@inproceedings{RaueVaidogasMueller1997,
  author    = {Raue, Erich and Vaidogas, E. R. and M{\"u}ller, Karl-Heinz},
  title     = {Bewertung der Grenzlast von elastisch-plastischen Tragwerken mit Hilfe stochastischer Methoden},
  doi       = {10.25643/bauhaus-universitaet.429},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4296},
  year      = {1997},
  abstract  = {F{\"u}r die Analyse von Tragwerken sowohl des Stahlbaus als auch des Massivbaus er{\"o}ffnet die nationale und internationale Normengebung in zunehmendem Maße die Anwendung physikalisch nichtlinearer Berechnungsmodelle. Es ist zu erwarten, daß neben dem traditionellen elastischen Berechnungsmodell das linearelastisch-idealplastische Materialmodell in die Tragwerksanalyse Eingang finden wird. W{\"a}hrend bei den traditionellen Berechnungsverfahren auf der Grundlage der Elastizit{\"a}tstheorie hinreichende Erfahrungen durch die Planungspraxis bestehen und umfangreiche Untersuchungen zur dabei erreichten Sicherheit vorliegen, stellen die nichtlinearen Berechnungsmethoden sowohl in mechanischer als auch in sicherheitstheoretischer Hinsicht ein neues Erfahrungsfeld dar. Im vorliegenden Beitrag werden aus der Vielzahl der anstehenden Probleme folgende Teilprobleme behandelt: Bestimmung der Versagenswahrscheinlichkeit elasto-plastischer Tragsysteme nach dem Kriterium der plastischen Grenzlast Ermittlung stochastischer Eigenschaften des plastischen Grenzlastparameters elasto-plastischer Tragsysteme. Die L{\"o}sung des mechanischen Problems geschieht {\"u}ber eine lineare Optimierungsaufgabe, die nach dem statischen Theorem der plastischen Grenzlast formuliert ist. Als stochastische Methode wird die Simulation angewandt, die zum einen auf einer zuf{\"a}lligen Erzeugung der Realisierungen (stochastische Simulation) und zum anderen auf einer planm{\"a}ßigen Erzeugung der Realisierungen (konstruktive Simulation) beruhen kann. F{\"u}r jedes der Teilprobleme wird ein Beispiel vorgestellt.},
  subject      = {Tragwerk},
  language  = {de}
}
@inproceedings{Montag1997,
  author    = {Montag, U.},
  title     = {A New Efficient Concept for Elasto-plastic Simulations of Shell Responses},
  doi       = {10.25643/bauhaus-universitaet.436},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4364},
  year      = {1997},
  abstract  = {For the analysis of arbitrary, by Finite Elements discretized shell structures, an efficient numerical simulation strategy with quadratic convergence including geometrically and physically nonlinear effects will be presented. In the beginning, a Finite-Rotation shell theory allowing constant shear deformations across the shell thickness is given in an isoparametric formulation. The assumed-strain concept enables the derivation of a locking-free finite element. The Layered Approach will be applied to ensure a sufficiently precise prediction of the propagation of plastic zones even throughout the shell thickness. The Riks-Wempner-Wessels global iteration scheme will be enhanced by a Line-Search procedure to ensure the tracing of nonlinear deformation paths with rather great load steps even in the post-peak range. The elastic-plastic material model includes isotropic hardening. A new Operator-Split return algorithm ensures considerably exact solution of the initial-value problem even for greater load steps. The combination with consistently linearized constitutive equations ensures quadratic convergence in a close neighbourhood to the exact solution. Finally, several examples will demonstrate accuracy and numerical efficiency of the developed algorithm.},
  subject      = {Schale},
  language  = {en}
}
@article{SemenovMelnikov1997,
  author    = {Semenov, Artem and Melnikov, B. E.},
  title     = {Multimodel Numerical Analysis of the Elasto-Visco-Plastic Deformation of Materials and Constructions},
  doi       = {10.25643/bauhaus-universitaet.528},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5282},
  year      = {1997},
  abstract  = {At the present time there is no a generally accepted theory of visco-plasticity which is applicable for a wide class of materials and arbitrary paths of loading. The multimodel approach, based on the creation of hierarchical sequence of the models, is the most rational. The developed library of elasto-visco-plastic models includes both simplest and sophistic models demanding numerous experimental data. A unified general form of constitutive equations for all used elasto-visco-plastic models are presented based upon the concept of tensorial internal state variables. It permits to use unified algorithm of boundary tasks solution for different variants of material models. The developed selection criteria system generates the necessary conditions and provides the choice of the simplest variant of theory sufficient for correct problem solution. Formulation of the selection criteria system is based on peculiarities of viscoplastic materials behavior for the wide range thermomechanical loading and numerous computational experiments with structures different complexity levels. A set of effective schemes of integration stress-strain relations and non-linear finite element system solution are discussed for the considered class of material models. Application possibility of different material models is studied both for material element and for complicated structures. Application of the multimodel approach in numerical computations has demonstrated possibility of reliable prediction of stress-strain response under wide variety of combined loading.},
  subject      = {Stoffgesetz},
  language  = {en}
}
@inproceedings{GurtovyPiskunov2000,
  author    = {Gurtovy, O. G. and Piskunov, V. G.},
  title     = {HIGH-PRECISION MODELING AND FINITE-ELEMENT INVESTIGATION OF ELASTOPLASTIC DEFORMATION OF NON-ISOTROPIC THICK SANDWICH PLATES AND SHELLS},
  doi       = {10.25643/bauhaus-universitaet.584},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5848},
  year      = {2000},
  abstract  = {There was suggested a phenomenological modified quadratic condition of the beginning of plasticity for plastic and quasifragile orthotropic materials. Limiting surface in the shape of a paraboloid with an axis bend over hydrostatic axis corresponds to the condition. The equations of theory of current with the isotropic and anisotropic hardenings, associated with the suggested yield condition, modified into the version of determining equations of strain theory of plasticity are received. These defining equations formed the basis of highlyprecise non-classic continual (along thickness) theory of non-linear deformation of thick sandwich plates and sloping shells. In the approximations along the cross coordinate the specificity of flexural and non-flexural deformations is taken into account. The necessity of introducing the approximations of higher order, as well as accounting for the cross compression while decreasing of the relatively cross normal and shear layer rigidness is shown. The specifications, obtained in comparison with the known physically nonlinear specified model of the bending of plates with orthotropic layers are distinguished. An effective procedure of linearization of the solving equations and getting the solutions in frames of the discrete-continual scheme of the finite-element method is suggested. The approximations of higher order let to model the appearance of the cracs of layers being split by the introducing of slightly hard thin layers into the finite element, not violating the idea of continuality of theory. Calculation of a threelayer plate with rigid face diaphragms on the contour is considered},
  subject      = {Platte},
  language  = {en}
}
@inproceedings{SchlegelRautenstrauch2000,
  author    = {Schlegel, Roger and Rautenstrauch, Karl},
  title     = {Numerische Simulation von Mauerwerk als Kontinuum},
  doi       = {10.25643/bauhaus-universitaet.610},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6106},
  year      = {2000},
  abstract  = {Im vorliegenden Beitrag wird ein in das FE-Programmsystem ANSYS implementiertes elastoplastisches Berechnungsmodell zur nichtlinearen, r{\"a}umlichen Untersuchung von Mauerwerkstrukturen vorgestellt. Die Modellierung des heterogenen Baustoffs Mauerwerk erfolgt mit Hilfe eines verschmierten Ersatzkontinuums. Das anisotrope Materialverhalten wird sowohl hinsichtlich der Spannungs-Dehnungsbeziehung als auch bei der Beschreibung der Festigkeit ber{\"u}cksichtigt. Durch die Verwendung einer zusammengesetzten Fließbedingung ist es m{\"o}glich, das Versagen der einzelnen Mauerwerkkomponenten Stein und M{\"o}rtelfugen und des Verbundes zu ber{\"u}cksichtigen. Dadurch ist die Anwendbarkeit des Modells f{\"u}r mehrere Mauerwerksarten gegeben. Die hierf{\"u}r verwendeten Materialparameter sind aus einfachen Kleink{\"o}rperversuchen bestimmbar oder innerhalb gewisser Grenzen aus empirischen Formeln berechenbar. Die notwendige Beschr{\"a}nkung der Anzahl der Materialparameter sichert die praktische Anwendbarkeit des entwickelten Berechnungsmodells. Die numerische Umsetzung des hier verwendeten impliziten Berechnungsverfahrens l{\"a}sst sich in eine lokale und eine globale Iterationsebene gliedern. Die lokale Iteration am Integrationspunkt dient der Spannungsr{\"u}ckf{\"u}hrung. Dabei sind die Besonderheiten der Verarbeitung mehrfl{\"a}chiger Fließfiguren zu beachten. Die globale Iteration auf Systemebene sichert die Umlagerung des Residuums. Mit der Nachrechnung von Versuchsergebnissen soll das entwickelte Modell verifiziert und seine physikalische Leistungsf{\"a}higkeit eingesch{\"a}tzt werden.},
  subject      = {Mauerwerk},
  language  = {de}
}
@article{MelnikovSemenov2004,
  author    = {Melnikov, B. E. and Semenov, Artem},
  title     = {Application of Multimodel Method of Elasto-Plastic Analysis for the Multilevel Computation of Structures},
  doi       = {10.25643/bauhaus-universitaet.248},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2487},
  year      = {2004},
  abstract  = {Creation of hierarchical sequence of the plastic and viscoplastic models according to different levels of structure approximations is considered. Developed strategy of multimodel analysis, which consists of creation of the inelastic models library, determination of selection criteria system and caring out of multivariant sequential clarifying computations, is described. Application of the multimodel approach in numerical computations has demonstrated possibility of reliable prediction of stress-strain response under wide variety of combined nonproportional loading.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}