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Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue

For a reinforced concrete beam subjected to fatigue loads, the structural stiffness and bearing capacity will gradually undergo irreversible degeneration, leading to damage. Moreover, there is an inherent relationship between the stiffness and bearing capacity degradation and fatigue damage. In this...

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Autores principales: Liu, Fangping, Zhou, Jianting, Yan, Lei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5844543/
https://www.ncbi.nlm.nih.gov/pubmed/29522572
http://dx.doi.org/10.1371/journal.pone.0192797
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author Liu, Fangping
Zhou, Jianting
Yan, Lei
author_facet Liu, Fangping
Zhou, Jianting
Yan, Lei
author_sort Liu, Fangping
collection PubMed
description For a reinforced concrete beam subjected to fatigue loads, the structural stiffness and bearing capacity will gradually undergo irreversible degeneration, leading to damage. Moreover, there is an inherent relationship between the stiffness and bearing capacity degradation and fatigue damage. In this study, a series of fatigue tests are performed to examine the degradation law of the stiffness and bearing capacity. The results pertaining to the stiffness show that the stiffness degradation of a reinforced concrete beam exhibits a very clear monotonic decreasing "S" curve, i.e., the stiffness of the beam decreases significantly at the start of the fatigue loading, it undergoes a linear decline phase in the middle for a long loading period, and before the failure, the bearing capacity decreases drastically again. The relationship between the residual stiffness and residual bearing capacity is determined based on the assumption that the residual stiffness and residual bearing capacity depend on the same damage state, and then, the bearing capacity degradation model of the reinforced concrete beam is established based on the fatigue stiffness. Through the established model and under the premise of the known residual stiffness degradation law, the degradation law of the bearing capacity is determined by using at least one residual bearing capacity test data, for which the parameters of the stiffness degradation function are considered as material constants. The results of the bearing capacity show that the bearing capacity degradation of the reinforced concrete beam also exhibits a very clear monotonic decreasing "S" curve, which is consistent with the stiffness degradation process and in good agreement with the experiment. In this study, the stiffness and bearing capacity degradation expressions are used to quantitatively describe their occurrence in reinforced concrete beams. In particular, the expression of the bearing capacity degradation can mitigate numerous destructive tests and save cost. The stiffness and bearing capacity degradation expressions for a reinforced concrete beam can be used to predict the deformation and bearing capacity of a structure during the service process and determine the structural fatigue damage and degree of degradation.
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spelling pubmed-58445432018-03-23 Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue Liu, Fangping Zhou, Jianting Yan, Lei PLoS One Research Article For a reinforced concrete beam subjected to fatigue loads, the structural stiffness and bearing capacity will gradually undergo irreversible degeneration, leading to damage. Moreover, there is an inherent relationship between the stiffness and bearing capacity degradation and fatigue damage. In this study, a series of fatigue tests are performed to examine the degradation law of the stiffness and bearing capacity. The results pertaining to the stiffness show that the stiffness degradation of a reinforced concrete beam exhibits a very clear monotonic decreasing "S" curve, i.e., the stiffness of the beam decreases significantly at the start of the fatigue loading, it undergoes a linear decline phase in the middle for a long loading period, and before the failure, the bearing capacity decreases drastically again. The relationship between the residual stiffness and residual bearing capacity is determined based on the assumption that the residual stiffness and residual bearing capacity depend on the same damage state, and then, the bearing capacity degradation model of the reinforced concrete beam is established based on the fatigue stiffness. Through the established model and under the premise of the known residual stiffness degradation law, the degradation law of the bearing capacity is determined by using at least one residual bearing capacity test data, for which the parameters of the stiffness degradation function are considered as material constants. The results of the bearing capacity show that the bearing capacity degradation of the reinforced concrete beam also exhibits a very clear monotonic decreasing "S" curve, which is consistent with the stiffness degradation process and in good agreement with the experiment. In this study, the stiffness and bearing capacity degradation expressions are used to quantitatively describe their occurrence in reinforced concrete beams. In particular, the expression of the bearing capacity degradation can mitigate numerous destructive tests and save cost. The stiffness and bearing capacity degradation expressions for a reinforced concrete beam can be used to predict the deformation and bearing capacity of a structure during the service process and determine the structural fatigue damage and degree of degradation. Public Library of Science 2018-03-09 /pmc/articles/PMC5844543/ /pubmed/29522572 http://dx.doi.org/10.1371/journal.pone.0192797 Text en © 2018 Liu et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Liu, Fangping
Zhou, Jianting
Yan, Lei
Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title_full Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title_fullStr Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title_full_unstemmed Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title_short Study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
title_sort study of stiffness and bearing capacity degradation of reinforced concrete beams under constant-amplitude fatigue
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5844543/
https://www.ncbi.nlm.nih.gov/pubmed/29522572
http://dx.doi.org/10.1371/journal.pone.0192797
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