Comparative Study of Tubular Joint Design Formulas According to API RP 2A WSD 21st Edition and 22nd Edition

Abstract

The strength of the jacket substructure on a fixed offshore platform is dictated by the strength of the tubular connecting the jacket leg and the braces. The accuracy of the static strength calculation of the tubular joint is very important to ensure the integrity of the structure during its operation. Therefore, as a Recommended Practice, API RP 2A WSD always regularly was updated based on the results of the latest research to obtain more accurate results in the analysis of the tubular joint. This paper discusses the difference between simple tubular joint design calculation based on API RP 2A WSD 21st Edition and API RP 2A WSD 22nd Edition. This study will show simple joint design calculation for joint types of K, T, and X. The results will be compared to the modelling results for validation. Furthermore, this paper will study variables affecting the difference in the calculation of the result between these two versions and which factors the API considers in changing the formula. This analysis results certainly show the difference in the formula between these two editions of the API, and the comparison with the finite element analysis demonstrates good results.

Bending load effects on stress concentration factor distribution of multi-planar DTKY tubular joints

“…To date, numerous studies have been carried out to analyze the behavior of tubular joints [4], including the stress concentration factor [5,6]. In practical application, the tubular joint's SCF is generally calculated from empirical formulas, recommended by American Petroleum Institute (API) [7,8]. However, most of those formulas focus on uniplanar tubular joints which are the formulas are limited in applicability and can only be used for uni-planar tubular joints.…”