Research On Seismic Design Of High-Strength Steel Frames

High-strength steel structure can reduce the cross-section of components,the weight of the structure and the construction cost.There are many application cases in large-span and high-rise steel structures,but in the structure of ordinary civil buildings such as residential buildings and office buildings,There are still few applications of high-strength steel.Due to the difference in material properties between high-strength steel and ordinary steel,the seismic response of high-strength steel structures may be different from that of ordinary steel structures.China’s current structural design specifications have not yet made special provisions for the seismic design of high-strength steel structures,and whether the seismic design of high-strength steel structures is reasonable according to the current specifications is urgently needed for special research.This paper takes a certain office building in Beijing as the engineering background,and uses the high-strength steel and ordinary steel pair to carry out structural seismic design according to the current seismic design specifications.The design results were compared and analyzed,and the dynamic time history analysis was carried out for the design examples.The effects of steel strength and panel width-to-thickness ratio on the seismic performance of the frame were studied by numerical simulation and theoretical analysis.The main contents are as follows:(1)Three steel frames are designed for the prototype building.The frame columns are made of Q345,Q460 and Q690 steel respectively,and the beams are all made of Q345 steel.Comparing the period,stiffness,deformation and steel consumption of each frame in the elastic response spectrum analysis of small earthquakes,the advantages and disadvantages of high-strength steel frame relative to ordinary steel frame are analyzed when seismic design is carried out according to the current specifications.(2)Using the validated finite element model,three framework examples were modeled in the finite element software ABAQUS.According to the Code for Seismic Design of Buildings(GB 50011-2010),three seismic waves were selected,and the dynamic time-history responses of three seismic examples at the three seismic wavesand small earthquakes were simulated.(3)For the above-mentioned prototype building of actual project,six different steel frames were designed according to the S2 and S4 plate slenderness ratio limits in the Standard for design of steel structures(GB 50017-2017),together with the above three steel frame examples.The ABAQUS finite element software was used for modeling.The static model and dynamic time-history analysis of the frame model were carried out.The seismic force reduction coefficients of different frames were calculated by the method provided in ATC-19.By comparing the plate slenderness ratio of different sections and the seismic force reduction factor of steel frames with different steel strength,the design suggestions for high-strength steel frames with S4 section and designed according to seismic specifications are proposed.