Threaded Rod Hanger Capacity

[BriceLee]

Hi all,

Ive got the following situation:

A 4.3m threaded rod is anchored to a composite concrete slab and this is divided into two sections of 2.15m connected by a M10 coupler. Assumming this rod is of Grade 8.8 and is also M10, how should I proceed to calculate its capacity? Would I have to consider the tensile load resistance, the concrete pull-out resistance and/or the coupler's resistance? (Both Preloaded and Non-Preloaded Conditions are to be considered. This is for the retrofitting of a BallRoom ceiling expected to carry gymnasts and lighting systems, etc).

I did my years in academia under the Eurocode, but now working in Asia, we follow quite a few codes, so any help is welcomed (if explanation could be in metrics would be preferable).

Thank you all in advance.

 

[desertfox]

hi

Tensile loading in the thread itself, stripping of the thread in the coupler and pullout resistance within the concrete slab.
A simple sketch of your situation might help to achieve better answers, the lengths of the threaded rod seem very long for an M10 thread.

 

[BriceLee]

Hi @desertfox,

Thank you for your showing of interest. At the moment I'm out of the office and don't have the photos from the ballroom I'm talking about. If you'll be around, I'm gonna post those pics here.

Be good

 

[kingnero]

M10 is hardly "structural", so to say. And visually not pleasing. I didn't even know that they came in lengths > 1m.

No matter what codes you follow, actual physics stay the same. If you're talking dynamic loading, better err towards the safe side.
I've specced full bars with threaded ends for a similar application, these exist under a brand name, and come tailormade to length. Maybe worth considering?

 

[drawoh]

BriceLee,

Questions about threaded rod embedded in concrete are structural (civil) rather than mechanical. This might be better asked in the structural forum.

--
JHG

 

[racookpe1978]

Yes. All of the above.

You MUST ensure the M10 rod stays in the concrete for the load and the safety factor and the concrete strength assumed.
You MUST ensure the coupler is adequate for the load and safety factor chosen.
You MUST ensure the M10 itself is adequate for he load and safety factor chosen.

And, an M10 rod WILL NOT carry the dynamic loads of even a child gymnast jumping, leaping, twisting from a M10 rod trying to also carry a ceiling deadload.

You need to assume (personal safety!!!!) a dynamic load of impact and falling loads being "jerked" to a stop irregularly.

 

[BriceLee]

Hi all,

Thank you for your replies. I really did not notice this thread was in the Mechanical Eng section.

Also, I did not mention either that this is to be used in a system of hangers. So, every 1.5m there will be a hanger and this will go 'round' a square. Hence, I am just looking to know the capacity of one threaded rod, which I would convert to the actual situation.

Attached are the photos of the actual place:

http://files.engineering.com/getfile.aspx?folder=b8c14d02-7576-4c9c-8c98-7428dc011763&file=BR1.PNG

http://files.engineering.com/getfile.aspx?folder=31097f9d-4362-4fd3-926f-8dc81d0c7b58&file=BR2.PNG

http://files.engineering.com/getfile.aspx?folder=fcef10c3-9d51-4dbe-b5ae-69d401b3beb1&file=BR3.PNG

http://files.engineering.com/getfile.aspx?folder=0971fc46-1c49-4a7b-80b4-bac7d8bed498&file=BR4.PNG

http://files.engineering.com/getfile.aspx?folder=cae660f3-f1b3-448d-b98f-685edd2785c3&file=BR5.PNG

http://files.engineering.com/getfile.aspx?folder=55c86b64-8759-491a-9ac1-13c59b3ae6b4&file=BR6.PNG

Thanks