Seismic behavior of K-shaped eccentrically braced frames with high-strength steel: Shaking table testing and FEM analysis

A shaking table test was carried out on 1:2 scale three-storey K-shaped eccentrically braced frames with high-strength steel (K-HSS-EBFs). The acceleration, displacement, and strain responses of the specimen under different peak acceleration ground motions were measured and analyzed. The natural frequency, acceleration amplification factor, storey drift, and distribution of horizontal seismic actions for the model structure were investigated. Finite element models were established for elastoplastic time history analysis on the model structure. Finite element analysis showed that the links were the weakest part of the structure, especially the webs of the links and welds near the connections between the links and frame beams. The results showed that K-HSS-EBFs may absorb excessive seismic energy, enter the elastoplastic state, and even fail under strong earthquakes owing to shear deformation of the links during vibration. The PBPD method is found to be suitable for use in the design of K-HSS-EBFs. In addition, the K-HSS-EBFs can fulfill the seismic requirements under limiting state. These findings will be helpful for the future design of K-HSS-EBFs.