LOAD-SHORTENING BEHAVIOUR OF DAMAGED TUBULAR COLUMNS

A simple 'engineering' method was formulated for computing the axial load versus axial shortening relationship of pin-ended tubular members damaged by a dent and/or out-of-straightness. The method predicts the pre- and post-ultimate load-shortening response and can be used in analysing the strength and behaviour of offshore platform frames containing damaged members. It is valid for member geometries and material properties typically found in fixed offshore platforms. The method was developed from a parametric study and regression analysis of a database containing load-shortening relationships from published test results on small-scale damaged specimens and data generated by finite element analysis. The finite element analysis considered the effects of geometric and material nonlinearity and was verified by comparisons with test results.