launch pad loads calculation 2

[dravid]

Does some body give me the direction in calculating the bending moment created in launch vehicle when standing on the launch pad due to wind.

 

[edbgtr]

Hello Dravid
You've had your question up here now for 16 days and not a peep out of the launch vehicle guys on this forum. Those across the border and close to you will not respond for obvious reasons and those further away have other motives.
The loads will depend on such things as the placement and size of the fins on your cylinder. Whether you launch from a flat open area (like Cape Kennedy) or from within a crater-like bunker will affect the wind speeds and the boundary layer profile of the wind impinging on the vehicle. I suggest you talk to the local civil engineers who design chimney stacks. The SFD and BMD on the cylinder will depend on the boundary conditions at the base of the vehicle and the positioning and support that your gantry offers the vehicle. Other than that, you have a vertical beam with some sort of distributed load on it, and you'll have to fathom out how to load it.
Let's see whether my response brings another engineer into this discussion.
Good luck,
Ed.

 

[tsurani]

I would have to agree with Ed on this. Surely its a [relatively] simple beam with distributed loading and multiple supports (base and gantry). The loading would come directly from whatever spec's the launch authority has on acceptable launch conditions. ie maximum allowable wind gusts. If you are doing the calcs to define a spec, then I suppose I would work the other way and find the max allowable (a) point load at the top, and (b) uniformly distributed load that you could apply without causing damage. Dont know if I helped or was just B.S.-ing.

Cheers,
tsurani

 

[dravid]

Thanks for the reply, infact i proceed the work by considering the vehicle as a beam and then calculate the SF & BM due to the distributed wind load. In this regard a book title "B.M and Air vehicle systems" by H.S.Seifert, Kenneth Brown , helped me a lot.