Effect of welding residual stress on plastic buckling of axially compressed cylindrical shells with patterned welds

An experimental-numerical investigation of the effect of welding residual stress on plastic buckling of axially compressed cylindrical shells with patterned welds is carried out. Two cylindrical shell specimens with different pattern of welds are made according to manufacturing process used in engineering. Their initial geometric imperfections, axial and circumferential strain, buckling load, etc., are experimentally obtained. Inherent strain method used for simulating welding residual stress field is presented. Two different numerical modeling methods for the purpose of evaluating the effect of welding residual stress on plastic buckling are illustrated and the validity is verified by experiment. It is found that, load-displacement curve before buckling is altered, plastic buckling critical load is decreased to some extent, and the buckling deformation such as the number and the uniformity of waveforms of circumferential welds are changed when welding residual stress exists. For the above phenomena, the reason why welding residual stress has an influence on plastic buckling is also quantitatively analyzed from the point of stress variation.