TY  - CHAP
A1  - Ebert, Matthias
A1  - Bucher, Christian
T1  - Modelling of changing of dynamic and static parameters of damaged R/C
N2  - Dynamic testing for damage assessment as non-destructive method has attracted growing in-terest for systematic inspections and maintenance of civil engineering structures. In this con-text the paper presents the Stochastic Finite Element (SFE) Modeling of the static and dy-namic results of own four point bending experiments with R/C beams. The beams are dam-aged by an increasing load. Between the load levels the dynamic properties are determined. Calculated stiffness loss factors for the displacements and the natural frequencies show differ-ent histories. A FE Model for the beams is developed with a discrete crack formulation. Cor-related random fields are used for structural parameters stiffness and tension strength. The idea is to simulate different crack evolutions. The beams have the same design parameters, but because of the stochastic material properties their undamaged state isn't yet the same. As the structure is loaded a stochastic first crack occurs on the weakest place of the structure. The further crack evolution is also stochastic. These is a great advantage compared with de-terministic formulations. To reduce the computational effort of the Monte Carlo simulation of this nonlinear problem the Latin-Hypercube sampling technique is applied. From the results functions of mean value and standard deviation of displacements and frequencies are calcu-lated. Compared with the experimental results some qualitative phenomena are good de-scribed by the model. Differences occurs especially in the dynamic behavior of the higher load levels. Aim of the investigations is to assess the possibilities of dynamic testing under consideration of effects from stochastic material properties
KW  - Stahlbetonbauteil
KW  - Bruchmechanik
KW  - Dynamische Belastung
KW  - Statische Last
KW  - Finite-Elemente-Methode
KW  - Stochastisches Modell
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5825
ER  - 
TY  - THES
A1  - Weitzmann, Rüdiger
T1  - Bemessungskonzept für Stahlbetontragwerke auf der Grundlage deformationsbasierter Grenzzustandsbetrachtungen
T1  - Design Concept For Reinforced Concrete Structures Using Deformation Based Limit State Analysis
N2  - Das Ziel der Arbeit besteht in der Entwicklung eines Bemessungskonzeptes auf der Basis nichtlinearer Schnittgrößen für statisch und dynamisch beanspruchte Stahlbetontragwer-ke. Das Konzept geht dabei von einheitlichen Kriterien zur Analyse der Tragfähigkeit und Gebrauchstauglichkeit auf der Grundlage deformationsbasierter Grenzzustandsbetrach-tungen aus. Der deformationsbasierte Grenzzustand ist dadurch charakterisiert, daß ne-ben der statischen und kinematischen Zulässigkeit eines Tragwerkszustandes auch die Einhaltung von definierten Verzerrungs- bzw. Verformungsgrenzwerten gewährleistet ist. Aus Betrachtungen im Kontinuum werden diskrete Modelle zur Lösung von physikalisch und geometrisch nichtlinearen Grenzwiderstandsaufgaben mit und ohne Berücksichtigung von Lastfolgeeffekten abgeleitet. Die numerische Untersetzung basiert auf Methoden der nichtlinearen Optimierung. Auf der Grundlage dieser Berechnungsmodelle wird eine Be-messungskonzeption entwickelt.
N2  - The objective is the development of a design strategy for statically or dynamically excited reinforced concrete structures based on nonlinear distributions of internal forces. The concept starts from an uniform criterion to describe the bearing capacity and serviceability on the bases of deformation based limit states. This limit state is characterized on the one hand by fulfilling the classical demands of ensuring the static and kinematic admissibility and on the other hand by considering predefined limits of deformations. Beginning from modelling under continious conditions discrete modells are derived for solving physical and geometrical nonlinear limit resistance problems with or without the option to consider effects caused by load sequencies. For solving these problems methods of nonlinear pro-gramming are used. On the basis of these calculation models a strategy for the design is developed.
KW  - Stahlbetonbauteil
KW  - Bemessung
KW  - Grenzzustand
KW  - Deformation
KW  - Stahlbeton
KW  - Nichtlineare Optimierung
KW  - Grenzzustandsanalyse
KW  - Statik
KW  - Dynamik
KW  - Reinforced Concrete
KW  - Nonlinear Programming
KW  - Limit Atate Analysis
KW  - Design
KW  - Statics
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20040216-334
ER  -