@inproceedings{BrossmannMueller, author = {Broßmann, Marko and M{\"u}ller, Karl-Heinz}, title = {STOCHASTISCHE ANALYSE VON STAHLBETONBALKEN IM GRENZZUSTAND DER ADAPTION UNTER BER{\"u}CKSICHTIGUNG DER STEIFIGKEITSDEGRADATION}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.2934}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-29341}, pages = {20}, abstract = {Am Beispiel eines 3-feldrigen Durchlauftr{\"a}gers wird die Versagenswahrscheinlichkeit von wechselnd belasteten Stahlbetonbalken bez{\"u}glich des Grenzzustandes der Adaption (Einspielen, shakedown) untersucht. Die Adaptionsanalyse erfolgt unter Ber{\"u}cksichtigung der beanspruchungschabh{\"a}ngigen Degradation der Biegesteifigkeit infolge Rissbildung. Die damit verbundene mechanische Problemstellung kann auf die Adaptionsanalyse linear elastisch - ideal plastischer Balkentragwerke mit unbekannter aber begrenzter Biegesteifigkeit zur{\"u}ckgef{\"u}hrt werden. Die Versagenswahrscheinlichkeit wird unter Ber{\"u}cksichtigung stochastischer Tragwerks- und Belastungsgr{\"o}ßen berechnet. Tragwerkseigenschaften und st{\"a}ndige Lasten gelten als zeitunabh{\"a}ngige Zufallsgr{\"o}ßen. Zeitlich ver{\"a}nderliche Lasten werden als nutzungsdauerbezogene Extremwerte POISSONscher Rechteck-Pulsprozesse unter Ber{\"u}cksichtigung zeitlicher {\"U}berlagerungseffekte modelliert, so dass die Versagenswahrscheinlichkeit ebenfalls eine nutzungsdauerbezogene Gr{\"o}ße ist. Die mechanischen Problemstellungen werden numerisch mit der mathematischen Optimierung gel{\"o}st. Die Versagenswahrscheinlichkeit wird auf statistischem Weg mit der Monte-Carlo-Methode gesch{\"a}tzt.}, subject = {Architektur }, language = {de} } @inproceedings{Raue, author = {Raue, Erich}, title = {NICHTLINEARE ANALYSE VON VERBUNDQUERSCHNITTEN - EIN NEUER ALTERNATIVER WEG}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3002}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30027}, pages = {13}, abstract = {A new approach to the non-linear analysis of cross-sections loaded by normal forces and bending moments is presented in the paper. The mechanical model is based on the LAGRANGE principle of minimum of total potential energy. Deformations, stresses and limit load parameters are obtained by solving a non-linear optimisation problem. The mathematical model is independent of the specifics of material. In addition to the stress strain relation and the specific strain energy W(ε) two further functions F(ε) and Φ(ε) are introduced to describe the material behaviour. Thus cracks in concrete, non-linearity of material etc. can be taken into account without basic modification of the numerical algorithm. For polygonal cross-sections the GAUSS' integral theorem is used. Numerical solutions of the non-linear optimisation problems can be found by application of standard software. Thus the analysis of reinforced concrete cross-sections or more general composite cross-sections with non-linear behaviour of material is as simple as in the case of linear elasticity. The application of the method is demonstrated for polygonal cross-sections. Pre-stresses or pre-strains can easily be included in the mathematical model.}, subject = {Architektur }, language = {en} } @inproceedings{RaueTimmler, author = {Raue, Erich and Timmler, Hans-Georg}, title = {NUMERISCHE ANALYSE VON VERBUNDQUERSCHNITTEN MIT NICHTLINEAREM MATERIALVERHALTEN UNTER BER{\"u}CKSICHTIGUNG VON VORVERFORMUNGEN}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3003}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30039}, pages = {9}, abstract = {The presented method for an physically non-linear analysis of stresses and deformations of composite cross-sections and members based on energy principles and their transformation to non-linear optimisation problems. From the LAGRANGE principle of minimum of total potential energy a kinematic formulation of the mechanical problem can be developed, which has the general advantage that pre-deformations excited by shrinkage, temperature, residual deformations after unloading et al., can be considered directly. Thus the non-linear analysis of composite cross-sections with layers of different mechanical properties and different preloading becomes possible and cracks in concrete, stiffness degradation and other specifics of the material behaviour can be taken into account without cardinal modification of the mathematical model. The impact of local defects on the bearing capacity of an entire element can also be analysed in this principle way. Standard computational systems for mathematical optimisation or general programs for spreadsheet analysis enable an uncomplicated implementation of the developed models and an effective non-linear analysis for composite cross-sections and elements.}, subject = {Architektur }, language = {en} } @inproceedings{Weitzmann, author = {Weitzmann, R{\"u}diger}, title = {SIMPLIFIED CYCLE-BASED DESIGN OF EXTREMELY LOADED STRUCTURES}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3033}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30338}, pages = {14}, abstract = {The design of safety-critical structures, exposed to cyclic excitations demands for non-degrading or limited-degrading behavior during extreme events. Among others, the structural behavior is mainly determined by the amount of plastic cycles, completed during the excitation. Existing simplified methods often ignore this dependency, or assume/request sufficient cyclic capacity. The paper introduces a new performance based design method that considers explicitly a predefined number of re-plastifications. Hereby approaches from the shakedown theory and signal processing methods are utilized. The paper introduces the theoretical background, explains the steps of the design procedure and demonstrates the applicability with help of an example. This project was supported by German Science Foundation (Deutsche Forschungsgemeinschaft, DFG)}, subject = {Architektur }, language = {en} }