Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates

We analyse the problem of a simply supported steel beam subjected to uniformly distributed load, strengthened with a pre-stressed fibre-reinforced polymer (FRP) laminate. We assume that the laminate is first put into tension, then bonded to the beam bottom surface, and finally fixed at both its ends...

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Main Authors: S. Bennati, D. Colonna, P.S. Valvo
Format: Article
Language:English
Published: Gruppo Italiano Frattura 2016-10-01
Series:Fracture and Structural Integrity
Subjects:
Online Access:http://www.gruppofrattura.it/pdf/rivista/numero38/numero_38_art_47.pdf
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author S. Bennati
D. Colonna
P.S. Valvo
author_facet S. Bennati
D. Colonna
P.S. Valvo
author_sort S. Bennati
collection DOAJ
description We analyse the problem of a simply supported steel beam subjected to uniformly distributed load, strengthened with a pre-stressed fibre-reinforced polymer (FRP) laminate. We assume that the laminate is first put into tension, then bonded to the beam bottom surface, and finally fixed at both its ends by suitable connections. The beam and laminate are modelled according to classical beam theory. The adhesive is modelled as a cohesive interface with a piecewise linear constitutive law defined over three intervals (elastic response, softening response, debonding). The model is described by a set of differential equations with suitable boundary conditions. An analytical solution to the problem is determined, including explicit expressions for the internal forces and interfacial stresses. As an application, we consider the standard IPE series for the steel beam and the Sika® CarboDur® system for the adhesive and laminate. For each considered cross section, we first carry out a preliminary design of the unstrengthened steel beam. Then, we imagine to apply the FRP strengthening and calculate the loads corresponding to the elastic limit states in the steel beam, adhesive, and laminate. Lastly, we take into account the ultimate limit state corresponding to the plasticisation of the mid-span steel cross section and evaluate the increased load bearing capacity of the strengthened beam
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institution Kabale University
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1971-8993
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publisher Gruppo Italiano Frattura
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series Fracture and Structural Integrity
spelling doaj-art-4d854ab85025446c89d0ad0fac757fc52025-02-03T00:42:47ZengGruppo Italiano FratturaFracture and Structural Integrity1971-89931971-89932016-10-01103837739110.3221/IGF-ESIS.38.47 Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminatesS. Bennati0D. Colonna1P.S. Valvo2Università di Pisa,ItalyUniversità di Pisa,ItalyUniversità di Pisa,ItalyWe analyse the problem of a simply supported steel beam subjected to uniformly distributed load, strengthened with a pre-stressed fibre-reinforced polymer (FRP) laminate. We assume that the laminate is first put into tension, then bonded to the beam bottom surface, and finally fixed at both its ends by suitable connections. The beam and laminate are modelled according to classical beam theory. The adhesive is modelled as a cohesive interface with a piecewise linear constitutive law defined over three intervals (elastic response, softening response, debonding). The model is described by a set of differential equations with suitable boundary conditions. An analytical solution to the problem is determined, including explicit expressions for the internal forces and interfacial stresses. As an application, we consider the standard IPE series for the steel beam and the Sika® CarboDur® system for the adhesive and laminate. For each considered cross section, we first carry out a preliminary design of the unstrengthened steel beam. Then, we imagine to apply the FRP strengthening and calculate the loads corresponding to the elastic limit states in the steel beam, adhesive, and laminate. Lastly, we take into account the ultimate limit state corresponding to the plasticisation of the mid-span steel cross section and evaluate the increased load bearing capacity of the strengthened beamhttp://www.gruppofrattura.it/pdf/rivista/numero38/numero_38_art_47.pdfSteel beamFRP strengtheningAdhesiveBeam theoryCohesive-zone modelAnalytical solutionPre-stressingUltimate limit stateLoad bearing capacity
spellingShingle S. Bennati
D. Colonna
P.S. Valvo
Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
Fracture and Structural Integrity
Steel beam
FRP strengthening
Adhesive
Beam theory
Cohesive-zone model
Analytical solution
Pre-stressing
Ultimate limit state
Load bearing capacity
title Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
title_full Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
title_fullStr Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
title_full_unstemmed Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
title_short Evaluation of the increased load bearing capacity of steel beams strengthened with pre-stressed FRP laminates
title_sort evaluation of the increased load bearing capacity of steel beams strengthened with pre stressed frp laminates
topic Steel beam
FRP strengthening
Adhesive
Beam theory
Cohesive-zone model
Analytical solution
Pre-stressing
Ultimate limit state
Load bearing capacity
url http://www.gruppofrattura.it/pdf/rivista/numero38/numero_38_art_47.pdf
work_keys_str_mv AT sbennati evaluationoftheincreasedloadbearingcapacityofsteelbeamsstrengthenedwithprestressedfrplaminates
AT dcolonna evaluationoftheincreasedloadbearingcapacityofsteelbeamsstrengthenedwithprestressedfrplaminates
AT psvalvo evaluationoftheincreasedloadbearingcapacityofsteelbeamsstrengthenedwithprestressedfrplaminates