Net section fracture of S700 high strength steel staggered bolted connections

The present paper describes a thorough experimental and numerical investigation into the net section failure and load-carrying capacities of S700 high strength steel staggered bolted connections subjected to tension. The experimental programme was carried out on fifteen S700 high strength steel double-shear staggered bolted connection specimens. The connection test setup and procedures as well as the key experimental results were reported in detail. Following the experimental programme, a numerical modelling programme was perform, where finite element models were initially developed to replicate the tests and then employed to conduct parametric studies. On the basis of the obtained test and numerical data, the effect of the transverse and staggered pitches on the net section failure loads and modes were studied and the accuracy of the relevant codified design rules was assessed. Generally, the American specification yields the highest level of design accuracy, though with some unsafe predicted resistances, while the European code and Australian standard lead to more conservative design resistances but all the design resistances are still relatively accurate and safe. Moreover, all the three design codes were shown to result in more accurate failure load predictions for 2-bolt staggered connections than for 3-bolt staggered connections.