Title:
Finite Element Simulation and Parametric Study of Anchored Fiber-Reinforced Polymer Sheets
Author(s):
Alaa T. Al-Sammari and Sergio F. Breña
Publication:
Structural Journal
Volume:
115
Issue:
2
Appears on pages(s):
365-377
Keywords:
carbon fiber-reinforced polymer (CFRP) sheets; carbon fiber anchors (CFRP anchors); CFRP anchor splay; CFRP concrete joints; fiber-reinforced polymer (FRP) debonding; fiber-reinforced sheet anchorage; FRP finite element modeling; strengthening of concret
DOI:
10.14359/51701094
Date:
3/1/2018
Abstract:
Design provisions for fiber-reinforced polymer (FRP) strengthening systems recognize the inability of FRP sheets to reach their ultimate strength because of debonding from the concrete substrate. These provisions therefore limit the maximum strain that can be used for design of FRP sheets. To increase the design efficiency of FRP sheets, past researchers have proposed anchoring the sheets to the concrete substrate instead of relying solely on bond to transfer stresses between concrete and FRP materials, yet the effect of applying anchors to FRP sheets is not well understood. This paper presents the results of a detailed finite element simulation of the FRP-concrete joint system that includes all the components of the system explicitly. This model was used to investigate the effect of key parameters of FRP anchors on the ultimate strength of the FRP system. The parameters that were studied include: the number of anchors used in the sheet; the distance between anchors; anchor depth; anchor shaft diameter; anchor splay angle; and anchor splay diameter. Modeling results show that only 62% of the strength of the FRP sheet is reached at ultimate load when anchors are not used. In contrast, the full strength of the sheet can be mobilized when FRP anchors are used. The analyses also demonstrated that the use of anchors did not arrest propagation of the debonding front behind the anchors, but did delay full separation of the FRP sheet from the concrete substrate, resulting in higher failure loads.
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