@inproceedings{MostBucher, author = {Most, Thomas and Bucher, Christian}, title = {ADAPTIVE RESPONSE SURFACE APPROACH USING ARTIFICIAL NEURAL NETWORKS AND MOVING LEAST SQUARES}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2992}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29922}, pages = {13}, abstract = {In engineering science the modeling and numerical analysis of complex systems and relations plays an important role. In order to realize such an investigation, for example a stochastic analysis, in a reasonable computational time, approximation procedure have been developed. A very famous approach is the response surface method, where the relation between input and output quantities is represented for example by global polynomials or local interpolation schemes as Moving Least Squares (MLS). In recent years artificial neural networks (ANN) have been applied as well for such purposes. Recently an adaptive response surface approach for reliability analyses was proposed, which is very efficient concerning the number of expensive limit state function evaluations. Due to the applied simplex interpolation the procedure is limited to small dimensions. In this paper this approach is extended for larger dimensions using combined ANN and MLS response surfaces for evaluating the adaptation criterion with only one set of joined limit state points. As adaptation criterion a combination by using the maximum difference in the conditional probabilities of failure and the maximum difference in the approximated radii is applied. Compared to response surfaces on directional samples or to plain directional sampling the failure probability can be estimated with a much smaller number of limit state points.}, subject = {Architektur }, language = {en} } @inproceedings{EckardtKoenke, author = {Eckardt, Stefan and K{\"o}nke, Carsten}, title = {ADAPTIVE SIMULATION OF THE DAMAGE BEHAVIOR OF CONCRETE USING HETEROGENEOUS MULTISCALE MODELS}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2947}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29478}, pages = {15}, abstract = {In this paper an adaptive heterogeneous multiscale model, which couples two substructures with different length scales into one numerical model is introduced for the simulation of damage in concrete. In the presented approach the initiation, propagation and coalescence of microcracks is simulated using a mesoscale model, which explicitly represents the heterogeneous material structure of concrete. The mesoscale model is restricted to the damaged parts of the structure, whereas the undamaged regions are simulated on the macroscale. As a result an adaptive enlargement of the mesoscale model during the simulation is necessary. In the first part of the paper the generation of the heterogeneous mesoscopic structure of concrete, the finite element discretization of the mesoscale model, the applied isotropic damage model and the cohesive zone model are briefly introduced. Furthermore the mesoscale simulation of a uniaxial tension test of a concrete prism is presented and own obtained numerical results are compared to experimental results. The second part is focused on the adaptive heterogeneous multiscale approach. Indicators for the model adaptation and for the coupling between the different numerical models will be introduced. The transfer from the macroscale to the mesoscale and the adaptive enlargement of the mesoscale substructure will be presented in detail. A nonlinear simulation of a realistic structure using an adaptive heterogeneous multiscale model is presented at the end of the paper to show the applicability of the proposed approach to large-scale structures.}, subject = {Architektur }, language = {en} } @inproceedings{WallFoersterNeumannetal., author = {Wall, Wolfgang A. and F{\"o}rster, Christiane and Neumann, Malte and Ramm, Ekkehard}, title = {ADVANCES IN FLUID-STRUCTURE INTERACTION}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2916}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29161}, pages = {17}, abstract = {For the dynamic behavior of lightweight structures like thin shells and membranes exposed to fluid flow the interaction between the two fields is often essential. Computational fluid-structure interaction provides a tool to predict this interaction and complement or eventually replace expensive experiments. Partitioned analyses techniques enjoy great popularity for the numerical simulation of these interactions. This is due to their computational superiority over simultaneous, i.e. fully coupled monolithic approaches, as they allow the independent use of suitable discretization methods and modular analysis software. We use, for the fluid, GLS stabilized finite elements on a moving domain based on the incompressible instationary Navier-Stokes equations, where the formulation guarantees geometric conservation on the deforming domain. The structure is discretized by nonlinear, three-dimensional shell elements. Commonly used sequential staggered coupling schemes may exhibit instabilities due to the so-called artificial added mass effect. As best remedy to this problem subiterations should be invoked to guarantee kinematic and dynamic continuity across the fluid-structure interface. Since iterative coupling algorithms are computationally very costly, their convergence rate is very decisive for their usability. To ensure and accelerate the convergence of this iteration the updates of the interface position are relaxed. The time dependent, 'optimal' relaxation parameter is determined automatically without any user-input via exploiting a gradient method or applying an Aitken iteration scheme.}, subject = {Architektur }, language = {en} } @inproceedings{ZangSommer, author = {Zang, Di and Sommer, G.}, title = {ALGEBRAICALLY EXTENDED 2D IMAGE REPRESENTATION}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3039}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30396}, pages = {10}, abstract = {We present an algebraically extended 2D image representation in this paper. In order to obtain more degrees of freedom, a 2D image is embedded into a certain geometric algebra. Combining methods of differential geometry, tensor algebra, monogenic signal and quadrature filter, the novel 2D image representation can be derived as the monogenic extension of a curvature tensor. The 2D spherical harmonics are employed as basis functions to construct the algebraically extended 2D image representation. From this representation, the monogenic signal and the monogenic curvature signal for modeling intrinsically one and two dimensional (i1D/i2D) structures are obtained as special cases. Local features of amplitude, phase and orientation can be extracted at the same time in this unique framework. Compared with the related work, our approach has the advantage of simultaneous estimation of local phase and orientation. The main contribution is the rotationally invariant phase estimation, which enables phase-based processing in many computer vision tasks.}, subject = {Architektur }, language = {en} } @inproceedings{SchererGrinewitschus, author = {Scherer, Klaus and Grinewitschus, Viktor}, title = {AMBIENT INTELLIGENCE IN RAUM UND BAU INNOVATIVE TECHNIKASSISTENZ F{\"U}R FACILITY MANAGEMENT UND ANWENDUNG}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2914}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29140}, pages = {9}, abstract = {Mikroelektronik und Mikrosystemtechnik in Kombination mit Informations- und Kommunikations-technik erlauben es mittlerweile, Rechenleistung und Kommunikationsf{\"a}higkeit in kleinsten Formaten, mit geringsten Energien und zu g{\"u}nstigen Preisen nutzbringend in unser privates und berufliches Umfeld einzubringen. Beispiele sind Notebook-PC, PDA, Handy und das Navigationßystem im Auto. Aber auch eingebettete Elektronik in Komponenten, Ger{\"a}ten und Systemen ist nunmehr zur Selbstverst{\"a}ndlichkeit geworden. Bekannte Beispiele aus der Haustechnik sind Mikroprozeßoren in Heizungs- und Alarmanlagen und aber auch in Komponenten wie Brand- und Bewegungsmelder. Wir n{\"a}hern uns dem vor einigen Jahren noch als Vision bezeichneten Zustand der {\"u}berall vorhandenen elektronischen Rechenleistung (engl. ubiquitous computing) bzw. des von Informationsverarbeitung durchdrungenen t{\"a}glichen Umfelds (engl. pervasive computing). Werden die TGA-Komponenten genau wie die gr{\"o}ßeren Computerkomponenten (z.B. PCs, Server) {\"u}ber Datenschnittstellen zu r{\"a}umlich verteilten Netzwerken verkn{\"u}pft (z.B. Internet, Intranet) und mit einer system{\"u}bergreifenden und ad{\"a}quaten Intelligenz (Software) programmiert, so k{\"o}nnen neuartige Funktionalit{\"a}ten im jeweiligen Anwendungsumfeld (engl. ambient intelligence, kurz AmI, [1]) entstehen. Hier liegt bei Geb{\"a}uden und R{\"a}umen speziell eine große Chance, die bislang einer ganzheitlichen Systemkonzeption unter Einschluß von Architektur, Geb{\"a}udephysik, technischer Geb{\"a}udeausr{\"u}stung (TGA) und Geb{\"a}udeautomation (GA) im Wege stehende Gewerketrennung zu {\"u}berwinden. Es entstehen f{\"u}r div. Anwendungszwecke systemisch integrierte >smart areas< (nach Prof. Becker, FH Biberach). Im vorliegenden Beitrag erl{\"a}uterte Beispiele f{\"u}r AmI-L{\"o}sungen im Immobilienbereich sind Raumsysteme zur automatischen und sicheren Erkennung von Notf{\"a}llen, z.B. in Pflegeheimen; sich automatisch an die Nutzung und den Nutzer bzgl. Klima und Beleuchtung adaptierende Raumsysteme im B{\"u}ro- oder Hotelbereich und die elektronische Aßistenz des Bau- und Betriebsprozeßes von Geb{\"a}uden. Im Duisburger inHaus-Innovationszentrum f{\"u}r Intelligente Raum- und Geb{\"a}udesysteme der Fraunhofer-Gesellschaft wurden in den letzten Jahren erste L{\"o}sungen mit diesem neuartigen Ansatz konzipiert, entwickelt und erprobt. Der Beitrag beschreibt nach einer kurzen Skizzierung des Ambient-Intelligence-Ansatzes an Beispielen M{\"o}glichkeiten f{\"u}r den Transfer dieser neuen Technologie in den Raum- und Geb{\"a}udebereich. Es folgt eine abschließende Zusammenfaßung und eine Einsch{\"a}tzung der Zukunftspotenziale der Ambient Intelligence in Raum und Bau.}, subject = {Architektur }, language = {de} } @inproceedings{MostEckardtSchraderetal., author = {Most, Thomas and Eckardt, Stefan and Schrader, Kai and Deckner, T.}, title = {AN IMPROVED COHESIVE CRACK MODEL FOR COMBINED CRACK OPENING AND SLIDING UNDER CYCLIC LOADING}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2993}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29933}, pages = {20}, abstract = {The modeling of crack propagation in plain and reinforced concrete structures is still a field for many researchers. If a macroscopic description of the cohesive cracking process of concrete is applied, generally the Fictitious Crack Model is utilized, where a force transmission over micro cracks is assumed. In the most applications of this concept the cohesive model represents the relation between the normal crack opening and the normal stress, which is mostly defined as an exponential softening function, independently from the shear stresses in tangential direction. The cohesive forces are then calculated only from the normal stresses. By Carol et al. 1997 an improved model was developed using a coupled relation between the normal and shear damage based on an elasto-plastic constitutive formulation. This model is based on a hyperbolic yield surface depending on the normal and the shear stresses and on the tensile and shear strength. This model also represents the effect of shear traction induced crack opening. Due to the elasto-plastic formulation, where the inelastic crack opening is represented by plastic strains, this model is limited for applications with monotonic loading. In order to enable the application for cases with un- and reloading the existing model is extended in this study using a combined plastic-damage formulation, which enables the modeling of crack opening and crack closure. Furthermore the corresponding algorithmic implementation using a return mapping approach is presented and the model is verified by means of several numerical examples. Finally an investigation concerning the identification of the model parameters by means of neural networks is presented. In this analysis an inverse approximation of the model parameters is performed by using a given set of points of the load displacement curves as input values and the model parameters as output terms. It will be shown, that the elasto-plastic model parameters could be identified well with this approach, but require a huge number of simulations.}, subject = {Architektur }, language = {en} } @inproceedings{SariyildizSchwenck1997, author = {Sariyildiz, Sevil and Schwenck, M.}, title = {An Integrated Software Environment for the Architectural Design Process}, doi = {10.25643/bauhaus-universitaet.444}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4447}, year = {1997}, abstract = {The general motivation of this research is to develop software to support the handling of the increased complexity of architectural design. In this paper we describe a system providing general support during the whole process. Instead of only developing design tools we are also addressing the problem of the operating environment of these tools. We conclude that design tools have to be integrated in an open, modular, distributed, user friendly and efficient environment. Two major fields have to be addressed - the development of design tools and the realisation of an integrated system as their operation environment. We will briefly focus on the latter by discussing known technologies in the field of information technology and other design disciplines that can be used to realise such an environment. Regarding the first subject we have to state the need of a detailed tool specification. As a solution we suggest a strategy where the tool functions are specified on the basis of a transformation, where a hierarchical process model is mapped into specifications of different design tools realising appropriate support for all sub-processes of architectural design. Using this strategy the main steps to develop such a support system are: implementation of a framework as basis for the integrated design system decision whether the tool specification are already implemented in available tools in this case these tools can be integrated using known methods for tool coupling otherwise new design tools have to be developed according to the framework}, subject = {Architektur}, language = {en} } @inproceedings{WoszczynaKaminskiMajetal., author = {Woszczyna, Anna and Kaminski, Mieczysław and Maj, Marek and Ubysz, Andrzej}, title = {ANALYSING THE INFLUENCE OF THE REINFORCED CONCRETE CHIMNEY GEOMETRY CHANGES ON THE STRESSES IN THE CHIMNEY SHAFT}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3038}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30388}, pages = {7}, abstract = {Analysis of the reinforced concrete chimney geometry changes and their influence on the stresses in the chimney mantle was made. All the changes were introduced to a model chimney and compared. Relations between the stresses in the mantle of the chimney and the deformations determined by the change of the chimney's vertical axis geometry were investigated. The vertical axis of chimney was described by linear function (corresponding to the real rotation of the chimney together with the foundation), and by parabolic function (corresponding to the real dislocation of the chimney under the influence of the horizontal forces - wind). The positive stress pattern in the concrete as well as the negative stress pattern in the reinforcing steel have been presented. The two cases were compared. Analysis of the stress changes in the chimney mantle depending on the modification in the thickness of the mantle (the thickness of the chimney mantle was altered in the linear or the abrupt way) was carried out. The relation between the stresses and the chimney's diameter change from the bottom to the top of the chimney was investigated. All the analyses were conducted by means of a specially developed computer program created in Mathematica environment. The program makes it also possible to control calculations and to visualize the results of the calculations at every stage of the calculation process.}, subject = {Architektur }, language = {en} } @inproceedings{RyanKrausshar, author = {Ryan, John and Kraußhar, Rolf S{\"o}ren}, title = {ANALYSIS OF DIRAC OPERATORS ON SOME CONFORMALLY FLAT MANIFOLDS}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3008}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30081}, pages = {5}, abstract = {In this paper we shall review the role of Dirac operators arising in Clifford analysis over some examples of conformally flat manifolds.}, subject = {Architektur }, language = {en} } @inproceedings{Knyziak, author = {Knyziak, Piotr}, title = {ANALYSIS THE TECHNICAL STATE FOR LARGE-PANEL RESIDENTIAL BUILDINGS BEHIND ASSISTANCE OF ARTIFICIAL NEURAL NETWORKS}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2979}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29792}, pages = {9}, abstract = {This paper presents two new methods for analysis of a technical state of large-panel residential buildings. The first method is based on elements extracted from the classical methods and on data about repairs and modernization collected from building documentations. The technical state of a building is calculated as a sum of several groups of elements defining the technical state. The deterioration in this method depends on: - time, which has passed since last repair of element or time which has passed since construction, - estimate of the state of element groups which can be determined on basis of yearly controls. This is a new unique method. it is easy to use, does not need expertise. The required data could be extracted easily from building documentations. For better accuracy the data from building inspections should be applied (in Poland inspections are made every year). The second method is based on the extracted data processing by means of the artificial neural networks. The aim is to learn the artificial neural network configurations for a set of data containing values of the technical state and information about building repairs for last years (or other information and building parameters) and next to analyse new buildings by the instructed neural network. The second profit from using artificial neural networks is the reduction of number of parameters. Instead of more then 40 parameters describing building, about 6-12 are usually sufficient for satisfactory accuracy. This method could have lower accuracy but it is less prone to data errors.}, subject = {Architektur }, language = {en} }