Rational Model for Multibolted Connections for GFRP Members

Bolted connections are most suitable for civil engineering applications since they are easy to inspect, have low construction costs, are easy to manufacture, and offer reliability compared with bonded joints. However, using advanced composite material members with unidirectional fibers could create a state of high stress concentration around the bolt holes due to their inherent geometric discontinuities. Due to a lack of information and the need for understanding the mechanism of these connections, a comprehensive experimental and analytical investigation was conducted at the University of Manitoba to study and to determine the behavior of bolted connections using glass fiber-reinforced plastic (GFRP) structural members. Based on the test results and observed behavior, a design procedure is introduced that accounts for the material orthotropy, pseudoyielding capability, and other factors that influence the connection behavior. The proposed rational model is capable of predicting the ultimate capacity of the multibolted connection and the failure mode. The generic nature of the proposed design guidelines can be applied to a multitude of composite material systems.