Influence of welding residual stress on bending resistance of hollow spherical joints

• Published in: Journal of constructional steel research 2023-09, Vol.208, p.108004, Article 108004
• Main Authors: Yan, Renzhang, Yu, Ziyan, Wang, Shuai, Liu, Jiaqi
• Format: Article
• Language: English
• Subjects: Bending stiffness; Experimental study; Ultimate bending capacity; Welded hollow spherical joints; Welding residual stress
• ISSN: 0143-974X
• DOI: 10.1016/j.jcsr.2023.108004

Welded hollow spherical joints are widely used in large-span spatial structures because of their simple organization and convenient construction. However, in the sphere-pipe connection welds of the joints, welding residual stress is generated, which will adversely affect the mechanical properties of the joints and the overall structure. In this paper, the parametric model of welded hollow spherical joints was established by employing the geometric configuration dimensions of those joints frequently used in engineering. Through the combination of experimental research and numerical simulation, the welding residual stress of welded hollow spherical joints and its impact on joints' bending resistance were studied. First of all, based on the distribution pattern of the stress, bending test of the joints was carried out and revealed the influence of welding residual stress on the bending stiffness and ultimate bending capacity of the joints; Then, through the results of experimental analysis and finite element calculation, and with parametric analysis, the impact of welding residual stress on joints' bending resistance was clarified with the variation of parameters such as the hollow sphere diameter D, wall thickness t and the connecting steel pipe diameter d. It is shown that welding residual stress has a great impact on joints' bending stiffness, with a reduction more than 10%, while it doesn't affect their ultimate bending capacity much, with an influence no more than 5%. In addition, as D increases, t, and d decrease, its impact on the bending resistance rises. •Tests show that the residual stress weakens the bending stiffness of hollow spherical joint by more than 10%.•The influence of residual stress on the ultimate bending capacity of hollow spherical joint is less than 5%.•When the parameter D increases, t and d decrease, the influence of residual stress on the joint's stiffness is enhanced.