@phdthesis{Wolff2009, author = {Wolff, Thomas}, title = {Ein methodischer Bemessungsansatz zur Absch{\"a}tzung des Tragverhaltens von Pfahlgr{\"u}ndungen in weichem kalkigen Sedimentgestein}, doi = {10.25643/bauhaus-universitaet.1414}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20100125-14993}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2009}, abstract = {In der vorliegenden Arbeit wird das Tragverhalten und das Sicherheitsniveau axial belasteter Großbohrpf{\"a}hle in den pleistoz{\"a}nen Kalkarenit der K{\"u}stenregion von Dubai untersucht. Zun{\"a}chst wird auf der Grundlage von Ergebnissen umfangreicher Baugrundanalysen und Probebelastungen das Tragverhalten detailliert beschrieben. Anschließend wird ein auf der Finiten-Elemente-Methode basierendes Strukturmodell zur Simulation des Last-Setzungsverhaltens von Großbohrpf{\"a}hlen im Sinne eines numerischen Versuchsstandes entwickelt. Um herstellungsbedingte Ver{\"a}nderungen der Baugrundeigenschaften in der Kontaktzone Pfahl-Baugrund zu ber{\"u}cksichtigen, die mit boden- und felsmechanischen Elementversuchen gew{\"o}hnlich nicht erfassbar sind, werden die Gr{\"o}ßen der relevanten konstitutiven Parameterwerte iterativ mittels inverser Optimierungsstrategien bestimmt. Abschließend wird eine methodische Vorgehensweise aufgezeigt, wie das Sicherheitsniveau axial belasteter Großbohrpf{\"a}hlen unter Ber{\"u}cksichtigung der r{\"a}umlichen Variabilit{\"a}t der Baugrundeigenschaften zuverl{\"a}ssig abgesch{\"a}tzt werden kann.}, subject = {Pfahl}, language = {de} } @book{Graetz2008, author = {Graetz, Holger}, title = {Synergiepotenzial einer fragmentierten Wasserwirtschaft}, isbn = {978-3-86068-335-4}, doi = {10.25643/bauhaus-universitaet.1225}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080207-12903}, year = {2008}, abstract = {Problemstellung, Stand der Forschung und Zielsetzung der Arbeit Seit mehreren Jahren bestimmen ver{\"a}nderte Zielsetzungen in Europa den politischen Handlungsrahmen in der Organisation der Wasserwirtschaft und folgen dem Trend zu st{\"a}rker {\"o}konomisch und {\"o}kologisch ausgerichtetem Handeln. So fordert die Europ{\"a}ische Wasserrahmenrichtlinie u.a. die Umsetzung einer flussgebietsorientierten Bewirtschaftung der Oberfl{\"a}chengew{\"a}sser und des Grundwassers innerhalb bestimmter Fristen. Derzeitige Modernisierungskonzepte der Wasserwirtschaft fokussieren im Wesentlichen die Organisationsstrukturen kommunaler Aufgabentr{\"a}ger und deren Unternehmen, nicht aber eine Ver{\"a}nderung der umfassenden politischen und verwaltenden Organisationsstrukturen zur Steuerung der operativen Ebene. Die angestrebte Modernisierung wird daher insbesondere in kleinteiligen und komplexen, so genannten fragmentierten Organisationsstrukturen mit einer ausschließlich auf Unternehmen fokussierten Betrachtung nicht erreichbar sein. Diese kaum erforschten Strukturen bieten aufgrund der bestehenden Intransparenz und Komplexit{\"a}t der zahlreichen Organisationselemente vielf{\"a}ltige Ansatzpunkte f{\"u}r Optimierungsm{\"o}glichkeiten. Den entsprechenden Stand der Forschung bilden nur grundlegende Ans{\"a}tze zur Betrachtung des Zusammenwirkens von Akteuren in Organisationsstrukturen sowie entsprechende Optimierungsans{\"a}tze der Organisations- und Managementtheorien. Sie beziehen sich meist nur auf Unternehmen allgemein. Es fehlen derzeit umfassende und transparente Darstellungen der komplexen Organisationsstruktur der Wasserwirtschaft. Zielsetzung der vorliegenden Arbeit ist es, eine ganzheitliche Modernisierung insbesondere fragmentierter Wasserwirtschaftsstrukturen voranzutreiben. Es soll eine Steigerung der gesamten Leistungsf{\"a}higkeit sowohl der politischen, der verwaltungs- als auch der unternehmensbezogenen Organisationsstrukturen in der Wasserwirtschaft erreicht werden. ...}, subject = {Entscheidungstr{\"a}ger}, language = {de} } @phdthesis{Weitzmann2009, author = {Weitzmann, R{\"u}diger}, title = {Theory and application of optimization strategies for the design of seismically excited structures}, doi = {10.25643/bauhaus-universitaet.1406}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20091030-14917}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2009}, abstract = {The study introduces into the theory and application of optimization strategies in earthquake engineering. The optimization algorithm substitutes the intuitive solution of practical problems done by the engineer in daily practice, providing automatic design tools and numerical means for further exploration of the design space for various extremum states. This requires a mathematical formulation of the design task, that is provided for typical seismic evaluations within this document. Utilizing the natural relation between design and optimization tasks, appropriate mechanical concepts are developed and discussed. The explanations start with an overview on the mechanical background for continua. Hereby the focus is placed on elasto-plastic structures. The given extremum formulations are treated with help of discretization methods in order to obtain optimization problems. These basics are utilized for derivation of programs for eigenvalue and stability analysis, that are applied in simplified linear analysis for the design of seismically excited structures. Another focus is set on the application in simplified nonlinear design, that uses limit state analyses on the basis of nonlinear problem formulations. Well known concepts as the response and pushover analysis are covered as well as alternative strategies on the basis of shakedown theory or cycle and deformation based evaluations. Furthermore, the study gives insight into the application of optimization problems in conjunction with nonlinear time history analyses. The solution of step-by-step procedures within optimization algorithms is shown and aspects of dynamic limit state analyses are discussed. For illustration of the great variety of optimization-based concepts in earthquake engineering, several specialized applications are presented, e.g. the generation of artificial ground motions and the determination of reduction coefficients for design spectrum reduction due to viscous and hysteretic damping. As well alternative strategies for the design of base isolated structures with controlled impact are presented. All presented applications are illustrated with help of various examples.}, subject = {Dynamik}, language = {en} } @inproceedings{SampaioHenriques2003, author = {Sampaio, Alcinia Zita and Henriques, Pedro}, title = {Interactive project planning in construction based on virtual reality technology}, doi = {10.25643/bauhaus-universitaet.358}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3588}, year = {2003}, abstract = {This paper describes a didactic application that is part of a research project whose main aim is to develop a computer-aided system which will assist design and construction processes. It is based on the visual simulation of construction activities. Geometric modeling and virtual reality techniques are used in the visualization of the design process and to define user-friendly interfaces in order to access construction information, which could prove useful to Civil Engineering professionals. As a first step, was developed a prototype that serves as a didactic tool for Civil Engineering students of disciplines concerned with building construction. The construction of a double brick wall is the case studied. The wall is defined as a three dimensional model formed with the several components needed to edify it. Using the wall's virtual model it is possible to show, in an interactive way, the sequence of the construction process and observe from any point of view the configurations in detail of the building components. This is then a didactic tool application in construction processes domain of great interest to Civil Engineering students.}, subject = {Bauwesen}, language = {en} } @article{TakagiTaniKawamura2004, author = {Takagi, Kousuke and Tani, Akinori and Kawamura, Hiroshi}, title = {Research on Intelligent Fuzzy Optimal Active and Hybrid Control Systems of Building Structures - Verification of Optimization Method on Switching Rules of Control Forces}, doi = {10.25643/bauhaus-universitaet.223}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2238}, year = {2004}, abstract = {Recently, many reseraches on active control systems of building structures are preformed based on modern control theory and are installed real buildings. The authors have already proposed intelligent fuzzy optimal active control (IFOAC) systems. IFOAC systems imitate intelligent activities of human brains such as prediction, adaptation, decision-kaking and so on. In IFOAC systems, objective and subjective judgements on the active control can be taken into account. However, IFOAC systems are considered to be suitable for far-field erathquake and control effect becomes small in case of near-field earthqaukes which include a few velosity pules with large amplitudes. To improve control effect in case of near-souece earthquakes, the authors have also proposed hybrid control (HC) systems, in which IFOAC systems and fuzzy control system are combined. In HC systems, the fuzzy control systems are introduced as a reflective fuzzy active control (RFAC) system and imitates spinal reflection of human. In HC systems, active control forces are activated to buildings in accordance with switching rules on active control forces. In this paper, optimizations on fuzzy control rules in RFAC system and switching rules of active control forces in HC system are performed by Parameter-Free Genetic Algorithms (PfGAs). Here, the optimization is performed by using different earthquake inputs. The results of digital simulations show that the HC system can reduce maximal response displacements under restrictions on strokes of the actuator effectively in case of a near-source earthquake and the effectiveness of the proposed HC system is discussed and clarified.}, subject = {Mehragentensystem}, language = {en} } @inproceedings{HaaseLangerMuehlhuber2003, author = {Haase, Gundolf and Langer, Ulrich and M{\"u}hlhuber, Wolfram}, title = {Optimal Sizing and Shape Optimization in Structural Mechanics}, doi = {10.25643/bauhaus-universitaet.300}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3005}, year = {2003}, abstract = {We consider an industrial application consisting of the mass minimization of a frame in an injection moulding machine. This frame has to compensate the forces acting on the mould inside the machine and has to fulfill certain critical constraints. The deformation of that frame with constant thickness is described by the plain stress state equations for linear elasticity. If the thickness varies then we use a generalized plain stress state with constant thickness in the coarse grid elements. These direct problems are solved by an adaptive multigrid solver. The mass minimization problem leads to a constrained minimization problem for a non-linear functional which will be solved by some standard optimization algorithm which requires the gradients with respect to design parameters. For the shape optimization problem, we assume that the machine components consist of simple geometrical primitives determined by a few design parameters. Therefore, we calculate the gradient in the shape optimization by means of numerical differentiation which requires the solution of approximately 4 direct problems per design parameter. The adaptive solver guarantees the detection of critical regions automatically, and ensures a good approximation to the exact solution of the direct problem. This rather slow approach can be significantly accelerated by using the adjoint method to express the gradient. It will be combined with a direct implementation of several terms that appear after applying the chain rule to the gradient.}, subject = {Baustatik}, language = {en} } @article{KicingerArciszewskiDeJong2004, author = {Kicinger, Rafal and Arciszewski, Tomasz and De Jong, Kenneth}, title = {Distributed Evolutionary Design: Island-Model-based Optimization of Steel Skeleton Structures in Tall Buildings}, doi = {10.25643/bauhaus-universitaet.219}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2195}, year = {2004}, abstract = {This paper presents results of a study on distributed, or parallel, evolutionary computation in the topological design of steel structural systems in tall buildings. It describes results of extensive experimental research on various parallel evolutionary architectures applied to a complex structural design problem. The experiments were conducted using Inventor 2003, a networkbased evolutionary design support tool developed at George Mason University. First, a general introduction to evolutionary computation is provided with an emphasis on recent developments in parallel evolutionary architectures. Next, a discussion of conceptual design of steel structural systems in tall buildings is presented. Further, Inventor 2003 is briefly introduced as well as its design representation and evolutionary computation characteristics. Next, the results obtained from systematic design experiments conducted with Inventor 2003 are discussed. The objective of these experiments was to qualitatively and quantitatively investigate evolution of steel structural systems in tall buildings during a distributed evolutionary design process as well as to compare efficiency and effectiveness of various parallel evolutionary architectures with the traditional evolutionary design approaches. Two connectivity topologies (ring topology and fully-connected topology) have been investigated for four populations of structural designs evolving in parallel and using various migration strategies. Also, results of the initial sensitivity studies are reported in which two ways of initializing distributed evolutionary design processes were investigated, using either arbitrarily selected designs as initial parents or randomly generated ones. Finally, initial research conclusions are presented.}, subject = {Mehragentensystem}, language = {en} } @inproceedings{RaueWeitzmann2004, author = {Raue, Erich and Weitzmann, R{\"u}diger}, title = {Analysis and Design of Hybrid Structures using Optimization Strategies}, doi = {10.25643/bauhaus-universitaet.102}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1023}, year = {2004}, abstract = {The paper gives a general overview and concerns with a specified set of computer-aided analysis modules for hybrid structures loaded by extreme excitations. All problems are solved by methods of linear, quadratic or nonlinear mathematical optimization, that leads to very effective and economic design solutions. All approaches are derived from general optimization problem that can be easily altered to conform to specific design tasks. Some advantages and possibilities of hybrid structural modeling (single or mixed model-supported) are discussed. The methods will be illustrated by an example structure and optimization schemes.}, subject = {Konzipieren }, language = {en} } @inproceedings{BrennigSanio2004, author = {Brennig, Thomas and Sanio, Hans-Peter}, title = {New Methods of Computer Aided Optimization of Investment and Operating Costs for Buildings During Their Useful Life}, doi = {10.25643/bauhaus-universitaet.96}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-965}, year = {2004}, abstract = {Current software solutions for real estate planning, construction and use, do not model the complete life cycle of a building. Well-integrated software tools exist for the planning and construction phases. Data integrity exists throughout the planning and construction phases, but problems occur at the transition to the use-phase. At this interface, the complete data set of planning and execution gets lost. Another software deficiency is that current software solutions don't handle construction work and maintenance work equally. This is why a new software generation is demanded, which continuously covers the entire workflow process from the planning phase to the demolition of a building. New data concepts have to be developed, which allow bringing work items for construction together with work items for real estate use.}, subject = {Optimierung}, language = {en} } @article{BerkowskiBoron1997, author = {Berkowski, P. and Boron, Jacek}, title = {An Algorithm of compromise structural Optimisation of Bar Structures}, doi = {10.25643/bauhaus-universitaet.526}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5264}, year = {1997}, abstract = {Authors' own research in applied unicriterial and multicriterial optimisation of bar structures, and also an analysis of accessible bibliography on structural synthesis allows to present herein an attempt to define a general algorithm for proceeding in formulation of a structural optimisation problem. A practical aspect of such an algorithm consists, in author's opinion, in enabling a designer a correct creation of a mathematical model of synthesis problems, independently of known mathematical methods employed to looking for an unconditional extremum of function of several variables. A proposed algorithm is not a ready-for-use tool for solving all the optimisation problems, but it constitutes an easy-to-expand theoretical basis. This basis should allow a designer to create a proper set of compromises on the way to construct a mathematical model of a specific optimisation problem. The algorithm, presented in the paper, is constructed as a sequence of the one-after-another problem questions, on which the designer answers: yes or no, and a set of selections from the knowledge base consisting of the elements of an optimisation problem components. The order of making questions adopted by the authors in the algorithm is subjective, however it is supported by their experience, both in applied optimisation and in designing of structures like trusses or frames.}, subject = {Stabwerk}, language = {en} }