This project will determine the fatigue strength of plates that have plasma (and possibly laser) cut holes in them. The initial matrix of specimens will be procured from three different sources that will be using different plasma-cutting machines and controlling software. The initial matrix of specimens will determine the effect on fatigue strength that the type of plasma shielding (either oxygen or air), steel type (either regular carbon or weathering grades), and the orientation of the cut termination relative to the primary stress direction may have. In addition, the hardness and cylindricality of the holes from the three different sources will be correlated to the fatigue strength to understand if it is dependent upon the machine making the cut and its controlling software. The project may also address the static strength of plasma cut holes, though this will be dependent upon procurement of a larger testing machine that has been programmed.
To determine the fatigue strength of plasma (and possibly laser) cut holes in steel plates. This fatigue strength would be compared to that of a drilled hole that is the currently accepted technique in steel bridge fabrication.