Research on seismic behaviors of RC frame retrofitted by bending-shear yielding energy dissipation brace

For improving the lateral stiffness and avoiding the compressive buckling of traditional central braces in RC frames, the bending-shear yielding energy dissipation braces were developed and adopted in the RC frames. For investigating the seismic behaviors of this brace, a single-span 1/3 scaled RC frame with bending-shear yielding energy dissipation brace was designed and subjected to low reversed cyclic loading. ABAQUS finite element software was used to further analyze the influences of the type of brace, the connection type of energy-dissipating component, the height-to-width ratio of shear plate, and the thickness-to-height ratio of shear plate on the seismic behaviors of RC frames. The experimental results show that under low reversed cyclic loading, the energy was mainly dissipated by shear plates and bending plates, and the failure modes include the tearing of the welds of the energy-dissipating components, the scaling of concrete at the column-beam joint, and crushing of concrete at the left foot of the column; Throughout the test, the brace did not buckle, the degradation of stiffness and strength of the specimen were expected, and the energy dissipation and ductility were superior. The numerical results indicate that the seismic behaviors of RC frames retrofitted by the energy dissipation brace are better than that with traditional central brace; When the shear plate and bending plate are welded together, the lateral stiffness and energy dissipation capacity of the structure are significantly improved; The influence of the height-to-width ratio of shear plates on the energy dissipation capacity of RC frames can be negligible, and the bearing capacity and energy dissipation capacity increase with the decrease in the height-to-thickness ratio of shear plates.