Direct displacement-based seismic performance design without iteration for steel frame structures

Direct displacement-based seismic design without iteration is a more simple and rational approach to displacement-based seismic design,which was used to design steel frame structures.In this method,the equivalent elastic and elastic-plastic response spectra are ensured considering of structural inelasticity,the explicit expression of response spectra including Newmark-Hall deformation reduction factors is achieved.According to the capacity-demand diagram method,the relationship formula among structural demand objective displacement and ductility,spectrum displacement,spectrum acceleration are derived,then base shears of structures are confirmed according to structural stiffness and strength,the structural component sections are designed.5 floors and 2 strides plane steel frames are designed with direct displacement-based seismic design method without iteration,the process of which is simple,response spectra diagram isn't necessary.The design results are proved reasonable and exact with time-history analysis.So the direct displacement-based seismic design without iteration is a simple,effective and accurate performance-based seismic design method.