恢复力模型对等延性地震抗力谱的影响分析

Influence analysis of hysteretic model on constant-ductility seismic resistance spectra for seismic design of structures

在基于位移的抗震设计理论中,等延性地震抗力谱对拟建结构的初步设计具有十分重要的作用.利用单自由度体系在大量强震记录作用下的弹塑性动力时程分析结果,分析讨论了结构的延性系数、周期及恢复力模型等因素对等延性地震抗力谱的影响规律,其中重点以双线型恢复力模型为例,从定性到定量深入研究了恢复力模型对等延性地震抗力谱的影响,总结了相应的规律和特征,给出了恢复力模型影响等延性地震抗力谱的实用修正公式,结果可供抗震研究和设计参考应用.

In the displacement - based design, the constant - ductility seismic resistance spectra are very useful for the preliminary design of new structures where the global displacement ductility capacity is known, and it can provide the required inelastic lateral strength of new structures from the required elastic lateral strength. The influence of period of vibration, level of ductility ratio, hysteretic model et. al on constant - ductility seismic resistance spectra are investigated in this paper. And the special emphasis is given to influence analysis of hysteretic model on the inelastic spectra. A statistical study are performed on inelastic response computed for different hysteretic model SDOF systems with different levels of lateral yielding strength required to maintain the given displacement ductility ratio when subjected to a large number earthquake accelerations. The main characteristics of hysteretic model effect on constant - ductility seismic resistance spectra are given. Finally, results from non - linear regression analysis provide a simplified expression to be used to approximately quantify the hysteretic model effect. Numerical analysis shows the simplified expressions are adaptable for the seismic design of structures.