Experimental Study And Finite Element Analysis Of Bond-Slip Between Circular Steel Tube And Concrete

The bond strength and the bond-slip constitutive equations at the interface between the steel tube and the concrete of concrete-filled circular steel tubes (CFCST) is one which is further concerned by more and more construction engineers and researchers. The study on the bond-slip behaviors at the interface of CFCST is significant on the theory and practical value.In this paper, axial push-out test of CFCST is carried out. Based on the results of experiment, composing of bond force, characteristic and rule of bond failure are discussed. The characteristics of load-slip curves (P-S curves) were summed up. According to the P-S curves, every stage of relationship between bond stress and slip was analyzed, the distribution of bond stresses and slip included cementation stage, slip stage, frictional resistance stage and after-slip stage.The numerical simulation of the push-out test specimens were conducted with the ANSYS programm. In order to take the interaction between the steel tube and the concrete core into account, combination 39 elements were used to simulate the three directional interactions. The methods and skills of nonlinear FEA numerical simulation by ANSYS program used in CFCST structures were summarized and presented. The simulation results were compared with the experimental results. The results indicated that the simulation results were good agreement with the experimental results. Therefore, the methods of numerical simulation of CFCST push-out test specimens in ANSYS program presented in this paper could be introduced into the simulation of the CFCST members and structures.