Tensile and Fatigue Behavior of Structural Steel Plates with Slotted Holes

This research is a continuation of a project sponsored by the Texas Department of Transportation (TxDOT) titled “Performance and Effects of Punched Holes and Cold Bending on Steel Bridge Fabrication.” The first two phases of the project was presented by Lubitz (2005) in “Tensile and Fatigue Behavior of Punched Structural Plates” and by Brown (2006) in “Punched Holes in Structural Connections.”

AASHTO does not allow full size punched round holes in primary load carrying members. The specifications state that holes in these members may be punched and then reamed full size (in order to remove the damaged zone immediately surrounding the hole) or drilled. The purpose of reaming is to remove the damaged material surrounding the hole and any micro-cracks formed during the punching operation. However, AASHTO Construction specifications do not specify which technique to be used for slotted holes, which is not consistent with round hole making specifications. Also, there isn’t much information about the behavior of members with slotted holes and round holes created using thermal cutting in the literature under static and fatigue loads.

The goal of the main part of the project was to investigate the effects of different hole making techniques on the tensile strength and the fatigue behavior. Static and fatigue loads tests were done in Ferguson Laboratory to gain more information about the issue. Based on the results of this study, possible modifications of AASHTO and AISC specifications were developed.