Wood-Armer Moments

SOFiSTiK Teddy
1

Hi All,

I understand that for the slab design, the BEMESS module uses the Baumann method (default) for the 2D elements design or the Layer method. I also understand that these two methods do not require the definition of global bending moments.
However, I was wondering if there is a way to calculate and visualise (in Wingraf) the design bending moments according to the Wood-Armer method.

Thanks.

2

Bemess:
CTRL DMOM 8000

Manual page 2-7 and 3-22

3

Thank you very much for the reply.

As far as I understand Sofistik is already coded to calculate the wood-armer bending, however, I’m still a novice with Teddy and I’m not sure how to properly set the user defined task.
Would you be able to give me some more basic guidance on how to set up the command in the task so that I can plot the wood-armer moments for top and bottom layers in the two directions?

Thanks.

4

Start of with one of the teddy examples.
You can find them under File->Examples in Teddy (not SSD):
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Take for instance:
bemess\english\special\design_of_external_forces.dat

Basically you will want to perform a reguler bemess calculation of reinforcements (use an ULS calculation, since convergence is usually better).
Then you add the line Ctrl Dmom 8000 somewhere in the bemess run. This will make bemess calculate and store the Wodd-Armer forces with a 8000 shift. E.g. the Wood-Armer forces of LC 5 will be stored in LC 8005.

In the example below I have added the line in the bemess ULS calculation.
design_of_external_forces.dat (3.6 KB)

5

Thanks sfr.

I actually intuitively added the line in the ULS design task and figured out myself how to output the wood-armer moments in Wingraf.
I’ll try the example as well.

Interestingly, if run the Maxima first, also enveloped wood-armer moments are calculated.

I’ll do some tests but I think I’m happy with the results.

Thanks again for your help.

6

Sorry for resurrecting a old topic, but I’m struggling with getting a visual of the Wood & Armer forces.

Running the design_of_external_forces.dat file you’ve uploaded, I expected to be able to find Wood & Armer forces in Wingraf>Results>Quadrilateral Elements>Forces (As per the bemess manual 2.2.7(8) [page 2-7]) for LC 8001 and 8002? However, I see no such option? Also, the wingraf manual doesn’t mention Wood & Armer at all.

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7

Hi MRCH,

it could be that the DMOM command did not run properly.
Try to post your text input so that we can check.

8

Hi FNatale

I’ve simply run the design_of_external_forces.dat file which sfr uploaded previously. Haven’t made any changes.

9

Hi MRCH,

The Wood & Armer forces overwrite the results of m-xx, m-yy, n-xx and n-yy for the appropriate loadcases (typically LC 8XXX).

For example if you want to see mxx according to Wood & Armer then you have to select quad force m-xx and loadcase 8001.

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You can see that in LC 8001 mxx = mxx in LC1 +/- |mxy| in LC1:

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With best regards,
Martin

2 Likes
10

Ahh I see. Thank you very much!