摘要
分析了动力P-△效应和结构抗侧强度对结构动力稳定的影响．利用单自由度（SDOF）体系弹塑性动力时程分析程序，分别对反向加载时刚度退化的修正克拉夫滞回模型（MC）和理想弹塑性（EPP）模型，计算了4类场地下各74～106条地震波输入后的结构动力响应，其中结构自振周期为0．1～6．0／s，延性取为2、3、4、5和6，二阶效应系数为0．025～0．100，得到了不考虑和考虑P-△效应的地震力调整系数，并计算了两者间的比值谱S，提出了S谱的简化计算公式，用以分析P-△效应对地震力调整系数的影响．结果表明，标准化周期、延性和二阶效应系数对S谱均有影响；不同滞回模型对动力P-△效应的敏感性是不同的，理想弹塑性模型为保持常延性而需增加的抗侧强度要大于修正克拉夫滞回模型．
The influence of dynamic P-△ effects and lateral strength on structure stability were investigated. Based on elastic-plastic time-history earthquake analysis of single degree of freedom system （SDOF）, the seismic force modification factors without and with P-A effects for modified-Clough（MC） model and elastic perfectly-plastic （EPP） model were investigated. A total of 370 earthquake records belonging to 4 site and soil conditions with each containing 74 to 106 records were used to calculate the structure response. The structure periods varied form 0.1 to 6 s and the ductility was taken to be 2, 3, 4, 5 and 6. Stability index of 0.025 to 0. 100 was used in the analysis. The ratio spectra S were constructed to analyze the influence of P-△ effects on seismic force modification factors. The S spectra depend on the normalized periods, stability index and ductility. It was found that different SDOF systems with different hysteretic models have different sensitivity to P-△ effects. The increase in strength required to maintain constant ductility in the presence of P-△ effects for EPP model is more than that of modified-Clough model. Formulae of S spectra for modified-Clough and EPP models were proposed.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2007年第1期120-125,192,共7页
Journal of Zhejiang University：Engineering Science
关键词
抗震设计
地震力调整系数
滞回模型
P-△效应
延性
seismic design
seismic force modification factor
hysteretic models
P-△ effect
ductility
