3种理想化滞回模型下的弹塑性反应谱对比

Comparative study on elastic-plastic response spectra of three idealized hysteretic models

对双线性(BIL)和剪切滑移(SSP)滞回模型的SDOF体系在地震作用下进行弹塑性动力分析,得到考虑和不考虑P-Δ效应时不同场地、延性等参数组合下双周期标准化的地震力调整系数R谱,并与理想弹塑性(EPP)滞回模型的R谱比较.结果表明:在Tga<T<TgR周期段,等能量准则在BIL模型中成立,EPP模型的R值大于等能量准则的值,显示耗能能力在此周期段中有重要影响;在T>2TgR周期段,3种滞回模型的R谱接近;P-Δ效应对BIL模型的影响可以忽略,对EPP和SSP模型的影响随延性的增大而增大;对于具有90%保证率的R谱,BIL模型在Tga<T<TgR范围内很小,SSP模型仅略有改善,EPP模型的谱值最大.

Abstract： The dynamic elastic-plastic analysis of systems of bilinear elastic （BIL） model and shear-slipped elastic-plastic （SSP） model was conducted to acquire the seismic force modification factor R for different site and ductility. The R-spectra were constructed with their abscissa normalized with two characteristic periods. The R-spectra with the dynamic P-Δ effect being considered and being not included were constructed. Results were compared with those of elastic-perfectly plastic （EPP） models. Results reveal that the equal-energy rule is valid only for BIL model in the range of Tga%T%TgR. For EPP and SSP, the R spectra are greater than for BIL, indicating the importance of energy dissipation capacity in the period range of Tg.~T^TgR. With T^2Tgk, the R spectra are similar for all three models. The p-A effect has almost no influence on the R spectra of BIL model, but for EPP and SSP models, its influence increases with the ductility factor. For the R spectra with 90% assurance, the R spectra are very small for BIL model in the period of Tga〈T〈TgR, the R spectra for SSP has only minor improvement and the R spectra of EPP model has the greatest value.