hook and sway brace loads
hook and sway brace loads
(OP)
hello all,
I've calculated a set of inertia load values at a store C.G. (military, wing mounted store) - Does anybody have (or know where to go to get) a good technique or tool for calculating bombrack hook and swaybrace loads independent of aero loads?
thanks
I've calculated a set of inertia load values at a store C.G. (military, wing mounted store) - Does anybody have (or know where to go to get) a good technique or tool for calculating bombrack hook and swaybrace loads independent of aero loads?
thanks





RE: hook and sway brace loads
RE: hook and sway brace loads
Steve R.
RE: hook and sway brace loads
RE: hook and sway brace loads
i mean, you've got maybe 6 loads applied to the CG, and two reaction places
RE: hook and sway brace loads
http://www.dtbtest.com/PDFs/MIL-STD-8591.pdf has a lot of the info you'd need in it.
Get yourself the set of AEII (Aircraft Equipment Installation Information) standards that give the relevant dimensional information for standard NATO stores and racks.
I think they may also have the dimensional information for standard bail lugs and possibly even the more exotic lug patterns such as MACE for Tornado or the T lug from I think it was Douglas.
There is also a standard for the bail lugs themselves if you need it.
You may also want to consider how you handle the G loads. I had always used them as quasi static loads, however at least one stress guy I worked with argued that the higher value G loads should be treated as an impulse or something like that as they weren't really sustained for long, the details escape me.
As I recall I did partial analysis based on just what 8591H has and knowing the C of G & mass of my store.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at http://eng-tips.com/market.cfm?
RE: hook and sway brace loads
typical bombrack is 2 hooks and 4 swaybraces. yeah, you could try basic statics but i think you'd get into a big trial and error loop cause you just don't know in advance which sway brace pads would be in compression during the flight maneuver - and you certainly can't make a pad effective in tension.
RE: hook and sway brace loads
Based on doing a vector analysis of the G load I'd think you could get a good approximation of what load the sway braces are reacting.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at http://eng-tips.com/market.cfm?
RE: hook and sway brace loads
really, it's quite like a pre-loaded tension bolt analysis ...
RE: hook and sway brace loads
I don't think a torque wrench is usually used, but I could be wrong, like I said you'd have to check the loading manual for the relevant store/rack combination.
I'd basically assume the sway braces are tightened up till there is no slack but aren't under significant compression. So they will react additional compressive loads but aren't 'unloading' any in the other direction.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at http://eng-tips.com/market.cfm?