Parametric Study of Strength of Tubular Multiplanar KK-Joints

Abstract

A parametric study of the static strength of circular hollow-section joints with the multiplanar KK configuration, commonly found in both onshore and offshore structures, is presented. The study, carried out using a well-calibrated and validated finite-element model, investigated the effects of the various geometric parameters on static strength. Particular attention was given to joints with γ ratios, where the amount of experimental data is scarce, to the effect of γ on strength, and to the influence of the two major failure modes. In all, a total of 50 joints were analyzed. The study has established a clear demarcation boundary between the two failure types as a function of the transverse gap between the braces. A strength database—compiled from the finite-element data generated and 37 existing test results—was used to formulate strength equations through multiple regression analyses. The equations were found to provide strength predictions to a very high degree of accuracy.