均布与局部轴压作用下薄壁钢筒仓屈曲性能研究

Buckling Behavior of Thin-Walled Steel Silos Subjected to Combination of Globally and Partially Distributed Axial Compression

均布与局部轴压共同作用下钢筒仓屈曲性能与仅均布轴压作用筒仓的屈曲性能有显著区别。采用有限元非线性屈曲分析方法,考虑环向焊缝几何缺陷,对均布与局部轴压作用下钢筒仓的屈曲性能进行了研究。分析参数包括均布轴压比、局部轴压分布角、仓体径厚比、缺陷幅值等。研究表明,局部轴压屈曲承载力随均布轴压比、缺陷幅值、局部轴压力分布角和径厚比的增加而降低。在有限元参数分析的基础上,提出了考虑均布轴压力影响的局部轴压临界屈曲应力计算公式,该计算公式与有限元分析结果基本吻合。

Buckling behavior of thin-walled steel silos subjected to combination of globally and partially distributed axial compression is different from that under global distributed axial compression only. Buckling behavior of thin walled steel silos subjected to combination of globally and partially distributed axial compression has been investigated using finite element analysis accounting for the geometric imperfection of circumferential weld. Effects of uniform compressive load ratio, distribution angel of partial compressive load, radius to thickness ratio, as well as magnitude of initial imperfection on the buckling strength are studied. Numerical results show that buckling strength of steel silo under the combination of globally and partially distributed axial compression decreases with the increase in uniform compressive load ratio, initial imperfection magnitude, distribution angle of partial compressive load and radius to thickness ratio. Based on the numerical analysis results, a design formula for the ultimate buckling stress is proposed. The buckling stress predicated by proposed equations agrees well with that obtained by the finite element model.