Nonlinear Analysis of Prestressed Concrete Beams with GFRP Sheets by Finite Element Method

Abstract

This paper describes a numerical method for the full-range analysis of prestressed concrete flexural beams strengthened with prestressed glass fiber-reinforced polymper (GFRP) sheets, focusing on ductility and flexural strength behaviour. Prestressing concrete structures cause increased flexural strength of these structures thus increased resistance of structures, increased span length, and reduced displacements of beams are resulted, which is very effective and economically feasible. The study of ductility of these structures that have been used a lot nowadays, has a great importance because it expresses the capability of structure in inelastic deformations before destruction of members. Present paper attempts to investigate the effect of prestressed GFRP sheets on ductility and deformation of beams strengthened by this method. Regarding to this, the modelling of three sample of beams in different conditions was studied using finite element software ANSYS. After comparing the results of numerical analysis of concrete beam with GFRP sheet and the numerical results of two types of prestressed concrete beam with wire and proofing the efficiency of presented model, the displacement and energy ductility index, deformation, resistance and the amount of displacement of concrete beams have been investigated. Three beams with 160mm*280mm*3600mm dimensions have been modelled. In summary, the results express that the application of prestressed GFRP sheet may cause the least displacements of beam and an increase of 10% and 10.4% will be achieved in the flexural stiffness and ductility.