设备-结构-土体系振动台实时子结构试验方法探讨

STUDY ON SHAKING TABLE REAL-TIME SUBSTRUCTURE EXPERIMENTAL METHODOLOGY OF EQUIPMENT-STRUCTURE-SOIL SYSTEM

该文探讨了设备-结构-土体系振动台实时子结构试验方法的可行性,将设备-结构体系作为由振动台加载控制的试验子结构,同时将自由度缩减后的土体作为由仿真软件计算的数值子结构,试验时两者之间进行数据实时交互。首先基于分支模态子结构方法推导了设备-结构-线性土体系运动方程,并对各体系运动方程进行了变换,将其应用于设备-结构-线性土体系振动台实时子结构试验。然后结合土体在强震作用下并非全部进入非线性阶段的特点,提出采用局部非线性土模型作为数值子结构参与振动台实时子结构试验的思路,并应用分支模态子结构法与线性-非线性混合约束模态子结构法推导了设备-结构-局部非线性土体系的运动方程。设计了设备-结构-土相互作用缩尺模型,进行了各地震动作用下的设备-结构-线性土体系振动台实时子结构试验。通过比较振动台实时子结构试验结果与数值计算结果,发现两者之间吻合良好,证明该试验方法是可靠有效的。

The feasibility study about the shaking table real-time substructure experimental method of an equipment-structure-soil system is discussed.The equipment-structure system is adopted as an experimental substructure loaded by a shaking table.Meanwhile,a finite-element model of soil is adopted as a numerical substructure after the degrees of freedom reduction.Real-time data communication occurs between the two parts during test.Based on a branch modal substructure method,the motion equation of an equipment-structure-soil system is deduced.The equation is converted and applied to the substructure experiment.Considering that the soil does not entirely enter the nonlinear stage under strong earthquakes,the local nonlinear soil model can be used as a numerical substructure and the equation of motion for the equipment-structure-local nonlinear soil system is derived using the branch modal substructure method and linear-nonlinear hybrid constraint modal substructure method.An equipment-structure-soil interaction scale model is designed and tested using the experimental method under different earthquake records.A good agreement is observed upon the comparison of results between the experimental and numerical calculation methods,which corroborates the reliability and validity of the proposed testing method.