Hello All,
I am trying to better understand the tension steel failure modes of fracture on the net section vs yield on the gross section. I was under the impression that when analyzing a tension member the net section was the total section minus any holes (bolt / rivet or weep holes) and the gross cross section was just the total area of the member. The confusion for me on this topic starts when I start looking at built up bridge members with access holes (large 12"-14" diameter holes for welding). On some of the old as-built plans they call out an effective gross area, which is the total area minus the access hole dimensions. My main question is there a certain holes size where you want to start reducing the gross area and not just the net area? What about if the member start losing significant section due to corrosion? Would the sections yield or fracture first? I am relatively new engineer so if there is guidance in AASHTO or AISC please point me there!
Thank you for your time.
I am trying to better understand the tension steel failure modes of fracture on the net section vs yield on the gross section. I was under the impression that when analyzing a tension member the net section was the total section minus any holes (bolt / rivet or weep holes) and the gross cross section was just the total area of the member. The confusion for me on this topic starts when I start looking at built up bridge members with access holes (large 12"-14" diameter holes for welding). On some of the old as-built plans they call out an effective gross area, which is the total area minus the access hole dimensions. My main question is there a certain holes size where you want to start reducing the gross area and not just the net area? What about if the member start losing significant section due to corrosion? Would the sections yield or fracture first? I am relatively new engineer so if there is guidance in AASHTO or AISC please point me there!
Thank you for your time.
