摘要
介绍了变曲率摩擦摆隔震支座的基本构成,从力学平衡原理出发对变频式摩擦摆隔震支座和锥形摩擦摆隔震支座两类变曲率摩擦摆隔震支座进行理论分析,推导出变曲率摩擦摆隔震支座的刚度,探讨了支座的自回复特性,得出支座最大残余位移的计算公式。采用ABAQUS软件对2类变曲率摩擦摆隔震支座进行实体单元建模,模拟了低周反复荷载作用下的滞回特性与回复特性,并与(球面)摩擦摆隔震支座进行对比分析。研究结果表明:1)理论分析和数值模拟结果吻合较好;2)变曲率摩擦摆隔震支座的滞回曲线饱满,具有良好的滞回性能,且与初始刚度相同的(球面)摩擦摆隔震支座相比,其等效粘滞阻尼比和耗能系数更大,具有更强的耗能能力;3)变曲率摩擦摆隔震支座的刚度由曲率半径,即曲面函数决定,经合理设计可使得其刚度随着位移增大呈现逐渐减小的趋势,从而使其自振周期随着位移增大而逐渐增大,可较好的解决隔震结构的低频共振问题;4)与(球面)摩擦摆隔震支座相比,该支座刚度软化的机制可使传递给上部结构的剪力减小;5)该支座的最大应力出现在支座位于设计位移时刻,且一般位于滑块或支座板球铰面边缘;6)该支座的最大残余位移由摩擦系数和曲面函数各参数共同决定,可通过理论分析和数值模拟进行合理的参数化设计将其控制在工程可接受的范围内。
The basic structure of Variable Curvature Friction Pendulum Isolation Bearing（VCFP） is introduced.Based on the principle of mechanical equilibrium,theoretical analysis on two types of VCFP which are Variable Frequency Pendulum Isolation Bearing（VFPI） and Conical Friction Pendulum Bearing（CFPI） are conducted.The stiffness of each VCFP is derived,and the recovery characteristics were discussed and the computing formula of maximum residual displacement was deduced as well.Moreover,with the use of ABAQUS software,the models with solid element of each VCFP are built,and the hysteresis property under low cyclic loading and recovery characteristic are simulated.The comparative analysis of VCFP and Friction Pendulum Bearing（FPB） are also conducted.The results show that： 1） the numerical simulation results are identical to the theoretical analysis;2） according to its plump hysteresis loops,the hysteresis property of VCFP is favorable,further more,its effective viscous damping ratio and coefficient of energy dissipation are higher than FPB,which indicates its greater ability in energy dissipation;3） the stiffness of the VCFP is determined by curvature radius,that is,sliding surface function.And its stiffness decreases with the increase of bearing displacement through rational design.And then its isolation period increases as the displacement increases and the low frequency resonance problem of isolated structures can be well solved;4） compared with FPB,the softening mechanism of stiffness can make the shear force transferred to superstructure decrease;5） the maximum stress of bearing appears when the bearing reaches its designed displacement,and in general it may situate in the edge of ball joint surface of slider or bearing plate 6） the maximum residual displacement of VCFP depends on both friction coefficient and the parameters of sliding surface function,therefore,parametric design based on analysis or simulation is necessary so as to control the maximum value in an acceptable range in engineering.
出处
《土木建筑与环境工程》
CSCD
北大核心
2011年第1期50-58,共9页
Journal of Civil,Architectural & Environment Engineering
基金
广东省自然科学基金研究团队项目(8351009101000001)
关键词
变曲率摩擦摆隔震支座
周期性荷载
滞回
回复能力
摩擦系数
曲率半径
variable curvature friction pendulum isolation bearing
cyclic loads
hysteresis
recovery capability
friction coefficient
curvature radius
