Plastic collapse load prediction of cracked circular hollow section T/Y-joints under in-plane and out-of-plane bending

• Main Authors: Li, Tao, Lie, Seng-Tjhen, Shao, Yong-Bo
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: Cracked CHS T/Y-joints; In-plane Bending; DRNTU::Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/90146; http://hdl.handle.net/10220/48430
• Institution: Nanyang Technological University

The plastic collapse loads of cracked circular hollow section (CHS) T/Y-joints under in-plane and out-of-plane bending are investigated using finite element (FE) analyses. An in-house 3D FE mesh generator is specifically developed to create the mesh models of the cracked joints containing a semi-elliptical surface crack located at the weld toe of the chord. Mesh convergence tests are then carried out to check the accuracy of the generated mesh models. The in-plane and out-of-plane plastic collapse moments of uncracked CHS T/Y-joints are calculated and compared with results obtained from three codes and experimental data. The comparison shows that the plastic collapse moments of uncracked CHS T/Y-joints obtained in this study are accurate and reliable. Subsequently, an extensive parametric study is carried out to investigate the plastic collapse moments of cracked CHS T/Y-joints under in-plane and out-of-plane bending. It is found that the in-plane and out-of-plane plastic collapse moments may decrease by up to 35.1% and 33.6% respectively when the crack area Anc reaches 25% of the intersectional area, t0*lw. Finally, two lower bound strength reduction factor FAR equations for cracked CHS T/Y-joints under in-plane and out-of-plane bending are proposed.