面向大型复杂结构的抗震混合试验方法关键问题研究

In hybrid seismic test method for large complex engineering structures, there are some major problems: huge and complex numerical substructure; simulation of complex boundary conditions of physical substructure; excessive number of physical substructure; split-combination of substructure in structure system. In this project, we present some resolutions: separate static degrees of freedom from dynamic degrees of freedom and fully reserve static degrees of freedom and propose a reduction synthesis method of substructure dynamic degrees of freedom based on structural mode to reduce dynamic degrees of freedom; study on the simulation of boundary condition and the collaborative loading method of physical substructure to avoid the over-simplification of boundary degrees of freedom in test units; present the concept of “Pseudo experimental element” to the problem of the large number of experimental units in hybrid seismic test for large complex structures and investigate the synchronous identification and adjustment method in restoring force model of Pseudo experimental element; provide an approach to ensure the coordination of displacement and equilibrium for the combination of varied substructure. Formulate an effective method through the connection of self-compiled programs, finite element software and test control system for the seismic research of large complex structure, and validate the method through a seismic hybrid simulation of high-rise isolated structure. This project can provide an effective method for the seismic performance and dynamic cataclysm process of large complex structure.

针对大型复杂工程结构抗震混合试验方法存在计算子结构庞大复杂、试验子结构复杂边界条件模拟、试验子结构过多、结构体系子结构拆分—溶合等问题，本项目将结构动力自由度与静力自由度分离，充分保留静力自由度，提出基于结构模态的子结构动力自由度减缩综合法减缩动力自由度；为了避免对试验单元边界自由度的过度简化，提出试验子结构边界条件模拟与协同加载方法；针对大型复杂结构抗震混合试验中存在大量力学性能相似的试验单元，提出“拟试验单元”，研究拟试验单元恢复力模型的同步识别调整方法；针对多类子结构溶合，研究多子结构边界上位移协调与力平衡的方法。通过自编程序、有限元软件与试验控制系统的联接，形成可用于大型复杂结构抗震研究的方法，并采用高层隔震结构抗震混合试验对所研究的方法进行验证。通过本项目的研究，为研究大型复杂结构抗震性能和动力灾变过程提供有效解决方法。

为提高大型复杂结构抗震分析的准确性和可靠性，在有限元分析方法与子结构拟动力试验方法的基础上，本项目提出"面向大型复杂结构的抗震混合试验方法关键问题研究"。针对混合实验中的数值积分方法、试验子结构的边界条件模拟以及模型更新混合试验算法等关键问题进行研究。为了提高试验协同处理多个子结构的计算精度与分析效率，提出了基于Newmark-β法的预测-几何修正算法；为了满足子结构间的平衡与协调，提出了复杂边界条件模拟方法；为了在材料本构端一定程度减少混合试验带来的误差，提出了双折线模型更新算法等其他混合试验研究方法。.项目研究成果对大型复杂结构开展混合试验中存在的科学问题进行了深入分析研究，对几个关键问题提出了实用方法，解决了一些大型复杂结构抗震混合试验方法的关键问题，为我国结构抗震混合试验方法在大型复杂结构的应用提供了必要的理论基础和方法。