Study On The Bias And Seismic Behavior Of BFRP Tube Reinforced Concrete Column

BFRP is basalt fiber reinforced composite material,which is composed of resin substrate and fibers.As a high-quality material originally applied in the aviation field,it has received wide attention from the civil engineering community by virtue of its excellent high tensile strength,corrosion resistance,light weight and convenient construction,etc.Combining with reinforced concrete can give full play to the material properties of both,so this paper proposes a BFRP pipe reinforced concrete column,which will BFRP pipe is used as a membrane tool,and the concrete is directly cast into the BFRP pipe to form.This combined column has high load-bearing capacity,good corrosion resistance,strong resistance to deformation,and good seismic performance and low cost.To explore the eccentricity performance of BFRP pipe reinforced concrete columns(BTRC),this paper designs a total of 53 footprint BTRC composite column elements with eccentricity(e),BFRP pipe thickness(t BFRP),reinforcement ratio(ρ),concrete length(fc),and length-to-diameter ratio(λ)as the main parameters.Based on the existing theories,five similar structural elements were successfully verified and analyzed by finite elements,and the errors were found to be within 10%,so the finite element modeling method was verified to be reasonable.On this basis,ABAQUS finite element software is used to establish and analyze the finite element simulation of 53 BFRP pipe reinforced concrete columns,and by studying the load-displacement curve of the components,the bias performance of different parameters on the components and the change law of the ultimate bearing capacity of the components under different parameters are analyzed,and the results show that the eccentricity is controlled below 75 mm,and the BFRP pipe can effectively strengthen the concrete components.When the thickness of BFRP pipe is in the range of 7mm-11 mm,the bearing capacity of the component is in the best state,and the material is cost-effective;With the increase of concrete strength,the ultimate bearing capacity of components is significantly improved.The reinforcement ratio and slenderness ratio have little influence on the components.Finally,according to the stress mechanism of the combined column,the calculation formula of the bias bearing capacity of BFRP pipe reinforced concrete is statistically regressed by using1 st Opt software.Moreover,the error between the formula calculation value and the finite element simulation value is within ±10%,and the calculation accuracy is good,which meets the needs of actual engineering.Based on the analysis of bias performance of BTRC composite columns,this paper analyzes the influence of different parameters on the hysteresis performance,skeleton curve,energy dissipation capacity,ductility performance and stiffness degradation of the components under low cycle repeated loading of 20 BTRC composite columns,taking three factors as the main parameters,namely axial compression ratio(nk),BFRP pipe thickness(t BFRP)and concrete strength(fc).When the axial compression ratio is determined,increasing the thickness of BFRP tube can also improve the bearing capacity of the component,but the ductility performance gradually weakens.The strength of concrete can effectively improve the bearing capacity and stiffness of components.Finally,according to the analyzed parameters,seismic design suggestions are provided for the application of such composite columns in practical engineering within a certain range.