Study on earthquake resistance test of L-shaped concrete-filled rectangular composite steel tubular columns

Through pseudo static test, the earthquake resistant capability of 3 L-shaped special-shaped concrete-filled rectangular composite steel tubular columns,3 L-shaped improved special-shaped concrete-filled rectangular composite steel tubular columns and 3 L-shaped improved special-shaped concrete-filled rectangular composite steel tubular columns with restrain sticks is studied under low cycle repeated load, and their failure mode, failure mode test phenomenon and failure mechanism is described. The results indicate that the hysteresis curves of the specimens have long and narrow hysteresis circles in elastic stage while begin to bend in elastic-plastic stage, and the shape become full; the specimens own good energy dissipation capacity. Specimen displacement ductility index can meet the requirements of seismic design. The equivalent viscous damping coefficient of all specimens are greater than ordinary concrete structures´, the energy dissipation of special-shaped concrete filled rectangular composite steel tubular column is much larger than ordinary concrete structures´; in general, rate of specimen stiffness degradation is relative slow, all specimens possess good lateral resistance ability.