Nonlinear Finite Element Analysis Of BFRP Bar-reinforced High-strength Concrete Beams With Steel Fibers

Fiber reinforced polymer(FRP) bars have characteristics such as light weight, high strength, corrosion resistance and fatigue resistance. Steel fibers can significantly improve the toughness and deformation of high strength concrete. Combining their advantages and studying FRP bar-reinforced high-strength concrete structures with steel fibers can well meet the demand of engineering. The study about the structures of the FRP bar-reinforced high-strength concrete with Steel fibers is relatively less. Based on the methods of experimental study and finite element analysis, bending properties of basalt fiber reinforced polymer(BFRP)bar reinforced high-strength concrete beams are studied. The main research contents and results are as follows:(1)Through three different diameters of BFRP bars tensile experiment, getting the BFRP bars tensile strength and elastic modulus and analysing the influence of diameters on them.(2)Based on the compression experiment and axial compression experiment of steel fiber reinforced high strength concrete, analysis the influence of steel fibers on strength,elastic modulus and constitutive relation of high strength concrete. Using different experimental methods for axial compression stress-strain full curves and comparison, summarizes the stiffness influence on experimental curve. Piecewise constitutive model is established.( 3) Based on bending performance experiment results of five BFRP bar-reinforced high-strength concrete beams with different steel fiber volume content, the finite element model is established. Setting various parameters and criterions reasonably on the basis of BFRP bars tensile experiment results and steel fiber reinforced high-strength concrete material experiment results. By numerical simulation this paper get the failure pattern, the load-deflection curves of different beams, material deformation and fracture distribution results. The numerical simulation results meet well with the experiment, and proved that the feasibility of the model and the program.(4)Combined with experiment and finite element simulation this paper analyzes the influence of steel fiber content on bending properties of beams. Otherwise, this paper analyzes the change of BFRP bars ratio and the concrete matrix strength on the bending properties of steel fiber reinforced concrete beams, providing reference for scientific research and engineering practice.