Analytical and numerical models are presented to simulate the failure of RC beams strengthened with FRP plates and flexible sheets. Different failure mechanisms, from ductile to brittle, can be simulated and verified. The proposed analytical model takes into account the influence of concrete confinement in the compression zone due to the presence of the stirrups and the tensile softening properties of concrete. This allows following more accurately the crack propagation and the failure mechanism of the flexural member. The numerical model is based on finite element analysis (FEA), follows the smeared crack approach, and uses standard elements available in a commercial package. Comparisons with experimental data obtained from strengthened RC beams tested in the laboratory are presented.
We study the stress-strain state and limiting equilibrium of a thin plate with curvilinear cracks reinforced by a wide patch. The patch is arbitrarily located relative to the cracks and attached to the plate with elastic rivets. The boundary-value problem is reduced to a system of singular integral and integro-algebraic equations and this system is solved by the method of mechanical quadratures. Numerical analysis is performed for the case of a plate with one curvilinear or rectilinear crack reinforced by an elliptic patch. The stress intensity factors formed in this reinforced cracked plate and ultimate loads are determined for various geometric and physical parameters of the plate, crack, patch, and rivets. 2b1af7f3a8