考虑退化、捏拢和双向耦合效应的等强度延性需求谱  

Constant-strength ductility demand spectra considering degradation,pinching and bi-directional coupling effect

作　　者：宁超列[1] 余波[2] NING Chao-Lie YU Bo(School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798 Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, School of Civil Engineering ＆ Architecture, Guangxi University, Nanning, 530004, China)

机构地区：[1]同济大学上海防灾救灾研究所,上海200092 [2]广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室,南宁530004

出　　处：《振动与冲击》2017年第11期57-64,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51368006);广西自然科学基金重大项目(2012GXNSFEA053002)

摘　　要：传统的等强度延性需求谱通常难以有效地考虑强度退化、刚度退化、捏拢效应以及双向恢复力耦合效应的影响。鉴于此,基于双轴Bouc-Wen-Baber-Noori模型,建立了双向地震激励作用下单质点双自由度体系非弹性地震反应谱的基本方程,并定量分析了强度退化、刚度退化、捏拢效应和双向恢复力耦合效应对结构地震延性需求的影响,进而分别建立了等强度延性需求的均值谱和标准差谱的预测方程。分析结果表明:强度退化、刚度退化和捏拢效应会增大结构的地震延性需求;双向恢复力的耦合效应对地震延性需求的影响,取决于结构沿两个主轴方向地震耗能能力的相互竞争;退化、捏拢和耦合效应会明显增大结构地震延性需求的标准差,且非线性程度越高,随机性表现越明显;随着结构沿两个主轴方向自振周期的增加,等强度地震延性需求的均值和标准差均逐渐减小。Traditional constant-strength ductility demand spectral is difficult to consider the influence of strength degradation, stiffness degradation, pinching effect and coupling effect of bi-directional restoring forces effectively. In this study, the fundamental equation of the inelastic seismic response spectral for the single mass with two-degree-of-freedom （SM-2DOF） system under bi-directional excitations was proposed based on the biaxial Bouc-Wen-Baber-Noori model. Then the influence of strength degradation, stiffness deterioration, pinching effect and coupling effect of the bi-directional restoring forces on the seismic ductility demand of the SM-2DOF system were investigated quantificationally. Furthermore, the mean and standard deviation prediction models for the constant-strength ductility demand spectral were developed. The results show that the strength degradation, stiffness deterioration and pinching effect could increase the seismic ductility demand of the SM-2DOF system significantly; and the influence of the coupling effect of bi-directional restoring forces on the seismic ductility demand is largely dependent on the competitive relationship between the hysteretic energy along the two principal direction of structures; the degradation, pinching and coupling effect could increase the standard deviation of the constant-strength ductility demand spectral, especially for the SM-2DOF system with high nonlinearity; Finally, the mean value and standard deviation of constant-strength ductility demand spectral decrease with the increasing of fundamental vibration period along the two principal direction of building structures.

关 键 词：双向地震激励 滞回模型 非弹性反应谱 BWBN模型 等强度延性需求谱 

分 类 号：TU318[建筑科学—结构工程]