钢框架结构直接基于位移抗震性能设计的非迭代法

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

为使直接基于位移的抗震性能设计方法更加简便准确,本文采用一种直接基于位移的非迭代抗震设计方法对钢框架结构进行设计。该方法首先考虑结构的非弹性反应确定等效弹性反应谱和弹塑性反应谱,并建立了使用Newmark-Hall变形折减系数的能力谱的明确表达式。采用能力-需求图方法,确定了结构需要的目标位移与延性、谱位移和谱加速度之间关系的明确表示式,得到结构的刚度和设计基底剪力,进而确定构件截面,完成结构设计。对五层两跨平面钢框架结构进行了直接基于位移的抗震性能设计,设计过程简便,无需迭代程序,不需画出反应谱,通过时程分析验证了设计结果的精确性。本文研究表明:直接基于位移的非迭代抗震设计方法是一种简便、高效、精确的抗震性能设计方法。

Direct displacement-based seismic design without iteration is a more simple and rational approach to dis- placement-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 accu- rate performance-based seismic design method.