TY - THES A1 - Zhang, Yongzheng T1 - A Nonlocal Operator Method for Quasi-static and Dynamic Fracture Modeling N2 - 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. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2022,9 KW - Variationsprinzip KW - Partial Differential Equations KW - Taylor Series Expansion KW - Peridynamics KW - Variational principle KW - Phase field method KW - Peridynamik KW - Phasenfeldmodell KW - Partielle Differentialgleichung KW - Nichtlokale Operatormethode Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221026-47321 ER - TY - JOUR A1 - Rabczuk, Timon A1 - Guo, Hongwei A1 - Zhuang, Xiaoying A1 - Chen, Pengwan A1 - Alajlan, Naif T1 - Stochastic deep collocation method based on neural architecture search and transfer learning for heterogeneous porous media JF - Engineering with Computers N2 - We present a stochastic deep collocation method (DCM) based on neural architecture search (NAS) and transfer learning for heterogeneous porous media. We first carry out a sensitivity analysis to determine the key hyper-parameters of the network to reduce the search space and subsequently employ hyper-parameter optimization to finally obtain the parameter values. The presented NAS based DCM also saves the weights and biases of the most favorable architectures, which is then used in the fine-tuning process. We also employ transfer learning techniques to drastically reduce the computational cost. The presented DCM is then applied to the stochastic analysis of heterogeneous porous material. Therefore, a three dimensional stochastic flow model is built providing a benchmark to the simulation of groundwater flow in highly heterogeneous aquifers. The performance of the presented NAS based DCM is verified in different dimensions using the method of manufactured solutions. We show that it significantly outperforms finite difference methods in both accuracy and computational cost. KW - Maschinelles Lernen KW - Neuronales Lernen KW - Fehlerabschätzung KW - deep learning KW - neural architecture search KW - randomized spectral representation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45835 UR - https://link.springer.com/article/10.1007/s00366-021-01586-2 VL - 2022 SP - 1 EP - 26 PB - Springer CY - London ER - TY - JOUR A1 - Kaps, Christian A1 - Schuch, Kai A1 - Stäblein, Stefan T1 - Silicate coatings for concrete components with waterglass systems by means of neutral salt initiation N2 - The objective of the investigations was the proof of the use of the neutral salt initiation as a construction material in the protecting silicate coating of concrete components, e.g. factory finished parts or reinforced concrete construction parts, by means of waterglass fused silica suspensions KW - Silicate KW - Coating KW - Wasserglas KW - Aggregation KW - Bindemittel KW - Waterglass KW - Alkalisilicate KW - Coating KW - Wasserglas KW - Sol-Gel Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20160601-25888 SP - 1 EP - 14 ER - TY - THES A1 - Abeltshauser, Rainer T1 - Identification and separation of physical effects of coupled systems by using defined model abstractions N2 - The thesis investigates at the computer aided simulation process for operational vibration analysis of complex coupled systems. As part of the internal methods project “Absolute Values” of the BMW Group, the thesis deals with the analysis of the structural dynamic interactions and excitation interactions. The overarching aim of the methods project is to predict the operational vibrations of engines. Simulations are usually used to analyze technical aspects (e. g. operational vibrations, strength, ...) of single components in the industrial development. The boundary conditions of submodels are mostly based on experiences. So the interactions with neighboring components and systems are neglected. To get physically more realistic results but still efficient simulations, this work wants to support the engineer during the preprocessing phase by useful criteria. At first suitable abstraction levels based on the existing literature are defined to identify structural dynamic interactions and excitation interactions of coupled systems. So it is possible to separate different effects of the coupled subsystems. On this basis, criteria are derived to assess the influence of interactions between the considered systems. These criteria can be used during the preprocessing phase and help the engineer to build up efficient models with respect to the interactions with neighboring systems. The method was developed by using several models with different complexity levels. Furthermore, the method is proved for the application in the industrial environment by using the example of a current combustion engine. T2 - Identifikation und Separation physikalischer Effekte von gekoppelten Systemen mittels definierter Modellabstraktionen T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2017,1 KW - Strukturdynamik KW - Wechselwirkung KW - Schwingung KW - Berechnung KW - Numerische Berechnung KW - Modellbildung KW - Schwingungsanalyse KW - Simulationsprozess Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28600 ER - TY - JOUR A1 - Lahmer, Tom T1 - FEM-Based determination of real and complex elastic, dielectric, and piezoelectric moduli in piezoceramic materials JF - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control N2 - We propose an enhanced iterative scheme for the precise reconstruction of piezoelectric material parameters from electric impedance and mechanical displacement measurements. It is based on finite-element simulations of the full three-dimensional piezoelectric equations, combined with an inexact Newton or nonlinear Landweber iterative inversion scheme. We apply our method to two piezoelectric materials and test its performance. For the first material, the manufacturer provides a full data set; for the second one, no material data set is available. For both cases, our inverse scheme, using electric impedance measurements as input data, performs well. KW - Finite-Elemente-Methode KW - Piezoelectric materials KW - Dielectric materials KW - Computational modeling KW - Frequency KW - Finite element methods KW - Manufacturing KW - Impedance measurement KW - Partial differential equations KW - Resonance KW - Resonanz Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20171030-36083 ER - TY - THES A1 - Schrader, Kai T1 - Hybrid 3D simulation methods for the damage analysis of multiphase composites T1 - Hybride 3D Simulationsmethoden zur Abbildung der Schädigungsvorgänge in Mehrphasen-Verbundwerkstoffen N2 - Modern digital material approaches for the visualization and simulation of heterogeneous materials allow to investigate the behavior of complex multiphase materials with their physical nonlinear material response at various scales. However, these computational techniques require extensive hardware resources with respect to computing power and main memory to solve numerically large-scale discretized models in 3D. Due to a very high number of degrees of freedom, which may rapidly be increased to the two-digit million range, the limited hardware ressources are to be utilized in a most efficient way to enable an execution of the numerical algorithms in minimal computation time. Hence, in the field of computational mechanics, various methods and algorithms can lead to an optimized runtime behavior of nonlinear simulation models, where several approaches are proposed and investigated in this thesis. Today, the numerical simulation of damage effects in heterogeneous materials is performed by the adaption of multiscale methods. A consistent modeling in the three-dimensional space with an appropriate discretization resolution on each scale (based on a hierarchical or concurrent multiscale model), however, still contains computational challenges in respect to the convergence behavior, the scale transition or the solver performance of the weak coupled problems. The computational efficiency and the distribution among available hardware resources (often based on a parallel hardware architecture) can significantly be improved. In the past years, high-performance computing (HPC) and graphics processing unit (GPU) based computation techniques were established for the investigationof scientific objectives. Their application results in the modification of existing and the development of new computational methods for the numerical implementation, which enables to take advantage of massively clustered computer hardware resources. In the field of numerical simulation in material science, e.g. within the investigation of damage effects in multiphase composites, the suitability of such models is often restricted by the number of degrees of freedom (d.o.f.s) in the three-dimensional spatial discretization. This proves to be difficult for the type of implementation method used for the nonlinear simulation procedure and, simultaneously has a great influence on memory demand and computational time. In this thesis, a hybrid discretization technique has been developed for the three-dimensional discretization of a three-phase material, which is respecting the numerical efficiency of nonlinear (damage) simulations of these materials. The increase of the computational efficiency is enabled by the improved scalability of the numerical algorithms. Consequently, substructuring methods for partitioning the hybrid mesh were implemented, tested and adapted to the HPC computing framework using several hundred CPU (central processing units) nodes for building the finite element assembly. A memory-efficient iterative and parallelized equation solver combined with a special preconditioning technique for solving the underlying equation system was modified and adapted to enable combined CPU and GPU based computations. Hence, it is recommended by the author to apply the substructuring method for hybrid meshes, which respects different material phases and their mechanical behavior and which enables to split the structure in elastic and inelastic parts. However, the consideration of the nonlinear material behavior, specified for the corresponding phase, is limited to the inelastic domains only, and by that causes a decreased computing time for the nonlinear procedure. Due to the high numerical effort for such simulations, an alternative approach for the nonlinear finite element analysis, based on the sequential linear analysis, was implemented in respect to scalable HPC. The incremental-iterative procedure in finite element analysis (FEA) during the nonlinear step was then replaced by a sequence of linear FE analysis when damage in critical regions occured, known in literature as saw-tooth approach. As a result, qualitative (smeared) crack initiation in 3D multiphase specimens has efficiently been simulated. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2013,2 KW - high-performance computing KW - finite element method KW - heterogeneous material KW - domain decomposition KW - scalable smeared crack analysis KW - FEM KW - multiphase KW - damage KW - HPC KW - solver Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20131021-20595 ER - TY - THES A1 - Nouri, Hamidreza T1 - Mechanical Behavior of two dimensional sheets and polymer compounds based on molecular dynamics and continuum mechanics approach N2 - Compactly, this thesis encompasses two major parts to examine mechanical responses of polymer compounds and two dimensional materials: 1- Molecular dynamics approach is investigated to study transverse impact behavior of polymers, polymer compounds and two dimensional materials. 2- Large deflection of circular and rectangular membranes is examined by employing continuum mechanics approach. Two dimensional materials (2D), including, Graphene and molybdenum disulfide (MoS2), exhibited new and promising physical and chemical properties, opening new opportunities to be utilized alone or to enhance the performance of conventional materials. These 2D materials have attracted tremendous attention owing to their outstanding physical properties, especially concerning transverse impact loading. Polymers, with the backbone of carbon (organic polymers) or do not include carbon atoms in the backbone (inorganic polymers) like polydimethylsiloxane (PDMS), have extraordinary characteristics particularly their flexibility leads to various easy ways of forming and casting. These simple shape processing label polymers as an excellent material often used as a matrix in composites (polymer compounds). In this PhD work, Classical Molecular Dynamics (MD) is implemented to calculate transverse impact loading of 2D materials as well as polymer compounds reinforced with graphene sheets. In particular, MD was adopted to investigate perforation of the target and impact resistance force . By employing MD approach, the minimum velocity of the projectile that could create perforation and passes through the target is obtained. The largest investigation was focused on how graphene could enhance the impact properties of the compound. Also the purpose of this work was to discover the effect of the atomic arrangement of 2D materials on the impact problem. To this aim, the impact properties of two different 2D materials, graphene and MoS2, are studied. The simulation of chemical functionalization was carried out systematically, either with covalently bonded molecules or with non-bonded ones, focusing the following efforts on the covalently bounded species, revealed as the most efficient linkers. To study transverse impact behavior by using classical MD approach , Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) software, that is well-known among most researchers, is employed. The simulation is done through predefined commands in LAMMPS. Generally these commands (atom style, pair style, angle style, dihedral style, improper style, kspace style, read data, fix, run, compute and so on) are used to simulate and run the model for the desired outputs. Depends on the particles and model types, suitable inter-atomic potentials (force fields) are considered. The ensembles, constraints and boundary conditions are applied depends upon the problem definition. To do so, atomic creation is needed. Python codes are developed to generate particles which explain atomic arrangement of each model. Each atomic arrangement introduced separately to LAMMPS for simulation. After applying constraints and boundary conditions, LAMMPS also include integrators like velocity-Verlet integrator or Brownian dynamics or other types of integrator to run the simulation and finally the outputs are emerged. The outputs are inspected carefully to appreciate the natural behavior of the problem. Appreciation of natural properties of the materials assist us to design new applicable materials. In investigation on the large deflection of circular and rectangular membranes, which is related to the second part of this thesis, continuum mechanics approach is implemented. Nonlinear Föppl membrane theory, which carefully release nonlinear governing equations of motion, is considered to establish the non-linear partial differential equilibrium equations of the membranes under distributed and centric point loads. The Galerkin and energy methods are utilized to solve non-linear partial differential equilibrium equations of circular and rectangular plates respectively. Maximum deflection as well as stress through the film region, which are kinds of issue in many industrial applications, are obtained. T2 - Mechanisches Verhalten von zweidimensionalen Schichten und Polymerverbindungen basierend auf molekulardynamischer und kontinuumsmechanischem Ansatz KW - Molekulardynamik KW - Polymerverbindung KW - Auswirkung KW - Molecular Dynamics Simulation KW - Continuum Mechnics KW - Polymer compound KW - Impact Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220713-46700 ER - TY - THES A1 - Jenabidehkordi, Ali T1 - An Efficient Adaptive PD Formulation for Complex Microstructures N2 - 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. KW - Peridynamik KW - Numerical Simulations KW - Peridynamics KW - Numerical Simulations Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221124-47422 ER - TY - THES A1 - Vogler, Verena T1 - 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 N2 - 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. N2 - Charakteristisch für das Zeitalter des Klimawandels sind die durch den Menschen verursachte Meeresverschmutzung sowie ein massiver Rückgang der Artenvielfalt in den Weltmeeren. Tropische Korallenriffe sind als eines der ältesten und artenreichsten Ökosysteme der Erde besonders stark gefährdet und stehen somit symbolisch für die zerstörerischen Auswirkungen menschlicher Aktivitäten auf die Natur [4], [5]. Um dem massiven Rückgang der Korallenriffe entgegenzuwirken, wurden von Menschen künstliche Riffsysteme entwickelt [6], [7]. Sie sind Beispiele dafür, wie Architektur und die Regenerierung von Ökosystemen miteinander verbunden werden können [8]. Eine Verknüpfung von einerseits künstlichen und andererseits komplexen, sich verändernden natürlichen Systemen, stellt jedoch eine Herausforderung dar, u.a. in Bezug auf die Computermodellierung (B-Rep Modellierung). Zum Erhalt der Korallenriffe werden in der vorliegende Doktorarbeit Strategien aus der digitalen Praxis neuartig auf das Entwerfen von künstlichen Korallenriffen angewendet. Die Hauptfrage befasst sich damit, wie der Entwurfsprozess von künstlichen Korallenriffen unter Einbeziehung von Computermodellierung und hochpräzisen Überwachungsstrategien optimiert werden kann. In diesem Zusammenhang werden Techniken, Methoden sowie ein übergeordnetes Framework erforscht, welche zukünftige Forschung und Praxis in Bezug auf Ökologie-geleitete Entwurfsprozesse fördern soll. In Anbetracht der vielen vorhandenen künstlichen Riffsysteme, kann man feststellen, dass die Zusammenhänge zwischen Architektur- und Ökosystem-Anforderungen nicht genau untersucht und dadurch bei der Umsetzung nicht entsprechend berücksichtigt werden. Zum Beispiel wie Oberflächenbeschaffenheit und Materialität eine Ansiedlung von Korallenlarven begünstigt oder wie eine räumlich vielseitige Struktur die Artenvielfalt verbessern kann. Zudem fehlt ein integrierter Unterwasser-Überwachungsprozess, welcher Informationen über das Ökosystem liefert und diese dem Entwurf bereitstellt. Zusätzlich ist eine Unterwasser-Überwachung notwendig, um herauszufinden, ob die künstlichen Riffstrukturen zur Regenerierung beitragen oder dem Ökosystem gänzlich schaden. In dieser Forschungsarbeit werden empirische und experimentelle Methoden angewendet: Algorithmisches Entwerfen für Korallenriffe, hochpräzise Unterwasser-Überwachung, Computermodellierung und -simulation. Die Forschung wird seit 2012 bis heute durch zwei Riffprototypen (Artificial Reef Prototypes – ARPs) in Gili Trawangan, Indonesien validiert. Zusätzlich wurden weitere separate Methoden und Techniken in insgesamt siebzehn computergestützten Experimenten entwickelt und so angewendet, dass viele kreuzvalidiert und in ein Framework integriert sind, welches dann als bedeutender Beitrag dem Forschungsgebiet zur Verfügung steht. Weitere Hauptbeiträge sind der Ökosystem-bewusste Entwurfsansatz (Ecosystem-aware design approach), Key Performance Indicators (KPIs) für das Gestalten von Korallenriffen, algorithmisches Entwerfen und die Herstellung von Biorock-Kathoden, neue hochpräzise Unterwasser-Überwachungsstrategien, reale Langzeitexperimente, neue digitale Analysemethoden, sowie zwei webbasierte Softwareanwendungen für die Gestaltung und die Überwachung von künstlichen Korallenriffen. Das methodische Framework ist das Hauptergebnis der Forschung, da die vielen technischen Komponenten in dieser Weise zum ersten Mal getestet und kombiniert wurden. Zusammenfassend reagiert die vorliegende Doktorarbeit sowohl auf die Dringlichkeit als auch auf die Relevanz der Erhaltung von Artenvielfalt in tropischen Korallenriffen in Zeiten eines massiven Aussterbens, indem sie einen differenzierten Entwurfsansatz für künstliche Korallenriffe offeriert. Die Arbeit zeigt auf, dass ein digitales Entwerfen einer solchen „lebendigen Architektur“ unter Berücksichtigung vielfältiger Anforderungen und Leistungsparametern machbar ist. Zusätzlich bietet sie eine ausführliche kritische Diskussion über die Rolle von computergestützten Entwerfen und Architektur im Zusammenhang mit Regenerierung von Ökosystemen und “Planetary Thinking”. In dieser Hinsicht fungiert die Doktorarbeit als theoretischer und praktischer Hintergrund für computergestütztes Entwerfen, Ökologie und Meeresschutz. Eine Verbesserung des Entwerfens von künstlichen Korallenriffen wird nicht nur auf technischer Ebene aufgezeigt, sondern es werden auch die wesentlichen Kriterien und Techniken für deren Umsetzung benannt. Schlüsselwörter: Künstliche Korallenriffe, Computermodellierung, hochpräzise Unterwasser-Überwachung, Ökologie im Architekturentwurf. KW - Korallenriff KW - Algorithmus KW - Architektur KW - Meeresökologie KW - Software KW - Artificial coral reefs KW - Computational modelling KW - High precision underwater monitoring KW - Ecology in design KW - Künstliche Korallenriffe KW - Unterwasserarchitektur Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220322-46115 UR - https://artificialreefdesign.com/ SN - 978-3-00-074495-2 N1 - Die URL führt zu 3D Modelle von echten Korallenriffen. ER - TY - THES A1 - Stäudel, Jürgen T1 - Development, Implementation and Operation of Integrated Sanitation Systems Based on Material-Flows – Integrated Sanitation in the City of Darkhan, Mongolia - A Practicable Example N2 - The world society faces a huge challenge to implement the human right of “access to sanitation”. More and more it is accepted that the conventional approach towards providing sanitation services is not suitable to solve this problem. This dissertation examines the possibility to enhance “access to sanitation” for people who are living in areas with underdeveloped water and wastewater infrastructure systems. The idea hereby is to follow an integrated approach for sanitation, which allows for a mutual completion of existing infrastructure with resource-based sanitation systems. The notion “integrated sanitation system (iSaS)” is defined in this work and guiding principles for iSaS are formulated. Further on the implementation of iSaS is assessed at the example of a case study in the city of Darkhan in Mongolia. More than half of Mongolia’s population live in settlements where yurts (tents of Nomadic people) are predominant. In these settlements (or “ger areas”) sanitation systems are not existent and the hygienic situation is precarious. An iSaS has been developed for the ger areas in Darkhan and tested over more than two years. Further on a software-based model has been developed with the goal to describe and assess different variations of the iSaS. The results of the assessment of material-flows, monetary-flows and communication-flows within the iSaS are presented in this dissertation. The iSaS model is adaptable and transferable to the socio-economic conditions in other regions and climate zones. N2 - Die Weltgesellschaft steht der großen Herausforderung gegenüber das Menschrecht auf Zugang zu Sanitärversorgung umzusetzen. Es wird zunehmend akzeptiert, dass konventionelle Ansätze der Abwasserwirtschaft dieses Problem nicht lösen können. Die vorliegende Dissertation untersucht die Möglichkeit eines integrierten Ansatzes, welcher Stoffflüsse, Geldflüsse und Kommunikationsflüsse gemeinsam betrachtet und komplementär zu existierenden Infrastruktursystemen angewendet werden kann. Der Begriff „integriertes Sanitärsystem (iSaS)“ wird definiert und anhand eines Fallbeispiels in der Stadt Darkhan in der Mongolei untersucht. Hierbei wurde ein Sanitärsystem für Jurtensiedlungen erarbeitet, pilothaft umgesetzt und über 2 Jahre betrieben. Weiterhin wurde ein software- basiertes Modell anhand der Prinzipien von iSaS entwickelt und verschiedene Variationen des Systems untersucht und diskutiert. Das Modell kann an die klimatischen und sozioökonomischen Rahmenbedingungen in anderen Regionen der Welt angepasst werden und damit die potentielle Umsetzung von iSaS unterstützen. KW - Abwasser KW - Infrastruktur KW - Entwicklungsländer KW - Abfall KW - iPiT® KW - Mongolia KW - integrated sanitation system KW - new alternative sanitation systems NASS KW - UDDT Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170512-31794 ER -