The Study On Bond-slip Behavior Of Concrete Filled Steel Tube

Concrete-filled steel tube structure, the bond behavior between steel and concrete canensure the coordination and unity to some extent and composes the foundation that two materialscan work together. The sliding phenomenon that exists on the connecting surface is typical ofconcrete-filled steel tube members. In order to decrease and avoid the sliding phenomenon andensure that steel and concrete can work together better, some reinforcement measures should betaken in steel pipes manufacturing procedures. However, these add addtional constructiveamounts and financial expenditure.Currently, there are few documents about the bond-slip behaviors in concrete-filled steeltubes. This paper lays emphasis on mechanical behavior and process of the bond-slip inconcrete-filled steel tubes on the bases of summarizing literature about this aspect at home andabroad.Several research methods were taken which include theoretical derivation、experimentargumentation、finite element simulation and so on. Major works are as follows:(1) experiment mechanical model, deduced from ultra-thick concrete-filled steel tube shortcolumn, was derived theoretically. We obtained mechanical behaviors of this kind of model, forexample, variation and distribution laws of each direction displacement, variation laws of bondstress. And through the model’s push out test, we obtained the variety rule chart that thedisplacement follows the test load.(2) Relatively to the mechanical behavior of push-out test model, which derivedtheoretically. on the condition of linear elasticity, the finite element software ANSYS wasapplied to simulate the push-out test model. Comparing with the results, We verified the eachother’s correctness. And the term of theoretical derivation is not limited, we use finite elementsoftware to approach the diversity of component model stress features in case of changing aseries of external conditions.(3) In terms of nonlinear behavior conditions, we conducted finite element simulationanalysis of axial compression tests on a variety of different form morphology of concrete-filledsteel tube component models by using ANSYS, a series of results about bond-slip problem arederived from the nonlinear simulation, and a new simulation approach was provided for dealingwith similar issues by using finite element simulation in the future.