基于振动台的实时动力子结构实验系统稳定性预测研究

基于振动台的实时子结构试验是重要的现代结构试验技术，能很好的对土-结相互作用、减震系统（比如TLD、TMD）等动力特性进行大尺寸试件试验研究。试验系统稳定性是实现子结构试验的关键，但复杂的振动台动力特性使其稳定性预测精度还难以满足试验要求。该文结合振动台系统综合建模和根轨迹技术发展了稳定性预测方法，通过试验验证了该方法的可行性。同时从相位和幅值影响两方面对比讨论了常用分析方法的局限性，并采用该方法就结构特性对稳定性的影响进行了分析。研究结果表明考虑振动台综合模型的方法能很好的预测子结构试验系统稳定性。

STUDY ON THE STABILITY PREDICTION OF REAL-TIME DYNAMIC SUBSTRUCTURING SYSTEM BASED ON SHAKING TABLE

The shaking table based real-time dynamic substructuring (RTDS) technique is an important branch of modern structural testing techniques, which can simulate the dynamic behaviors of soil-structure interactions and vibration absorber systems (e.g. TLD and TMD) experimentally in terms of a large specimen. The stability of RTDS plays a key role in the implementation of a test. However, the complex dynamics of a shaking table causes the inaccuracy of RTDS stability prediction. A new predication method was developed with the combination of root locus technique and the modeled comprehensive dynamics of a shaking table. The feasibility of this method was verified experimentally. Meanwhile, the drawback of the commonly used method was analyzed comparatively through phase lag and magnitude error. Finally, the influence of structural properties on RTDS stability was discussed. This results show that, with the consideration of the integral dynamics of a shaking table, the predication accuracy of RTDS stability can be improved greatly.