UG-34 " Unstayed flat head or cover "

[designer716]

Im trying to calculate the thickness of an " Unstayed flat head or cover " . I looked at the formula in the code book, but i am having some troubles calculating this, anyone out there familiar with how to do this calculation?

 

[gr2vessels]

I assume the cover you design is a swing bolt cover;- you might need to search on this topic (the search box in top of this page), it was debated earlier.
Cheers,
gr2vessels

 

[prex]

You shouldn't worry about using code formulae. The fact that you are lacking the metal between the bolt holes doesn't change anything, as code formulae do not account for metal outside d, the diameter of the sealing circle (not shown on your drawing).
This is easily proved, as the bending stress in a supported circular plate with uniform pressure is [σ]=3(3+[ν])Pd²/32t² (where d is the outer diameter of the plate) and this gives C very close to 0.3. To be noted that [ν] should be set to zero, as it gives rise to secondary stresses, and this makes the code formula a little conservative (C=0.28). Also this means that the code formula doesn't account for an allowable stress in bending equal to 1.5SE.
Concerning the bolt load, this gives a uniform bending stress in the plate equal to [σ]=6Wh_G/[π]dt² that gives exactly the formula in the code.

prex

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