STRENGTH OF MOMENT-LOADED TUBULAR T/Y-JOINTS IN OFFSHORE PLATFORMS

Current design guidelines on the capacity of T/Y-joints in circular hollow sections under out-of-plane moment loading are derived from a database having a limited range of geometric parameters. Although further test results have become available since, certain geometric parameters are still not adequately covered. This paper presents the results of an experimental and numerical study investigating the effects of the various geometric purameters as well as the influence of the tensile strength to yield stress ratio on the ultimate moment capacity. The results of this investigation show that, whilst the effect of the ratio is minimal, the effect of is very significant at the larger â ratios and it has not been accounted for in existing design formulations. The finite element results obtained were used together with existing test data as the database in a statistical regression analysis, and a new capacity estimation equation is proposed. The new equation is found to be more accurate and reliable than those included in current design codes.