Model components and experimental methods for improved characterization of fatigue behavior of plain and reinforced concrete
| Autor: | Baktheer, Abedulgader Rasheed Ahmed |
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| Přispěvatelé: | Hegger, Josef, Chudoba, Rostislav, Vořechovský, Miroslav |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2022). doi:10.18154/RWTH-2022-07281 = Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022 |
| DOI: | 10.18154/RWTH-2022-07281 |
| Popis: | Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2022). = Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022 In spite of the considerable achievements that have been made in recent years in modeling and characterizing the fatigue behavior of concrete, still many open questions need to be fundamentally addressed in order to gain a deep and general insight into the fatigue phenomenology of concrete. In this thesis, a numerical, theoretical and experimental framework for the analysis and characterization of the fatigue behavior of concrete is developed to improve the understanding of the fatigue phenomenology in terms of the fundamental fatigue damage mechanisms occurring in the internal structure of the material. The presented framework aims to provide the basis for a more efficient analysis and evaluation of the fatigue behavior of structural concrete, which in the long run can contribute to the formulation of reliable and economical design concepts and codes for reinforced concrete structures under fatigue loading. The developed modeling components in this thesis are based on an enhanced fatigue modeling hypothesis that consistently represents the dissipative mechanisms associated with cumulative cyclic shear deformation at subcritical loading levels and is formulated within the thermodynamic framework. The refined fatigue hypothesis is applied within the context of bond fatigue to describe the bond deterioration under fatigue loading, and is calibrated and validated for ductile and brittle types of bond behavior. Further enhancement of the one-dimensional interface model is provided to consistently capture the 3D kinematics of zero-thickness interfaces response under monotonic and fatigue loading and providing a generic fatigue constitutive law that can be applied in a wide range of structural applications. To capture the tri-axial stress redistribution within the concrete structure under compressive fatigue loading, a novel microplane fatigue model is developed that employs the introduced fatigue hypothesis with cumulative fatigue damage due to sliding. A systematic calibration and validation procedure of the model response is provided based on accompanying performed experimental program including normal- and high-strength concretes subjected to several loading scenarios of compressive loading. Moreover, in comparison of the current fatigue characterization methods, which require a large number of expensive experiments, a combined numerical, experimental and theoretical methodology is employed to characterize the effects of the loading sequence on the fatigue behavior of concrete. As a result, an enhanced assessment rule for predicting the fatigue life of concrete under compression is proposed that takes into account the effects of the loading sequence. This rule demonstrates the potential contribution of the advanced and efficient numerical modeling approaches to the formulation of reliable design concepts related to the fatigue response of materials and structures. Published by RWTH Aachen University, Aachen |
| Databáze: | OpenAIRE |
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