Static strength of thick-walled CHS X-joints - Part I. New approach in strength definition

Abstract

This paper presents a new approach in the definition of joint strength for thick-walled circular hollow section (CHS) X-joint subjected to brace axial loading. This is based on the plastic load approach for limit analysis of pressure vessel components proposed by Gerdeen. A consistent coefficient λ associated with the plastic load approach has been determined, and the corresponding joint strength for X-joint under brace axial loads is found to correlate closely with the results obtained using Lu's deformation limit. The strength prediction for thick-walled CHS X-joint using the present approach is found to be in good agreement with design recommendations by ISO and CIDECT for joints with chord radius-to-thickness ratio γ > 7. For X-joints with γ < 7, significant difference in results is observed especially with the ISO recommendation for joints with brace-chord diameter ratio β≥0.7. © 2003 Elsevier Ltd. All rights reserved.