combined contact thermomechanical analysis
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combined contact thermomechanical analysis
Hello,
the controlling-engineer got me...
I must calculate a tube connection with flanges and prestressed bolts.
(steel S235, all bolts M20 10.9, prestressing 160 kN each bolt)
Running a contact analysis without prestressing works fine.
When "cooling" the bolt (-180 K) to simulate prestressing, I get strange results.
Some questions:
When running the thermomechanical analysis including the contact definition,
it seems ccx does not detect the contact option (but it is written in the inp).
For contact analysis gmsh with 1.order elements is ok. Right?
But for stress analysis I need 2.order elements...
What value must I use for the contact-stiffness: stiffness=E-steel?
In ccx-manual v14 chapter 7.93 there is a pretension option, how can I use this?
Thomas
the controlling-engineer got me...
I must calculate a tube connection with flanges and prestressed bolts.
(steel S235, all bolts M20 10.9, prestressing 160 kN each bolt)
Running a contact analysis without prestressing works fine.
When "cooling" the bolt (-180 K) to simulate prestressing, I get strange results.
Some questions:
When running the thermomechanical analysis including the contact definition,
it seems ccx does not detect the contact option (but it is written in the inp).
For contact analysis gmsh with 1.order elements is ok. Right?
But for stress analysis I need 2.order elements...
What value must I use for the contact-stiffness: stiffness=E-steel?
In ccx-manual v14 chapter 7.93 there is a pretension option, how can I use this?
Thomas
Re: combined contact thermomechanical analysis
A screw joint with pretension is shown in this example:
https://forum.freecadweb.org/viewtopic. ... on#p266772
It works without *PRETENSION card
https://forum.freecadweb.org/viewtopic. ... on#p266772
It works without *PRETENSION card
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Re: combined contact thermomechanical analysis
Sorry, I couldnt remember the postUR_ wrote: ↑Thu May 02, 2019 4:35 pm A screw joint with pretension is shown in this example:
https://forum.freecadweb.org/viewtopic. ... on#p266772
It works without *PRETENSION card
To "shorten" the bolt works fine. Prestressing a M20 bolt with 160 kN
gives approx 460 MPa sigma-z in the bolt. The deflection/stress in
the flange-plate is no problem ==> controlling-engineer will be happy.
Re: combined contact thermomechanical analysis
Cool picture Thomas. What graphical software is this?thschrader wrote: ↑Tue May 07, 2019 12:17 pmSorry, I couldnt remember the postUR_ wrote: ↑Thu May 02, 2019 4:35 pm A screw joint with pretension is shown in this example:
https://forum.freecadweb.org/viewtopic. ... on#p266772
It works without *PRETENSION card
To "shorten" the bolt works fine. Prestressing a M20 bolt with 160 kN
gives approx 460 MPa sigma-z in the bolt. The deflection/stress in
the flange-plate is no problem ==> controlling-engineer will be happy.
Flanschsegment mit Fv und Last.JPG
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Re: combined contact thermomechanical analysis
good to have the controlling engineer, you would not have posted this if he would not have claimed ...
Re: combined contact thermomechanical analysis
How did you get the vertical distance scale overlays?
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