@inproceedings{DaniunasKomkaWerner2000, author = {Daniunas, A. and Komka, A. and Werner, F.}, title = {ANALYSIS AND DETERMINATION OF STRENGTH IN PLASTIC STAGE OF FREE FORM STEEL SHAPES}, doi = {10.25643/bauhaus-universitaet.580}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5803}, year = {2000}, abstract = {The steel structure design codes require to check up the member strength when evaluating plastic deformations. The model of perfectly plastic material is accepted. The strength criteria for simple cross-sections (I section, etc.) of steel members are given in design codes. The analytical strength criteria for steel cross-sections and numerical approaches based on stepwise procedure are investigated in many articles. Another way for checking the carrying capacity of cross-sections is the use of methods that are applied for defining strain-deformed state of elastic perfectly plastic systems. In this paper non-iterative methods are suggested for checking strength of cross-sections. Carrying capacity of cross section is verified according to extremum principle of plastic fail under monotonically loading and the strain-deformed state of cross-section is defined according to extremum energy principals of elastic potential of residual stresses and complementary work of residual displacements. The mathematical expressions of these principals for discrete cross-section are formulated as problems of convex mathematical programming. The cross-section of steel member using finite element method is divided into free form plane elements. The constant distribution of stresses along the finite element is accepted. The relationships of finite elements for static formulation of the problem are formed so, that kinematics formulation relationships could be obtained in a formal way using the theory of duality. Numerical examples of determination of cross-section strength, composition of interactive curves and composition of moment-curvature curves for different axial force levels are presented.}, subject = {Stahlkonstruktion}, language = {en} } @inproceedings{BurghardtMeissner2000, author = {Burghardt, Michael and Meißner, Udo F.}, title = {Dreidimensionale Finite-Element-Baugrundmodelle f{\"u}r Ingeniuerprobleme}, doi = {10.25643/bauhaus-universitaet.575}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5750}, year = {2000}, abstract = {Bei komplexen Gr{\"u}ndungskonstruktionen sind Planungsfehler durch eine konsistente Modellierung vermeidbar. Manuelle Berechnungsmethoden erm{\"o}glichen im allgemeinen ein dreidimensionales Vorgehen nicht. Numerische Berechnungsmethoden, wie z.B. die Finite-Element-Methode, sind ein optimales Werkzeug zur ganzheitlichen Simulation des Problems. Die f{\"u}r die Finite-Element-Analyse notwendige Diskretisierung komplexer Bau- grundstrukturen ist manuell nicht zu bew{\"a}ltigen. Der vorliegende Beitrag zeigt wie ein Finite-Element-Modell automatisch aus einem geotechnischen Modell unter Ber{\"u}cksichtigung der spezifischen Anforderungen der Baugrund-Tragwerk-Struktur und des Bauablaufes erzeugt werden kann. Hierbei wird die Ber{\"u}cksichtigung der geometrischen und der mechanischen Besonderheiten bei der Netzgenerierung dargestellt.}, subject = {Baugrund}, language = {de} } @inproceedings{KonradChudobaButenweg2003, author = {Konrad, Martin and Chudoba, Rostislav and Butenweg, Christoph}, title = {Textile Reinforced Concrete Part II: Multi-Level Modeling Concept}, doi = {10.25643/bauhaus-universitaet.323}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3230}, year = {2003}, abstract = {The development of a consistent material model for textile reinforced concrete requires the formulation and calibration of several sub-models on different resolution scales. Each of these models represents the material structure at the corresponding scale. While the models at the micro-level are able to capture the fundamental failure and damage mechanisms of the material components (e.g. filament rupture and debonding from the matrix) their computational costs limit their application to the small size representative unit cells of the material structure. On the other hand, the macro-level models provide a sufficient performance at the expense of limited range of applicability. Due to the complex structuring of the textile reinforced concrete at several levels (filament - yarn - textile - matrix) it is a non-trivial task to develop a multiscale model from scratch. It is rather more effective to develop a set of conceptually related sub-models for each structural level covering the selected phenomena of the material behavior. The homogenized effective material properties obtained at the lower level may be verified and validated using experiments and models at the higher level(s). In this paper the development of a consistent material model for textile reinforced concrete is presented. Load carrying and failure mechanisms at the micro, meso and macro scales are described and models with the focus on the specified scales are introduced. The models currently being developed in the framework of the collaborative research center are classified and evaluated with respect to the failure mechanisms being captured. The micromechanical modeling of the yarn and bonding behavior is discussed in detail and the correspondence with the experiments focused on the selected failure and interaction mechanisms is shown. The example of modeling the bond layer demonstrates the application of the presented strategy.}, subject = {Beton}, language = {en} } @inproceedings{KohlerBodin2003, author = {Kohler, Niklaus and Bodin, Olivier}, title = {Dealing with sensitivity and uncertainty analysis in integrated buildung LCA model : Dealing with Uncertainty in Life Cyle Analysis of Building Model by Using Experiment Design Methods}, doi = {10.25643/bauhaus-universitaet.322}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3220}, year = {2003}, abstract = {Building design, realization, operation and refurbishment have to take into account the environmental impacts as well as the resulting costs over a long period of time. LCA methods had to be developed for buildings because of their complexity, their long life duration and through a large number of actors who are involved. This was realized by integrating life cycle analysis, life cycle costing and building product models in integrated LCA models. However the use of such models leads to difficulties. The principal ones are the uncertainty treatment in LCA models and the lack of experience of practitioners who are not LCA specialists. Answers to these problems are the management of uncertainty and the development of simplified models for building design, construction and operation. This can be achieved with the mean of experimental plans or Monte Carlo simulation. The paper will focus on how these techniques can be used, what are their possibilities and disadvantages, particularly concerning the development of simplified models.}, subject = {Bauwerk}, language = {en} } @inproceedings{BrackxDeSchepperLagae2003, author = {Brackx, Fred and De Schepper, Hennie and Lagae, Johan}, title = {Mathematical model of the laminated frame for a dome}, doi = {10.25643/bauhaus-universitaet.280}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2803}, year = {2003}, abstract = {On the basis of the little material available (an architecture plan and some photographs) a computer model is developed for a bullet shaped dome, part of the Belgian Congo pavilion, created by the architect Henry Lacoste for the International Colonial Exhibition of 1931 in Paris. The ingenious and elegant wooden skeleton of the dome is approximated in two stages. The first approximation focusses on the curves traced on the dome by the wooden laminae, which appear to be loxodromes, cutting the meridians by a constant angle. In a second approximation the very specific joints of the laminae are taken into consideration. The resulting computer image shows an astonishing resemblance with the photographs. Finally, the shapes and dimensions of all laminae are calculated, enabling a possible reconstruction of the dome.}, subject = {Kuppel}, language = {en} }