BOLTED JOINT FREE BODY DIAGRAM 2

[eli28]

Hello,

I would like to make sure I frew the bolted joint Free Body Diagram correctly?
The motivation is identifying which force act directly on the joint surfaces for friction calculations and local normal stresses.

 

[drawoh]

How are your forces being applied? Here is my free[‑]body diagram of a screw, which does show an external force...

On my drawing, I have labelled enough forces that I can intelligently discuss whether or not that screw will lift off. I ought to show a compressive force between the bracket and the fixed beam.

--
JHG

 

[hydtools]

drawoh, that's a poor free body diagram. Should not show internal forces.

Ted

 

[GregLocock]

When I draw an FBD I draw each body separately when I'm wearing school uniform. Otherwise it does my head in if it is complex (and preload is one of the hilarious ones).


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[dik]

You might try here, too...

https://files.engineering.com/getfile.aspx?folder=1d2bec37-aa01-4384-a9dc-e

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[3DDave]

Try what where? The link doesn't link to a file.

 

[dik]

It's gone... I think this was the file I downloaded... I don't know what happened... it was just there.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[GregLocock]

worked for me

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[desertfox]

dik

That was an interesting link thanks

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[rb1957]

ok, I'll ask ... why are you interested in friction forces ? the variation in CoF will make a mockery of any analysis.

another day in paradise, or is paradise one day closer ?

 

[dik]

friction... bigtime.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[rb1957]

@dik ... ??

another day in paradise, or is paradise one day closer ?

 

[dik]

The tension in the bolt is hugely dependent on the friction... that's why calibrated torque wrenches are contraindicated as a means of checking tensioning.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[rb1957]

yes, friction of the nut on the threads ... I thought the OP was looking for friction on the clamped plates.

another day in paradise, or is paradise one day closer ?

 

[dik]

it's all part of the turkey shoot... I have a couple of papers that address all components... I'll see if I can dig them up.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[eli28]

Hey dik
Thanks for the book, I reviewed it but couldn't find an entire free body diagram in it for comparing to mine.
At least it's a good book, so I keep it

 

[dik]

Maybe mechanical... but, your FBD is not common...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[eli28]

dik - I didn't understand...?

 

[drawoh]

drawoh, that's a poor free body diagram. Should not show internal forces.

The internal forces are what I am interested in.

--
JHG

 

[rb1957]

I think it's a bit pedantic to say the diagram posted is not a FBD. It is in balance, it shows the loadpaths, it shows the detail that the poster wants to discern; that's good enough for me.

another day in paradise, or is paradise one day closer ?