Study On Static Pure Shearing Performances Of Circular Concrete Filled CFRP-steel Tubes

The research of CFRP-steel pipe concrete experts and scholars conducted experimental research and simulation.for example,axial compression,bending,bending and other common force,and,these studies tend to be mature,However,the study of CFRP-concrete filled steel tubular members under shear load has not been involved,it is necessary to study the concrete filled circular CFRP-steel tubular members pure shear in the static performance of this area.This article is based on the previous research on CFRP-concrete-filled steel tube,static behavior of pure shear on circular CFRP-concrete filled steel tube under shear load,The following aspects are carried out in detail:(1)The mechanical properties of twelve CFRP-concrete-filled steel tubes are studied,The main parameters considered for pure shear specimens are:concrete strength(fcu),30,40 and 50 respectively,and the number of lateral CFRP layers(mt)is 0,1,2 and 3 respectively.With the increase of concrete strength of concrete circular CFRP-steel tube shear component elastic stiffness and shear bearing capacity increases,and the effect is remarkable;with the increase of the number of CFRP concrete circular CFRP-steel pure shear member elastic stiffness and shear strength increase with a small increase,but the effect is not significant;and the strength of concrete the number of CFRP only changes the pure shear specimen elastic stiffness and shear strength,no influence on macro curve shape.(2)Using ABAQUS finite element analysis circular CFRP-steel tube shear loading were simulated.the ABAQUS simulation curve and experimental curve extraction were compared,and the simulation of failure modes and test failure modes are compared,so as to achieve the simulation and test verification purposes.The simulation curve is in good agreement with the test curve,and the simulated deformation mode is in good agreement with the experimental deformation mode.(3)The full force process and parameters of the pure shear model of circular CFRP-concrete filled steel tube were analyzed.Parameter analysis mainly considers parameters:the yield strength of steel,the strength of concrete,the rate of steel content and the number of transverse CFRP layers.CFRP-concrete circular steel tube shear bearing capacity and elastic stiffness with steel yield strength,concrete strength,steel ratio increases with increased significantly,with the pure shear component increased the number of CFRP of the shear bearing capacity and elastic stiffness of small amplitude increased,but the effect is not significant;the above parameters to curve shape effect.(4)Through fitting the data through the data fitting software MATLAB,the formula for calculating the shear strength of the circular CFRP-steel tube concrete member is given.The shear strength calculation formula is used to calculate the bearing capacity of the specimens.The calculated values are in good agreement with the experimental values,which validates the correctness of the formula for calculating the shear strength of circular CFRP-concrete-filled steel members.