Dynamic Behavior Of CFRP-Concrete-Steel Composite Column Under Low Velocity Lateral Impact Load

FRP-concrete-steel double skin tubular column is a new type of composite structure proposed on the basis of concrete-filled double skin steel tube column and FRP-confined concrete column.The structure not only has the advantages of CFDST column,such as light weight,high compressive bearing capacity,high bending rigidity,good shape and toughness,but also has excellent performance of FRP,such as corrosion resistance,fatigue resistance and convenient construction.So it is often used as a pillar of bridge and marine exploration platform.During the service of the structure,it will inevitably suffer the impact of accidental load,often lead to local damage and even the overall damage.In this paper,the experimental study and theoretical analysis on the mechanical properties of CFRP-concrete-steel tubular columns under low velocity impact are carried out.Main contents include:(1)The lateral impact test carried out on the drop hammer tester named DHR9401 in Taiyuan University of Technology and the testers are distinguished by changing the drop height and the number of CFRP.The date of impact force,mid-span deflection and critical point strain time history curves are recorded during experiment.Then the overall residual deformation and local damage morphology of the specimens were obtained after test.(2)Based on the full consideration of contact type and strain rate effect of material,a both ends fixed CFRP-concrete-steel double-skin tubular column under impact load model is set up with ABAQUS finite element software.The simulation results are compared with the test results to verify the accuracy of the model.(3)The dynamic response of a typical specimen under lateral impact load is analyzed based on the validated finite element model.Building the analysis model of different parameter of CFRP-concrete-steel composite columns with both ends fixed,the test results are analyzed by range method,so as to determine the influence ratio of force peak value,force platform value and the residual deflection by all parameters,then further study on the main influencing parameters is essential.