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#69034 - 05/18/17 06:32 AM Friction
Jacky Offline
Member

Registered: 02/28/17
Posts: 9
Loc: NRW, Germany
Hello all,
I was trying to do some friction examples but dont understand how to see results. From my view, when i apply a Mu value of 0.3 in the guide restraint with +Y support, the forces should be increased or decrease in X direction.
For example, i have taken a simple pipe of 5meters anchored at both the ends. and broke it at middle and applied guide with +Y support with Mu value on guide.
The forces before this supports are same even after applying friction.
i dont know if i am doing right.
Can anyone help me in this.

Regards,
Jacky

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#69036 - 05/18/17 07:04 AM Re: Friction [Re: Jacky]
Richard Ay Offline
Member

Registered: 12/13/99
Posts: 6226
Loc: Houston, Texas, USA
There is a section on how friction is computed in the User's Guide, please review that to understand how friction is implemented in the software.

Also be careful with the load cases. For example, in your model above, if the load case included only the WIN1 (wind 1) primitive in the Z direction, then there won't be any friction (because there is no normal force.
_________________________
Regards,
Richard Ay - Consultant

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#69038 - 05/18/17 07:55 AM Re: Friction [Re: Jacky]
Michael_Fletcher Offline
Member

Registered: 01/29/10
Posts: 1025
Loc: Louisiana, US
CAESAR estimates piping as line elements. As the pipe heats up, it will expand in diameter, but by default, CAESAR does not calculate this. To mimic this phenomenon, you would need to include (rigid) piping elements between the center of your pipe to the guide/pipe interfaces, and place a "stop" on each rigid element that acts as a "guide" for the main pipe.

Edited to add:

Note that this will not take credit for flexibility of the piping via ovalization. This you will have to calculate on your own and input as the spring constant for your two "stops." Without this flexibility, you will end up with monstrous loads and therefore monstrous amounts of friction.

Edited again to add:

Note that your guide might also be more flexible than the pipe itself, in which case, use that instead.


Edited by Michael_Fletcher (05/18/17 07:59 AM)

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