| The beam-to-column connections is the key part of the frame structure. In this paper, the research object is to the joint of steel beam to concrete filled steel tube(CFST) column with stiffening ring and its composite structure frame system. Three questions are researched: the semi-rigid joint impacts characteristics on the mechanical properties of composite frame; the cost of numerical seismic performance analysis of composite frame; hysteretic model of composite frame.Based on the previous research, this paper improved the calculation method of the elastic rotation stiffness of the joints based on the correlation. By using the improved sensitivity analysis method and the multi-scale finite element method, the rotational stiffness of the composite joint was studied. The accuracy and superiority of the multi-scale finite element method applied to the seismic performance analysis of the composite frame are studied. The calculation model of the skeleton curve of the composite frame is modified, that is, the theoretical calculation of the skeleton curve of the composite frame is carried out under the premise of considering the semi-rigid of the connections. The main work and conclusions are as follows:(1) The method of realizing multi-scale finite element method in ANSYS were introduced, the shortages of these methods were pointed out. The MPC method was used to establish the model of multi-scale cantilever beam which verified the accuracy of the MPC method. The multi-scale model and fine model of the joint of steel beam to CFST column with stiffening ring were built. and the comparison with the experimental data verified the correctness of the multi scale node model.(2) On the basis of previous studies, a new method to consider the correlation of parameters is proposed. Using MATLAB combined with ANSYS to carry on the parameter sensitivity analysis of stochastic finite element, the problem of PDS ANSYS module was overcome. The parameter sensitivity analysis was done, the initial node with a clear physical meaning of the rotational stiffness calculation model was obtained, and then the whole process of joint moment rotation curve was presented.(3) Semi-rigid typical plane frame models, modal analysis and three kinds of typical earthquake wave dynamic time history analysis were carried out, to study the effect of semi-rigid on the seismic performance of composite frame. Multi-scale method is used to establish the semi-rigid frame, and the time history analysis of various seismic waves was carried out, the effectiveness and superiority of multi scale application in seismic analysis are studied.(4) Based on OpenSEES, semi-rigid frames model was established, and the parameters of the skeleton curve are analyzed. Considering the semi-rigid connections, on the application of two order analysis method, a practical calculation model of semi rigid composite skeleton curves was established. |
PDF Full Text Request