大型空间结构的地震响应分析须要考虑多点多维地震动输入,常规动力试验方法在研究相关问题时存在一定困难。本文将实时耦联动力试验方法引入这一问题的试验研究,以两个固支于半无限地基的单层刚架模型为例,进行了考虑行波效应的实时耦联动力试验。在试验中,两个单层刚架作为试验子结构分别在两个振动台上进行加载,半无限地基作为数值子结构用有限元法进行数值模拟,两个子结构之间实时进行数据交互,模拟地震波的传播和整体结构的动力响应。试验结果与有限元数值模拟吻合良好,该试验方法具有理想的精度,是一个研究行波效应的可靠试验方法。对不同剪切波速地基的试验结果对比分析表明,软土地基中行波效应的影响更为明显。
Multi-dimensional and multi-support excitation should be employed for seismic analysis of large space structures, but its study is difficult if using traditional dynamic testing. This paper presents a real-time dynamic hybrid testing method for traveling wave effect testing on a model of two shear frames mounted on semi-infinite soil foundation. In this test method, the steel frames as experimental substructure were loaded on two shaking tables, respectively, while the semi-infinite foundation as numerical substructure was numerically modeled by finite element method. Real-time data interaction between these substructures was maintained, so seismic wave propagation and dynamic responses of the coupled system can be simulated. Comparison of the present results with FEM analysis shows that this new testing method can achieve a good accuracy, a reliable method for traveling wave effect study. Application to different soils shows greater influence of soft soil on traveling wave effect.