FRP Material

[behradgh]

Hi everyone

I have to create a FEM model of an RC bridge pier retrofitted with FRP.

I used Concrete07 for all bridge piers and developed fragility curves of the not retrofitted bridge. Now, I want to retrofit bridge piers with FRP and develop fragility curves for the retrofitted system.

Which material is better to model FRP? ConfinedConcrete01 or FRPConfinedConcrete?

Is it better to be seen the effect of FRP confinement on the concrete core and concrete cover in formulations that were proposed by Mander for Concrete07? or is it better to use from those two materials that I mentioned before?

Thanks.

Behrad.

[selimgunay]

With Concrete07, it looks like you need to compute the confined concrete properties yourself, The others would do it for you, but I don't know how good they are. You can always try different materials and record the stress and strain at a fiber and check if it looks like what you want

[kmegal01]

https://doi.org/10.1016/j.compstruct.2017.07.075
Ahmed M. Ismail, Mohamed F.M. Fahmy, Zhishen Wu,
Simulating the lateral performance of FRP-confined RC circular columns using a new eccentric-based stress-strain model,
Composite Structures,
Volume 180,
2017,
Pages 88-104,
ISSN 0263-8223,
https://doi.org/10.1016/j.compstruct.2017.07.075.
(https://www.sciencedirect.com/science/a ... 2316330306)
Abstract: In this study, a stress-strain model of fiber-reinforced polymers (FRPs)-confined concrete based on the lateral confinement stiffness was adopted to simulate the lateral response of RC columns retrofitted with external FRP jackets and tested under axial and lateral loads. The adopted model and other five-stress-strain models (established in former studies) were comparatively studied to simulate the seismic response of eight RC-circular columns retrofitted with FRP jackets and experimentally tested under both axial and lateral loads. Compared to the experimental results, the simulation results indicated that all stress-strain models could not identify properly the ultimate lateral displacements of the simulated columns. The adopted stress-strain model was revised to consider the effect of a key influential parameter (eccentricity ratio), which showed a critical impact on the simulation of the seismic response of RC-columns under combined bending and axial loadings. Finally, the proposed model was evaluated in predicting the lateral response of additional three columns and the simulation results exhibited a good agreement with the experimental results.
Keywords: Eccentricity; Design-oriented model; Lateral loading; Circular column; FRP-jacket; OpenSees

[kmegal01]

P.S: In the above version of the paper the FRP jacket failure criterion due to buckling of longitudinal compressive steel bars was not included in FRPConfinedConcrete uniaxial material. More information could be found here:

https://bigeconomy.gr/wp-content/upload ... ournal.pdf

[kmegal01]

For 'FRPConfinedConcrete' performance you could check also the following PhD thesis:

https://theses.lib.polyu.edu.hk/handle/200/8695

[kmegal01]

OpenSees Seminar on FRPConfinedConcrete Material Model

Please click on the following link: https://www.youtube.com/watch?v=kGiHERNnfTM

[kmegal01]

MEGALOOIKONOMOU K.G. (2019, December). Modeling the behavior of shear-critical reinforced concrete columns under lateral loads. Ph.D. Thesis, Department of Civil and Environmental Engineering, Faculty of Engineering, University of Cyprus, Nicosia, Cyprus. https://doi.org/10.12681/eadd/47504

Online Reader: https://freader.ekt.gr/eadd/index.php?doc=47504&lang=el