Damage model for FRP-confined concrete columns under cyclic loading

In structural engineering, seismic vulnerability reduction of existing structures is a crucial issue. External reinforcement with fiber-reinforced polymer (FRP) holds interest in achieving this aim. Its use as a retrofitting method is limited, however, for a number of reasons, including the lack of numerical tools for predicting cyclic loading. This paper presents a simplified stress-strain model suitable for monotonic and cycling loading capable of predicting the FRP's effect on reinforced-concrete columns. The model was inspired by two well-known concrete constitutive laws: one based on damage mechanics (La Borderie's concrete-damage model, 1991); the other on extensive experimental studies (Eid and Paultre's confined-concrete model, 2008). Validation is provided using experimental results on reinforced concrete columns subjected to axial and flexural cyclic loading. The proposed approach also deals with steel-bar rupture, considering low-cycle fatigue effects. All the simulations were conducted with multifiber Timoshenko beam elements.

[1]  Yan Xiao,et al.  Steel Jacket Retrofitting of Reinforced Concrete BridgeColumns for Enhanced Shear Strength-Part 1: TheoreticalConsiderations and Test Design , 1994 .

[2]  Patrick Paultre,et al.  Analytical Model for FRP-Confined Circular Reinforced Concrete Columns , 2008 .

[3]  Nathalie Roy,et al.  Performance-based seismic retrofit of a bridge bent: Design and experimental validation , 2010 .

[4]  E. W. C. Wilkins,et al.  Cumulative damage in fatigue , 1956 .

[5]  F. E. Richart,et al.  Failure of plain and spirally reinforced concrete in compression , 1929 .

[6]  R. M. Zimmerman,et al.  Compressive Strength of Plain Concrete Under Multiaxial Loading Conditions , 1970 .

[7]  Patrick Paultre,et al.  Stress-Strain Model for Confined High-Strength Concrete , 1995 .

[8]  Jeeho Lee,et al.  Plastic-Damage Model for Cyclic Loading of Concrete Structures , 1998 .

[9]  J. Mander,et al.  Theoretical stress strain model for confined concrete , 1988 .

[10]  Kazuhiko Kawashima,et al.  Unloading and Reloading Stress–Strain Model for Confined Concrete , 2006 .

[11]  Amir Mirmiran,et al.  Model of Concrete Confined by Fiber Composites , 1998 .

[12]  Cédric Desprez.  Analyse et Réduction de la Vulnérabilité Sismique des Structures Existantes : Renforcement par Collage de Tissus de Fibres de Carbone (TFC) , 2010 .

[13]  Amir Mirmiran,et al.  Fiber-element model for cyclic analysis of concrete-filled fiber reinforced polymer tubes , 2005 .

[14]  Panagiotis Kotronis,et al.  SIMPLIFIED MODELLING STRATEGIES TO SIMULATE THE DYNAMIC BEHAVIOUR OF R/C WALLS , 2005 .

[15]  Yan Xiao,et al.  SEISMIC RETROFIT OF RC CIRCULAR COLUMNS USING PREFABRICATED COMPOSITE JACKETING , 1997 .

[16]  A. S. Elnashai,et al.  Confined concrete model under cyclic load , 1997 .

[17]  Jacky Mazars,et al.  Damage Mechanics Modeling of Nonlinear Seismic Behavior of Concrete Structures , 2005 .

[18]  M. Priestley,et al.  Ductility of Square-Confined Concrete Columns , 1982 .

[19]  L. Coffin,et al.  A Study of the Effects of Cyclic Thermal Stresses on a Ductile Metal , 1954, Journal of Fluids Engineering.

[20]  C. Borderie.  Phénomènes unilatéraux dans un matériau endommageable : Modélisation et application à l'analyse de structures en béton. , 1991 .

[21]  Mathieu Boucher-Trudeau.  Comportement en flexion composée de poteaux circulaires en béton armé confinés par des polymères renforcés de fibre de carbone (PRFC) , 2010 .

[22]  J. Mazars,et al.  Using multifiber beams to account for shear and torsion: Applications to concrete structural elements , 2006 .

[23]  Yan Xiao,et al.  FRP-confined concrete under axial cyclic compression , 2006 .