| Concrete filled double skin tubular(CFDST) column is a new novel structure.This structures is placed on two inner and outer concentric steel tubes, pouring concrete between inner and outer layers of formed steel components. In addition to maintaining the traditional characteristics of concrete filled steel tube structures, also has carried out cross-section, bending stiffness, light weight, good seismic performance and fire performance characteristics, having a good prospect in engineering fields for building large diameter column, offshore platform structure of stent posts and other tall structures.Currently, many studies for the basic performance of concrete filled double skin steel member have been carried out by scholars,and also conducted a small amount of experimental and theretical analysis of concrete filled double skin steel rigid joints.However, there are lack of investigation of static performance,hysteretic behavior and failure mechanism of concrete filled double skin steel semi-rigid joints.This joints are adopted by end plate connection with unilateral high-strength bolts,with significant advantages like seismic performance and easy construction.It is expected to facilitate their application and promotion in the actual project. Therefore, the study of seismic behavior and failure mode of concrete filled double skin steel semi-rigid joints has important theoretical and engineering significance. The research of the seismic performance studies on seimi-rigid joints for CFDST columns with square hollow section (SHS) inner and square hollow section (SHS) outer has been done in this paper,and the main word has been done as follow:(1) Theoretical models under monotonic and cycle loading have been established for concrete filled double skin steel semi-rigid joints.The material nonlinearity, geometric nonlinearity and complexity of the contact angle have been considered. The rationality of meshing and convergence solution have been solved.The rationality of the model has been verified by the result of static and seismic test.(2) The entire process nonlinear analysis of concrete filled double skin steel semi-rigid joints under monotonic and cycle loading have been carried out.The stress distribution of key parts and key components of combinate joints have been obtained from micro and macro perspective, revealing the mechanical characteristics and failure mechanism. Different components of the failure stress states have been analysed deeply.(3) Using the finite element software ABAQUS, from material,geometry and load parameters,static and hysteretic performance have been systematic analysed for concrete filled double skin steel semi-rigid joints. The influence of main parameters for nodal moment-rotation relationship was clear. |
