Water Resources and Power

To discuss the cumulative damage of hollow concrete-filled steel tubular bent frame columns under seismic loading,three-dimensional finite element simulation model under static and dynamic conditions was established based on ADINA.According to the mechanical characteristics and damage deformation of the steel tube and core concrete in concrete-filled steel tube structure,a multi-axial damage and cracking constitutive model was applied to concrete materials, and double linear constitutive model was applied to steel tube.The plastic damage law of steel tube and concrete were investigated under static working loads and seismic loading.The results showed that the concrete was without damage under static working loads,but the core concrete was prone to cracking and the steel tube was prone to buckling if the hollow ratio was greater than 0.35under seismic loading;the maximum horizontal displacement was in line with the requirements of the current specification and the hollow concrete-filled steel tubular composite bent frame column was quite capable of seismic resistance obviously.