THREE-DIMENSIONAL NONLINEAR ANALYSIS OF RC BEAMS STRENGTHENED WITH EXTERNALLY BONDED CFRP SYSTEMS

Resumo

The strengthening and rehabilitation of concrete structures using carbon fiber reinforced
polymers (CFRP) has consolidated itself as an attractive alternative in civil construction. Some factors
that led to a greater use of this material are its excellent mechanical properties, low specific weight and
high durability. The development of this type of strengthening, and the concrete technology as a whole,
require refined analysis methods. Therefore, it is proposed to perform a computational modeling of
flexural beams with CFRP externally bonded (EB) strengthening systems, through the finite element
method (FEM) in the commercial software ANSYS. The physical nonlinearities of the materials are
included. A special focus is given to the behavior of the bond between the structure and reinforcement,
through contact elements and bilinear cohesive zone models provided by the program. In this way, it is
possible to detect in the computational simulations, premature failure modes that occur by detachment
of the reinforcement and that often limit full employment of CFRP’s resistance properties. The
developed numerical model was able to predict the instantaneous behavior from systems involving
reinforced concrete beams strengthened with CFRP, analyzed through load-displacement curves, as well
as the failure mode and ultimate load.