基于动力推覆方法的储液罐抗震分析

为有效评估储液罐在弹塑性阶段的抗震性能，经凝聚流体域压力自由度，建立流固耦合系统的等效动力方程，然后合并同频振型并基于广义逆理论导出谱加速度-谱位移性能曲线的投影方程，并通过控制谐波参数实现流固耦合系统的单向动力推覆，以此确定性能曲线并作为储液罐的单自由度广义本构模型。时程分析表明:上述广义本构模型的滞回曲线及时程结果与流固耦合系统吻合良好，罐体刚度均呈渐近退化。该文方法与静力推覆分析的计算耗时大致相仿，消除了特征节点对性能曲线的影响，并可考虑弹塑性阶段内罐体抗力分布的改变。

SEISMIC ANALYSIS OF LIQUID STORAGE TANKS BASED ON DYNAMIC PUSHOVER METHOD

To effectively assess the seismic capability of liquid storage tanks in the elastoplastic stage, the equivalent dynamic equations of a fluid-solid coupled system were established by condensing the pressure degrees of freedom in a fluid domain, the projection equation for a spectral acceleration-displacement capacity curve was then derived, based on generalized inverse theory after merging the vibration modes with the corresponding frequencies, and the unidirectional dynamic pushover of the fluid-solid coupled system was realized by controlling the harmonic parameters, by which the capacity curve was determined and used as a generalized constitutive model with a single degree of freedom for liquid storage tanks. The time history analysis showed that the hysteretic curves and time history results of above generalized constitutive model were quite consistent with those of the fluid-solid coupled system, and the tank stiffness degenerated progressively. The proposed method consumes relatively similar computation time as a static pushover method, and eliminates the influence of the characteristic node on the capacity curve, and can consider the distribution change of tank resistance forces in the elastoplastic stage.