Recent development and innovation in tubular structures

Abstract

This paper highlights some of the research results achieved by the author and his teammates on tubular structures and thick-walled circular hollow section (CHS) connections. Excellent research and developmental work on thin-walled CHS connections has been conducted by a number of world renowned experts. However, there is little available information on thick-walled CHS connections, which are joints with chord outer radius-to-wall thickness ratio γ ≤ 10. This paper first presents the plastic load approach for strength definition of tubular joints and shows that current design recommendations may be un-conservative for thick-walled joints with equal diameter brace and chord members with γ ≤ 3.5. The behaviour of CHS K-joints, including the chord stress effect, is then summarized. The results from a detailed study on an innovative and effective external reinforcement scheme for CHS joints are presented. The paper also highlights the results obtained for the strength of fabricated pipe trunnions using the through brace scheme and novel implementation for plated structures which resulted in cost effective designs for heavy lift installation of structures.