Experimental and numerical analysis of preload in Extended Hollo-Bolt blind bolts

Cabrera, Manuela; Tizani, Walid; Ninic, Jelena; Wang, Fangying

Abstract

Adequate initial bolt preload is necessary to ensure the strength and stiffness of bolted connections. In this study, an experimental torque control method was used to determine the relationship between tightening torque and preload of nine Extended Hollo-Bolt (EHB) blind bolted connections to Concrete-Filled Steel Hollow Sections (CFSHS). In order to obtain the EHB nut factors, which allow to calculate the level of preload for any value of applied torque, torque versus preload curves were drawn based on the experimental results and curve fitting method was carried out. Bolt preload relaxation was also recorded for a period of 7 days while concrete hardening occurred. Additionally, a detailed 3D Finite Element (FE) model of the tightening stage of the EHB was established. The experimental and numerical results show that the nut factor for the EHB is higher than that of standard bolts and bolt relaxation is not affected by the concrete presence during the hardening stage. Adequate friction coefficients were proposed as well as an equation for calculating the residual preload of the EHB.

Citation

Cabrera, M., Tizani, W., Ninic, J., & Wang, F. (2021). Experimental and numerical analysis of preload in Extended Hollo-Bolt blind bolts. Journal of Constructional Steel Research, 186, https://doi.org/10.1016/j.jcsr.2021.106885

• Journal Article Type: Article
• Acceptance Date: Jul 29, 2021
• Online Publication Date: Aug 5, 2021
• Publication Date: Nov 1, 2021
• Deposit Date: Aug 12, 2021
• Publicly Available Date: Aug 6, 2022
• Journal: Journal of Constructional Steel Research
• Print ISSN: 0143-974X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 186
• Article Number: 106885
• DOI: https://doi.org/10.1016/j.jcsr.2021.106885
• Keywords: Metals and Alloys; Mechanics of Materials; Building and Construction; Civil and Structural Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/6014174
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0143974X21003679