焊接残余应力对钢制组合圆柱壳轴压塑性屈曲的影响

In this paper, experimental and numerical methods are adoped to learn the influence of welding residual stress on plastic buckling of combined steel cylindrical shells under axial load. The reason of the influence is also explored quantitatively proceeding from the stress state of buckling region. For the above purpose, two steel cylindrical shell specimens are manufactured. Their initial geometric imperfections, axial and circumferential strain, buckling load, etc., are obtained by using self-designed axial buckling experimental platform and dynamic strain measure instrument. Numerical modeling calculations in two different combination of the collected initial geometric imperfections and artificialy constructed welding residual stress field are carried out. Conclutions are made by comparing numerical results and experimental results. Results show that, not only is plastic buckling critical load decreased, but also relationship between load and displacement before buckling as well as buckling deformation are changed when welding residual stress exists. The reason for the above influence lies that,'bending' stress state of buckling region induced by initial welding residual stress or axial load can be superimposed.