Experimental Study On Carbon Fiber-PVC Concrete Composite Column Built Into Steel Tube

The carbon fiber-PVC concrete column built into the steel pipe is a new type of frame column.The new frame column is composed of steel pipe,concrete and carbon fiber-PVC pipe.This composite column is made of carbon fiber-PVC in the concrete of the traditional concrete-filled steel tubular column.Thus forming a new combined structure.The mechanical properties of the concrete filled steel tube are improved by adding a carbon fiber-PVC pipe to the concrete filled steel tube.The biggest advantage of this kind of combined column is that the outer steel pipe and the inner carbon fiber-PVC pipe can jointly restrain the concrete,make full use of the strength of the material,and improve the overall bearing capacity and ductility of the concrete filled steel tubular column.Based on the previous research on concrete-filled steel tube,a total of 12 steel pipe-built carbon fiber-PVC composite column specimens were designed in this test.The test parameters include carbon fiber-PVC pipe diameter,aspect ratio and load loading mode.The effects of carbon fiber-PVC pipe on the core concrete of steel tube were studied by changing the above parameters.The failure mode and displacement-load curve of the built-in carbon fiber-PVC steel pipe composite column and the transverse and longitudinal load-strain curves of the steel pipe surface were obtained.The test results show that the larger the diameter of the PVC pipe in the concrete filled steel tube,the higher the bearing capacity of the test piece,the smaller the strain of the test piece;the larger the aspect ratio,the lower the bearing capacity of the test piece,the greater the strain of the test piece;the concrete filled with steel tube and steel pipe carbon fiber-PVC concrete damage is similar.According to the data obtained from the test and the constitutive relationship of carbon fiber cloth,steel pipe and concrete,the nonlinear finite element simulation of the 12 composite column specimens of this test was carried out.The software used was ABAQUS.The model of the test piece under different loads was simulated and simulated by software,and the test process of each test piece in the actual test was restored by software.At the same time,the stress cloud diagram of the specimen under simulated conditions is obtained.Through the comparative analysis of the deformation cloud diagram,the force principle and the overall damage phenomenon of each material in the composite column specimen are studied.Finally,the displacement of each simulated specimen is drawn by software.The load curve is compared with the corresponding curve of the actual test,and the simulated curve is in good agreement with the actual test results.