【摘要】 采用自定义钢材本构模型,考虑压杆失稳后的力学性能,对格构式拱结构进行增量动力分析(Incremental Dynamic Analysis,IDA),得到格构式拱结构的薄弱位置以及倒塌破坏极限位移。不同跨度的格构式拱在竖向地震作用下,结构概率分位值为95%对应的结构倒塌极限竖向位移为结构跨度的1/154~1/104。在水平地震作用下,结构概率分位值为95%对应的结构倒塌极限水平位移为结构柱高的1/40~1/28。在竖向地震作用下,结构的薄弱位置主要位于跨中;在水平地震作用下结构薄弱位置主要位于桁架柱身;考虑压杆失稳时,1/4跨度处的斜腹杆由于长细比较大将会发生失稳破坏。在双向地震作用下,主桁架失效位置主要集中于桁架柱腹杆和1/4跨度处。IDA分析结果与试验结果一致,可为格构式拱结构的抗倒塌设计提供参考。更多还原

【Abstract】 User defined constitutive model of steel was adopted to analyze the collapse mechanism of spatial latticed steel arches considering the impact of member buckling by IDA( Incremental Dynamic Analysis) method. The weak positions and the collapse ultimate displacements of spatial latticed arch were identified. The results show that the 95% fractiles of the collapse ultimate vertical displacement ranges from 1 /154 to 1 /104 of the structural span under vertical ground motion records. The middle of main truss is most weak. And under horizontal ground motion records,the 95% fractiles of the collapse ultimate horizontal displacement ranges from 1 /40 to 1 /28 of the column height. In such case,the weak position is at the column of main truss. When considering member buckling,the webs at the one-quarter point of the main truss will buckle due to large slenderness ratio. The numerical results based on IDA method are agree well with those by shaking table tests,which can provide reference for the collapse-resistant design of spatial latticed steel arches.更多还原