@phdthesis{Reshetnikova, author = {Reshetnikova, Tatiana}, title = {Transformation of the Environment: Influence of "Urban Reagents." German and Russian Case Studies}, doi = {10.25643/bauhaus-universitaet.4351}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210128-43517}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {256 (thesis) + 23 (Folder) + 83 (CD)}, abstract = {An urban regeneration manifests itself through urban objects operating as change agents. The en-tailed diverse effects on the surroundings demonstrate experimental origin - an experiment as a preplanned but unpredictable method. An understanding of influences and features of urban ob-jects requires scrutiny due to a high potential of the elements to force an alteration and reactions. This dissertation explores the transformation of the milieu and mechanisms of this transformation.}, subject = {Stadtentwicklung}, language = {en} } @article{LashkarAraKalantariSheikhKhozanietal., author = {Lashkar-Ara, Babak and Kalantari, Niloofar and Sheikh Khozani, Zohreh and Mosavi, Amir}, title = {Assessing Machine Learning versus a Mathematical Model to Estimate the Transverse Shear Stress Distribution in a Rectangular Channel}, series = {Mathematics}, volume = {2021}, journal = {Mathematics}, number = {Volume 9, Issue 6, Article 596}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/math9060596}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210504-44197}, pages = {15}, abstract = {One of the most important subjects of hydraulic engineering is the reliable estimation of the transverse distribution in the rectangular channel of bed and wall shear stresses. This study makes use of the Tsallis entropy, genetic programming (GP) and adaptive neuro-fuzzy inference system (ANFIS) methods to assess the shear stress distribution (SSD) in the rectangular channel. To evaluate the results of the Tsallis entropy, GP and ANFIS models, laboratory observations were used in which shear stress was measured using an optimized Preston tube. This is then used to measure the SSD in various aspect ratios in the rectangular channel. To investigate the shear stress percentage, 10 data series with a total of 112 different data for were used. The results of the sensitivity analysis show that the most influential parameter for the SSD in smooth rectangular channel is the dimensionless parameter B/H, Where the transverse coordinate is B, and the flow depth is H. With the parameters (b/B), (B/H) for the bed and (z/H), (B/H) for the wall as inputs, the modeling of the GP was better than the other one. Based on the analysis, it can be concluded that the use of GP and ANFIS algorithms is more effective in estimating shear stress in smooth rectangular channels than the Tsallis entropy-based equations.}, subject = {Maschinelles Lernen}, language = {en} } @phdthesis{Sproete, author = {Spr{\"o}te, Daniel}, title = {Immobilienportfoliomanagement {\"o}ffentlicher musealer Schl{\"o}sserverwaltungen - Daten zur Investitionssteuerung}, doi = {10.25643/bauhaus-universitaet.4426}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210510-44260}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {220}, abstract = {Die Arbeit leistet einen wissenschaftlichen Beitrag zur Erforschung der Einsatzm{\"o}glichkeiten eines Immobilienportfoliomanagements f{\"u}r {\"o}ffentliche museale Schl{\"o}sserverwaltungen in Deutschland. Insbesondere wird ein f{\"u}r deren Organisation spezifisches Modell zur Investitionssteuerung herausgearbeitet und dessen Anwendbarkeit in der Praxis mit Experten diskutiert.}, subject = {Unbewegliche Sache}, language = {de} } @misc{Schuster, author = {Schuster, Lara}, title = {Die Haltungen des Architekten Luigi Snozzi. Untersucht am Beispiel des Projektes Monte Carasso}, volume = {2021}, publisher = {Lucia Verlag}, address = {Weimar}, doi = {10.25643/bauhaus-universitaet.4438}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210603-44386}, pages = {17}, abstract = {Welche Haltung spricht aus den Werken von Architekt*innen? Lassen sich Werte und Handlungsanweisungen von Mauern und Pl{\"a}nen ablesen? Luigi Snozzis Entw{\"u}rfe f{\"u}r Monte Carasso werden in dieser Arbeit exemplarisch darauf untersucht. Sie zeugen von der Verantwortung, die jede*r Architekt*in f{\"u}r das Umfeld hat, in dem sie oder er baut.}, subject = {Architektur}, language = {de} } @article{HarirchianKumariJadhavetal., author = {Harirchian, Ehsan and Kumari, Vandana and Jadhav, Kirti and Raj Das, Rohan and Rasulzade, Shahla and Lahmer, Tom}, title = {A Machine Learning Framework for Assessing Seismic Hazard Safety of Reinforced Concrete Buildings}, series = {Applied Sciences}, volume = {2020}, journal = {Applied Sciences}, number = {Volume 10, issue 20, article 7153}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app10207153}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20201022-42744}, pages = {18}, abstract = {Although averting a seismic disturbance and its physical, social, and economic disruption is practically impossible, using the advancements in computational science and numerical modeling shall equip humanity to predict its severity, understand the outcomes, and equip for post-disaster management. Many buildings exist amidst the developed metropolitan areas, which are senile and still in service. These buildings were also designed before establishing national seismic codes or without the introduction of construction regulations. In that case, risk reduction is significant for developing alternatives and designing suitable models to enhance the existing structure's performance. Such models will be able to classify risks and casualties related to possible earthquakes through emergency preparation. Thus, it is crucial to recognize structures that are susceptible to earthquake vibrations and need to be prioritized for retrofitting. However, each building's behavior under seismic actions cannot be studied through performing structural analysis, as it might be unrealistic because of the rigorous computations, long period, and substantial expenditure. Therefore, it calls for a simple, reliable, and accurate process known as Rapid Visual Screening (RVS), which serves as a primary screening platform, including an optimum number of seismic parameters and predetermined performance damage conditions for structures. In this study, the damage classification technique was studied, and the efficacy of the Machine Learning (ML) method in damage prediction via a Support Vector Machine (SVM) model was explored. The ML model is trained and tested separately on damage data from four different earthquakes, namely Ecuador, Haiti, Nepal, and South Korea. Each dataset consists of varying numbers of input data and eight performance modifiers. Based on the study and the results, the ML model using SVM classifies the given input data into the belonging classes and accomplishes the performance on hazard safety evaluation of buildings.}, subject = {Erdbeben}, language = {en} } @phdthesis{Kavrakov, author = {Kavrakov, Igor}, title = {Synergistic Framework for Analysis and Model Assessment in Bridge Aerodynamics and Aeroelasticity}, publisher = {Bauhaus-Universit{\"a}tsverlag}, address = {Weimar}, isbn = {978-3-95773-284-2}, doi = {10.25643/bauhaus-universitaet.4109}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200316-41099}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {314}, abstract = {Wind-induced vibrations often represent a major design criterion for long-span bridges. This work deals with the assessment and development of models for aerodynamic and aeroelastic analyses of long-span bridges. Computational Fluid Dynamics (CFD) and semi-analytical aerodynamic models are employed to compute the bridge response due to both turbulent and laminar free-stream. For the assessment of these models, a comparative methodology is developed that consists of two steps, a qualitative and a quantitative one. The first, qualitative, step involves an extension of an existing approach based on Category Theory and its application to the field of bridge aerodynamics. Initially, the approach is extended to consider model comparability and completeness. Then, the complexity of the CFD and twelve semi-analytical models are evaluated based on their mathematical constructions, yielding a diagrammatic representation of model quality. In the second, quantitative, step of the comparative methodology, the discrepancy of a system response quantity for time-dependent aerodynamic models is quantified using comparison metrics for time-histories. Nine metrics are established on a uniform basis to quantify the discrepancies in local and global signal features that are of interest in bridge aerodynamics. These signal features involve quantities such as phase, time-varying frequency and magnitude content, probability density, non-stationarity, and nonlinearity. The two-dimensional (2D) Vortex Particle Method is used for the discretization of the Navier-Stokes equations including a Pseudo-three dimensional (Pseudo-3D) extension within an existing CFD solver. The Pseudo-3D Vortex Method considers the 3D structural behavior for aeroelastic analyses by positioning 2D fluid strips along a line-like structure. A novel turbulent Pseudo-3D Vortex Method is developed by combining the laminar Pseudo-3D VPM and a previously developed 2D method for the generation of free-stream turbulence. Using analytical derivations, it is shown that the fluid velocity correlation is maintained between the CFD strips. Furthermore, a new method is presented for the determination of the complex aerodynamic admittance under deterministic sinusoidal gusts using the Vortex Particle Method. The sinusoidal gusts are simulated by modeling the wakes of flapping airfoils in the CFD domain with inflow vortex particles. Positioning a section downstream yields sinusoidal forces that are used for determining all six components of the complex aerodynamic admittance. A closed-form analytical relation is derived, based on an existing analytical model. With this relation, the inflow particles' strength can be related with the target gust amplitudes a priori. The developed methodologies are combined in a synergistic framework, which is applied to both fundamental examples and practical case studies. Where possible, the results are verified and validated. The outcome of this work is intended to shed some light on the complex wind-bridge interaction and suggest appropriate modeling strategies for an enhanced design.}, subject = {Br{\"u}cke}, language = {en} } @misc{Rauch2008, type = {Master Thesis}, author = {Rauch, Kristin}, title = {Simulation - Termincontrolling beim Bau einer Br{\"u}ckenkappe}, doi = {10.25643/bauhaus-universitaet.1362}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20081111-14414}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2008}, abstract = {Die Simulation ist vor allem in der Forschung und Wissenschaft ein bekanntes Ver-fahren zur Untersuchung von dynamischen Prozessen. Fachgebiete wie u.a. die Medizin und Biologie, das Verkehrswesen, die Automobilindustrie, die Meteorologie und die Fertigungstechnik gewinnen neue Erkenntnisse aus dem Einsatz derartiger Analyseverfahren. Gr{\"u}nde f{\"u}r die Anwendung von Computersimulationen erstrecken sich von finanziellen und zeitlichen Aspekten {\"u}ber eine Risikoverringerung bis hin zu einer vereinfachten Vorgehensweise. Nicht in allen Bereichen aber werden die viel-seitigen Vorteile von Simulationsmethoden genutzt. In der Baubranche wird Simulation derzeit nur ansatzweise eingesetzt. Doch vor al-lem Baustellen bieten durch den zunehmenden Kosten- und Termindruck sowie viel-seitige andere Einfl{\"u}sse eine gute Basis f{\"u}r die Anwendung von Simulationsmetho-den. Der Bauablauf kann dadurch besser kontrolliert und gesteuert werden. In der Planungsphase von Bauprojekten wird Simulation bereits in Grundz{\"u}gen f{\"u}r die Op-timierung von Bauablauf- und Logistikprozessen genutzt. Allerdings ist besonders die Ausf{\"u}hrungsphase durch St{\"o}rungen und {\"A}nderungen gepr{\"a}gt, sodass hier Simu-lationsmethoden noch effektiver eingesetzt werden k{\"o}nnen. Im Rahmen dieser Arbeit sollen die Einsatzm{\"o}glichkeiten von Simulationsmethoden f{\"u}r die Optimierung des Termincontrollings untersucht werden. Durch das Aufzeigen verschiedener Methoden sowie einem Vergleich {\"u}ber ihre Vor- und Nachteile wird herausgefiltert, welches Simulationswerkzeug am effektivsten im Termincontrolling eingesetzt werden kann. Ein weiteres Ziel dieser Arbeit ist die Modellierung eines Beispielprozesses anhand eines ausgew{\"a}hlten Simulationsverfahrens. Die Herstellung einer Br{\"u}ckenkappe wird in diesem Zusammenhang umfangreich dargestellt und analysiert. Eventuelle Zwangspunkte bei der Umsetzung und verschiedene L{\"o}sungsm{\"o}glichkeiten werden aufgezeigt.}, subject = {Simulation}, language = {de} } @article{HarirchianJadhavMohammadetal., author = {Harirchian, Ehsan and Jadhav, Kirti and Mohammad, Kifaytullah and Aghakouchaki Hosseini, Seyed Ehsan and Lahmer, Tom}, title = {A Comparative Study of MCDM Methods Integrated with Rapid Visual Seismic Vulnerability Assessment of Existing RC Structures}, series = {Applied Sciences}, volume = {2020}, journal = {Applied Sciences}, number = {Volume 10, issue 18, article 6411}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app10186411}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200918-42360}, pages = {24}, abstract = {Recently, the demand for residence and usage of urban infrastructure has been increased, thereby resulting in the elevation of risk levels of human lives over natural calamities. The occupancy demand has rapidly increased the construction rate, whereas the inadequate design of structures prone to more vulnerability. Buildings constructed before the development of seismic codes have an additional susceptibility to earthquake vibrations. The structural collapse causes an economic loss as well as setbacks for human lives. An application of different theoretical methods to analyze the structural behavior is expensive and time-consuming. Therefore, introducing a rapid vulnerability assessment method to check structural performances is necessary for future developments. The process, as mentioned earlier, is known as Rapid Visual Screening (RVS). This technique has been generated to identify, inventory, and screen structures that are potentially hazardous. Sometimes, poor construction quality does not provide some of the required parameters; in this case, the RVS process turns into a tedious scenario. Hence, to tackle such a situation, multiple-criteria decision-making (MCDM) methods for the seismic vulnerability assessment opens a new gateway. The different parameters required by RVS can be taken in MCDM. MCDM evaluates multiple conflicting criteria in decision making in several fields. This paper has aimed to bridge the gap between RVS and MCDM. Furthermore, to define the correlation between these techniques, implementation of the methodologies from Indian, Turkish, and Federal Emergency Management Agency (FEMA) codes has been done. The effects of seismic vulnerability of structures have been observed and compared.}, subject = {Erdbebensicherheit}, language = {en} } @phdthesis{Oucif, author = {Oucif, Chahmi}, title = {Analytical Modeling of Self-Healing and Super Healing in Cementitious Materials}, doi = {10.25643/bauhaus-universitaet.4229}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200831-42296}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {208}, abstract = {Self-healing materials have recently become more popular due to their capability to autonomously and autogenously repair the damage in cementitious materials. The concept of self-healing gives the damaged material the ability to recover its stiffness. This gives a difference in comparing with a material that is not subjected to healing. Once this material is damaged, it cannot sustain loading due to the stiffness degradation. Numerical modeling of self-healing materials is still in its infancy. Multiple experimental researches were conducted in literature to describe the behavior of self-healing of cementitious materials. However, few numerical investigations were undertaken. The thesis presents an analytical framework of self-healing and super healing materials based on continuum damage-healing mechanics. Through this framework, we aim to describe the recovery and strengthening of material stiffness and strength. A simple damage healing law is proposed and applied on concrete material. The proposed damage-healing law is based on a new time-dependent healing variable. The damage-healing model is applied on isotropic concrete material at the macroscale under tensile load. Both autonomous and autogenous self-healing mechanisms are simulated under different loading conditions. These two mechanisms are denoted in the present work by coupled and uncoupled self-healing mechanisms, respectively. We assume in the coupled self-healing that the healing occurs at the same time with damage evolution, while we assume in the uncoupled self-healing that the healing occurs when the material is deformed and subjected to a rest period (damage is constant). In order to describe both coupled and uncoupled healing mechanisms, a one-dimensional element is subjected to different types of loading history. In the same context, derivation of nonlinear self-healing theory is given, and comparison of linear and nonlinear damage-healing models is carried out using both coupled and uncoupled self-healing mechanisms. The nonlinear healing theory includes generalized nonlinear and quadratic healing models. The healing efficiency is studied by varying the values of the healing rest period and the parameter describing the material characteristics. In addition, theoretical formulation of different self-healing variables is presented for both isotropic and anisotropic maerials. The healing variables are defined based on the recovery in elastic modulus, shear modulus, Poisson's ratio, and bulk modulus. The evolution of the healing variable calculated based on cross-section as function of the healing variable calculated based on elastic stiffness is presented in both hypotheses of elastic strain equivalence and elastic energy equivalence. The components of the fourth-rank healing tensor are also obtained in the case of isotropic elasticity, plane stress and plane strain. Recent research revealed that self-healing presents a crucial solution also for the strengthening of the materials. This new concept has been termed ``Super Healing``. Once the stiffness of the material is recovered, further healing can result as a strengthening material. In the present thesis, new theory of super healing materials is defined in isotropic and anisotropic cases using sound mathematical and mechanical principles which are applied in linear and nonlinear super healing theories. Additionally, the link of the proposed theory with the theory of undamageable materials is outlined. In order to describe the super healing efficiency in linear and nonlinear theories, the ratio of effective stress to nominal stress is calculated as function of the super healing variable. In addition, the hypotheses of elastic strain and elastic energy equivalence are applied. In the same context, new super healing matrix in plane strain is proposed based on continuum damage-healing mechanics. In the present work, we also focus on numerical modeling of impact behavior of reinforced concrete slabs using the commercial finite element package Abaqus/Explicit. Plain and reinforced concrete slabs of unconfined compressive strength 41 MPa are simulated under impact of ogive-nosed hard projectile. The constitutive material modeling of the concrete and steel reinforcement bars is performed using the Johnson-Holmquist-2 damage and the Johnson-Cook plasticity material models, respectively. Damage diameters and residual velocities obtained by the numerical model are compared with the experimental results and effect of steel reinforcement and projectile diameter is studied.}, subject = {Schaden}, language = {en} } @article{HarirchianLahmer, author = {Harirchian, Ehsan and Lahmer, Tom}, title = {Improved Rapid Visual Earthquake Hazard Safety Evaluation of Existing Buildings Using a Type-2 Fuzzy Logic Model}, series = {Applied Sciences}, volume = {2020}, journal = {Applied Sciences}, number = {Volume 10, Issue 3, 2375}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app10072375}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200331-41161}, pages = {14}, abstract = {Rapid Visual Screening (RVS) is a procedure that estimates structural scores for buildings and prioritizes their retrofit and upgrade requirements. Despite the speed and simplicity of RVS, many of the collected parameters are non-commensurable and include subjectivity due to visual observations. This might cause uncertainties in the evaluation, which emphasizes the use of a fuzzy-based method. This study aims to propose a novel RVS methodology based on the interval type-2 fuzzy logic system (IT2FLS) to set the priority of vulnerable building to undergo detailed assessment while covering uncertainties and minimizing their effects during evaluation. The proposed method estimates the vulnerability of a building, in terms of Damage Index, considering the number of stories, age of building, plan irregularity, vertical irregularity, building quality, and peak ground velocity, as inputs with a single output variable. Applicability of the proposed method has been investigated using a post-earthquake damage database of reinforced concrete buildings from the Bing{\"o}l and D{\"u}zce earthquakes in Turkey.}, subject = {Fuzzy-Logik}, language = {en} }