Identification of probability distributions of SCFs in three-planar KT-joints

Abstract

KT-joints are crucial in jacket platforms, providing structural integrity by effectively transferring loads between the main chord and braces. Their robust design ensures stability and durability in harsh offshore environments, preventing structural failures and enhancing the platform's overall safety and performance. This study presents the findings of finite element (FE) analysis conducted on 324 tubular three-planar KT-joints subjected to in-plane bending (IPB) loadings. The purpose of the research was to generate a probability distribution (PD) for the stress concentration factors (SCFs) under bending moments. To the authors' knowledge, no previous research has analyzed the PD of the maximum SCFs in three-planar KT-joints. Consequently, data representing the maximum SCFs were collected from the three-planar KT connections. The maximum likelihood method was used to determine the distribution parameters. The goodness-of-fit of the Generalized Extreme Value distribution was assessed using the Kolmogorov-Smirnov (KS) and Chi-square (CS) tests. The results indicated that this distribution is the most suitable for modeling three-planar KT-joints under IPB loading. In the subsequent stage, well-defined theoretical probability density functions (PDFs) and cumulative distribution functions (CDFs) were developed. Furthermore, probability-probability diagrams demonstrated that the proposed PD closely aligns with the observed data.