Bearing Limit State of High-Strength Frictional Bolted Joints Consisted of Several Bolts Based on Bolt Hole Deformation

Abstract

The high-strength frictional bolted joints should be designed considering not only slip resistance but also bearing resistance. This study focused on bearing resistance based on deformation of bolt holes. This resistance contributes to obtain high structural redundancy because we can control safety margins of resistance and ductility. Tensile tests of the joints consisted of four bolts arrayed along two rows and columns was conducted, which varies a pitch and an edge distance, to clarify the relationship between these parameters and the deformed bearing limit state. It is found that the bearing stress when the deformation of one of all bolt-holes reaches 10% dimeter of bolt shank was more than three times of the yield stress of the connected plate in all cases. As the pitch/the edge distance increases, the safety margin of resistance and ductility in 10% deformed bearing limit state for failure ν_R and ν_D becomes larger. Comparing the maximum strength, the strain distributions, and the safety margin and so on, it’s concluded that the specimen “p/d4.0-e₂/d4.0” has one of desirable structural configurations to expect high resistance and ductility after major slip.