SEISMIC BEHAVIOR AND INFLUENCE FACTOR ANALYSIS ON 3D SIDE JOINTS COMPOSED OF STEEL REINFORCED CONCRETE SPECIAL-SHAPED COLUMNS AND STEEL BEAMS

In order to research the influence relationship between the mechanical behavior under an earthquake action and a steel form, the loading angle, axial compression ratio, one plane side joint and nine space side joints composed of SRC special-shaped columns and steel beams were tested under low frequency cyclic loading. The hysteretic relationships between load and displacement were obtained. Based on these, the aseismic behavior of space joints was discussed. The results show that there are steepest skeleton curves, largest bearing capacity, and lightest stiffness degradation for specimens with solid-web steel. However, the specimens with T-shaped steel form are the optimal in energy dissipation capacity and ductility performance. There are some of the differences in aseismic behaviors of these space joints under different loading angles. The skeleton curves under the rest of loading angles are surrounded by those curves under the loading angle of 45 degrees. The shear capacity under 45degrees is the largest and its energy dissipating capacity is stronger than those under 0 degree and 60 degrees, but lower than that under 30 degrees. The displacement ductility of a plane joint is the best. With the increase of axial compression ratios, the shear bearing capacity and energy dissipation capacity of the SRC side joints of a special-shaped column frame can be enhanced and it is good for the initial stiffness but leads to be a phenomenon of a rapid late-stiffness degradation.