there is a rack at work and the shelf is held by 6 bolts. how do i calculate if 4 bolts will hold the weight.
cheers first time questioner :)
cheers first time questioner :)
-
Depends how in-depth you want to go with this...
1. You could make a rough guess by finding the rated strength of the shelf (how much weight is safe for it to hold) then multiply it by 0.667 (4 divided by 6).
2. Or... If you assume the shelf doesn't bend, you can calculate the shear stress on each bolt by the equation:
tau = (4 * weight(kg) * 9.81) / (Number of bolts * pi * (diameter of each bolt)^2)
...then if this answer if sufficiently below the material's Yield Stress (completely your discretion...), you're good to go! You should be able to find any material's yield stress from a search engine.
1. You could make a rough guess by finding the rated strength of the shelf (how much weight is safe for it to hold) then multiply it by 0.667 (4 divided by 6).
2. Or... If you assume the shelf doesn't bend, you can calculate the shear stress on each bolt by the equation:
tau = (4 * weight(kg) * 9.81) / (Number of bolts * pi * (diameter of each bolt)^2)
...then if this answer if sufficiently below the material's Yield Stress (completely your discretion...), you're good to go! You should be able to find any material's yield stress from a search engine.
-
The bolts will likely hold without any engineering needed. Unless it is an abnormally heavy load on the shelf which I suspect it is not. One thing to remember though is make sure the bolts are dug into the studs of the building and not just hanging on the sheet rock. That should work just fine :).