@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}
}
@unpublished{KavrakovArgentiniOmarinietal.,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}
}
@misc{Bendalla,
  type      = {Master Thesis},
  author    = {Bendalla, Abdulmagid Sedig Khalafallah},
  title     = {Nonlinear Numerical Modelling of Cable Elements in Bridges for Dynamic Analysis},
  doi       = {10.25643/bauhaus-universitaet.3994},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191007-39940},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {107},
  abstract  = {Identifying cable force with vibration-based methods has become widely used in engineering practice due to simplicity of application. The string taut theory provides a simple definition of the relationship between natural frequencies and the tension force of a cable. However, this theory assumes a perfectly flexible non-sagging cable pinned at its ends. These assumptions do not reflect all cases, especially when the cable is short, under low tension forces or the supports are partially flexible. Extradosed bridges, which are distinguished from cable-stayed bridges by their low pylon height, have shorter cables. Therefore the application of the conventional string taut theory to identify cable forces on extradosed bridge cables might be inadequate to identify cable forces. In this work, numerical modelling of an extradosed bridge cable saddled on a circular deviator at pylon is conducted. The model is validated with the catenary analytical solution and its static and dynamic behaviours are studied. The effect of a saddle support is found to positively affect the cable stiffness by geometric means; longer saddle radius increases the cable stiffness by suppressing the deformations near the saddle. Further, accounting the effects of bending stiffness in the numerical model by using beam elements show considerable deviation from models with truss elements (i.e. zero bending stiffness). This deviation is manifested when comparing the static and dynamic properties. This motivates a more thorough study of bending stiffness effects on short cables. Bending stiffness effects are studied using two rods connected with several springs along their length. Under bending moments, the springs resist the rods' relative axial displacement by the springs' transverse component. This concept is used to identify bending stiffness values by utilizing the parallel axis theorem to quantify ratios of the second moment of area. These ratios are calculated based on the setup of the springs (e.g. number of springs per unit length, transverse stiffness, etc...). The numerical model based on this concept agrees well with the theoretical values computed using upper and lower bounds of the parallel axis theorem. The proposed concept of quantifying ratios of the second moment of area using springs as connection between cable rods is applied on an actual extradosed bridge geometry. The model is examined by comparison to the previously validated global numerical model. The two models showed good correlation under various changing parameters. This allowed further study of the effects of stick/slip behaviour between cable rods on an actual bridge geometry.},
  subject      = {Kabel},
  language  = {en}
}
@misc{Zafar,
  type      = {Master Thesis},
  author    = {Zafar, Usman},
  title     = {Probabilistic Reliability Analysis of Wind Turbines},
  doi       = {10.25643/bauhaus-universitaet.3977},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20240507-39773},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  abstract  = {Renewable energy use is on the rise and these alternative resources of energy can help combat with the climate change. Around 80\% of the world's electricity comes from coal and petroleum however, the renewables are the fastest growing source of energy in the world. Solar, wind, hydro, geothermal and biogas are the most common forms of renewable energy. Among them, wind energy is emerging as a reliable and large-scaled source of power production. The recent research and confidence in the performance has led to the construction of more and bigger wind turbines around the world. As wind turbines are getting bigger, a concern regarding their safety is also in discussion. Wind turbines are expensive machinery to construct and the enormous capital investment is one of the main reasons, why many countries are unable to adopt to the wind energy. Generally, a reliable wind turbine will result in better performance and assist in minimizing the cost of operation. If a wind turbine fails, it's a loss of investment and can be harmful for the surrounding habitat. This thesis aims towards estimating the reliability of an offshore wind turbine. A model of Jacket type offshore wind turbine is prepared by using finite element software package ABAQUS and is compared with the structural failure criteria of the wind turbine tower. UQLab, which is a general uncertainty quantification framework developed at ETH Z{\"u}rich, is used for the reliability analysis. Several probabilistic methods are included in the framework of UQLab, which include Monte Carlo, First Order Reliability Analysis and Adaptive Kriging Monte Carlo simulation. This reliability study is performed only for the structural failure of the wind turbine but it can be extended to many other forms of failures e.g. reliability for power production, or reliability for different component failures etc. It's a useful tool that can be utilized to estimate the reliability of future wind turbines, that could result in more safer and better performance of wind turbines.},
  subject      = {Windturbine},
  language  = {en}
}
@unpublished{RadmardRahmaniKoenke,
  author    = {Radmard Rahmani, Hamid and K{\"o}nke, Carsten},
  title     = {Passive Control of Tall Buildings Using Distributed Multiple Tuned Mass Dampers},
  doi       = {10.25643/bauhaus-universitaet.3859},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190311-38597},
  pages     = {43},
  abstract  = {The vibration control of the tall building during earthquake excitations is a challenging task due to their complex seismic behavior. This paper investigates the optimum placement and properties of the Tuned Mass Dampers (TMDs) in tall buildings, which are employed to control the vibrations during earthquakes. An algorithm was developed to spend a limited mass either in a single TMD or in multiple TMDs and distribute them optimally over the height of the building. The Non-dominated Sorting Genetic Algorithm (NSGA - II) method was improved by adding multi-variant genetic operators and utilized to simultaneously study the optimum design parameters of the TMDs and the optimum placement. The results showed that under earthquake excitations with noticeable amplitude in higher modes, distributing TMDs over the height of the building is more effective in mitigating the vibrations compared to the use of a single TMD system. From the optimization, it was observed that the locations of the TMDs were related to the stories corresponding to the maximum modal displacements in the lower modes and the stories corresponding to the maximum modal displacements in the modes which were highly activated by the earthquake excitations. It was also noted that the frequency content of the earthquake has significant influence on the optimum location of the TMDs.},
  subject      = {Schwingungsd{\"a}mpfer},
  language  = {en}
}