Hysteretic model of SRUHSC column and SRC beam joints considering damage effects

This paper focuses on developing a hysteretic model of steel reinforced ultra high strength concrete column and steel reinforced concrete beam joint. Characteristics of the hysteretic curve from twelve specimens under cyclic loading were analyzed in terms of damage pattern, residual deformation, loop unloading stiffness deterioration, relative unloading stiffness deterioration and strength degradation. Methods to quantify seismic damage and attenuation coefficient were presented. The proposed methods consider number of loading cycles and controlled displacements which cause seismic damage. The experimental skeleton curve is simplified as a trilinear model, where calculated attenuation coefficient is used to obtain deteriorated stiffness of every segment, deteriorated unloading stiffness, and degraded strength in the hysteretic model. The proposed hysteretic model considering damage effects can describe well the characteristics of experimental hysteretic curves.