Test Research And Simulation Analysis Of Steel Tube-Confined Concrete With Different Restrain Condition In The Lateral Impact

In recent years, the construction structure is repeatedly hit and destructed, which is taken more and more advantage by the engineering. Steel tube-confined concrete is a strcture formed by filling concrete in steel tube. The study of damage and destruction in this kind of composed structure under impact is in the range of plastic-dynamics. Because the response of the structure in impact load is a complicated non-linear mechanics problem, the research of this field is still lacking, especially, on the impact of the STCC. But as application of the STCC being extensive day by day, the research of the STCC structure impact resistance is becoming very essential.In this paper, 3.5mm STCC pieces are taken as the object and researched in the lateral impact refoced by the drop hammer. This paper also utilize finite element software ANSYS/LS-DYNA to go on related numerical simulation analysis, comparing and analysis the impact resistance and influence factor of impact loads on STCC.In the paper, first, impact resistance experiment of STCC has been carried on, which are in three boundary condition as simply, fixed-simple and fixed-fixed support. The dynamic response and destruction course of the model is measured under impact load. The travel time curve and deflection of the test specimen is drawn up on the drop hammer. STCC is also tested under the still load test, and the steel tube is tested under the same impact circumatances. By this the mechnical characters of the test piece are measured.In this paper, second, the explicit finite element calculation theory and method is applied to set up compared numerical model. It has been basically researched on numerical calculation principle and theoretics method of the impact contact dynamics.In this paper, entity's modeling is bulid, and then impact realistic simulation of the test model is studied. Contrasted to the experimentation, the simulate results has been verified. Further the computational model is searched, which can describe the test results reasonably. On the contrary, through a large amount of simulation, the impact resistance of test sample is discussed. In this way, the experimental number and the cost are effectively reduced. In the course of simulation, it is studed that the stress, strain, size and regularities of distribution of impacting force and deflection. At the same time, the deflection and impacting force curve are made. To combine with experiment, failure criteria of the sample are given. The critical energy of sample has been found out. And through a large number of data regress, the experience formula of the critical energy and critical impacting force are acquired.On influencing component impact resistance factor, mainly several fators are gone on restrain condition and impact energy. At the same time , dynamic plastic limit bending moment which is borne by the plastic hinge , the deform , impact force and the position of plastic hinge with position of impact block is got by analyzed further with ANSYS/LS-DYNA program , concluding and calculating.Finally, it is shown by means of test and computer simulation: The STCC has good resistance to impact laod, when the component is added the loads suddenly; the STCC demonstrates very good ductility, the materials have obvious yield stadge. The bigger the speed and energy of the drop hammer, the more fragile of STCC dynamic response. In regard to affecting factor of the STCC resistance to impact, the stronger restraint that the component is subjected to, the better the impact resistance of the component.