Analysis of Fabricated Tubular Columns

In recent papers, the results of tests on ten long, fabricated tubular columns, of relatively large diameter with essentially pin-ended condition, were presented. The purpose of the present paper is to describe an analytical model for predicting theoretically the behavior of such columns. The computer model developed includes the effects of residual stresses, geometric imperfections, unavoidable end eccentricities and nonhomogeneity in material yield strength. Using this computer model, extensive comparisons have been made with the results of ten tests on actual columns, providing the needed confirmation of the validity of the model. A considerable amount of numerical data has been obtained and presented concerning the behavior of fabricated tubular columns with various combinations of residual stresses and imperfections. Against the background of this information, design formulas based essentially on simple modifications of current design formulas are derived and developed for practical use.