Stress concentrations of K tubular joints subjected to basic and combined loadings

Abstract

A large-scale test rig was designed specially and built to study the behaviour of tubular joints subjected to basic and combined loadings. Detailed experimental studies were carried out on a K round-to-round tubular joint subjected to three basic load cases: i.e. axial loading, in-plane bending and out-of-plane bending, and various combinations of these basic load cases. The results were verified by those obtained using the finite element technique. The study shows that the peak hot spot locations on the K joint subjected to combined loadings shifted from those of the basic load cases. Moreover, the peak hot spot stresses (HSSs) due to combined loadings were underpredicted by superposition of the basic load cases in some instances. Comparison of the results obtained by the direct analysis method and some conventional superposition procedures reveals that the latter is inadequate in predicting the peak HSSs of K round-to-round tubular joints.