考虑空间相干的虚拟激励法在大跨度空间结构随机振动分析中的应用

采用虚拟激励法分析大跨度空间结构的随机地震响应,通过对网架、网壳、索网和索穹顶4种结构形式在一致和多点输入下结构节点的位移响应方差及加速度功率谱的分析,给出了考虑空间相干性的多点输入法与一致输入法之间结构响应的差异以及变化规律,并探讨了拟静力项对不同结构形式的影响,为大跨空间结构设计提供理论依据。同时,计算还表明虚拟激励法是一种高效且精确的方法,对于分析大跨度网格和索结构这样复杂结构在多点输入下的地震响应是很合适的。

Application of the pseudo- excitation method with spatial coherence in random vibration analysis of long span space structures

Pseudo-excitation method was applied the random seismic response analysis of long span space structures.The differences and change rules of the structural response were studied generally under multiple support excitation and simple support excitation from two aspects,i.e. the displacement response variance and the acceleration power spectrum for four form of structures,such as space truss,shell,cable and dome.Furthermore,the effects of the pseudo static response on some kind of structures were discussed.Several important conclusions are obtained which presented the theoretic foundation on aseismatic projects for long span space structures.On the other hand,it shows the pseudo excitation method is efficient and precise and is applicable to the random seismic response analysis of the complicate structure under multiple support excitation,such as long span reticulated structures and cable structures.