Blind Bolts with Headed Anchors Under Combined Tension and Shear

This paper deals with the resistance of blind-bolts with headed anchors when subjected to various ratios of combined tension and shear forces. The study investigates a modified blind-bolt – named the Extended Hollo-bolt (EHB) – which was developed in view of extending the application of blind-bolting technology to moment-transmitting connections. To determine the resistance of the EHB, a test rig was designed and manufactured in order to apply simultaneous monotonic tension and shear forces on the bolt. The experimental programme is described in detail, where a total of 13 tests were conducted involving tension to shear ratios of 3.7, 1.7, 1.0, and 0.4, as well as pure shear tests. Pure tension tests reported in the literature are used for comparison. The ultimate loads achieved are used to model the tension-shear interaction diagram, the failure modes are reported, and the effect of altering tension and shear ratios on the bolt behaviour is discussed. Finally, the normalised data is compared with the current design procedures for standard structural bolts. A new interaction model is proposed on the basis of the test data presented in this paper. It is also established that the Eurocode 3 EN 1993-1-8:2005 bi-linear curve and the rules found in the American ANSI/AISC 360–16 could be safely used to model the particular anchored blind-bolt.