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Modelling of tension-stiffening in bending RC elements based on equivalent stiffness of the rebar

The contribution of tensioned concrete between cracks (tension-stiffening) cannot be ignored when analysing deformation of reinforced concrete elements. The tension-stiffening effect is crucial when it comes to adequately estimating the load-deformation response of steel reinforced concrete and the more recently appeared fibre reinforced polymer (FRP) reinforced concrete. This paper presents a unified methodology for numerical modelling of the tension-stiffening effect in steel as well as FRP reinforced flexural members using the concept of equivalent deformation modulus and the smeared crack approach to obtain a modified stress-strain relation of the reinforcement. A closed-form solution for the equivalent secant modulus of deformation of the tensioned reinforcement is proposed for rectangular sections taking the Eurocode 2 curvature prediction technique as the reference. Using equations based on general principles of structural mechanics, the main influencing parameters are obtained. It is found that the ratio between the equivalent stiffness and the initial stiffness basically depends on the product of the modular ratio and reinforcement ratio (nρ), the effective-to-total depth ratio (d/h), and the level of loading. The proposed methodology is adequate for numerical modelling of tension-stiffening for different FRP and steel reinforcement, under both service and ultimate conditions. Comparison of the predicted and experimental data obtained by the authors indicates that the proposed methodology is capable to adequately model the tension-stiffening effect in beams reinforced with FRP or steel bars within wide range of loading

The authors acknowledge the support provided by the Spanish Government (Ministerio de Ciencia e Innovación), Project ref. BIA2010-20234-C03-02. The authors also gratefully acknowledge the financial support provided by the Research Council of Lithuania (Project No.MIP–083/2012) and the European Social Fund (Project No. VP1-3.1-ŠMM-08-K-01-020). Furthermore, the authors would like to thank COST Action TU 1207 “Next Generation Design Guidelines for Composites in Construction” for facilitating their collaboration

© Structural Engineering and Mechanics, 2015, vol. 53, núm. 5, p. 997-1016

Techno-Press

Author: Torres Llinàs, Lluís
Barris Peña, Cristina
Kaklauskas, Gintaris
Gribniak, Viktor
Date: 2015
Abstract: The contribution of tensioned concrete between cracks (tension-stiffening) cannot be ignored when analysing deformation of reinforced concrete elements. The tension-stiffening effect is crucial when it comes to adequately estimating the load-deformation response of steel reinforced concrete and the more recently appeared fibre reinforced polymer (FRP) reinforced concrete. This paper presents a unified methodology for numerical modelling of the tension-stiffening effect in steel as well as FRP reinforced flexural members using the concept of equivalent deformation modulus and the smeared crack approach to obtain a modified stress-strain relation of the reinforcement. A closed-form solution for the equivalent secant modulus of deformation of the tensioned reinforcement is proposed for rectangular sections taking the Eurocode 2 curvature prediction technique as the reference. Using equations based on general principles of structural mechanics, the main influencing parameters are obtained. It is found that the ratio between the equivalent stiffness and the initial stiffness basically depends on the product of the modular ratio and reinforcement ratio (nρ), the effective-to-total depth ratio (d/h), and the level of loading. The proposed methodology is adequate for numerical modelling of tension-stiffening for different FRP and steel reinforcement, under both service and ultimate conditions. Comparison of the predicted and experimental data obtained by the authors indicates that the proposed methodology is capable to adequately model the tension-stiffening effect in beams reinforced with FRP or steel bars within wide range of loading
The authors acknowledge the support provided by the Spanish Government (Ministerio de Ciencia e Innovación), Project ref. BIA2010-20234-C03-02. The authors also gratefully acknowledge the financial support provided by the Research Council of Lithuania (Project No.MIP–083/2012) and the European Social Fund (Project No. VP1-3.1-ŠMM-08-K-01-020). Furthermore, the authors would like to thank COST Action TU 1207 “Next Generation Design Guidelines for Composites in Construction” for facilitating their collaboration
Format: application/pdf
ISSN: 1225-4568 (versió paper)
1598-6217 (versió electrònica)
Document access: http://hdl.handle.net/10256/12347
Language: eng
Publisher: Techno-Press
Collection: MICINN/PN 2011-2013/BIA2010-20234-C03-02
Reproducció digital del document publicat a: http://dx.doi.org/10.12989/sem.2015.53.5.997
Articles publicats (D-EMCI)
Is part of: © Structural Engineering and Mechanics, 2015, vol. 53, núm. 5, p. 997-1016
Rights: Tots els drets reservats
Subject: Assaigs de materials
Materials -- Testing
Resistència de materials
Strength of materials
Esforç i tensió
Strains and stresses
Formigó armat -- Proves
Reinforced concrete -- Testing
Title: Modelling of tension-stiffening in bending RC elements based on equivalent stiffness of the rebar
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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