Analysis of stress intensity factor (SIF) for cracked tubular K-joints subjected to balanced axial load

Abstract

Numerical modelling of cracked tubular K-joint is presented in this study. A new mesh generator for a tubular K-joint with a surface crack was developed and finite element analysis of stress intensity factor (SIF) for cracked K-joint was conducted by using the proposed numerical modelling. Numerical results of SIF were then verified from experimental tests on a full-scale K-joint specimen. The verifications show that numerical results agree reasonably well with experimental results. Based on the accuracy of numerical analysis, 5120 numerical models of K-joints subjected to balanced axial load were analyzed. SIF results of these numerical models were used to build up a database. An interpolation method was introduced to calculate SIF of each model in a valid range by using the analyzed SIF results in the database. The accuracy of the SIF obtained from interpolation method was verified from 972 numerical models which were also analyzed from finite element analysis. The comparisons between SIFs from interpolation method and numerical results show that the introduced interpolation method can provide accurate SIF values for cracked tubular K-joints and thus it is both reliable and efficient to be used in design in practice.