Fatigue performance of preloaded bolted connection with oversized holes

Moving towards a more sustainable and circular infrastructure has increased the demand for demountable connectors in hybrid structures combining steel, concrete, and nowadays FRP composite components. Large, prefabricated components need to be transported to the construction site and assembled by means of bolted connections for easy reuse of the components. Slip‐resistant connections are required for such hybrid structures in bridges, which are usually provided by injection or preloaded bolts. The former satisfies the need for large tolerances during execution. However, the behavior of such injection bolts depends on the environmental conditions and the resin complicates the installation and demountability. The current practice of preloaded bolts uses standard hole clearances that do not provide sufficient tolerance for the assembly of large structural components made of different materials and many connectors. This paper focuses on the fatigue performance of preloaded bolted connections with excessively oversized holes that could provide sufficient tolerance for execution. Double lap bolted joints for two different bolt‐hole diameters, regular and 60 mm oversized, are tested under cyclic loading and the increase in slip displacement during the load cycles is compared. The static performance is numerically obtained in terms of residual stiffness, slip and ultimate resistance. It was found the stiffness variation between normal holes and significantly oversized holes is insignificant.