基于长周期地震动记录的SDOF体系能量谱探讨  

Energy spectrum of SDOF system based on long-period ground motion records

作　　者：陈清军[1] 袁伟泽[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《振动与冲击》2013年第10期36-42,54,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(50978198;90915011)

摘　　要：为分析长周期地震动作用下结构的能量反应谱及其影响因素,从1985年墨西哥8.1级地震、1999年集集7.6级地震和2003年日本十胜冲8.0级地震记录库中,选取了36条具有可靠长周期信息的强震记录,以此作为输入,采用能量谱面积归一的方法,首先对单自由度体系的弹性能量谱进行了分析,建议了适用于长周期地震动的简化三段式输入能量谱。在此基础上,讨论了延性系数、阻尼比对弹塑性能量谱的影响;给出了通过调整长周期地震动弹性能量谱参数来确定长周期地震动弹塑性能量谱的方法,并与长周期地震动弹塑性能量谱的拟合结果进行了比较,验证了上述方法的可行性。最后,通过分析长周期地震动累积滞回耗能与弹塑性输入能量之间的比值关系,给出了长周期地震动累积滞回耗能比值谱的计算公式。In order to analyze energy response spectrum of structures under long-period ground motions and to inspect its influential factors, 36 long-period strong earthquake records were used as inputs, which were chosen from 1985's Mexico earthquake (M8.1), 1999's Chi-Chi earthquake (M7.6) and 2003's Japan Tokachi-oki earthquake (M8.0). With the normalized method with respect to the area of input energy spectrum, the earthquake energy spectrum of elastic single degree of freedom (SDOF) system was studied. The input elastic energy spectrum of long-period ground motions was suggested to be simplified into three portions. Subsequently, the influences of ductility factors and damping ratios on elastic-plastic energy spectrum were analyzed. A method to get the elastic-plastic energy spectrum under long-period ground motions was proposed by adjusting the factors of input elastic energy spectrum of long-period ground motions, and the feasibility of the method was verified by comparing with the fitting results of long-period ground motions. Finally, based on the analysis of the relationship between cumulative hysteretic energy and elastic-plastic energy, a formula for calculating the cumulative hysteretic energy spectrum under long-period ground motions was suggested.

关 键 词：长周期地震动 单自由度体系 能量谱 滞回耗能谱 影响因素分析 

分 类 号：TU311[建筑科学—结构工程]