FE Modeling of CFRP-Retrofitted RC Frames with Masonry Infill Walls

Mohamed Sakr, Saher R. El-khoriby, Ayman A. Seleemah, Essam A. Darwish


A number of numerical and experimental studies have been reported in recent literature to investigate the effects of infill walls on the seismic response of RC infilled frames. Many experimental studies used CFRP sheets as an external bracing system for retrofitting the infilled RC frames. It has been found that the common mode of failure of such retrofitted frames is the debonding of the CFRP-concrete adhesive material. In the current study, the behaviour of CFRP retrofitted infilled RC frames was investigated with a finite element micro model. In that model, a four-node shell element was used for modeling the concrete, infill panel and CFRP sheets. The interaction between concrete frame and infill panel was modelled using contact surfaces to allow the occurrence of separation and prevent penetration. Nonlinearities of the concrete, infill panel, steel and CFRP sheets were considered. To allow the occurrence of debonding mode of failure, the adhesive layer was modelled using cohesive surface-to-surface interaction model, which assumes that the failure of cohesive bond is characterized by progressive degradation of the cohesive stiffness, which is driven by a damage process based on the fracture energy. The proposed model was verified using experimental results from the literature. Results indicated that the cohesive model could capture the debonding mode of failure which has been observed experimentally. The validated micro model was used to investigate the effects of the strip end area, the anchor location and partial bonding of the CFRP sheet to the infill panel surface on the behaviour of infilled frames. The results of parametric study showed that, to get the highest efficiency of the CFRP retrofitted infilled frame, bonding about 25% only of the diagonal length from each end is sufficient to get the same behaviour of the totally bonded sheet.


Infilled RC frames; CFRP Retrofitted; Finite Element Model; Debonding.


Hashemi A, Mosalam KM. Shake-table experiment on reinforced concrete structure containing masonry infill wall. Earthquake Engineering & Structural Dynamics. 2006;35:1827-52.

Al-Chaar G, Issa M, Sweeney S. Behavior of Masonry-Infilled Nonductile ReinforcedConcrete Frames. JOURNAL OF STRUCTURAL ENGINEERING © ASCE. Augest 2002.

Kakaletsis DJ, Karayannis CG. Influence of Masonry Strength and Openings on Infilled R/C Frames Under Cycling Loading. Journal of Earthquake Engineering. 2008.

Tasnimi AA, Mohebkhah A. Investigation on the behavior of brick-infilled steel frames with openings, experimental and analytical approaches. Engineering Structures. 2011;33:968-80.

Ozsayin B, Yilmaz E, Ispir M, Ozkaynak H, Yuksel E, Ilki A. Characteristics of CFRP retrofitted hollow brick infill walls of reinforced concrete frames. Construction and Building Materials. 2011;25:4017-24.

Altin S, Anil Ö, Kara ME, Kaya M. An experimental study on strengthening of masonry infilled RC frames using diagonal CFRP strips. Composites Part B: Engineering. 2008;39:680-93.

Erdem I, Akyuz U, Ersoy U, Ozcebe G. An experimental study on two different strengthening techniques for RC frames. Engineering Structures. 2006;28:1843-51.

Yuksel E, Ozkaynak H, Buyukozturk O, Yalcin C, Dindar AA, Surmeli M, et al. Performance of alternative CFRP retrofitting schemes used in infilled RC frames. Construction and Building Materials. 2010;24:596-609.

Chen W-W, Yeh Y-K, Hwang S-J, Lu C-H, Chen C-C. Out-of-plane seismic behavior and CFRP retrofitting of RC frames infilled with brick walls. Engineering Structures. 2012;34:213-24.

Agency FEM, Engineers ASoC. FEMA 356. Prestandard and commentrary for the seismic rehabilitation of bouldings: FEDERAL EMERGENCY MANAGEMENT AGENCY-Washington, D.C.; 2000.

Fiore A, Netti A, Monaco P. The influence of masonry infill on the seismic behaviour of RC frame buildings. Engineering Structures. 2012;44:133-45.

Asteris PG, Giannopoulos IP, Chrysostomou CZ. Modeling of Infilled frames with openings. The Open Construction and Building Technology Journal. 2012;M6:81-91.

Alam MS, Nehdi M, Amanat KM. Modelling and analysis of retrofitted and un-retrofitted masonry-infilled RC frames under in-plane lateral loading. Structure and Infrastructure Engineering. 2009;5:71-90.

D’Ayala D, Worth J, Riddle O. Realistic shear capacity assessment of infill frames: Comparison of two numerical procedures. Engineering Structures. 2009;31:1745-61.

Doudoumis IN. Finite element modelling and investigation of the behaviour of elastic infilled frames under monotonic loading. Engineering Structures 29 (2007) 1004–1024. 2007.

Asteris PG. Finite element micro-modeling of Infilled frames. Electronic Journal of Structural Engineering. 2008.

Asteris PG, Kakaletsis DJ, Chrysostomou CZ, Smyrou EE. Failure modes of in-filled frames. Electronic Journal of Structural Engineering 11(1) 2011. 2011.

Nwofor TC, Chinwah JG. Finite element modeling of shear strength of Infilled frames with openings. International Journal of Engineering and Technology. 2012;Volume 2 No. 6.

Nwofor TC. Numerical micro-modeling of masonry in filled frames Scholars Research Library-Archives of Applied Science Research (Nigeria). 2012;4 (2):764-771.

Mohyeddin A, Goldsworthy HM, Gad EF. FE modelling of RC frames with masonry infill panels under in-plane and out-of-plane loading. Engineering Structures. 2013;51:73-87.

Dehghani A, Nateghi-Alahi, Fischer F. Engineered cementitious composites for strengthening masonry infilled reinforced concrete frames. Engineering Structures. 2015;105:197–208.

Erol, Karadogan G, Faruk H. Seismic strengthening of infilled reinforced concrete frames by CFRP Composites: Part B. Engineering Structures. 2016;91:473–91.

KAKALETSIS DJ. Comparison of CFRP and Alternative Seismic Retrofitting Techniques for Bare and Infilled RC Frames. Journal of Composites for Construction. 2011;15.

Pitytzogia Aea. Strengthening of Infilled Reinforced Concrete Frames with TRM: Study on the Development and Testing of Textile-Based Anchors. Journal of Composites for Construction. 2014;18.

Bousias, al. SNe. Experimental Investigation of Concrete Frames Infilled with rc for Seismic Rehabilitation. JOURNAL OF STRUCTURAL ENGINEERING © ASCE. 2014;140.

Akin, Emre. Effects of Various Parameters on CFRP Strengthening of Infilled RC Frames’. Journal of Performance of Constructed Facilities. 2016;30.

Binici, al. Be. Numerical Study on CFRP Strengthening of Reinforced Concrete Frames with Masonry Infill Walls. Journal of Composites for Construction. 2014;18.

system Sos. Abaqus/CAE User's Manual.

318 AC. Building code requirements for structural concrete and commentary (ACI 318-99). Detroit (MI): American Concrete Institute. 1999.

Saenz L. Discussion of ‘‘Equation for the stress-strain curve of concrete” by Desayi P, Krishnan S. ACI Journal. 1964.

Obaidat YT, Heyden S, Dahlblom O. The effect of CFRP and CFRP/concrete interface models when modelling retrofitted RC beams with FEM. Composite Structures. 2010.

Abaqus analysis user manual.

Sakr MA. FE modeling of simply supported RC beams strengthened with FRP plates Structural Faults & Repair, 13th International Conference, Edinburgh – UK. June 2010.

Obaidat YT, Heyden S, Dahlblom O, Farsakh GA-, Yahia, Abdel-Jawad. Retrofitting of reinforced concrete beams using composite laminates. Construction & Building Materials. 2010.

Brena SF, McGuirk GN. Advances on the Behavior Characterization of FRP-Anchored Carbon Fiber-Reinforced Polymer (CFRP) Sheets Used to Strengthen Concrete Elements. International Journal of Concrete Structures and Materials. March 2013;Vol.7, No.1:pp.3–16.

Niemitz CW, James R, Brena SF. Experimental behavior of carbon fiber-reinforced polymer (CFRP) sheets attached to concrete surfaces using CFRP anchors. Journal of Composites for Construction. 2010;14(2):185–94.

Full Text: PDF

DOI: 10.28991/cej-2017-00000090


  • There are currently no refbacks.

Copyright (c) 2017 Mohamed Sakr

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.