目前滞回能量反应谱的研究几乎都是以单自由度体系和单向地震输入为前提,没有考虑地震动的多维性和结构非线性反应的空间耦合性,为此建立了屈服关系满足二维屈服面函数的单质点双自由度体系能量分析模型,提出双向地震下标准化滞回能量反应谱理论。以硬、中、软土场地的178条地震记录为激励,建立了统计平均的标准化滞回能量谱。与单自由度体系滞回能量谱的比较表明在很多情况下单自由度体系滞回能量谱值偏低。分析了场地类别、延性系数、两主轴方向周期比对标准化滞回能量谱的影响,分析表明:标准化滞回能量谱具有典型的场地特征;延性系数对软土场地的谱值影响比较明显,而对硬土和中等场地的谱值影响相对较小;周期比对谱值也具有一定影响.
The current theory of hysteretic energy response spectra depends on the theory of single degree of freedom system subjected to single directional earthquake motion, in which the imbalance and coupled characteristics of multi-dimensional responses of structures are not considered. So, the standard hysteretic energy spectrum is presen- ted by considering the single-mass bi-degrees of freedom system subjected to bi-directional earthquake motions. The spectral values between bi-degrees of freedom system and single degree of freedom system are compared and the re- sults show that the latter are lower in some cases. The statistical average spectra for hard soil site, medium soil site and soft soil site are established and analyzed on the basis of 178 earthquake motion records. Analytic results show that : the standard hysteretic energy spectra for each soil site have their own characteristics ; the influence of ductili- ty factor on spectral value is obvious in soft soil site, but it is not obvious in hard and medium soil sites.