Energy-based Seismic Design Method Of K Type Steel Eccentrically Braced Frame Underfar Field Earthquake

The current seismic design method is an elastic design method mainly based on strength, which considers little about the inelastic behavior of structure. The energy-based seismic design method can take force, displacement, duration etc. into account at the same time, and can evaluate the damage level when structure comes into plastic effectively, which is a tendency of seismic design philosophy development.Based on the hysteretic energy spectra and accumulated ductility ratio spectrum, the paper proposes a performance-based seismic design method of K type steel eccentrically braced frame under far field earthquake according to the energy balance equation. This method can clearly consider the realationship between the cumulative hysteretic energy and one-way pushover energy, which is clear in concept, convenient and practical.Using the method mentioned above, the paper designs two K type steel eccentrically braced frame of 10 story and 15 story, and verifies the yield displacement and yield mode of structure by Pushover method. The paper also establishes models in ABAQUS, using shell element for links and beam element for other parts of the model, and then chooses 20 far field earthquake waves for each model to evaluate the seismic performance by time history analysis. The results demonstrates that the structure takes on the ideal progressively plastic mechanism, and the yield displacement keeps stable while not far from the design value. The story drift of structure under occasional and rare earthquake level can satisfy the deformation limit of the seismic code while keeps relatively average, and the energy dissipation in component and through height are also reasonable, which proves the method proposed in this paper to be reasonable and reliable.