Study On Seismeic Behavior Of Stud Welding Steel Reinforced Concrete Columns Under Combined Compression, Flexure, Shear And Torsion

In order to investigate the seismic performance of stud welding steel reinforced concrete (SSRC) columns under combined compression, flexure, shear and torsion, nine SSRC columns subjected to combined compression, flexure, shear and torsion were tested under quasi-static. The main test parameters were positions, space and lengths of welded stud. The failure process and pattern of SSRC columns were revealed. The mechanical behaviors such as hysteretic loops, skeleton curves, bearing capacity, stiffness degradation, ductility and energy dissipation of SSRC columns were analyzed. Based on the interaction relationship of strength, the torsion bearing capacity calculation method of steel reinforced concrete members was put forward. The practicability of building the torsion bearing capacity fitting calculation formula of SSRC columns was discussed. Study proves that:The torsion-bending failure is the main patterns of specimens, the inclined crack connects together, and crosses as "X", the concrete cover crushes and desquamates.The hysteretic loops of specimens are similar, the flexure-displacement hysteretic loops are in plump spindle-shape, the torsion-angle hysteretic loops are in S-shape or Z-shape. The SSRC columns have good seismic performance.In the sight of flexure, the energy dissipation of steel reinforced concrete columns with stud welded on flange is stronger, the ductility is best, welding stud on flange can improve seismic performance of specimens. In the sight of torsion, the ductility of SSRC columns are better than steel reinforced concrete columns without studs. The ductility becomes better with space of studs decreases.The flexure bearing capacity of SSRC columns increases little with the studs. The studs have a mild effect on torsion bearing capacity of SSRC columns. The torsion bearing capacity of specimens decreases about 9.66%. The flexure and torsion bearing capacity of SSRC columns can be calculated according to the method of steel reinforced concrete columns.A unified strength equation of steel reinforced concrete members under combined compression, flexure, shear and torsion was built. Considering the interaction relationship of strength, the torsion bearing capacity calculation method of steel reinforced concrete members was put forward, and the calculation results are consistent with experimental value.It is feasible that building the torsion bearing capacity fitting calculation formula of SSRC columns.