Experimental study of hemispheric rolling cable-strut joints for cable dome applications

• Published in: Journal of constructional steel research 2022-07, Vol.194, p.107336, Article 107336
• Main Authors: Zhang, Ai-lin, Zhao, Xi, Luo, Chao-yi, Zhang, Yan-xia, Wang, Qing-bo, Su, Mei-ni
• Format: Article
• Language: English
• Subjects: Bearing; Cable dome; Cable-strut joint; Prestress loss; Reduction of frictions
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2022.107336

Cable domes achieve structural stiffness and loading capacity through tension cables and compression struts. Friction from cable-strut joints contributes a major prestress loss during tensioning. This paper presents a novel hemispheric rolling cable-strut joint which provides smooth load transmission and high prestress efficiency. It comprises a hemispheric cover plate, a bottom plate, a roller, and top and bottom bearings. The bearings embedded in the roller reduce friction transmission from the tensioned cable; thus, prestress loss is minimized. A theoretical analysis of load transmission and prestress loss is conducted for the cable-strut joint, followed by an experimental study. The experiments test cable-strut joints with different types of bearings, using a fixed-roller joint as a reference, and are shown to validate the theoretical approach. A potential method to improve the prestress efficiency during tensioning is discussed. Prestress loss rates are compared for the test joints and an optimum bearing type is recommended in consideration of both friction coefficients and service time. The hemispheric rolling cable-strut joint accommodates complex cable and strut configurations with clear load path and minimal prestress loss. Our results show that it provides a high-performance solution that can be used to improve the structural stability and stiffness of next generation long-span spatial structures. •A novel hemispheric rolling cable-strut (HRCS) joint with unique bearing design was proposed for the cable domes.•The HRCS joints accommodate multi-direction struts and cables but reduce prestress loss by reducing frictions in tensioning.•Force transmission and prestress loss control of the HRCS joint are studied both theoretically and experimentally.•The prestress loss of HRCS joints was explored. A bearing is selected according to friction coefficients and service life.•The prestress loss in HRCS joint is eliminated through the over-tension-retract technique