Static Strength of Axially Loaded Tubular K-Joints. II: Ultimate Capacity

Abstract

The ultimate capacity results from an extensive finite-element study of balanced axially loaded K-joints (reported in a companion paper) are reviewed and compared with predictions from available design guidance. Both overlap and small-gap K-joints are included. Overlapping the braces was shown to have a beneficial effect on joint strength for the joints with relatively thick brace walls, where the strength was found to be up to four and a half times that of the corresponding gap joint. The performance of the available onshore and offshore design guidance for predicting joint capacities was poor, particularly for the overlap joints. The interactive effects of varying geometric parameters are not fully accounted for, generally resulting in high levels of conservatism. A new strength equation developed for the overlap joints has been shown to predict the capacities of the numerical joints studied, as well as those from a test database, with a high degree of accuracy.