Finite element analysis of anti-seismic property of steel reinforced lightweight concrete frame joints

Six frame middle joint specimens were designed with steel lightweight aggregate concrete column and lightweight aggregate concrete beam in order to study the anti-seismic properties. Such influence factors as steel shape, stirrup ratio and axial compression ratio were considered and the bond-slip constitutive relationship was introduced in the nonlinear finite element analysis. Nonlinear finite element analysis was carried out about the hysteresis curves, skeleton curves of the specimens and equivalent viscous damping coefficient, thus, the steel shape, stirrup ratio and axial compression ratio influence laws on seismic behavior of the joints were obtained. Calculation results show that the designed joints have good seismic performance; increasing the stirrup ratio, using cross steel shape can improve the ductility and seismic energy dissipation capacity of the joints; increasing the axial compression ratio can improve the bearing capacity of the joints, but declines the ductility and energy dissipation capacity.