TY - THES A1 - Karaki, Ghada T1 - Assessment of coupled models of bridges considering time-dependent vehicular loading N2 - Bridge vibration due to traffic loading has been a subject of extensive research in the last decades. The focus of such research has been to develop solution algorithms and investigate responses or behaviors of interest. However, proving the quality and reliability of the model output in structural engineering has become a topic of increasing importance. Therefore, this study is an attempt to extend concepts of uncertainty and sensitivity analyses to assess the dynamic response of a coupled model in bridge engineering considering time-dependent vehicular loading. A setting for the sensitivity analysis is proposed, which enables performing the sensitivity analysis considering random stochastic processes. The classical and proposed sensitivity settings are used to identify the relevant input parameters and models that have the most influence on the variance of the dynamic response. The sensitivity analysis exercises the model itself and extracts results without the need for measurements or reference solutions; however, it does not offer a means of ranking the coupled models studied. Therefore, concepts of total uncertainty are employed to rank the coupled models studied according to their fitness in describing the dynamic problem. The proposed procedures are applied in two examples to assess the output of coupled subsystems and coupled partial models in bridge engineering considering the passage of a heavy vehicle at various speeds. N2 - Brückenschwingungen infolge von Verkehrslasten sind seit mehreren Jahrzehnten Gegenstand intensiver Forschung. Im Fokus stand hierbei im Besonderen die Entwicklung von Lösungsalgorithmen zur Ermittlung des dynamischen Bauwerkverhaltens. Begleitet ist diese Entwicklung von der Frage nach der Qualität und Zuverlässigkeit dieser Modelle für den Gebrauch im konstruktiven Ingenieurbau. In diesem Zusammenhang werden in der vorliegenden Arbeit Konzepte der Unsicherheits- und Sensitivitätsanalyse erweitert, um das dynamische Bauwerkverhalten unter Berücksichtigung transienter Fahrzeuglasten bei gekoppelten Modellen des Brückenbaus zu bewerten. Bestehende Sensitivitätsanalysen werden ergänzt, um diese auch unter Berücksichtigung von stochastischen Prozessen durchführen zu können. Die klassische und die erweiterte Methode werden angewandt, um relevante Eingangsparameter sowie Partialmodelle mit wesentlichem Einfluss auf die Varianz der dynamischen Strukturantwort zu identifizieren. Die mit Hilfe der Sensitivitätsanalyse ermittelbaren Kennzahlen können ohne Bezug zu einer Referenzlösung in die Modellbewertung einfließen, allerdings ist es nicht möglich, die Modelle hinsichtlich der realitätsnahen Abbildung des dynamischen Problems zu bewerten. Um dies zu ermöglichen, wurden Konzepte der Gesamtunsicherheit verwendet. Die vorgestellten Methoden wurden auf zwei Beispiele angewandt, um die Ergebnisse von gekoppelten Subsystemen und gekoppelten Partialmodellen des Brückenbaus zu evaluieren. Hierbei handelt es sich um die Überfahrt von schweren Fahrzeugen mit verschiedenen Geschwindigkeiten. T3 - Schriftenreihe des DFG Graduiertenkollegs 1462 Modellqualitäten // Graduiertenkolleg Modellqualitäten - 5 KW - Ingenieurbau KW - bridge-vehicle interaction KW - random vibrations KW - sensitivity and uncertainty analysis Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20120402-15894 ER - TY - CHAP A1 - Karaki, Ghada ED - Gürlebeck, Klaus ED - Lahmer, Tom ED - Werner, Frank T1 - DEPENDENCY OF THE INFLUENCE OF INPUT PARAMETERS OF BVI MODELS ON THE INITIAL EXCITATIONS AND SPEED RANGES T2 - Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar N2 - Bridge vibration due to traffic loading has been subject of extensive research in the last decades. Such studies are concerned with deriving solutions for the bridge-vehicle interaction (BVI) and analyzing the dynamic responses considering randomness of the coupled model’s (BVI) input parameters and randomness of road unevenness. This study goes further to examine the effects of such randomness of input parameters and processes on the variance of dynamic responses in quantitative measures. The input parameters examined in the sensitivity analysis are, stiffness and damping of vehicle’s suspension system, axle spacing, and stiffness and damping of bridge. This study also examines the effects of the initial excitation of a vehicle on the influences of the considered input parameters. Variance based sensitivity analysis is often applied to deterministic models. However, the models for the dynamic problem is a stochastic one due to the simulations of the random processes. Thus, a setting using a joint meta-model; one for the mean response and other for the dispersion of the response is developed. The joint model is developed within the framework of Generalized Linear Models (GLM). An enhancement of the GLM procedure is suggested and tested; this enhancement incorporates Moving Least Squares (MLS) approximation algorithms in the fitting of the mean component of the joint model. The sensitivity analysis is then performed on the joint-model developed for the dynamic responses caused by BVI. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Computerunterstütztes Verfahren Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-27675 UR - http://euklid.bauing.uni-weimar.de/ikm2012 SN - 1611-4086 ER -