Parametric study of blind bolted end-plate connection on structural square hollow section

Abstract

This project involves the parametric study of blind-bolted end-plate connections between square hollow section columns and open beams. Blind bolts are defined as bolts that can be access for installation from one side of the connection only, where the application can referring to the case of connecting the end-plate of a beam to a hollow column. Blind bolts offer many advantages including strengths and sizes comparable to ordinary bolts and therefore it has potential use in tension applications as well as in moment resisting connections. Currently, many research works have been carried out using H or I profiles but not many using structural hollow sections. Furthermore, the theoretical method to predict moment resistance of an I-beam connected to square hollow section column is not established yet. Study has been conducted by firstly, predicting the moment resistance and rotational stiffness using theoretical Gomes method and component method. Secondly, theoretical model and experimental results will be validated. The proposed theoretical model with higher accuracy is used to perform a parametric investigation into the key factors influencing the behaviour of blind-bolted end-plate connections. Parameters such as column face thickness, yield strength, blind-bolt types and sizes, gauge length and end-plate thickness are investigated. Moment resistance and rotational stiffness have been established using theoretical Gomes method and component method. Based on the results, the comparison to the experimental results shows that component approach has over predicted the initial stiffness of the connection by a ratio of 3.93 to 6.02 and underestimated the moment resistance of the connection by ratio of 0.52 to 0.96. The parametric study shows that column thickness, bolt size and end plate thickness are the main key factors that influence the moment resistance and initial stiffness of the connections.