[PSUBS-MAILIST] reinforcement

[Sean T. Stevenson via Personal_Submersibles]

If you were to meticulously torque the bolts to a sufficient preload to ensure that the connection could reliably carry shear forces, then technically it would carry some load; however, it is unwise to rely on that for the purpose of determining required penetration reinforcement - certainly if the forces are transferred entirely in shear. If instead, the plate was loaded in radial compression (i.e. inset into the seat and bearing on the outer cylindrical surface), then there would be some direct load transfer, but the exercise is academic. As with an acrylic window, design the ring under the assumption that the seat ring and associated reinforcement must carry all hull stresses. The flat plate that bolts on should then be designed in accordance with the rules for unstayed flat heads (ABS Steel Vessel Rules).

Sean

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-------- Original Message --------
On Nov 14, 2017, 15:43, hank pronk via Personal_Submersibles wrote:

> HI Sean,
> I am taking your suggestion and ordering a heavy ring to mount my motor assembly to rather than use the original pipe assembly.  .  It will be like a port frame but with a 5\8 steel plate with a prop shaft tube weld to the centre with giant gussets.  Normally I would weld in a ring that is several time heavier than it needs to be, but in this case I can not get crazy with weight.  The weight is important because it is still an escape pod.  I have sized the ring to be 20% heavier than the material removed from the sphere.  I am assuming that the 5\8 plate that is bolted to the ring adds support to the ring.  I realize the added plate is only as strong as the bolts securing it, but there must be a benefit, or does this not count?
> Hank
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