molybdenum disulfide (MoS2), the thermal conductivity of 2D materials attracts wide attentions. The thermal conductivity of graphene nanoribbons (GNRs) is found to appear a tendency of decreasing under tensile strain by classical molecular dynamics (MD) simulations. Hence, the strain effects of graphene can play a key role in the continuous tunability and applicability of its thermal conductivity property at nanoscale, and the dissipation of thermal conductivity is an obstacle for the applications of thermal management. Up to now, the thermal conductivity of graphene under shear deformation has not been investigated yet. From a practical point of view, good thermal managements of GNRs have significantly potential applications of future GNR-based thermal nanodevices, which can greatly improve performances of the nanosized devices due to heat dissipations. Meanwhile, graphene is a thin membrane structure, it is also important to understand the wrinkling behavior under shear deformation. MoS2 exists in the stable semiconducting 1H phase (1H-MoS2) while the metallic 1T phase (1T-MoS2) is unstable at ambient conditions. As it's well known that much attention has been focused on studying the nonlinear optical properties of the 1H-MoS2. In a very recent research, the 1T-type monolayer crystals of TMDCs, MX2 (MoS2, WS2 ...) was reported having an intrinsic in-plane negative Poisson's ratio. Luckily, nearly at the same time, unprecedented long-term (>3months) air stability of the 1T-MoS2 can be achieved by using the donor lithium hydride (LiH). Therefore, it's very important to study the thermal conductivity of 1T-MoS2. The thermal conductivity of graphene under shear strain is systematically studied in this dissertation by MD simulations. The results show that, in contrast to the dramatic decrease of thermal conductivity of graphene under uniaxial tensile, the thermal conductivity of graphene is not sensitive to the shear strain, and the thermal conductivity decreases only 12-16\%. The wrinkle evolves when the shear strain is around 5\%-10\%, but the thermal conductivity barely changes. The thermal conductivities of single-layer 1H-MoS2(1H-SLMoS2) and single-layer 1T-MoS2 (1T-SLMoS2) with different sample sizes, temperatures and strain rates have been studied systematically in this dissertation. We find that the thermal conductivities of 1H-SLMoS2 and 1T-SLMoS2 in both the armchair and the zigzag directions increase with the increasing of the sample length, while the increase of the width of the sample has minor effect on the thermal conductions of these two structures. The thermal conductivity of 1HSLMoS2 is smaller than that of 1T-SLMoS2 under size effect. Furthermore, the temperature effect results show that the thermal conductivities of both 1H-SLMoS2 and 1T-SLMoS2 decrease with the increasing of the temperature. The thermal conductivities of 1HSLMoS2 and 1T-SLMoS2 are nearly the same (difference <6\%) in both of the chiral orientations under corresponding temperatures, especially in the armchair direction (difference <2.8\%). Moreover, we find that the strain effects on the thermal conductivity of 1HSLMoS2 and 1T-SLMoS2 are different. More specifically, the thermal conductivity decreases with the increasing tensile strain rate for 1T-SLMoS2, while fluctuates with the growth of the strain for 1HSLMoS2. Finally, we find that the thermal conductivity of same sized 1H-SLMoS2 is similar with that of the strained 1H-SLMoS2 structure.}, subject = {crack}, language = {en} } @article{GuerlebeckLegatiukNilssonetal., author = {G{\"u}rlebeck, Klaus and Legatiuk, Dmitrii and Nilsson, Henrik and Smarsly, Kay}, title = {Conceptual modelling: Towards detecting modelling errors in engineering applications}, series = {Mathematical Methods in Applied Sciences}, journal = {Mathematical Methods in Applied Sciences}, doi = {10.1002/mma.5934}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200110-40614}, pages = {1 -- 10}, abstract = {Rapid advancements of modern technologies put high demands on mathematical modelling of engineering systems. Typically, systems are no longer "simple" objects, but rather coupled systems involving multiphysics phenomena, the modelling of which involves coupling of models that describe different phenomena. After constructing a mathematical model, it is essential to analyse the correctness of the coupled models and to detect modelling errors compromising the final modelling result. Broadly, there are two classes of modelling errors: (a) errors related to abstract modelling, eg, conceptual errors concerning the coherence of a model as a whole and (b) errors related to concrete modelling or instance modelling, eg, questions of approximation quality and implementation. Instance modelling errors, on the one hand, are relatively well understood. Abstract modelling errors, on the other, are not appropriately addressed by modern modelling methodologies. The aim of this paper is to initiate a discussion on abstract approaches and their usability for mathematical modelling of engineering systems with the goal of making it possible to catch conceptual modelling errors early and automatically by computer assistant tools. To that end, we argue that it is necessary to identify and employ suitable mathematical abstractions to capture an accurate conceptual description of the process of modelling engineering systems.}, subject = {Angewandte Mathematik}, language = {en} } @misc{Noeske, author = {Noeske, Jannik}, title = {Campus Bockenheim Revisited}, series = {sub\urban. Zeitschrift f{\"u}r Kritische Stadtforschung}, volume = {2019}, journal = {sub\urban. Zeitschrift f{\"u}r Kritische Stadtforschung}, number = {Band 9, Nr. 3}, publisher = {sub\urban e. V.}, address = {Berlin}, doi = {10.36900/suburban.v7i3.553}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45583}, pages = {144 -- 150}, abstract = {J{\"u}rgen Schardt legt eine umfassende Studie zur Architektur der Stadt- und Universit{\"a}tsbauten in Frankfurt am Main von 1906 bis 1956 vor. Besonderer Schwerpunkt liegt dabei auf den gesellschaftlichen und politischen Rahmenbedingungen der Architekturproduktion und einer kritischen Revision der etablierten Historiografie der Goethe-Universit{\"a}t. Der Autor widmet sich in drei Teilen jeweils dem Kaiserreich und der Gr{\"u}ndung der Hochschule im Jahr 1914, der Zeit der Weimarer Republik sowie der Jahre des Aufbaus nach dem Zweiten Weltkrieg. Schardt untersucht die entstandenen Geb{\"a}ude hinsichtlich schl{\"u}ssiger Kriterien b{\"u}rgerlicher Architektur, beleuchtet aber auch andere f{\"u}r die Hochschulgeschichte relevante Rahmenbedingungen. Die lesenswerte Studie verbindet dabei Aspekte der Sozial-, Wissenschafts- und Architekturgeschichte.}, subject = {Frankfurt am Main}, language = {de} } @phdthesis{Nogueira2018, author = {Nogueira, Priscilla}, title = {Brazilian battlers' housing. Histories of self-production - histories of social rise}, doi = {10.25643/bauhaus-universitaet.3895}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190506-38953}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {357}, year = {2018}, abstract = {Brazilian battlers' housing discusses the self-production of dwellings in the circumstances of the socioeconomic rise of the so-called Brazilian new middle class, occurred on the first decade of the years 2000. Battlers are a precarious working class of about 100 million people, who have used their recently increased purchase power to informally solve their private housing demands, planning, building and renovating their homes themselves, with limited technical knowledge and almost no access to formal technicians as for example architects. The result is a mode of housing production, which spreads over the territory in micro-local self-initiatives and informal social practices of construction and management. With the support of a controversial manpower, this practice presents all sorts of technical complications, but at the same time expedient ways of affordability and creative spatial solutions for ordinary constructive problems. Such initiatives have consolidated Brazilian informal settlements and peripheral subdivisions, attending a demand poorly responded by the government. This research recognises the benefits of the self-production, but questions the conditions under which it happens and asks if it really collaborates for a true social rise of those who are engaged in it. With an empirical and qualitative approach and taking dwelling construction processes leaded by battlers as main information sources, the academic work responds if and how the socioeconomic rise of the Brazilian battlers has exactly affected the self-production of dwellings. For that, battlers' self-production of dwellings is analysed and discussed in five main aspects: 1) acquisition of land and real state, 2) building overtime, 3) space and creative power, 4) technical complications and building materials and 5) manpower and know-how.}, subject = {Sozialwohnung}, language = {en} } @misc{Duering, type = {Master Thesis}, author = {D{\"u}ring, Serjoscha}, title = {Between plan and reality: tracing the development dynamics of the Lanzhou New Area - a computational approach}, doi = {10.25643/bauhaus-universitaet.4000}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191108-40002}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {78}, abstract = {Contemporary planning practice is often criticized as too design-driven with a lack of both quantitative evaluation criteria and employment of models that anticipate the self-organizational forces shaping cities, resulting in significant gaps between plan and reality. This study aims to introduce a modular toolbox prototype for spatial-analysis in data-poor environments. It is proposed to integrate designing, evaluation, and monitoring of urban development into one framework, thus supporting data-driven, on-demand urban design, and planning processes. The proposed framework's value will exemplarily be tested, focussing on the analysis and simulation of spatiotemporal growth trajectories taking the Lanzhou New Area as a case-study - a large scale new town project that struggles to attract residents and businesses. Conducted analysis suggests that more attention should be given to spatiotemporal development paths to ensure that cities work more efficiently throughout any stage of development. Finally, early hints on general design strategies to achieve this goal are discussed with the assistance of the proposed toolbox.}, subject = {Stadtplanung}, language = {en} } @phdthesis{Alalade, author = {Alalade, Muyiwa}, title = {An Enhanced Full Waveform Inversion Method for the Structural Analysis of Dams}, doi = {10.25643/bauhaus-universitaet.3956}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190813-39566}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Since the Industrial Revolution in the 1700s, the high emission of gaseous wastes into the atmosphere from the usage of fossil fuels has caused a general increase in temperatures globally. To combat the environmental imbalance, there is an increase in the demand for renewable energy sources. Dams play a major role in the generation of "green" energy. However, these structures require frequent and strict monitoring to ensure safe and efficient operation. To tackle the challenges faced in the application of convention dam monitoring techniques, this work proposes the inverse analysis of numerical models to identify damaged regions in the dam. Using a dynamic coupled hydro-mechanical Extended Finite Element Method (XFEM) model and a global optimization strategy, damage (crack) in the dam is identified. By employing seismic waves to probe the dam structure, a more detailed information on the distribution of heterogeneous materials and damaged regions are obtained by the application of the Full Waveform Inversion (FWI) method. The FWI is based on a local optimization strategy and thus it is highly dependent on the starting model. A variety of data acquisition setups are investigated, and an optimal setup is proposed. The effect of different starting models and noise in the measured data on the damage identification is considered. Combining the non-dependence of a starting model of the global optimization strategy based dynamic coupled hydro-mechanical XFEM method and the detailed output of the local optimization strategy based FWI method, an enhanced Full Waveform Inversion is proposed for the structural analysis of dams.}, subject = {Talsperre}, language = {en} } @inproceedings{DokhanchiArnoldVogeletal., author = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad}, title = {Acoustic Travel-Time Tomography: Optimal Positioning of Transceiver and Maximal Sound-Ray Coverage of the Room}, series = {Fortschritte der Akustik - DAGA 2019}, booktitle = {Fortschritte der Akustik - DAGA 2019}, doi = {10.25643/bauhaus-universitaet.3877}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190408-38778}, pages = {4}, abstract = {Acoustic travel-time tomography (ATOM) determines the distribution of the temperature in a propagation medium by measuring the travel-time of acoustic signals between transmitters and receivers. To employ ATOM for indoor climate measurements, the impulse responses have been measured in the climate chamber lab of the Bauhaus-University Weimar and compared with the theoretical results of its image source model (ISM). A challenging task is distinguishing the reflections of interest in the reflectogram when the sound rays have similar travel-times. This paper presents a numerical method to address this problem by finding optimal positions of transmitter and receiver, since they have a direct impact on the distribution of travel times. These optimal positions have the minimum number of simultaneous arrival time within a threshold level. Moreover, for the tomographic reconstruction, when some of the voxels remain empty of sound-rays, it leads to inaccurate determination of the air temperature within those voxels. Based on the presented numerical method, the number of empty tomographic voxels are minimized to ensure the best sound-ray coverage of the room. Subsequently, a spatial temperature distribution is estimated by simultaneous iterative reconstruction technique (SIRT). The experimental set-up in the climate chamber verifies the simulation results.}, subject = {Bauphysik}, language = {en} } @phdthesis{MizrakBilen, author = {Mizrak Bilen, Burcin}, title = {A Power-Centered Approach to the Capitalization of Climate Change in Property Sector and Strategic Limitation}, doi = {10.25643/BAUHAUS-UNIVERSITAET.3840}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190107-38406}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {256}, abstract = {The capitalization of 'certified' sustainable building sector will be investigated over the power theory of value approach of Jonathan Nitzan and Shimshon Bichler. The study will be initiated by questioning why the environment problems are one of the first items on the agenda and by sharing the ideas of scholars who approaches the subject skeptically, because the predominant literature underlying the necessity and prominence of the topic is already well-known and adapted by the majority. Over the theory developed by Nitzan and Bichler, the concepts of capitalization, strategic sabotage, power, legitimacy, and obedience will be discussed. The hypothesis of "the absentee owners of the construction sector, holding the whip hand and capitalizing the ecology, control the growth and the creativity of green building production and make it carbon-dependent, in order to increase their profit margin" will be questioned. To strengthen the arguments in the hypothesis, the factors, the institutional arrangements, value measurement methods, which affect directly the net present value, will be investigated both in corporation and in building scale in detail, because net present value/ capitalization is asserted as the most important criteria by Nitzan and Bichler to make the investment decisions in the capitalist economic system. To trace the implications of power and the strategic sabotage that power caused, as the empirical dimension of this dissertation, an interface exploring the correlational ties between the climate responsive architecture and the ever changing political, economical, and social contexts and building economics praxis by decades will be developed and the expert interviews will be conducted with the design teams and the appraisers.}, subject = {Klima{\"a}nderung}, language = {en} } @article{KavrakovLegatiukGuerlebecketal., author = {Kavrakov, Igor and Legatiuk, Dmitrii and G{\"u}rlebeck, Klaus and Morgenthal, Guido}, title = {A categorical perspective towards aerodynamic models for aeroelastic analyses of bridge decks}, series = {Royal Society Open Science}, journal = {Royal Society Open Science}, number = {Volume 6, Issue 3}, doi = {/10.1098/rsos.181848}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190314-38656}, pages = {20}, abstract = {Reliable modelling in structural engineering is crucial for the serviceability and safety of structures. A huge variety of aerodynamic models for aeroelastic analyses of bridges poses natural questions on their complexity and thus, quality. Moreover, a direct comparison of aerodynamic models is typically either not possible or senseless, as the models can be based on very different physical assumptions. Therefore, to address the question of principal comparability and complexity of models, a more abstract approach, accounting for the effect of basic physical assumptions, is necessary. This paper presents an application of a recently introduced category theory-based modelling approach to a diverse set of models from bridge aerodynamics. Initially, the categorical approach is extended to allow an adequate description of aerodynamic models. Complexity of the selected aerodynamic models is evaluated, based on which model comparability is established. Finally, the utility of the approach for model comparison and characterisation is demonstrated on an illustrative example from bridge aeroelasticity. The outcome of this study is intended to serve as an alternative framework for model comparison and impact future model assessment studies of mathematical models for engineering applications.}, subject = {Br{\"u}cke}, language = {en} } @phdthesis{Chen, author = {Chen, Na}, title = {A Balance between Ideals and Reality — Establishing and Evaluating a Resilient City Indicator System for Central Chinese Cities}, doi = {10.25643/bauhaus-universitaet.4030}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191121-40309}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {212}, abstract = {Recent years have seen a gradual shift in focus of international policies from a national and regional perspective to that of cities, a shift which is closely related to the rapid urbanization of developing countries. As revealed in the 2011 Revision of the World Urbanization Prospects published by the United Nations, 51\% of the global population (approximately 3.6 billion people) lives in cities. The report predicts that by 2050, the world's urban population will increase by 2.3 billion, making up 68\% of the population. The growth of urbanization in the next few decades is expected to primarily come from developing countries, one third of which will be in China and India. With rapid urbanization and the ongoing growth of mega cities, cities must become increasingly resilient and intelligent to cope with numerous challenges and crises like droughts and floods arising from extreme climate, destruction brought by severe natural disasters, and aggregated social contradictions resulting from economic crises. All cities face the urban development dynamics and uncertainties arising from these problems. Under such circumstances, cities are considered the critical path from crisis to prosperity, so scholars and organizations have proposed the construction of "resilient cities." On the one hand, this theory emphasizes cities' defenses and buffering capacity against disasters, crises and uncertainties, as well as recovery after destruction; on the other hand, it highlights the learning capacity of urban systems, identification of opportunities amid challenges, and maintenance of development vitality. Some scholars even believe that urban resilience is a powerful supplement to sustainable development. Hence, resilience assessment has become the latest and most important perspective for evaluating the development and crisis defense capacity of cities. Rather than a general abstract concept, urban resilience is a comprehensive measurement of a city's level of development. The dynamic development of problems is reflected through quantitative indicators and appraisal systems not only from the perspective of academic research, but also governmental policy, so as to scientifically guide development, and measure and compare cities' development levels. Although international scholars have proposed quantitative methods for urban resilience assessment, they are however insufficiently systematic and regionally adaptive for China's current urban development needs. On the basis of comparative study on European and North American resilient city theories, therefore, this paper puts forwards a theoretical framework for resilient city systems consistent with China's national conditions in light of economic development pressure, natural resource depletion, pollution, and other salient development crises in China. The key factors influencing urban resilience are taken into full consideration; expert appraisal is conducted based on the Delphi Method and the analytic hierarchy process (AHP) to design an extensible and updatable resilient city evaluation system which is sufficiently systematic, geographically adaptable, and sustainable for China's current urban development needs. Finally, Changsha is taken as the main case for empirical study on comprehensive evaluation of similar cities in Central China to improve the indicator system.}, subject = {Stadtplanung}, language = {en} } @phdthesis{Everts, author = {Everts, Lotte}, title = {"Hey! I'm an Angel!" Zum Verh{\"a}ltnis von Medium, Subjekt und Wirklichkeit in Eija-Liisa Ahtilas Videoinstallationen}, doi = {10.25643/bauhaus-universitaet.3947}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190730-39471}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {229}, abstract = {Die Dissertation „Hey! I'm an Angel! Zum Verh{\"a}ltnis von Medium, Subjekt und Wirklichkeit in Eija-Liisa Ahtilas Videoinstallationen" untersucht in der Hauptsache vier zentrale Videoinstallationen Ahtilas aus den Jahren 1995 bis 2014. Grundlegend ist die These, dass Ahtilas Arbeiten nicht, wie bisher angenommen, in den Kontext einer medien-, erkenntnis- und subjektkritischen Videokunst einzuordnen sind. Stattdessen werden sie als mediale Vehikel intersubjektiv gepr{\"a}gter Wirklichkeitserfahrungen f{\"u}r das Subjekt bereitgestellt: Entgegen dem aktuellen Forschungsstand arbeitet sich Ahtila nicht an der Kritik des Mediums Film/Video ab, das einen wirklichkeitsverf{\"a}lschenden oder -ersetzenden Einfluss auf das manipulierte Subjekt nimmt. Vielmehr nutzt die K{\"u}nstlerin das Potenzial des Mediums Film/Video aus, um einem relativ stabilen Subjekt die Wirklichkeitserfahrungen Anderer zu {\"o}ffnen und auf diese Weise seinen Erfahrungshorizont zu erweitern. Der systematische Schwerpunkt der Arbeit liegt erstens darauf, ein sich durch Ahtilas bisheriges Schaffen ziehendes ‚Ziel' der Integration der Betrachterin in eine intersubjektive Erfahrungssph{\"a}re nachvollziehbar zu machen. Hierf{\"u}r wird insbesondere eine Perspektive auf die fr{\"u}hen Arbeiten entwickelt, in der die Br{\"u}che in Ahtila Arbeiten integrative statt distanzierende Wirkung haben. Zweitens wird in eingehenden Analysen der Wandel verst{\"a}ndlich, der sich zwischen Ahtilas fr{\"u}her Schaffensphase (1995 - 2002) und der aktuellen Schaffensphase (seit 2010) hinsichtlich der Art und Weise vollzieht, wie diese Integration gelingt. Es zeigt sich, dass der Einstieg in die intersubjektiv gepr{\"a}gten Erfahrungssph{\"a}ren in der fr{\"u}hen Phase {\"a}sthetisch konstituiert ist. Mit der aktuellen Schaffensphase werden hingegen allt{\"a}gliche Formen der Empathie und Mimesis zentral, sowie deren leibliche Konsequenzen f{\"u}r die Betrachterin. Drittens wird eine zunehmende pragmatische Tendenz darin deutlich, die Integration der Betrachterin in die Erfahrungen Anderer zu erm{\"o}glichen. Dies wird vor dem Hintergrund eines allgemeinen pragmatischen Zuges aktueller zeitgeistiger Bewegungen erl{\"a}utert. Viertens wird gezeigt, dass Ahtilas Arbeiten auf der Annahme einer Kontinuit{\"a}t in gewisser Hinsicht von der außerfilmischen Wirklichkeit in die filmische Fiktion hinein basieren, sowie auf dem Verst{\"a}ndnis filmischer Fiktionen als virtuelle Weltfassungen. Ahtila fragt auf der Grundlage dieses Verst{\"a}ndnisses filmischer Fiktion nicht nach der Wahrheit dieser Fiktion als These {\"u}ber die Wirklichkeit, wie es dem Forschungskanon {\"u}ber die K{\"u}nstlerin zu entnehmen ist. Sondern nach der Wirksamkeit der filmischen Fiktion f{\"u}r die Wirklichkeit.}, subject = {Videokunst}, language = {de} }