Pressure Hull Optimization Using General Instability Equations Admitting More than One Longitudinal Buckling Half-Wave,

摘要

An improved method for predicting general instability admitting more than one longitudinal half-wave is adapted to an automated optimal design precedure described in NCE Reports NV5and NV6. The original procedure assumes that the critical buckling shape contains only one longitudinal half-wave. This assumption is incorrect when ultra-high strength steels are used if what appears to be a questionable independent frame buckling constraint,used in the original design procedure,is relaxed. Design studies demonstrate that substantial weight benefits are possible at conventional operating depths (around 1,000feet) if ultra-high strength steels are utilized and the new design equations are employed. Little weight improvement results from the use of high strength steels using the original design procedure. (Author)