Effect of contact surface type on the slip resistance in bolted connections

Abstract

The use of slip-critical bolted connections is strongly emphasized for steel structures located in seismic zones by building codes. Obviously, the type of contact surface has a significant effect on the slip resistance of such connections. The purpose of this research is to experimentally and numerically evaluate the effect of the type of plate contact surface on the frictional resistance of these structural components. To this end, some samples of bolted connections with different contact situations were selected and tested. The surfaces selected for this purpose include sandblasted, painted (with different thicknesses), and grooved (triangular and square shapes with two different groove's heights). Subsequently, in order to perform numerical analyses, the force-displacement relationship of the connections are simulated by constructing some Finite Element (F.E.) models for each case. The obtained data from numerical simulations were verified by the experiments, indicating an acceptable match. Overall, the results of this study showed that the square-grooved sample had the highest frictional resistance; while, the painted specimen exhibited the least frictional resistance. The frictional resistance of grooved samples with regard to sandblasted, ordinary, and painted are significantly higher. These values imply that with grooving the steel surface, in practice, the strength of such connections can be effectively improved.