Imperfections in cylindrical shells resulting from fabrication misfits

This paper presents part of a rigorous numerical study of the geometry chan ges in cylindrical shells due to localized fabrication misfit and the assoc iated consistent residual stress field. The search for practically useful a nd credible modes of imperfections has led to this study of the geometric i mperfections arising from misfits of construction. These are treated here b y using a geometrically nonlinear analysis to study the effect of a mismatc h in geometry at a point or a seam in a cylinder, or alternatively to explo re the role of weld shrinkage in the formation of geometric imperfections. The imperfect geometries arising from these misfits are demonstrated, and s ome simplifications are given so that their shape may later be used in meth ods for characterizing imperfection patterns that can be applied to measure ments of structures in service. It is found that the geometrical changes ar e essentially linear for most of the shrinkages considered.