@article{ArtusAlabassyKoch, author = {Artus, Mathias and Alabassy, Mohamed Said Helmy and Koch, Christian}, title = {A BIM Based Framework for Damage Segmentation, Modeling, and Visualization Using IFC}, series = {Applied Sciences}, volume = {2022}, journal = {Applied Sciences}, number = {volume 12, issue 6, article 2772}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app12062772}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220314-46059}, pages = {1 -- 24}, abstract = {Paper-based data acquisition and manual transfer between incompatible software or data formats during inspections of bridges, as done currently, are time-consuming, error-prone, cumbersome, and lead to information loss. A fully digitized workflow using open data formats would reduce data loss, efforts, and the costs of future inspections. On the one hand, existing studies proposed methods to automatize data acquisition and visualization for inspections. These studies lack an open standard to make the gathered data available for other processes. On the other hand, several studies discuss data structures for exchanging damage information among different stakeholders. However, those studies do not cover the process of automatic data acquisition and transfer. This study focuses on a framework that incorporates automatic damage data acquisition, transfer, and a damage information model for data exchange. This enables inspectors to use damage data for subsequent analyses and simulations. The proposed framework shows the potentials for a comprehensive damage information model and related (semi-)automatic data acquisition and processing.}, subject = {Building Information Modeling}, language = {en} } @article{HarirchianIsik, author = {Harirchian, Ehsan and Isik, Ercan}, title = {A Comparative Probabilistic Seismic Hazard Analysis for Eastern Turkey (Bitlis) Based on Updated Hazard Map and Its Effect on Regular RC Structures}, series = {Buildings}, volume = {2022}, journal = {Buildings}, number = {Volume 12, issue 10, article 1573}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/buildings12101573}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221028-47283}, pages = {1 -- 19}, abstract = {Determining the earthquake hazard of any settlement is one of the primary studies for reducing earthquake damage. Therefore, earthquake hazard maps used for this purpose must be renewed over time. Turkey Earthquake Hazard Map has been used instead of Turkey Earthquake Zones Map since 2019. A probabilistic seismic hazard was performed by using these last two maps and different attenuation relationships for Bitlis Province (Eastern Turkey) were located in the Lake Van Basin, which has a high seismic risk. The earthquake parameters were determined by considering all districts and neighborhoods in the province. Probabilistic seismic hazard analyses were carried out for these settlements using seismic sources and four different attenuation relationships. The obtained values are compared with the design spectrum stated in the last two earthquake maps. Significant differences exist between the design spectrum obtained according to the different exceedance probabilities. In this study, adaptive pushover analyses of sample-reinforced concrete buildings were performed using the design ground motion level. Structural analyses were carried out using three different design spectra, as given in the last two seismic design codes and the mean spectrum obtained from attenuation relationships. Different design spectra significantly change the target displacements predicted for the performance levels of the buildings.}, subject = {Erbeben}, language = {en} } @article{AlaladeReichertKoehnetal., author = {Alalade, Muyiwa and Reichert, Ina and K{\"o}hn, Daniel and Wuttke, Frank and Lahmer, Tom}, title = {A Cyclic Multi-Stage Implementation of the Full-Waveform Inversion for the Identification of Anomalies in Dams}, series = {Infrastructures}, volume = {2022}, journal = {Infrastructures}, number = {Volume 7, issue 12, article 161}, editor = {Qu, Chunxu and Gao, Chunxu and Zhang, Rui and Jia, Ziguang and Li, Jiaxiang}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/infrastructures7120161}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221201-48396}, pages = {19}, abstract = {For the safe and efficient operation of dams, frequent monitoring and maintenance are required. These are usually expensive, time consuming, and cumbersome. To alleviate these issues, we propose applying a wave-based scheme for the location and quantification of damages in dams. To obtain high-resolution "interpretable" images of the damaged regions, we drew inspiration from non-linear full-multigrid methods for inverse problems and applied a new cyclic multi-stage full-waveform inversion (FWI) scheme. Our approach is less susceptible to the stability issues faced by the standard FWI scheme when dealing with ill-posed problems. In this paper, we first selected an optimal acquisition setup and then applied synthetic data to demonstrate the capability of our approach in identifying a series of anomalies in dams by a mixture of reflection and transmission tomography. The results had sufficient robustness, showing the prospects of application in the field of non-destructive testing of dams.}, subject = {Damm}, language = {en} } @phdthesis{Vogler, author = {Vogler, Verena}, title = {A framework for artificial coral reef design: Integrating computational modelling and high precision monitoring strategies for artificial coral reefs - an Ecosystem-aware design approach in times of climate change}, isbn = {978-3-00-074495-2}, doi = {10.25643/bauhaus-universitaet.4611}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220322-46115}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {243}, abstract = {Tropical coral reefs, one of the world's oldest ecosystems which support some of the highest levels of biodiversity on the planet, are currently facing an unprecedented ecological crisis during this massive human-activity-induced period of extinction. Hence, tropical reefs symbolically stand for the destructive effects of human activities on nature [4], [5]. Artificial reefs are excellent examples of how architectural design can be combined with ecosystem regeneration [6], [7], [8]. However, to work at the interface between the artificial and the complex and temporal nature of natural systems presents a challenge, i.a. in respect to the B-rep modelling legacy of computational modelling. The presented doctorate investigates strategies on how to apply digital practice to realise what is an essential bulwark to retain reefs in impossibly challenging times. Beyond the main question of integrating computational modelling and high precision monitoring strategies in artificial coral reef design, this doctorate explores techniques, methods, and linking frameworks to support future research and practice in ecology led design contexts. Considering the many existing approaches for artificial coral reefs design, one finds they often fall short in precisely understanding the relationships between architectural and ecological aspects (e.g. how a surface design and material composition can foster coral larvae settlement, or structural three-dimensionality enhance biodiversity) and lack an integrated underwater (UW) monitoring process. Such a process is necessary in order to gather knowledge about the ecosystem and make it available for design, and to learn whether artificial structures contribute to reef regeneration or rather harm the coral reef ecosystem. For the research, empirical experimental methods were applied: Algorithmic coral reef design, high precision UW monitoring, computational modelling and simulation, and validated through parallel real-world physical experimentation - two Artificial Reef Prototypes (ARPs) in Gili Trawangan, Indonesia (2012-today). Multiple discrete methods and sub techniques were developed in seventeen computational experiments and applied in a way in which many are cross valid and integrated in an overall framework that is offered as a significant contribution to the field. Other main contributions include the Ecosystem-aware design approach, Key Performance Indicators (KPIs) for coral reef design, algorithmic design and fabrication of Biorock cathodes, new high precision UW monitoring strategies, long-term real-world constructed experiments, new digital analysis methods and two new front-end web-based tools for reef design and monitoring reefs. The methodological framework is a finding of the research that has many technical components that were tested and combined in this way for the very first time. In summary, the thesis responds to the urgency and relevance in preserving marine species in tropical reefs during this massive extinction period by offering a differentiated approach towards artificial coral reefs - demonstrating the feasibility of digitally designing such 'living architecture' according to multiple context and performance parameters. It also provides an in-depth critical discussion of computational design and architecture in the context of ecosystem regeneration and Planetary Thinking. In that respect, the thesis functions as both theoretical and practical background for computational design, ecology and marine conservation - not only to foster the design of artificial coral reefs technically but also to provide essential criteria and techniques for conceiving them. Keywords: Artificial coral reefs, computational modelling, high precision underwater monitoring, ecology in design.}, subject = {Korallenriff}, language = {en} } @phdthesis{Zhang, author = {Zhang, Yongzheng}, title = {A Nonlocal Operator Method for Quasi-static and Dynamic Fracture Modeling}, doi = {10.25643/bauhaus-universitaet.4732}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221026-47321}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Material failure can be tackled by so-called nonlocal models, which introduce an intrinsic length scale into the formulation and, in the case of material failure, restore the well-posedness of the underlying boundary value problem or initial boundary value problem. Among nonlocal models, peridynamics (PD) has attracted a lot of attention as it allows the natural transition from continuum to discontinue and thus allows modeling of discrete cracks without the need to describe and track the crack topology, which has been a major obstacle in traditional discrete crack approaches. This is achieved by replacing the divergence of the Cauchy stress tensor through an integral over so-called bond forces, which account for the interaction of particles. A quasi-continuum approach is then used to calibrate the material parameters of the bond forces, i.e., equating the PD energy with the energy of a continuum. One major issue for the application of PD to general complex problems is that they are limited to fairly simple material behavior and pure mechanical problems based on explicit time integration. PD has been extended to other applications but losing simultaneously its simplicity and ease in modeling material failure. Furthermore, conventional PD suffers from instability and hourglass modes that require stabilization. It also requires the use of constant horizon sizes, which drastically reduces its computational efficiency. The latter issue was resolved by the so-called dual-horizon peridynamics (DH-PD) formulation and the introduction of the duality of horizons. Within the nonlocal operator method (NOM), the concept of nonlocality is further extended and can be considered a generalization of DH-PD. Combined with the energy functionals of various physical models, the nonlocal forms based on the dual-support concept can be derived. In addition, the variation of the energy functional allows implicit formulations of the nonlocal theory. While traditional integral equations are formulated in an integral domain, the dual-support approaches are based on dual integral domains. One prominent feature of NOM is its compatibility with variational and weighted residual methods. The NOM yields a direct numerical implementation based on the weighted residual method for many physical problems without the need for shape functions. Only the definition of the energy or boundary value problem is needed to drastically facilitate the implementation. The nonlocal operator plays an equivalent role to the derivatives of the shape functions in meshless methods and finite element methods (FEM). Based on the variational principle, the residual and the tangent stiffness matrix can be obtained with ease by a series of matrix multiplications. In addition, NOM can be used to derive many nonlocal models in strong form. The principal contributions of this dissertation are the implementation and application of NOM, and also the development of approaches for dealing with fractures within the NOM, mostly for dynamic fractures. The primary coverage and results of the dissertation are as follows: -The first/higher-order implicit NOM and explicit NOM, including a detailed description of the implementation, are presented. The NOM is based on so-called support, dual-support, nonlocal operators, and an operate energy functional ensuring stability. The nonlocal operator is a generalization of the conventional differential operators. Combining with the method of weighted residuals and variational principles, NOM establishes the residual and tangent stiffness matrix of operate energy functional through some simple matrix without the need of shape functions as in other classical computational methods such as FEM. NOM only requires the definition of the energy drastically simplifying its implementation. For the sake of conciseness, the implementation in this chapter is focused on linear elastic solids only, though the NOM can handle more complex nonlinear problems. An explicit nonlocal operator method for the dynamic analysis of elasticity solid problems is also presented. The explicit NOM avoids the calculation of the tangent stiffness matrix as in the implicit NOM model. The explicit scheme comprises the Verlet-velocity algorithm. The NOM can be very flexible and efficient for solving partial differential equations (PDEs). It's also quite easy for readers to use the NOM and extend it to solve other complicated physical phenomena described by one or a set of PDEs. Several numerical examples are presented to show the capabilities of this method. -A nonlocal operator method for the dynamic analysis of (thin) Kirchhoff plates is proposed. The nonlocal Hessian operator is derived from a second-order Taylor series expansion. NOM is higher-order continuous, which is exploited for thin plate analysis that requires \$C^1\$ continuity. The nonlocal dynamic governing formulation and operator energy functional for Kirchhoff plates are derived from a variational principle. The Verlet-velocity algorithm is used for time discretization. After confirming the accuracy of the nonlocal Hessian operator, several numerical examples are simulated by the nonlocal dynamic Kirchhoff plate formulation. -A nonlocal fracture modeling is developed and applied to the simulation of quasi-static and dynamic fractures using the NOM. The phase field's nonlocal weak and associated strong forms are derived from a variational principle. The NOM requires only the definition of energy. We present both a nonlocal implicit phase field model and a nonlocal explicit phase field model for fracture; the first approach is better suited for quasi-static fracture problems, while the key application of the latter one is dynamic fracture. To demonstrate the performance of the underlying approach, several benchmark examples for quasi-static and dynamic fracture are solved.}, subject = {Variationsprinzip}, language = {en} } @article{Lutolli, author = {Lutolli, Blerim}, title = {A Review of Domed Cities and Architecture: Past, Present and Future}, series = {Future cities and environment}, volume = {2022}, journal = {Future cities and environment}, number = {Volume 8, issue 1}, publisher = {Ubiquity Press Limited}, address = {London}, doi = {10.5334/fce.154}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221103-47335}, pages = {1 -- 9}, abstract = {The goal of architecture is changing in response to the expanding role of cities, rapid urbanization, and transformation under changing economic, environmental, social, and demographic factors. As cities increased in the early modern era, overcrowding, urbanization, and pollution conditions led reformers to consider the future shape of the cities. One of the most critical topics in contemporary architecture is the subject of the future concepts of living. In most cases, domed cities, as a future concept of living, are rarely considered, and they are used chiefly as "utopian" visions in the discourse of future ways of living. This paper highlights the reviews of domed cities to deepen the understanding of the idea in practice, like its approach in terms of architecture. The main aim of this paper is to provide a broad overview for domed cities in the face of pollution as one of the main concerns in many European cities. As a result, the significance of the reviews of the existing projects is focused on their conceptual quality. This review will pave the way for further studies in terms of future developments in the realm of domed cities. In this paper, the city of Celje, one of the most polluted cities in Slovenia, is taken as a case study for considering the concept of Dome incorporated due to the lack of accessible literature on the topic. This review's primary contribution is to allow architects to explore a broad spectrum of innovation by comparing today's achievable statuses against the possibilities generated by domed cities. As a result of this study, the concept of living under the Dome remains to be developed in theory and practice. The current challenging climatic situation will accelerate the evolution of these concepts, resulting in the formation of new typologies, which are a requirement for humanity.}, subject = {Architektur}, language = {en} } @misc{Vollmer, author = {Vollmer, Lisa}, title = {Aber das sind doch die Guten - oder? Wohnungsgenossenschaften in Hamburg. Rezension zu Jo-scha Metzger (2021): Genossenschaften und die Wohnungsfrage. Konflikte im Feld der Sozialen Wohnungswirtschaft. M{\"u}nster: Westf{\"a}lisches Dampfboot}, series = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, volume = {2022}, journal = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, number = {Band 10, Nr. 1}, publisher = {sub\urban e. V.}, address = {Berlin}, doi = {10.36900/suburban.v10i1.795}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220713-46691}, pages = {261 -- 267}, abstract = {Warum werden in aktuellen Diskussionen Wohnungsgenossenschaften immer wieder als zentrale Akteure einer gemeinwohlorientierten Wohnraumversorgung benannt - obwohl sie kaum zur Schaffung neuen bezahlbaren Wohnraums beitragen? Warum wehrt sich die Mehrzahl der Wohnungsgenossenschaften mit H{\"a}nden und F{\"u}ßen gegen die Wiedereinf{\"u}hrung eines Gesetzes zur Wohnungsgemeinn{\"u}tzigkeit, obwohl es doch gerade dieses Gesetz war, dass sie im 20. Jahrhundert zu im internationalen Vergleich großen Unternehmen wachsen ließ? Sind Wohnungsgenossenschaften nun klientilistische, wenig demokratische und nur halb dekommodifizierte Marktteilnehmer oder wichtiger Teil der Wohnungsversorgung der unteren Mittelschicht? Wer Antworten auf diese und andere Fragen sucht und Differenziertheit in ihrer Beantwortung aush{\"a}lt, lese Joscha Metzers Dissertation „Genossenschaften und die Wohnungsfrage.}, subject = {Gentrifizierung}, language = {de} } @inproceedings{Dokhanchi, author = {Dokhanchi, Najmeh Sadat}, title = {Acoustic travel time tomography: Applicability of an array of directional sound sources}, editor = {Arnold, J{\"o}rg}, doi = {10.25643/bauhaus-universitaet.4658}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46589}, abstract = {The technique of Acoustic travel-time TOMography (ATOM) allows for measuring the distribution of air temperatures throughout the entire room based on the determined sound-travel-times of early reflections, currently up to second order reflections. The number of detected early reflections in the room impulse response (RIR) which stands for the desired sound paths inside the room, has a significant impact on the resolution of reconstructed temperatures. This study investigates the possibility of utilizing an array of directional sound sources for ATOM measurements instead of a single omnidirectional loudspeaker used in the previous studies [1-3]. The developed measurement setup consists of two directional sound sources placed near the edge of the floor in the climate chamber of the Bauhaus-University Weimar and one omnidirectional receiver at center of the room near the ceiling. In order to compensate for the reduced number of sound paths when using directional sound sources, it is proposed to take high-energy early reflections up to third order into account. For this purpose, the simulated travel times up to third-order image sources were implemented in the image source model (ISM) algorithm, by which these early reflections can be detected effectively for air temperature reconstructions. To minimize the uncertainties of travel-times estimation due to the positioning of the sound transducers inside the room, measurements were conducted to determine the exact emitting point of the utilized sound source i.e. its acoustic center (AC). For these measurements, three types of excitation signals (MLS, linear and logarithmic chirp signals) with various frequency ranges were used considering that the acoustic center of a sound source is a frequency dependent parameter [4]. Furthermore, measurements were conducted to determine an optimum excitation signal based on the given condition of the ATOM measurement set-up which defines an optimum method for the RIR estimation correspondingly. Finally, the uncertainty of the measuring system utilizing an array of directional sound sources was analyzed.}, subject = {Bauphysik}, language = {en} } @article{TeitelbaumAlsaadAvivetal., author = {Teitelbaum, Eric and Alsaad, Hayder and Aviv, Dorit and Kim, Alexander and V{\"o}lker, Conrad and Meggers, Forrest and Pantelic, Jovan}, title = {Addressing a systematic error correcting for free and mixed convection when measuring mean radiant temperature with globe thermometers}, series = {Scientific reports}, volume = {2022}, journal = {Scientific reports}, number = {Volume 12, article 6473}, publisher = {Springer Nature}, address = {London}, doi = {10.1038/s41598-022-10172-5}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220509-46363}, pages = {18}, abstract = {It is widely accepted that most people spend the majority of their lives indoors. Most individuals do not realize that while indoors, roughly half of heat exchange affecting their thermal comfort is in the form of thermal infrared radiation. We show that while researchers have been aware of its thermal comfort significance over the past century, systemic error has crept into the most common evaluation techniques, preventing adequate characterization of the radiant environment. Measuring and characterizing radiant heat transfer is a critical component of both building energy efficiency and occupant thermal comfort and productivity. Globe thermometers are typically used to measure mean radiant temperature (MRT), a commonly used metric for accounting for the radiant effects of an environment at a point in space. In this paper we extend previous field work to a controlled laboratory setting to (1) rigorously demonstrate that existing correction factors used in the American Society of Heating Ventilation and Air-conditioning Engineers (ASHRAE) Standard 55 or ISO7726 for using globe thermometers to quantify MRT are not sufficient; (2) develop a correction to improve the use of globe thermometers to address problems in the current standards; and (3) show that mean radiant temperature measured with ping-pong ball-sized globe thermometers is not reliable due to a stochastic convective bias. We also provide an analysis of the maximum precision of globe sensors themselves, a piece missing from the domain in contemporary literature.}, subject = {Strahlungstemperatur}, language = {en} } @phdthesis{Malik, author = {Malik, Irfan}, title = {An adaptive contact formulation for Isogeometric Finite Element Analysis}, doi = {10.25643/bauhaus-universitaet.4612}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220324-46129}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {124}, abstract = {Numerical simulation of physical phenomena, like electro-magnetics, structural and fluid mechanics is essential for the cost- and time-efficient development of mechanical products at high quality. It allows to investigate the behavior of a product or a system far before the first prototype of a product is manufactured. This thesis addresses the simulation of contact mechanics. Mechanical contacts appear in nearly every product of mechanical engineering. Gearboxes, roller bearings, valves and pumps are only some examples. Simulating these systems not only for the maximal/minimal stresses and strains but for the stress-distribution in case of tribo-contacts is a challenging task from a numerical point of view. Classical procedures like the Finite Element Method suffer from the nonsmooth representation of contact surfaces with discrete Lagrange elements. On the one hand, an error due to the approximate description of the surface is introduced. On the other hand it is difficult to attain a robust contact search because surface normals can not be described in a unique form at element edges. This thesis introduces therefore a novel approach, the adaptive isogeometric contact formulation based on polynomial Splines over hierarchical T-meshes (PHT-Splines), for the approximate solution of the non-linear contact problem. It provides a more accurate, robust and efficient solution compared to conventional methods. During the development of this method the focus was laid on the solution of static contact problems without friction in 2D and 3D in which the structures undergo small deformations. The mathematical description of the problem entails a system of partial differential equations and boundary conditions which model the linear elastic behaviour of continua. Additionally, it comprises side conditions, the Karush-Kuhn-Tuckerconditions, to prevent the contacting structures from non-physical penetration. The mathematical model must be transformed into its integral form for approximation of the solution. Employing a penalty method, contact constraints are incorporated by adding the resulting equations in weak form to the overall set of equations. For an efficient space discretization of the bulk and especially the contact boundary of the structures, the principle of Isogeometric Analysis (IGA) is applied. Isogeometric Finite Element Methods provide several advantages over conventional Finite Element discretization. Surface approximation with Non-Uniform Rational B-Splines (NURBS) allow a robust numerical solution of the contact problem with high accuracy in terms of an exact geometry description including the surface smoothness. The numerical evaluation of the contact integral is challenging due to generally non-conforming meshes of the contacting structures. In this work the highly accurate Mortar Method is applied in the isogeometric setting for the evaluation of contact contributions. This leads to an algebraic system of equations that is linearized and solved in sequential steps. This procedure is known as the Newton Raphson Method. Based on numerical examples, the advantages of the isogeometric approach with classical refinement strategies, like the p- and h-refinement, are shown and the influence of relevant algorithmic parameters on the approximate solution of the contact problem is verified. One drawback of the Spline approximations of stresses though is that they lack accuracy at the contact edge where the structures change their boundary from contact to no contact and where the solution features a kink. The approximation with smooth Spline functions yields numerical artefacts in the form of non-physical oscillations. This property of the numerical solution is not only a drawback for the simulation of e.g. tribological contacts, it also influences the convergence properties of iterative solution procedures negatively. Hence, the NURBS discretized geometries are transformed to Polynomial Splines over Hierarchical T-meshes (PHT-Splines), for the local refinement along contact edges to reduce the artefact of pressure oscillations. NURBS have a tensor product structure which does not allow to refine only certain parts of the geometrical domain while leaving other parts unchanged. Due to the B{\´e}zier Extraction, lying behind the transformation from NURBS to PHT-Splines, the connected mesh structure is broken up into separate elements. This allows an efficient local refinement along the contact edge. Before single elements are refined in a hierarchical form with cross-insertion, existing basis functions must be modified or eliminated. This process of truncation assures local and global linear independence of the refined basis which is needed for a unique approximate solution. The contact boundary is a priori unknown. Local refinement along the contact edge, especially for 3D problems, is for this reason not straight forward. In this work the use of an a posteriori error estimation procedure, the Super Convergent Recovery Solution Based Error Estimation Scheme, together with the D{\"o}rfler Marking Method is suggested for the spatial search of the contact edge. Numerical examples show that the developed method improves the quality of solutions along the contact edge significantly compared to NURBS based approximate solutions. Also, the error in maximum contact pressures, which correlates with the pressure artefacts, is minimized by the adaptive local refinement. In a final step the practicability of the developed solution algorithm is verified by an industrial application: The highly loaded mechanical contact between roller and cam in the drive train of a high-pressure fuel pump is considered.}, subject = {Isogeometrische Analyse}, language = {en} } @phdthesis{Jenabidehkordi, author = {Jenabidehkordi, Ali}, title = {An Efficient Adaptive PD Formulation for Complex Microstructures}, doi = {10.25643/bauhaus-universitaet.4742}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221124-47422}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {118}, abstract = {The computational costs of newly developed numerical simulation play a critical role in their acceptance within both academic use and industrial employment. Normally, the refinement of a method in the area of interest reduces the computational cost. This is unfortunately not true for most nonlocal simulation, since refinement typically increases the size of the material point neighborhood. Reducing the discretization size while keep- ing the neighborhood size will often require extra consideration. Peridy- namic (PD) is a newly developed numerical method with nonlocal nature. Its straightforward integral form equation of motion allows simulating dy- namic problems without any extra consideration required. The formation of crack and its propagation is known as natural to peridynamic. This means that discontinuity is a result of the simulation and does not demand any post-processing. As with other nonlocal methods, PD is considered an expensive method. The refinement of the nodal spacing while keeping the neighborhood size (i.e., horizon radius) constant, emerges to several nonphysical phenomena. This research aims to reduce the peridynamic computational and imple- mentation costs. A novel refinement approach is introduced. The pro- posed approach takes advantage of the PD flexibility in choosing the shape of the horizon by introducing multiple domains (with no intersections) to the nodes of the refinement zone. It will be shown that no ghost forces will be created when changing the horizon sizes in both subdomains. The approach is applied to both bond-based and state-based peridynamic and verified for a simple wave propagation refinement problem illustrating the efficiency of the method. Further development of the method for higher dimensions proves to have a direct relationship with the mesh sensitivity of the PD. A method for solving the mesh sensitivity of the PD is intro- duced. The application of the method will be examined by solving a crack propagation problem similar to those reported in the literature. New software architecture is proposed considering both academic and in- dustrial use. The available simulation tools for employing PD will be collected, and their advantages and drawbacks will be addressed. The challenges of implementing any node base nonlocal methods while max- imizing the software flexibility to further development and modification will be discussed and addressed. A software named Relation-Based Sim- ulator (RBS) is developed for examining the proposed architecture. The exceptional capabilities of RBS will be explored by simulating three dis- tinguished models. RBS is available publicly and open to further develop- ment. The industrial acceptance of the RBS will be tested by targeting its performance on one Mac and two Linux distributions.}, subject = {Peridynamik}, language = {en} } @phdthesis{Jenabidehkordi, author = {Jenabidehkordi, Ali}, title = {An efficient adaptive PD formulation for complex microstructures}, doi = {10.25643/bauhaus-universitaet.4738}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221116-47389}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {118}, abstract = {The computational costs of newly developed numerical simulation play a critical role in their acceptance within both academic use and industrial employment. Normally, the refinement of a method in the area of interest reduces the computational cost. This is unfortunately not true for most nonlocal simulation, since refinement typically increases the size of the material point neighborhood. Reducing the discretization size while keep- ing the neighborhood size will often require extra consideration. Peridynamic (PD) is a newly developed numerical method with nonlocal nature. Its straightforward integral form equation of motion allows simulating dynamic problems without any extra consideration required. The formation of crack and its propagation is known as natural to peridynamic. This means that discontinuity is a result of the simulation and does not demand any post-processing. As with other nonlocal methods, PD is considered an expensive method. The refinement of the nodal spacing while keeping the neighborhood size (i.e., horizon radius) constant, emerges to several nonphysical phenomena. This research aims to reduce the peridynamic computational and imple- mentation costs. A novel refinement approach is introduced. The pro- posed approach takes advantage of the PD flexibility in choosing the shape of the horizon by introducing multiple domains (with no intersections) to the nodes of the refinement zone. It will be shown that no ghost forces will be created when changing the horizon sizes in both subdomains. The approach is applied to both bond-based and state-based peridynamic and verified for a simple wave propagation refinement problem illustrating the efficiency of the method. Further development of the method for higher dimensions proves to have a direct relationship with the mesh sensitivity of the PD. A method for solving the mesh sensitivity of the PD is intro- duced. The application of the method will be examined by solving a crack propagation problem similar to those reported in the literature. New software architecture is proposed considering both academic and in- dustrial use. The available simulation tools for employing PD will be collected, and their advantages and drawbacks will be addressed. The challenges of implementing any node base nonlocal methods while max- imizing the software flexibility to further development and modification will be discussed and addressed. A software named Relation-Based Sim- ulator (RBS) is developed for examining the proposed architecture. The exceptional capabilities of RBS will be explored by simulating three distinguished models. RBS is available publicly and open to further develop- ment. The industrial acceptance of the RBS will be tested by targeting its performance on one Mac and two Linux distributions.}, subject = {Peridynamik}, language = {en} } @phdthesis{Mojahedin, author = {Mojahedin, Arvin}, title = {Analysis of Functionally Graded Porous Materials Using Deep Energy Method and Analytical Solution}, doi = {10.25643/bauhaus-universitaet.4867}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221220-48674}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Porous materials are an emerging branch of engineering materials that are composed of two elements: One element is a solid (matrix), and the other element is either liquid or gas. Pores can be distributed within the solid matrix of porous materials with different shapes and sizes. In addition, porous materials are lightweight, and flexible, and have higher resistance to crack propagation and specific thermal, mechanical, and magnetic properties. These properties are necessary for manufacturing engineering structures such as beams and other engineering structures. These materials are widely used in solid mechanics and are considered a good replacement for classical materials by many researchers recently. Producing lightweight materials has been developed because of the possibility of exploiting the properties of these materials. Various types of porous material are generated naturally or artificially for a specific application such as bones and foams. Like functionally graded materials, pore distribution patterns can be uniform or non-uniform. Biot's theory is a well-developed theory to study the behavior of poroelastic materials which investigates the interaction between fluid and solid phases of a fluid-saturated porous medium. Functionally graded porous materials (FGPM) are widely used in modern industries, such as aerospace, automotive, and biomechanics. These advanced materials have some specific properties compared to materials with a classic structure. They are extremely light, while they have specific strength in mechanical and high-temperature environments. FGPMs are characterized by a gradual variation of material parameters over the volume. Although these materials can be made naturally, it is possible to design and manufacture them for a specific application. Therefore, many studies have been done to analyze the mechanical and thermal properties of FGPM structures, especially beams. Biot was the pioneer in formulating the linear elasticity and thermoelasticity equations of porous material. Since then, Biot's formulation has been developed in continuum mechanics which is named poroelasticity. There are obstacles to analyzing the behavior of these materials accurately like the shape of the pores, the distribution of pores in the material, and the behavior of the fluid (or gas) that saturated pores. Indeed, most of the engineering structures made of FGPM have nonlinear governing equations. Therefore, it is difficult to study engineering structures by solving these complicated equations. The main purpose of this dissertation is to analyze porous materials in engineering structures. For this purpose, the complex equations of porous materials have been simplified and applied to engineering problems so that the effect of all parameters of porous materials on the behavior of engineering structure has been investigated. The effect of important parameters of porous materials on beam behavior including pores compressibility, porosity distribution, thermal expansion of fluid within pores, the interaction of stresses between pores and material matrix due to temperature increase, effects of pore size, material thickness, and saturated pores with fluid and unsaturated conditions are investigated. Two methods, the deep energy method, and the exact solution have been used to reduce the problem hypotheses, increase accuracy, increase processing speed, and apply these in engineering structures. In both methods, they are analyzed nonlinear and complex equations of porous materials. To increase the accuracy of analysis and study of the effect of shear forces, Timoshenko and Reddy's beam theories have been used. Also, neural networks such as residual and fully connected networks are designed to have high accuracy and less processing time than other computational methods.}, subject = {Por{\"o}ser Stoff}, language = {en} } @article{GuoZhuangChenetal., author = {Guo, Hongwei and Zhuang, Xiaoying and Chen, Pengwan and Alajlan, Naif and Rabczuk, Timon}, title = {Analysis of three-dimensional potential problems in non-homogeneous media with physics-informed deep collocation method using material transfer learning and sensitivity analysis}, series = {Engineering with Computers}, volume = {2022}, journal = {Engineering with Computers}, doi = {10.1007/s00366-022-01633-6}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220811-46764}, pages = {1 -- 22}, abstract = {In this work, we present a deep collocation method (DCM) for three-dimensional potential problems in non-homogeneous media. This approach utilizes a physics-informed neural network with material transfer learning reducing the solution of the non-homogeneous partial differential equations to an optimization problem. We tested different configurations of the physics-informed neural network including smooth activation functions, sampling methods for collocation points generation and combined optimizers. A material transfer learning technique is utilized for non-homogeneous media with different material gradations and parameters, which enhance the generality and robustness of the proposed method. In order to identify the most influential parameters of the network configuration, we carried out a global sensitivity analysis. Finally, we provide a convergence proof of our DCM. The approach is validated through several benchmark problems, also testing different material variations.}, subject = {Deep learning}, language = {en} } @inproceedings{GeskeBenzVoelker, author = {Geske, Mara and Benz, Alexander and V{\"o}lker, Conrad}, title = {Anwendung georeferenzierter Bilddaten bei energetischen Quartiersanalysen}, series = {Tagungsband Bauphysiktage Kaiserslautern 2022}, booktitle = {Tagungsband Bauphysiktage Kaiserslautern 2022}, editor = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad}, publisher = {Eigenverlag der Technischen Universit{\"a}t Kaiserslautern}, address = {Kaiserslautern}, isbn = {987-3-95974-176-7}, issn = {2363-8206}, doi = {10.25643/bauhaus-universitaet.4654}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46544}, pages = {127-129}, abstract = {Bei Analysen des Geb{\"a}udebestands im Quartierskontext werden zu Dokumentationszwecken viele Bilddaten erzeugt. Diese Daten sind im Nachhinein h{\"a}ufig keinen eindeutig genauen Standorten und Blickwinkeln auf das Bauwerk zuzuordnen. Insbesondere gilt dies f{\"u}r Ortsunkundige oder f{\"u}r Detailaufnahmen. Eine zus{\"a}tzliche Herausforderung stellt die Aufnahme von W{\"a}rmebr{\"u}cken- oder andersartigen Geb{\"a}udedetails durch Thermogramme dar. In der Praxis kommen hier oftmals analoge, fehleranf{\"a}llige L{\"o}sungen zum Einsatz. Durch die Nutzung von Georeferenzierung kann diese L{\"u}cke geschlossen und eine eindeutige Kommunikation und Auswertung gew{\"a}hrleistet werden. Im Gegensatz zu den {\"u}blichen Kameras sind Smartphones nach Stand der Technik ausreichend ausgestattet, um neben Daten zu Standort auch die Orientierungswinkel einer Bildaufnahme zu dokumentieren. Die georefenzierten Bilder k{\"o}nnen auf Grundlage der in den sogenannten Exif-Daten mitgeschriebenen Informationen h{\"a}ndisch in ein bestehendes Quartiersmodell integriert werden. Anhand eines universit{\"a}ren Musterquartiers wird die nutzerfreundliche Realisierung beispielhaft erprobt und auf ihre Potentiale zur Automatisierung in Python untersucht. Hierf{\"u}r wurde ein bestehendes Quartiersmodell als geometrische Grundlage genutzt und um RGB-Bilder sowie Thermogramme erweitert. Das beschriebene Vorgehen wird im Rahmen der Anwendung auf seinen m{\"o}glichen Einsatz im Rahmen einer energetischen Quartierserfassung sowie einer Bauschadensdokumentation untersucht. Mit dem vorliegenden Beitrag wird dem Nutzenden ein Werkzeug bereitgestellt, das die hochwertige Dokumentation einer Bestandserfassung, auch im Quartierskontext, erm{\"o}glicht.}, subject = {Quartiersanalyse}, language = {de} } @book{BreuerBartFreieretal., author = {Breuer, Johannes and Bart, Marlene and Freier, Alex Leo and R{\"u}nker, Maximilian and Jakubek, Kristin and Rubiano, Juan and Groos, Cora and Š{\´a}lek, Martin and Fritz, Henrieke and Kokkinidou, Eirini and Richter, Fabian and Liu, Ani and Held, Tobias and Moses, Gabriel S and Blasius, Clara Maria and Sp{\aa}ng, Fanny and Bencicova, Evelyn and R{\"u}ckeis, Julia and Thurow, Katharina and Maas, Frederike and Farf{\´a}n, Vanessa and Tikka, Emilia and Lee, Sang and Holzheu, Stefanie}, title = {Atlas der Datenk{\"o}rper. K{\"o}rperbilder in Kunst, Design und Wissenschaft im Zeitalter digitaler Medien}, volume = {2022}, editor = {Breuer, Johannes and Bart, Marlene and Freier, Alex Leo}, publisher = {transcript Verlag}, address = {Bielefeld}, issn = {2750-7483}, doi = {10.1515/9783839461785}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220411-46248}, publisher = {Bauhaus-Universit{\"a}t Weimar}, pages = {172}, abstract = {Digitale Technologien und soziale Medien ver{\"a}ndern die Selbst- und K{\"o}rperwahrnehmung und verzerren, verst{\"a}rken oder produzieren dabei spezifische K{\"o}rperbilder. Die Beitr{\"a}ger*innen kartographieren diese Ph{\"a}nomene, fragen nach ihrer medialen Existenzweise sowie nach den M{\"o}glichkeiten ihrer Kritik. Dabei begegnen sie ihrer Neuartigkeit mit einer transdisziplin{\"a}ren Herangehensweise. Aus sowohl der Perspektive k{\"u}nstlerischer und gestalterischer Forschung als auch der Kunst-, Kultur- und Medienwissenschaft sowie der Psychologie und Neurowissenschaft wird die Landschaft rezenter K{\"o}rperbilder und Techniken einer digitalen K{\"o}rperlichkeit untersucht.}, subject = {K{\"o}rperbild}, language = {de} } @book{OPUS4-4604, title = {Ausgr{\"u}ndung aus der Universit{\"a}t - Ein praktischer Leitfaden f{\"u}r Wissenschaftler*innen}, editor = {Zorn, Josephine}, doi = {10.25643/bauhaus-universitaet.4604}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220311-46048}, publisher = {Bauhaus-Universit{\"a}t Weimar}, pages = {74}, abstract = {Ob MP3-Player, Elektro-Jet oder Hochgeschwindigkeits-R{\"o}ntgendetektor - hinter erfolgreichen Produkten stehen wissenschaftliche Erfindungen und Wissenschaftler*innen, die ihre Technologien kommerzialisiert haben. Auch Ihre Forschungsergebnisse k{\"o}nnten Potenzial f{\"u}r eine Ausgr{\"u}ndung bieten. Doch vor dem Wechsel aus der Universit{\"a}t in die Selbstst{\"a}ndigkeit stehen viele Fragen: Welche Marktchancen ergeben sich f{\"u}r meine Technologie? Welche Kompetenzen ben{\"o}tige ich in meinem Gr{\"u}ndungsteam? Wie entwickle ich ein tragf{\"a}higes Gesch{\"a}ftsmodell? Und nicht zuletzt: Welche F{\"o}rderprogramme und Finanzierungsoptionen gibt es f{\"u}r forschungsbasierte Ausgr{\"u}ndungen? Das Workbook der Gr{\"u}nderwerkstatt neudeli m{\"o}chte Ihnen als Wissenschaftler*in Unterst{\"u}tzung bei der Beantwortung dieser und vieler weiterer Fragen geben. Liebevoll gestaltet durch die parzelle34 bietet das Workbook den geeigneten Einstieg zum Thema »Ausgr{\"u}ndung aus der Wissenschaft«, gibt Ihnen erste Informationen sowie weiterf{\"u}hrende Beratungsangebote an die Hand und animiert mit interaktiven Elementen dazu, direkt durchzustarten!}, subject = {Wissenschaft}, language = {de} } @misc{Miller, type = {Master Thesis}, author = {Miller, Martin}, title = {BIM-basierte Digitalisierung von Bestandsgeb{\"a}uden aus Sicht des FM am Beispiel von Heizungsanlagen}, doi = {10.25643/bauhaus-universitaet.4661}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220623-46616}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {101}, abstract = {Das Ziel der Arbeit ist, f{\"u}r das Facility Management relevante Informationen f{\"u}r die mit Building Information Modeling basierende Erstellung von Bestandsgeb{\"a}uden am Beispiel einer Hei- zungsanlage zu definieren. Darauf basierend sind die notwendigen Arbeitsschritte der Objek- taufnahme abgeleitet. F{\"u}r die Definition der Arbeitsschritte wurden das grundlegende Vorge- hen bei einer Objektaufnahme sowie die gesetzlichen Gegebenheiten f{\"u}r den Betrieb einer Heizungsanlage dargelegt. Dar{\"u}ber hinaus sind in der vorliegenden Ausarbeitung die Vorteile und Herausforderungen hinsichtlich des Zusammenspiels von Building Information Modeling und Facility Management analysiert. Die definierten Arbeitsschritte sind anhand eines Beispiel- projektes angewendet worden. Im Rahmen des Beispielprojekts sind die entscheidenden Be- triebsdaten je Anlagenteil in Form von Informationsanforderungen nach DIN 17412 definiert. Das Geb{\"a}udemodell ist durch Parameter mit den f{\"u}r das Facility Management relevanten In- formationen erg{\"a}nzt. Die Resultate des Beispielprojektes sind mit aussagekr{\"a}ftigen Schnitten, Pl{\"a}nen sowie 3-D-Visualisierungen dargestellt. Abschließend sind die Ergebnisse in Bezug auf das FM validiert. Aus den Arbeitsschritten und Ergebnissen ist eine Leitlinie erstellt worden f{\"u}r den Digitalisierungsprozess von Bestandsgeb{\"a}uden f{\"u}r das Facility Management.}, subject = {Facility Management}, language = {de} } @article{HahlbrockBraunHeideletal., author = {Hahlbrock, David and Braun, Michael and Heidel, Robin and Lemmen, Patrik and Boumann, Roland and Bruckmann, Tobias and Schramm, Dieter and Helm, Volker and Willmann, Jan}, title = {Cable Robotic 3D-printing: additive manufacturing on the construction site}, series = {Construction Robotics}, volume = {2022}, journal = {Construction Robotics}, publisher = {Springer International Publishing}, address = {Cham}, doi = {10.1007/s41693-022-00082-3}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230124-48791}, pages = {1 -- 14}, abstract = {This paper outlines an important step in characterizing a novel field of robotic construction research where a cable-driven parallel robot is used to extrude cementitious material in three-dimensional space, and thus offering a comprehensive new approach to computational design and construction, and to robotic fabrication at larger scales. Developed by the Faculty of Art and Design at Bauhaus-University Weimar (Germany), the faculty of Architecture at the University of Applied Sciences Dortmund (Germany) and the Chair of Mechatronics at the University of Duisburg-Essen (Germany), this approach offers unique advantages over existing additive manufacturing methods: the system is easily transportable and scalable, it does not require additional formwork or scaffolding, and it offers digital integration and informational oversight across the entire design and building process. This paper considers 1) key research components of cable robotic 3D-printing (such as computational design, material exploration, and robotic control), and 2) the integration of these parameters into a unified design and building process. The demonstration of the approach at full-scale is of particular concern.}, subject = {Robotik}, language = {en} } @phdthesis{Tatarin, author = {Tatarin, Ren{\´e}}, title = {Charakterisieren struktureller Ver{\"a}nderungen in zementgebundenen Baustoffen durch akustische zerst{\"o}rungsfreie Pr{\"u}fverfahren}, publisher = {Cuvillier Verlag}, address = {G{\"o}ttingen}, isbn = {978-3-7369-7575-0}, doi = {10.25643/bauhaus-universitaet.4592}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220215-45920}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {293}, abstract = {Im Rahmen dieser Arbeit wird das Charakterisieren struktureller Ver{\"a}nderungen zementgebundener Baustoffe durch zwei auf dem Ultraschall-Transmissionsverfahren beruhenden Methoden der zerst{\"o}rungsfreien Pr{\"u}fung (ZfP) mit mechanischen Wellen vorgenommen. Zur kontinuierlichen Charakterisierung der Erstarrung und Erh{\"a}rtung frischer zementgebundener Systeme wird ein auf Ultraschallsensoren f{\"u}r Longitudinal- und Scherwellen basierendes Messsystem in Kombination mit zugeh{\"o}rigen Verfahrensweisen zur Datenauswertung konzipiert, charakterisiert und angewandt. Gegen{\"u}ber der bislang {\"u}blichen alleinigen Bewertung der Verfestigung anhand indirekter Ultraschallparameter wie Ausbreitungsgeschwindigkeit, Signalenergie oder Frequenzgehalt der Longitudinalwelle l{\"a}sst sich damit eine direkte, sensible Erfassung der sich w{\"a}hrend der Strukturbildung entwickelnden dynamischen elastischen Eigenschaften auf der Basis prim{\"a}rer physikalischer Werkstoffparameter erreichen. Insbesondere Scherwellen und der dynamische Schubmodul sind geeignet, den graduellen {\"U}bergang zum Festk{\"o}rper mit {\"U}berschreiten der Perkolationsschwelle sensibel und unabh{\"a}ngig vom Luftgehalt zu erfassen. Die zeitliche Entwicklung der dynamischen elastischen Eigenschaften, die Strukturbildungsraten sowie die daraus extrahierten diskreten Ergebnisparameter erm{\"o}glichen eine vergleichende quantitative Charakterisierung der Strukturbildung zementgebundener Baustoffe aus mechanischer Sicht. Dabei lassen sich typische, oft unvermeidbare Unterschiede in der Zusammensetzung der Versuchsmischungen ber{\"u}cksichtigen. Der Einsatz laserbasierter Methoden zur Anregung und Erfassung von mechanischen Wellen und deren Kombination zu Laser-Ultraschall zielt darauf ab, die mit der Anwendung des konventionellen Ultraschall-Transmissionsverfahrens verbundenen Nachteile zu eliminieren. Diese resultieren aus der Sensorgeometrie, der mechanischen Ankopplung und bei einer Vielzahl von Oberfl{\"a}chenpunkten aus einem hohen pr{\"u}ftechnischen Aufwand. Die laserbasierte, interferometrische Erfassung mechanischer Wellen ist gegen{\"u}ber Ultraschallsensoren rauschbehaftet und vergleichsweise unsensibel. Als wesentliche Voraussetzung der scannenden Anwendung von Laser-Ultraschall auf zementgebundene Baustoffe erfolgen systematische experimentelle Untersuchungen zur laserinduzierten ablativen Anregung. Diese sollen zum Verst{\"a}ndnis des Anregungsmechanismus unmittelbar auf den Oberfl{\"a}chen von zementgebundenen Baustoffen, Gesteinsk{\"o}rnungen und metallischen Werkstoffen beitragen, relevante Einflussfaktoren aus den charakteristischen Materialeigenschaften identifizieren, geeignete Prozessparameter gewinnen und die Verfahrensgrenzen aufzeigen. Unter Einsatz von Longitudinalwellen erfolgt die Anwendung von Laser-Ultraschall zur zeit- und ortsaufgel{\"o}sten Charakterisierung der Strukturbildung und Homogenit{\"a}t frischer sowie erh{\"a}rteter Proben zementgebundener Baustoffe. W{\"a}hrend der Strukturbildung wird erstmals eine simultane ber{\"u}hrungslose Erfassung von Longitudinal- und Scherwellen vorgenommen. Unter Anwendung von tomographischen Methoden (2D-Laufzeit¬tomo¬graphie) werden {\"u}berlagerungsfreie Informationen zur r{\"a}umlichen Verteilung struktureller Gef{\"u}gever{\"a}nderungen anhand der longitudinalen Ausbreitungsgeschwindigkeit bzw. des relativen dynamischen Elastizit{\"a}tsmoduls innerhalb von virtuellen Schnittebenen gesch{\"a}digter Probek{\"o}rper gewonnen. Als beton-sch{\"a}digende Mechanismen werden exemplarisch der kombinierte Frost-Tausalz-Angriff sowie die Alkali-Kiesels{\"a}ure-Reaktion (AKR) herangezogen. Die im Rahmen dieser Arbeit entwickelten Verfahren der zerst{\"o}rungsfreien Pr{\"u}fung bieten erweiterte M{\"o}glichkeiten zur Charakterisierung zementgebundener Baustoffe und deren strukturellen Ver{\"a}nderungen und lassen sich zielgerichtet in der Werkstoffentwicklung, bei der Qualit{\"a}tssicherung sowie zur Analyse von Schadensprozessen und -ursachen einsetzen.}, subject = {Beton}, language = {de} }