A Load Shortening Curve Library for Longitudinally Stiffened Panels

Efficient methods for determining the load versus end-shortening response of longitudinally stiffened panels are considered. A library of load-shortening curves for a wide range of design parameters is developed using an automated finite element analysis (FEA) procedure. The loadshortening response of twenty benchmark stiffened panels is estimated by interpolation of the library curves. These are compared with similar curves calculated using nonlinear FEA and using design formulas published by the International Association of Classification Societies (IACS). The ultimate strength of eight benchmark hull girders is predicted using the interpolation and IACS methods for estimating the load-shortening response of stiffened panel structure, all within the framework of a Smith's method algorithm implemented in ULTMAT. Comparisons with previously published results indicate that acceptable accuracy can usually be obtained with the approximate methods. The scatter in strength predictions using Smith's method is considered, and is sometimes found to be greater than the recommended safety factor of 1.1.