Request for help meshing and and analysing a part {Solved}

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Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

thschrader wrote: Sun Sep 12, 2021 4:05 pm Hinges in beams:
https://www.youtube.com/watch?v=wzo_YxOBshw
I see - now that I know what hinges are I have a clearer idea of what you are thinking of Thomas. Let’s see what I can come up with!

@cad123 - this thread is growing arms and legs :D

@bernd - great.
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Re: Request for help meshing and and analysing a part

Post by thschrader »

bernd wrote: Mon Sep 13, 2021 8:41 pm updated BOLTS ...
For me it works, thanks.
Found this (rename extension to xls):
AISC141viewer_xls.txt
(647 KiB) Downloaded 521 times
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Re: Request for help meshing and and analysing a part

Post by thschrader »

cad1234 wrote: Mon Sep 13, 2021 11:20 am ... the max element force is now in the lower chord and rises up to -103 KN, ...
I get 102 kN with pcae, delta T= +40 degrees C alone, no external loads.
This is a fine example of how important it is to model the fixings correct.
And to built them in this way!
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

thschrader wrote: Tue Sep 14, 2021 6:24 am I get 102 kN with pcae, delta T= +40 degrees C alone, no external loads.
This is a fine example of how important it is to model the fixings correct.
And to built them in this way!
Thanks for feedback. I understand..
better to make the “thermal system check” first without external loads, to see more closely where the forces come from.

Mastan (T=+40) C alone, no external loads: 98.8 kN -> 99 kN, fits well with pcae 102 kN I think.
Used Thermal Coef. (alpha) in our MASTAN model : 12e-06 ...hope, this was correct..

Sorry Laurie, to be a bit beside the track..my mistake !! Next time I will open a new thread, if it does not fit well!
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

cad1234 wrote: Tue Sep 14, 2021 7:58 am
thschrader wrote: Tue Sep 14, 2021 6:24 am I get 102 kN with pcae, delta T= +40 degrees C alone, no external loads.
This is a fine example of how important it is to model the fixings correct.
And to built them in this way!
Sorry Laurie, to be a bit beside the track..my mistake !! Next time I will open a new thread, if it does not fit well!
Cad 1234 . No apology needed - if anything I should apologise to you for my peculiar sense of humour. I am delighted with the interest amongst the engineering community this thread has generated. Please continue to do all the checks and balances you want and post your results on this thread. It would be a shame to interrupt the flow now after we have come this far.

The contribution of you guys could result in something special for FreeCAD. I am enjoying it very much.

I been very busy with mundane tasks this week like helping with the housework and shopping so I haven’t been able to get very far with my parametric task but I think I have a good concept of what it is going to look lie.

Here is a question for you guys - why did the frame “bend upwards”? :)
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Re: Request for help meshing and and analysing a part

Post by bernd »

thschrader wrote: Tue Sep 14, 2021 5:53 am
bernd wrote: Mon Sep 13, 2021 8:41 pm updated BOLTS ...
For me it works, thanks.
Found this (rename extension to xls):
AISC141viewer_xls.txt
cool ... have you seen the units ... :o
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Re: Request for help meshing and and analysing a part

Post by thschrader »

bernd wrote: Tue Sep 14, 2021 12:32 pm
thschrader wrote: Tue Sep 14, 2021 5:53 am
bernd wrote: Mon Sep 13, 2021 8:41 pm updated BOLTS ...
For me it works, thanks.
Found this (rename extension to xls):
AISC141viewer_xls.txt
cool ... have you seen the units ... :o
Yes, imperial units ;)
I used the viewer when running the Mastan2 tutorials from Prof. Ziemian, all imperial:
https://www.youtube.com/user/ronziemian/videos
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Re: Request for help meshing and and analysing a part

Post by thschrader »

Laurie Hartley wrote: Tue Sep 14, 2021 11:59 am Here is a question for you guys - why did the frame “bend upwards”? :)
Imagine the spaceframe as a solid brick. The upper side can stretch...
spaceframe_thermomech.FCStd
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brick.JPG
brick.JPG (67.54 KiB) Viewed 26290 times
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

Everything is fine Laurie, like this thread as much as you do.
Learned so much from it and still learning...
Let`s continue this great FC-FEM party with great people..
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

I have been trying to develop a parametric model of this frame as discussed above. I have progressed quite well with the spreadsheet but I am struggling to get the model sorted out.

I have been trying to create datum planes on each face of the model offset from the face by 2.5mm (Hinge Offset in spreadsheet) from each of the faces. (If the offset needs increasing or decreasing this can be done from the spreadsheet).

I then want to sketch a circle on the relevant faces from which I can pad a chord, strut, or plan brace, based on the data taken from the spreadsheet which will provide the pad length.

I then want to create hinges between each component and their corresponding faces.

If I can produce each of these components and features I am hoping I can then construct the frame using the array tools in the draft workbench.

After watching numerous tutorials and many attempts I can get the “node” body to increase or decrease in size but I can’t get the datum planes to move in unison or I can’t offset them because they are stuck to the faces, or I can’t offset the sketches from the datum planes.

First question - will this approach work. If no it’s back to the drawing board ;). If yes:-

Second question - can anyone offer help with the datum plane conundrum please.
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