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Wrong graphical presentation of surface uniform planar load on contour

23 REPLIES 23
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Message 1 of 24
gliga
1541 Views, 23 Replies

Wrong graphical presentation of surface uniform planar load on contour

Dear Developer,

something is wrong with GRAPHICAL PRESENTATION ONLY for surface uniform planar  load (planar load 3p) on contour.

According to reaction (applied force) summary loads are OK but graphical presentation make work to be hard for control.

Sincerely,

Gliga

23 REPLIES 23
Message 2 of 24
Artur.Kosakowski
in reply to: gliga

Run calculations and display

forces generated automatically5.PNG

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 3 of 24
gliga
in reply to: Artur.Kosakowski

Dear Arthur,

Yes I know (because of that I wrote that only graphical presentation is wrong).

But, we usually use surface loads screen captures for presentation of load input (I believe that other user doing the same).

Correct this, do not be lasy 🙂 At least put this in wish list.

This is mistake anyway, there is no difference in graphical presentations between "global" and "local" loads for "surface planar load on contour".

Sincerely,

Gliga

Message 4 of 24
Artur.Kosakowski
in reply to: gliga

This is as designed. The moment you apply such load its 'real' direction is unknown until the model generation has been launched. Then you should look at the 'result' of this process which is display forces generated automatically instead of loads (and this is what you should print). This is why this option is available in the Display dialog. The same applies e.g. for some types of a vehicle used for moving load.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 5 of 24
gliga
in reply to: Artur.Kosakowski

> Re: Wrong graphical presentation of surface uniform planar load on contour
 
> 02-06-2014 05:25 AM in reply to: gliga

> This is as designed. The moment you apply such load its 'real' direction is unknown until the model generation has been launched. 

 

I realy can not accept that this is with intention in design of software. I repet that this issue work correct (I have already checked) in structural analisys - we are talking just about graphical presentation in load definition phase.

In this phase is important that we have help from graphical presentation (whole interface is graphically based) - we lost a lot of time because of this issue until we realized what is going on. 

 

To eleminate possibility that I have not been clear enough in very first message look. please, screencaptures and comments in attachment.

 

On page 1-5 and 7 you can see that that for other similar situation graphical presentation (in sence I am talking about) is correct, and this is proof that correct graphical presentation is possible too, as well as that software is not designed to "wait" for calculation during preprocessing of load data.

 

On pages 6 an 8 are examples we have realized that some mistake in program code is present (maby is present in other surface load option, bit we have not investigate all options - so, this is just example of issue). It look like graphical presentation ALWAY take GLOBAL coord. sysrem, even in case where LOCAL is applied. This is not present in all surface load situatuons - on pages 2, 4 are analog situation in which graphical presenation are correct.

 

So, this could not be global defect or design intention - could be small omission in program code.

 

By the way, surface load on claddings is EXCELANT and very usefull idea ONLY if things that have to be checked are value, direction, contour and load distribution regions ONLY. This is usefull for graphical part of INPUT DATA for technical documentation because is clear and "load value" switch can be "on" (small number of labels are present). Forces generated automatically is usefull just for investigation of particulary element - we have not reached good way to use this option in INPUT  DATA - specially in case we want load value labels to be visible.

 

Sincerely,

 

Gliga

 

Message 6 of 24
Artur.Kosakowski
in reply to: gliga

I do understand you comments but you have to consider that the application of this load type is not limited to situations when you define your contour on a panel you want to apply the load to. I'm attaching the example of more general way of using it. Please notice that in addition you may also apply some geometrical limits to reduce the load's 'range of application' comparing the the selected panels or their areas. To have this information displayed correctly you need to run model generation (no need to calculate the model) and display forces generated automatically.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 7 of 24
PABLO.SANCHEzZTKJ5
in reply to: gliga

Dear all,

 

Has anything about this issue been updated in version 2023 since 2014?

 

I'm trying to apply the @Artur.Kosakowski method in a cladding case, but it seems don't works. Is it only for panels? not for claddings?

 

Thanks in advance.

Message 8 of 24
PABLO.SANCHEzZTKJ5
in reply to: gliga

Hi,

 

Please, some feedback about this?

The load is well distribuited as you can see in next pic

PABLOSANCHEzZTKJ5_0-1667497077497.png

But the orientation of the superficial load is not perpendicular to the cladding, the superficial load is shown as global direction in Z, instead of local.

 

Thanks in advance.

Message 9 of 24
okapawal
in reply to: gliga

Hi @PABLO.SANCHEzZTKJ5 

Please, pay attention if you apply Global Z direction load to the cladding

okapawal_1-1667562711071.png

Or  you want to apply surface load as local Z (perpendicular) ?

okapawal_2-1667562791927.png

 

 

 



Waldemar Okapa

Sr Product Owner
Message 10 of 24

Thanks @okapawal,

 

I'm using "Uniform planar load on contour" by 4 points, and "local" direction z (perpendicular to the cladding).

PABLOSANCHEzZTKJ5_0-1667583616351.png

 

As you can see in my previous pict, the superficial load is "loc" but in the drawing the load is showed as z global.

 

If i use a load like yours (in the entire cladding), the drawing is OK, perpendicular to the cladding.

But i need to define a contour, the load is not in the entire cladding.

 

Thanks a lot.

Message 11 of 24

Hi @PABLO.SANCHEzZTKJ5 

Load defined on contour is not applied to the object until model will be generated.

After model generation loads generated automatically presents loads which are applied to the structure.

 

In case of contour load, defined on cladding (in local system), loads generated automatically are applied to bars. Loads on bars presents loads, actually applied to the structure (while contour load direction remains in global direction).

Loads are distributed correctly. You can check reactions if you want to be sure.

To avoid presentation of contour load with incorrect diredction, switch off 

Load symbols and  leave Loads generated automatically in Display settings.

 

Krzysztof_Wasik_0-1667598159795.png

For more information refer to this article.

 



Krzysztof Wasik
Message 12 of 24
PABLO.SANCHEzZTKJ5
in reply to: gliga

Thanks @Krzysztof_Wasik for your patience,

The thing is i know the loads are distributed correctly, i checked it from the beginning, and the reactions are OK. But the representation of surfice load always is in global z, althought I generate the model and then active "loads generated automatically". That is, I never can see the surface load in local axis of the cladding.

In next pic you can see the transmission load to the beams is OK, there are components in global z & y. But the model with "load symbols" activated (left) shows the surface load in wrong z global direction, and with "load symbols" desactivated (right), in this case the surface load is not showed. 

PABLOSANCHEzZTKJ5_0-1667728042143.png

 

One adittional question, I'm generating the model & loads by API, It would be the same thing to introduce the surface loads in global axis but afected by "cos" and "sin" to convert them internaly in local. The point is this way the load are correctly showed, and i need it like this in order to show them in my Report.

Message 13 of 24

Hi @PABLO.SANCHEzZTKJ5 

It is not possible 9n case of contour load definition for claddings (1) . It is possible now only for panels (2)

Krzysztof_Wasik_0-1667746070340.png

 

 

 



Krzysztof Wasik
Message 14 of 24
PABLO.SANCHEzZTKJ5
in reply to: gliga

Thanks @Krzysztof_Wasik,

 

I was afraid that it was a problem because of the claddings, anyway I don't understand why this process of representation cannot be improved. Specially when if the load is applied in global axes by 2 components the contour load is showed correctly, as you can see:

- left,  1KN in global for 20 degrees plane, componens Py1=sin 20=0.342 kN, Pz1=-cos 20=-0.94

- right, 1KN in local cladding at 20 degrees plane

 

PABLOSANCHEzZTKJ5_1-1667814900299.png

 

Anyway, thanks for your help.

 

 

Message 15 of 24

Hi @PABLO.SANCHEzZTKJ5 

This is the way contour load works. This tool allow to load objects not only in defined contour plane (contour can be projected on objects in other planes).

 

Contour load (defined in local system of coordinates) does not know local member axes direction (to which load should be applied) before model generation. After model generation load is represented as forces generated automatically.

 

Example

Contour load A is applied to 3 panels with different local z directions. Before model generation load is not presented on panels 2 and 3. Load is presented only on defined contour.

 

Krzysztof_Wasik_0-1667817201748.png

after model generation forces generated automatically presented (real forces direction - example for shell model)

Krzysztof_Wasik_1-1667817307459.png

 

Defined contour load symbol has no physical meaning before loads will be created while model generation.

 

 

 

 

Example



Krzysztof Wasik
Message 16 of 24
PABLO.SANCHEzZTKJ5
in reply to: gliga

Hi @Krzysztof_Wasik 

Thanks, yes I know how it works, I was reading numerous posts about this.

The thing is i'm working with claddings, and as you said in the 13th mesagge,  "It is not possible 9n case of contour load definition for claddings (1)".

 

My problem is I need claddings and i need load in contours, because the superficial load is not applied on the entire cladding.

 

Anyway, Thank you very much.

Message 17 of 24

hi @PABLO.SANCHEzZTKJ5 

You must cut the claddings or create openings to define the areas to be uniformly loaded as many times as necessary.

Best regards

Message 18 of 24
DonBAE
in reply to: gliga

@PABLO.SANCHEzZTKJ5 "..because the superficial load is not applied on the entire cladding."

 

I think it is important that you understand partially loading cladding will not give proper load distribution, the cladding model adopted in Robot only gives accurate results for full uniform distributed loads. One-Way cladding distributes 100% of the load on each side of the cladding midline to the edge members (although this behavior also is not consistent), the cladding does not distribute load following simple span beam mechanics.

 

DonBAE_0-1667857144874.png

 

Message 19 of 24
andi4G4Z4
in reply to: okapawal

Hi @okapawal 

 

How did you represented "Force generated automatically" UDL in your screenshot with "Blue" coloured lines?

 

Is it possible to alter line colour in RSA 2023?

Message 20 of 24

hi @andi4G4Z4 

<Tools> <Preferences>

Stephanekapetanovic_0-1676368499035.png

Stephanekapetanovic_1-1676368523819.png

Best regards

 

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