ANALYSIS OF ASEISMIC PERFORMANCE OF HIGH STRENGTH STEEL COMPOSITE K-ECCENTRICALLY BRACED FRAMES

To evaluate the aseismic performance of high-strength steel composite eccentrically braced frames (K-HSS-EBFs), a finite element analysis of a shaking table test specimen was carried out. The simulated results are consistent with the test results, which proves the feasibility of the finite element method. A ten-story K-HSS-EBF was designed, and incremental dynamic analysis (IDA) was carried out with 10 seismic ground motions. The weak parts of the structure, the formation and development of the plastic zones of the link and the relationship between the base shear force and maximum story drift under the action of strong earthquakes were researched. The IDA curves of 10%, 50% and 90% fractiles and the displacement ductility coefficient were ascertained. The aseismic performance was assessed by combining it with the defined performance parameters. The results show that with the increase in the peak ground acceleration, the links successively entered the plastic state and absorbed the seismic energy. The collapse fragility curve can reflect the aseismic performance of the K-HSS-EBFs. The K-HSS-EBFs designed according to the current seismic code have the negligible risk of collapse and high security reserve, which will cause the waste of structural design.