Dynamic Response Of CFRP-steel Tube Confined Concrete Subjected To Pre Axial Loading

CFRP material is light weight and high strength.It can replace some steel to reduce the weight of concrete filled steel tube specimens and prevent corrosion in wet and saline soil.CFRP-steel tube confined concrete specimen is a new type of composite structure,which has been applied to large-span bridges,multi-storey and high-rise buildings and other large infrastructure.In order to study the dynamic response of CFRP-steel tube confined concrete specimens under impact load systematically,the impact model of specimens is established by using ABAQUS software,and the influencing factors of impact performance are explored,which can provide reference for the design and application of specimens under impact conditions.The research contents are as follows:(1)The impact model of CFRP-steel tube confined concrete specimens is established by using ABAQUS software.The simulation impact time-history curve and displacement time-history curve of specimens under impact are compared with the test results.The correctness of the model is verified.It is shown that the method can effectively simulate the impact process of specimens.(2)The lateral impact simulation of CFRP-steel tube confined concrete specimens under prestressing axial force is carried out,and the stress-strain time history curve of specimens is obtained.Based on the peak value of impact force and mid-span deflection,the influence of four factors on the lateral impact performance of specimens under pre-applied axial force,restraint effect coefficient,concrete strength and steel tube strength is investigated.(3)The axial impact simulation of CFRP-steel confined concrete specimens is carried out to analyze the restraining effect of CFRP and steel on the core eoncrete.Based on the impact peak value and the mid-span deflection peak,the effects of impact energy,confinement effect coefficient and concrete strength on the axial impact performance of the specimen are investigated.(4)Using Duhane integral to calculate the displacement of the specimen after the lateral impact load,calculate the lateral impact deflection of the specimen under the elastoplastic model,and derive the lateral impact load and deflection of the specimen under the rigid plastic model.The calculation formula provides a theoretical calculation reference for the lateral impact dynamic response of the specimens.