Analysis of RC Continuous Beams Strengthened with FRP Plates: A Finite Element Model
Abstract: Strengthening of
reinforced concrete (RC) beams with externally bonded fibre reinforced polymer
(FRP) plates/sheets technique has become widespread in the last two decades.
Although a great deal of research has been conducted on simply supported RC
beams, a few studies have been carried out on continuous beams strengthened
with FRP composites. This paper presents
a simple uniaxial nonlinear finite-element model (UNFEM) that is able to
accurately estimate the load-carrying capacity and the behaviour of RC
continuous beams flexurally strengthened with externally bonded FRP plates on
both of the upper and lower fibres. A 21-degree of freedom element is proposed
with layer-discretization of the cross-sections for finite element (FE)
modelling. Realistic nonlinear constitutive relations are employed to describe
the stress-strain behaviour of each component of the strengthened beam. The FE
model is based on nonlinear fracture mechanics. The interfacial shear and
normal stresses in the adhesive layer are presented using an analytical
uncoupled cohesive zone model with a mixed-mode fracture criterion. The results
of the proposed FE model are verified by comparison with various selected
experimental measurements available in the literature. The numerical results of
the plated beams (beams strengthened with FRP plates) agreed very well with the
experimental results. The use of FRP increased the ultimate load capacity up to
100 % compared with the non-strengthened beams as occurred in series (S). The
major objective of the current model is to help engineers’ model
FRP-strengthened RC continuous beams in a simple manner.
Keywords: Finite Element;
Continuous Beams; Plated Beam; Interfacial Stresses; Maximum Capacity;
Debonding
Author: Mohamed A. Sakr, Tarek
M. Khalifa, Walid N. Mansour
Journal Code: jptsipilgg160062
