Research on the Seismic Performance of High Strength Steel Frames

The rational utilization of steel is essential to leverage the respective advantages of high-strength steel (HSS) and conventional steel. HSS, with nominal yield strength >= 460 MPa, has gained wide application in bridge and building structures due to its significant economic and structural benefits. The authors have conducted extensive research on high-strength steel materials, beam-columns, connections, and structural systems. This paper serves as a follow-up study to further explore the seismic performance and reliable seismic design of high-strength steel moment frames. Firstly, this paper reviewed the cyclic tests conducted on six full-scale one-bay two-story steel moment frames made of HSS and conventional steel. Subsequently, fifteen six-story prototype frames with different combinations of steel grades and cross-sectional ductility classes were designed. Nonlinear static analysis and increment dynamic analysis (IDA), performed using validated multi-scale finite element models, were conducted to comprehensively investigate the effects of steel grades and member cross-section ductility classes on seismic performance factors and deformation demands during maximum considered earthquake. The research findings indicate that the reduction factor R decreases with increasing yield strength of the steel, implying that HSS frames may need to withstand greater seismic forces. All calculated reduction factors R are higher than the code-specified values, indicating the safety of HSS moment frames designed according to the current code.