基于振动台的动力子结构试验界面反力获取方法

Research on the methods of evaluating reaction force for dynamic sub-structure experiments using shaking table

基于振动台的实时子结构动力试验是一种新型的结构动力试验方法。该试验方法引入了"子结构"这一概念,不仅减小了常规振动台试验对于试验规模的限制,而且克服了拟动力子结构试验中无法考虑加载速率影响的问题。由于该试验方法将整体结构拆分为数值子结构和物理子结构两部分,二者之间通过交界面相互作用力实现实时数据交互,以保证子结构体系与整体结构体系的等效性。因此,如何方便、准确地获取界面反力是实现该试验方法的关键之一。文中对四种界面反力的获取方法进行了理论推导和对比分析。并通过钢框架结构模型振动台试验进行分析验证,最后给出了4种方法的适用条件及使用建议。

Real-time dynamic substructure testing by using shaking table is a novel structure testing method in recent years.Because of the application of sub-structure technique,the real-time dynamic substructure testing overcomes the test model scale limitation,which is inevitable in traditional shaking-table test.Meanwhile,the loading rate dependent behavior of testing materials could be considered,since the tests are operated in real-time.In the proposed technique,the upper part of the object structure is the experimental substructure and the lower part is the numerical substructure.The force exerted on the interface of the two separated substructures is used as exchange platform to keep equivalence between the substructure and whole structure.So it is key to obtain the interface force conveniently and accurately.In this study,the authors make a comparative analysis of the four common methods used to get the interface force.The four methods can obtain interface force accurately by the analysis of the shaking table test results of a steel frame model structure.Applicable conditions and some suggestions about these methods are proposed at last.