Experimental study on seismic performance of steel frame- K-shaped brace structure system

Steel frame-K shaped brace structure system using small section steel member was proposed in the paper to realize the architectural effect of no convex beams and no convex columns in steel structure buildings. By using K-shaped steel brace, the cross-section size of structure members was reduced effectively. In order to investigate the seismic performance of steel frame-K shaped brace structure system, a pseudo-static test was conducted on a full size specimen, taking a typical lateral force resistance unit as prototype. Finite element analysis was carried out using ABAQUS. The results indicate that the structure system can achieve the design goal of ‘elasticity under small earthquake and non-collapse under large earthquake’. The bearing capacity is maintained with drift ratio of 1/30, which shows excellent performance in terms of seismic performance. Diagonal braces yield first, followed by vertical braces, frame beams and columns, thus the frame is well protected by diagonal braces. The displacement ductility factor of the specimen is 10.0, exhibiting plumper hysteretic curves. The equivalent damping ratio is 18.9% at drift ratio of 1/50, showing perfect energy dissipation capacity.