残余应力对局部轴压焊接圆柱壳承载力的影响

Effect of residual stresses on buckling strength of welded cylinders under partial axial compression

焊接钢圆柱薄壳广泛应用于钢筒仓和钢油罐结构中,屈曲通常是该结构的设计控制条件,圆柱薄壳的屈曲在大多数荷载工况下对焊接几何缺陷十分敏感.现有研究标明,焊接残余应力可少量提高均匀轴压圆柱壳的稳定承载力,但对于局部轴压荷载下圆柱薄壳中残余应力的效应,相关的研究很少.采用施加"收缩应变法",建立了分别考虑焊接几何缺陷以及考虑或不考虑焊接残余应力焊接圆柱薄壳的数值分析模型,研究了含有周向焊缝、竖向焊缝以及砌砖式焊缝(patterned welds)的局部轴压焊接圆柱壳屈曲行为,通过比较考虑/不考虑残余应力圆柱薄壳的计算结果,得到残余应力对局部轴压圆柱壳承载力的影响.

Welded thin cylindrical shells have found wide applictions in steel silos and tanks,buckling often governs their design.For most load cases,buckling of the shell is often acutely sensitive to weld-induced geometric imperfections.Exist research suggests that residual stresses are some beneficial to buckling strength of the shell under uniform compression.However,effect of residual stresses on partially-axially-compressed cylinders can be hardly found in literature.This paper employed ＂shirnkage strain approach＂to build numerical models for welded cylinders.The partially-axially-compressed cylinders with circumferential weld,meridional weld,and patterned welds were studied respectively.By compared the results from the models taking/without taking the residual stresses into account,the effect of residual stresses on shells under partial axial compressed was obtained.