Numerical Simulation Study On FRP-concretesteel Double Skin Tubular Beam Under Lateral Impact

FRP-concrete-steel double skin tubular member is a new type of composite member developed from the concrete-filled double skin steel tubular member.It has the advantages of good plasticity,toughness,light weight and corrosion resistance.The pipeline is also easy to be arranged in the member.FRP tube is a kind of multi-directional fiber laid laminated shell.It has superior corrosion resistance and its strength is higher than steel.Therefore,it is widely used in structural reinforcement in humid,freezing and other corrosive environments.But the structure may be subjected to explosion and impact force in its service life,so it is necessary to consider the impact resistance and energy absorption effect of the structure while strengthening the corrosion resistance of the structure.Therefore,this paper will do some research on the impact resistance of FRP-concrete-steel double skin tubular member and FRP tube reinforced hollowcore concrete member based on the drop weight impact test model.The model of FRP-concrete-steel double skin tubular member based on the experiments of related articles with fixed ends under lateral impact is established by using the LS-DYNA.Then the material of concrete,steel and FRP are selected in LS-DYNA material constitutive model.The strain rate effect under dynamic load is considered in material constitutive model,and the material parameters are determined according to the test.In the aspect of contact,the influence of two kinds of contact conditions between FRP and concrete on the simulation is considered and analyzed.Finally,the numerical models of FRP-concrete-steel double skin tubular member subjected to drop weigh impact are verified by available testing data.After verifying the correct models,the parameter tests of the model were carried out,including drop weight geometry,mass,location of impact,boundary conditions,member’s pan length and CFRP reinforcement length.The Influence of different parameters on the impact resistance of member were analyzed.Then,the application of GFRP tube reinforced hollowcore concrete member under lateral impact is analyzed by the time history curves of impact force,displacement of mid-span and energy dissipation from the aspects of the contact condition between GFRP and concrete,the thickness of GFRP tube,the ply design of GFRP tube and so on.And the impact resistance of GFRP tube reinforced hollow-core concrete member and FRP-concrete-steel double skin tubular member are compared.The discussion in this part proves the feasibility of using GFRP tube instead of steel tube to resist impact load.