摘要
与传统隔震支座相比,形状记忆合金(shape memory alloys,SMA)隔震支座能够提升结构的自复位和耗能能力。然而过早介入的SMA可能会增加中、小震时上部结构的内力和加速度响应。为解决这一问题,在SMA隔震支座中引入间隙形成间隙式SMA隔震支座,以满足不同设防目标的隔震需求。首先,提出了间隙式SMA支座的物理构造形式,并开展了SMA丝循环拉伸试验;随后,以两自由度的框架结构简化模型为例,探讨间隙长度以及SMA屈服力对隔震效果的影响;最后,旨在降低大震、巨震下间隙式SMA隔震支座的内力与加速度响应,进一步引入负刚度机制改进间隙式SMA隔震体系,并探究了负刚度-间隙式SMA支座隔震的可行性。计算结果显示,间隙式SMA隔震支座可以有效降低中震、小震时上部结构的内力与加速度响应;上部结构加速度响应与间隙长度负相关,与SMA屈服力正相关;下部结构位移响应与间隙长度正相关,与SMA屈服力负相关。引入负刚度后,间隙式SMA支座可在有效控制大震或巨震下支座位移响应的同时,显著减小上部结构内力与加速度响应。
Compared with traditional isolation bearings,shape memory alloy(SMA)isolation bearings can improve the self-resetting and energy dissipation capacity of structures.However,early intervention of SMA may increase internal forces and acceleration responses of superstructure during moderate and small earthquakes.Here,to solve this problem,gap-SMA isolation bearing was formed by introducing gap into SMA isolation bearing to meet isolation requirements of different fortification targets.Firstly,the physical structural form of gap-SMA bearing was proposed,and cyclic tensile tests of SMA wire were conducted.Then,a simplified model of 2DOF frame structure was taken as an example to explore effects of gap length and SMA yield force on isolation effect.Finally,internal force and acceleration response of gap-SMA isolation bearing was reduced under large or great earthquake,the negative stiffness mechanism was further introduced to improve gap-SMA isolation system,and explore the feasibility of negative stiffness-gap type SMA bearing isolation.The calculation results showed that gap-SMA isolation bearing can effectively reduce internal forces and acceleration responses of superstructure during moderate and small earthquakes;acceleration responses of superstructure are negatively related to gap length,and positively related to SMA yield force;displacement responses of substructure are positively related to gap length and negatively related to SMA yield force;after introducing negative stiffness,gap-SMA bearing can effectively control bearing displacement response under large or great earthquake,and significantly reduce internal forces and acceleration responses of superstructure.
作者
邱灿星
吴诚静
杜修力
王萌
QIU Canxing;WU Chengjing;DU Xiuli;WANG Meng(Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2023年第9期19-26,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(52178267)
中国博士后科学基金(2021M700310)。
关键词
隔震支座
形状记忆合金(SMA)
负刚度
摩擦摆系统
减震性能
seismic isolator
shape memory alloy(SMA)
negative stiffness
friction pendulum system
seismic performance
