| Concrete filled steel tubes have the advantages of high bearing capacity, good plasticity, elasticity, and being convenient for construction etc. so they are widely and widely used in civil engineering. Steel castellated beams have the virtues of saving steel material and being convenient for construction etc. and are paid much more attention by civil engineers. So how to connect the above two kinds of material and how the mechanical properties of the connect joint is become a problem that the civil engineers eager to know. So the force behavior of outer annular-stiffener type steel castellated beam- concrete filled steel tube is deeply analyzed in this thesis, which will provide theory reference for the application of this kind of joint and the formulation of the relevant codes. The following work is done.Based on the finite element software ABAQUS, an outer annular-stiffener type steel beam-concrete filled steel tube joint finite element model is established, and the loading process of the joint is simulated and analyzed. The validity of the simulation method is tested by using the previous experiment data, It shows that the results from the finite element simulation method and the experiment are similar to each other, which verified the feasibility of simulating the loading process of outer annular-stiffener type steel castellated beam-concrete filled steel tube joint. According to actual engineering scaling, round outer annular-stiffer concrete filled steel tube-steel beam and castellated beam models are established. By comparing the hysteresis curves, skeleton curves, ductility and energy dissipation capacity the both in low cycle, it shows that the joint has good ductility and energy dissipation capacity, and it is easier to achieve "strong column weak beam" mechanism of yield, which illustrate the outer annular-stiffener type steel castellated beam-concrete filled steel tube joint has good engineering application value.Many outer annular-stiffener type steel castellated beam-concrete filled steel tube joints with different parameters are designed, and their loading process is simulated by the above finite element simulation method. The results showed that all the hysteresis curves of these joints have full shapes, no obvious stiffness degradation, The displacement ductility coefficient is between 4.32-5.19, the equivalent viscous damping coefficient is between 0.31-0.36, which shows that the overall component has good capability of plastic, good ductility and energy dissipation capacity. Based on the above simulation results, the effect factors that influenced the hysteresis curves are analyzed, the results shows that the width of stiffener ring, the strength of steel, the steel ratio, the beam to column linear stiffness ratio, the opening rate, the hole spacing, the distance of the first hole center beam to the column are the main factors, yet the axial compression ratio is not an important factor. According the above results, the parameters that influence flexural bearing capacity, ultimate flexural capacity initial stiffness are further studied, and simplified calculation formula is regressed and verified. It can be referenced in engineering. |
PDF Full Text Request