隔震结构等效线性化计算方法对比研究

通过10种等效周期及等效阻尼比计算方法、4种阻尼调整系数和5种加速度反应谱组合而成的200种等效线性化设计方法,分别对初始周期在0.6～1.5s之间、屈服位移在2～11mm之间的100个单自由度隔震模型进行位移估算,并与时程分析结果进行对比。结果表明：采用拟合中国加速度反应谱人工波计算隔震体系的延性系数较采用拟合美国、日本和欧洲加速度反应谱人工波计算结果大,具有较高的安全储备;采用拟合类似美国、日本和欧洲规范中的加速度反应谱与其对应的阻尼调整系数匹配较好,通过选择合理的等效参数计算方法进行等效线性化分析,可以获得精度较高的计算结果;现有的等效参数计算方法和阻尼调整系数方法很难使基于中国规范加速度反应谱的等效线性化分析具有较高计算精度。

Comparative study on equivalent linearization calculation method in design of seismic isolated structure

200 equivalent linearization methods, composed of 10 calculation methods for equivalent period and equivalent damping ratios, 4 damping scaling factors and 5 acceleration response spectra, were used to estimate the displacement response of 100 single degree of freedom models of seismic isolated structures with initial natural periods between 0.6-1.5 s and yield displacements between 2-11 mm. The results were compared with those from time-history analysis. The investigations show that the seismic response calculated by artificial waves matching the Chinese acceleration spectrum is larger than those calculated by other artificial waves matching the American, Japanese and European acceleration spectra, therefore the calculation has the high safety margin. Damping scaling factor is well matched with acceleration response spectrum in American, Japanese and European codes, and high precision result can be obtained by the adoption of reasonable equivalent parameters in equivalent linearization method. It’s not accurate to analyze the isolated structure by using equivalent linearization method including Chinese acceleration response spectrum with the existing equivalent parameters and damping scaling factor.