@inproceedings{MostBucherMacke,
  author    = {Most, Thomas and Bucher, Christian and Macke, M.},
  title     = {A NATURAL NEIGHBOR BASED MOVING LEAST SQUARES APPROACH WITH INTERPOLATING WEIGHTING FUNCTION},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2994},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29943},
  pages     = {17},
  abstract  = {The Element-free Galerkin Method has become a very popular tool for the simulation of mechanical problems with moving boundaries. The internally applied Moving Least Squares approximation uses in general Gaussian or cubic weighting functions and has compact support. Due to the approximative character of this method the obtained shape functions do not fulfill the interpolation condition, which causes additional numerical effort for the imposition of the essential boundary conditions. The application of a singular weighting function, which leads to singular coefficient matrices at the nodes, can solve this problem, but requires a very careful placement of the integration points. Special procedures for the handling of such singular matrices were proposed in literature, which require additional numerical effort. In this paper a non-singular weighting function is presented, which leads to an exact fulfillment of the interpolation condition. This weighting function leads to regular values of the weights and the coefficient matrices in the whole interpolation domain even at the nodes. Furthermore this function gives much more stable results for varying size of the influence radius and for strongly distorted nodal arrangements than classical weighting function types. Nevertheless, for practical applications the results are similar as these obtained with the regularized weighting type presented by the authors in previous publications. Finally a new concept will be presented, which enables an efficient analysis of systems with strongly varying node density. In this concept the nodal influence domains are adapted depending on the nodal configuration by interpolating the influence radius for each direction from the distances to the natural neighbor nodes. This approach requires a Voronoi diagram of the domain, which is available in this study since Delaunay triangles are used as integration background cells. In the numerical examples it will be shown, that this method leads to a more uniform and reduced number of influencing nodes for systems with varying node density than the classical circular influence domains, which means that the small additional numerical effort for interpolating the influence radius leads to remarkable reduction of the total numerical cost in a linear analysis while obtaining similar results. For nonlinear calculations this advantage would be even more significant.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@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 <Informatik>},
  language  = {en}
}
@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 <Informatik>},
  language  = {en}
}
@inproceedings{MelnikovSemenov,
  author    = {Melnikov, B. E. and Semenov, Artem},
  title     = {MULTILEVEL COMPUTATION IN CIVIL ENGINEERING BASED ON MULTIMODEL ELASTO-PLASTIC ANALYSIS},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2991},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29911},
  pages     = {11},
  abstract  = {Requires for reliability and durability of structures and their elements with simultaneous material economy have stimulated improvement of constitutive equations for description of elasto-plastic deformation processes. This has led to the development of phenomenological modelling of complex phenomena of irreversible deformation including history-dependent and rate-dependent effects. During the last several decades many works have been devoted to the development of elasto-plastic models, in order to better predict the material behavior under combined variable thermo-mechanical loading. The increase of accuracy of stress analysis and safety factors for complex structures with the help of modern finite-element packages (ABAQUS, ANSYS, COSMOS, LS-DYNA, MSC.MARC, MSC.NASTRAN, PERMAS and other) can be provided only by use of complex and special variants of plasticity theories, which are adequate for the considered loading conditions and based on authentic information about properties of materials. The areas of application of the various theories (models) are as a rule unknown to the users of finite-element packages at the existing variety loading condition sin machine-building designs. At the moment a universal theory of inelasticity is absent and even the most accomplished theories can not guarantee adequate description of deformation processes for arbitrary structure under wide range of loading programs. The classifier of materials, loading conditions, effects (phenomena) and list of basic experiments are developed by the authors. Use of these classifiers for an establishment of hierarchy of models is a first step for introduction of the multimodel analysis into computational practice. The set of the classic and modern inelasticity theories is considered, so that they are applicable for stress analysis of structures under complex loading programs. Among them there are plastic flow theories with linear and nonlinear isotropic and kinematic hardening, multisurface theories, endochronic theory, holonomic theory, rheologic models, theory of elasto-plastic processes, slip theory, physical theories (single crystal and polycrystalline models) and others. The classification of materials provides rearranging by a degree of homogeneous, chemical composition, level of strength and plasticity, behavior under cyclic loading, anisotropy of properties at initial condition, anisotropy of properties during deformation process, structural stability. The classification of loading conditions takes into consideration proportional and non-proportional loading, temperature range, combination of cyclic and monotonous loading, one-axial, two-axial and complex stress state, curvature of strain path, presence of stress concentrators and level of strain gradient. A unified general form of constitutive equations is presented for all used material models based upon the concept of internal state variables. The wide range of mentioned above inelastic material models has been implemented into finite element program PANTOCRATOR developed by authors (see for details www.pantocrator.narod.ru). Application possibility of different material models is considered both for material element and for complex structures subjected to complex non-proportional loading.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{Meis,
  author    = {Meis, Jochen},
  title     = {SERVICE DESIGN AND SERVICE MANAGEMENT WITH THE SERVICE BLUEPRINTING METHODOLOGY},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2990},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29908},
  pages     = {11},
  abstract  = {A new application of software technology is the application area of smart living or sustainable living. Within this area application platforms are designed and realized with the goal to support value added services. In this context value added services integrates microelectronics, home automation and services to enhance the attractiveness of flats, homes and buildings. Especially real estate companies or service providers dealing with home services are interested in an effective design and management of their services. Service Engineering is the approved approach for designing customer oriented service processes. Service engineering consists of several phases; from situation analysis to service creation and service design to service management. This article will describe how the method service blueprint can be used to design service processes. Smart living includes all actions to enlarge a flat to a smart home for living. One special requirement of this application domain is the use of local components (actuators, sensors) within service processes. This article will show how this extended method supports service providers to improve the quality of customer oriented service processes and the derivation of needed interfaces of involved actors. For the civil engineering process it will be possible to derive needed information from a built in home automation system. The aim is to show, how to get needed smart local components to fullfill later offered it-supported value added services. Value added services focused on inhabitants are grouped to consulting and information, care and supervision, leisure time activities, repairs, mobility and delivery, safety and security, supply and disposal.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{Markwardt,
  author    = {Markwardt, Klaus},
  title     = {WAVELET ANALYSIS AND FREQUENCY BAND DECOMPOSITIONS},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2989},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29895},
  pages     = {22},
  abstract  = {In many applications such as parameter identification of oscillating systems in civil enginee-ring, speech processing, image processing and others we are interested in the frequency con-tent of a signal locally in time. As a start wavelet analysis provides a time-scale decomposition of signals, but this wavelet transform can be connected with an appropriate time-frequency decomposition. For instance in Matlab are defined pseudo-frequencies of wavelet scales as frequency centers of the corresponding bands. This frequency bands overlap more or less which depends on the choice of the biorthogonal wavelet system. Such a definition of frequency center is possible and useful, because different frequencies predominate at different dyadic scales of a wavelet decomposition or rather at different nodes of a wavelet packet decomposition tree. The goal of this work is to offer better algorithms for characterising frequency band behaviour and for calculating frequency centers of orthogonal and biorthogonal wavelet systems. This will be done with some product formulas in frequency domain. Now the connecting procedu-res are more analytical based, better connected with wavelet theory and more assessable. This procedures doesn't need any time approximation of the wavelet and scaling functions. The method only works in the case of biorthogonal wavelet systems, where scaling functions and wavelets are defined over discrete filters. But this is the practically essential case, because it is connected with fast algorithms (FWT, Mallat Algorithm). At the end corresponding to the wavelet transform some closed formulas of pure oscillations are given. They can generally used to compare the application of different wavelets in the FWT regarding it's frequency behaviour.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{LutherKoenke,
  author    = {Luther, Torsten and K{\"o}nke, Carsten},
  title     = {INVESTIGATION OF CRACK GROWTH IN POLYCRYSTALLINE MESOSTRUCTURES},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2988},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29886},
  pages     = {11},
  abstract  = {The design and application of high performance materials demands extensive knowledge of the materials damage behavior, which significantly depends on the meso- and microstructural complexity. Numerical simulations of crack growth on multiple length scales are promising tools to understand the damage phenomena in complex materials. In polycrystalline materials it has been observed that the grain boundary decohesion is one important mechanism that leads to micro crack initiation. Following this observation the paper presents a polycrystal mesoscale model consisting of grains with orthotropic material behavior and cohesive interfaces along grain boundaries, which is able to reproduce the crack initiation and propagation along grain boundaries in polycrystalline materials. With respect to the importance of modeling the geometry of the grain structure an advanced Voronoi algorithm is proposed to generate realistic polycrystalline material structures based on measured grain size distribution. The polycrystal model is applied to investigate the crack initiation and propagation in statically loaded representative volume elements of aluminum on the mesoscale without the necessity of initial damage definition. Future research work is planned to include the mesoscale model into a multiscale model for the damage analysis in polycrystalline materials.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{Loemker,
  author    = {L{\"o}mker, Thorsten Michael},
  title     = {SOLVING REVITALIZATION-PROBLEMS BY THE USE OF A CONSTRAINT PROGRAMING LANGUAGE},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2987},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29874},
  pages     = {13},
  abstract  = {This research focuses on an approach to describe principles in architectural layout planning within the domain of revitalization. With the aid of mathematical rules, which are executed by a computer, solutions to design problems are generated. Provided that "design" is in principle a combinatorial problem, i.e. a constraint-based search for an overall optimal solution of a problem, an exemplary method will be described to solve such problems in architectural layout planning. To avoid conflicts relating to theoretical subtleness, a customary approach adopted from Operations Research has been chosen in this work. In this approach, design is a synonym for planning, which could be described as a systematic and methodical course of action for the analysis and solution of current or future problems. The planning task is defined as an analysis of a problem with the aim to prepare optimal decisions by the use of mathematical methods. The decision problem of a planning task is represented by an optimization model and the application of an efficient algorithm in order to aid finding one or more solutions to the problem. The basic principle underlying the approach presented herein is the understanding of design in terms of searching for solutions that fulfill specific criteria. This search is executed by the use of a constraint programming language.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{LourensvanRooyen,
  author    = {Lourens, Eliz-Mari and van Rooyen, G.C.},
  title     = {Automating Preliminary Column Force Calculations In Multy-Storey Buildings},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2986},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29864},
  pages     = {10},
  abstract  = {In civil engineering practice, values of column forces are often required before any detailed analysis of the structure has been performed. One of the reasons for this arises from the fast-tracked nature of the majority of construction projects: foundations are laid and base columns constructed whilst analysis and design are still in progress. A need for quick results when feasibility studies are performed or when evaluating the effect of design changes on supporting columns form other situations in which column forces are required, but where a detailed analysis to get these forces seems superfluous. Thus it was concluded that the development of an efficient tool for column force calculations, in which the extensive input required in a finite element analysis is to be avoided, would be highly beneficial. The automation of the process is achieved by making use of a Voronoi diagram. The Voronoi diagram is used a) for subdividing the floor into influence areas and b) as a basis for automatic load assignment. The implemented procedure is integrated into a CAD system in which the relevant geometric information of the floor, i.e. its shape and column layout, can be defined or uploaded. A brief description of the implementation is included. Some comparative results and considerations regarding the continuation of the study are given.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}
@inproceedings{StoimenovaLinsDatchevaetal.,
  author    = {Stoimenova, Eugenia and Lins, Yvonne and Datcheva, Maria and Schanz, Tom},
  title     = {INVERSE MODELLING OF SOIL HYDRAULIC CHARACTERISTIC FUNCTIONS},
  editor    = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  doi       = {10.25643/bauhaus-universitaet.2985},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29858},
  pages     = {12},
  abstract  = {In this paper we evaluate 2D models for soil-water characteristic curve (SWCC), that incorporate the hysteretic nature of the relationship between volumetric water content θ and suction ψ. The models are based on nonlinear least squares estimation of the experimental data for sand. To estimate the dependent variable θ the proposed models include two independent variables, suction and sensors reading position (depth d in the column test). The variable d represents not only the position where suction and water content are measured but also the initial suction distribution before each of the hydraulic loading test phases. Due to this the proposed 2D regression models acquire the advantage that they: (a) can be applied for prediction of θ for any position along the column and (b) give the functional form for the scanning curves.},
  subject      = {Architektur <Informatik>},
  language  = {en}
}