Bending of Fastener
Bending of Fastener
(OP)
Hello all,
I have a condition where I have a sandwich panel with metal facings let's say 4'' apart and is fastened down into steel purlins. However, there is a 3'' air gap (left out details for simplicity) between the sandwich panel and the girts. The panels are subject to a snow drag load, lets say 100 PSF. How do I account for the bending of the fastener between the purlins and the sandwich panel? I have attached a drawing for reference.
Thanks for the help.
I have a condition where I have a sandwich panel with metal facings let's say 4'' apart and is fastened down into steel purlins. However, there is a 3'' air gap (left out details for simplicity) between the sandwich panel and the girts. The panels are subject to a snow drag load, lets say 100 PSF. How do I account for the bending of the fastener between the purlins and the sandwich panel? I have attached a drawing for reference.
Thanks for the help.






RE: Bending of Fastener
another day in paradise, or is paradise one day closer ?
RE: Bending of Fastener
I suspect that the left out details may, in fact, be necessary to generate a reasonable answer.
Mobilizing fastener bending in these situations is usually not the way to go. Even if the fasteners can take the bending, the cold form probably can't handle it locally. If there's actually something of substance in the air gap, even insulation, you may be able to use it in compression to set up a strut and tie kind of mechanism with the fasteners in tension. Some wood screws work that way.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Bending of Fastener
RE: Bending of Fastener
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Bending of Fastener
if the metal deck is castellated, why not pick up the "highs" ?
another day in paradise, or is paradise one day closer ?
RE: Bending of Fastener
RE: Bending of Fastener
RE: Bending of Fastener
RE: Bending of Fastener
Here's another scenario:
Same drawing as the one I previously posted. Say there isn't a 3'' air gap between the sandwich panel and supports (and that it'snot attached to a metal deck.) The sandwich panels have 22 gauge facings on the top and bottom side with foam in the center. Assuming adhesion between facings and foam is adequate, would the two facings resist the same amount of shear? That is, if the shear load for the 22 gauge facing is 600 lbs, can this be treated as 1200 lbs? I would think in a homogeneous material, say a 1/2'' steel plate, the plate or fastener/bolt would shear. But can we treat it the same way in a composite material?
RE: Bending of Fastener
another day in paradise, or is paradise one day closer ?
RE: Bending of Fastener