基于构件模态应变能比的隔震烟风道结构等效线性化分析

对大型烟风道采用热滑移型双凹摩擦摆(thermal sliding double concave friction pendulum system,TS-DCFP)隔震的结构等效线性化方法进行研究。推导了TS-DCFP采用滑移面等效半径、等效摩擦系数表达的三线性滞回模型的等效刚度和等效阻尼比,适于以非线性变形为主的摩擦摆隔震结构。建立了横向地震作用下的二自由度结构动力分析模型,基于构件模态应变能比,推导了振型组合阻尼比公式。采用提出的等效参数对二自由度烟风道隔震结构进行线性时程分析,并与三维模型非线性时程分析结果进行比较。分析表明,TS-DCFP用于烟风道隔震效果相当显著,且本文提出的等效线性化方法对道体反力、底部剪力的估计接近非线性时程分析结果,用于结构初步设计选型很有效。

Equivalent linear analysis of isolated gas duct based on the modal potential energy ratio

An equivalent linear model for the seismic analysis of the isolated gas duct using thermal sliding double concave friction pendulum(TS-DCFP)system is established. The structure is modeled as a two-degree-of-freedom system in the transverse direction. Meanwhile, the effective stiffness and equivalent viscous damping ratio of an isolation bearing with tri-linear behavior are derived and the modal-combined damping ratio is obtained from the modal potential energy ratio of components. The model is verified by comparing the response of a linear time history analysis of the two-degree-of-freedom system with that from the 3D nonlinear time history analysis using the directly integrating method.