子结构试验的多自由度力-位移混合控制方法研究  

Force-displacement mixed control of substructure test with multiple degrees of freedom

作　　者：周惠蒙[1] 李梦宁 王涛[1] ZHOU Hui-meng;LI Meng-ning;WANG Tao(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所地震工程与工程振动重点实验室

出　　处：《振动工程学报》2020年第1期168-178,共11页Journal of Vibration Engineering

基　　金：中国地震局工程力学研究所基本科研业务专项(2016A06,2016B09);国家自然科学基金资助项目(51378478,51408565,51678538,51161120360)

摘　　要：现代结构试验通常抽取结构的一部分进行子结构拟静力或拟动力试验,同时对子结构边界进行近似处理,简化加载方案,以期在现有试验条件下满足大比例尺试验的需求。然而,这种方法应用于复杂构件时会带来较大的误差,特别是各向刚度差异很大的构件,由于各自由度之间的耦合效应,以及传统试验装置控制模式和精度的限制,难以实现轴向、剪切、弯曲以及扭转自由度之间的同步协调加载,加载误差严重影响了结构抗震性能评估试验的准确性。针对子结构试验中耦合多自由度同步协调加载问题,利用力-位移混合双闭环控制策略实现多自由度之间的解耦,采用鲁棒性PID控制方法,以减少多自由度同步协调加载过程中试件的材料非线性和加载装置的几何非线性带来的误差,提高子结构试验的精度。通过以某构件的子结构拟动力试验为例验证了所提出的力-位移混合控制方法的可行性和正确性。In modern structural experiments,the most-concerned subassemblies are often taken out as the specimens.Meanwhile,the associated boundary conditions are significantly simplified to meet the capacity of test facilities for large-scale specimens.This simplification might introduce unavoidable and non-negligible errors for complex substructures,particularly for those with large mechanical differences in various directions.The strong coupling effects between the axial,shear,flexural,and even torsional degrees of freedom(DOF)make the synchronous and harmonized loading extremely difficult,which together with the inflexible loading mode and the limited resolution of loading facilities would lead to an inaccurate evaluation of structural seismic performance.In this connection,this paper proposes a new force-displacement mixed control strategy that designs a dual closed-loop scheme to realize the decoupling of multiple DOFs.In order to fully consider the effects of the geometric nonlinearity and the material nonlinearity,a robust PID control method is developed to reduce the synchronization errors and further to improve the testing accuracy.Finally,both the feasibility and validity of the proposed method are demonstrated by a substructure pseudo-dynamic test.

关 键 词：多自由度力-位移混合控制 PID鲁棒控制器 子结构拟动力试验 抗震性能 力-位移转换系数 

分 类 号：TU352.11[建筑科学—结构工程] TB535[理学—物理]