能力谱法中等效阻尼比的误差分析及假设检验  

Error analysis and assumption test on the equivalent damping ratio in capacity spectrum method

作　　者：梁仁杰[1] 吴京[1] 孟少平[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京210096

出　　处：《土木工程学报》2010年第S1期33-36,共4页China Civil Engineering Journal

基　　金：国家自然科学基金(50878055);江苏省自然科学基金(BK2008313);江苏省土木工程研究生科技创新基金

摘　　要：通过一单自由度和一多自由度算例,对考虑等效阻尼比的传统能力谱法和采用弹塑性反应谱的改进方法进行比较,并和非线性动力分析对比。为验证等效阻尼比的假定,构造了能产生完整、对称滞回环的特殊地震动。结果表明:采用等效线性体系考虑附加阻尼的传统方法低估了结构响应,有较大误差;同时说明结构的塑性滞回耗能与等效阻尼比并无直接联系,即等效阻尼比的假设并不准确;而采用弹塑性需求曲线的改进方法和真实反应吻合较好。Numerical examples are performed for a single-degree-of-freedom system and a multi-degree-of-freedom system by the traditional capacity spectrum method(CSM) which considers the structural non-linear behavior as the additional damping and the improved method which uses the inelastic response spectrum directly.The results are compared with each other and those from the non-linear dynamic analysis,respectively.In order to verify the concept assumption of the equivalent damping ratio,a special ground motion which makes a structure form a complete and symmetrical hysteretic loop is constructed.The results show that the traditional CSM which uses the equivalent linear system and the additional damping underestimates the response of structures,indicating the structural hysteretic energy dissipation has no direct relationship with the equivalent damping ratio,as the assumption of it is proved incorrect.The improved method which uses the inelastic demand curve generates more accurate results,which is close to the actual response.

关 键 词：基于性态抗震 能力谱法 等效阻尼比 弹塑性反应谱 

分 类 号：P315.9[天文地球—地震学]