Moving load in combinations

[vuk.vukanic]

Results form moving load in combinations are not calculated.

In the attached picture you can see that the combinations are generated, but the resulting reactions are the same regardless wher the force is located.

link to sample file:

https://www.dropbox.com/s/5ej5qed0a7ldmm0/Structure.rtd?dl=0

What am I doing wrong?

[Artur.Kosakowski · Accepted solution]

Hi @vuk.vukanic

Please check the definitions of the combinations:

 

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[vuk.vukanic]

Thx this was helpful, but still I have no clue how it works...

So even if the name is correct there is a chance that the definitions is no good?

How come?

Looks like to create combinations with moving loads first one needs to run the calculstion without the comb. and only after reset the combination rules and generate them.

Is this correct?

[Artur.Kosakowski · Accepted solution]

Hi @vuk.vukanic

If you want to create manual combinations generate the positions of the vehicle (run model generation) first.

If one or more of these posts answered your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Anonymous]

Hi. Sorry, i read every thread of this topic in the forums but i still can´t see it clear.

Here´s a simple case: a single spam beam with a moving load (let´s call it M), plus a uniform permanent load (D). Now let´s say that the moving load generates a 10 kNm moment in the center of the spam, and the permanent load generates 5 kNm in the same point. By simple effect overlay, total moment is 10 + 5 = 15 kNm.

Now, if i create a manual combination un RS which includes moving load and permanent load, i don´t get a moment diagram at all. I have to ask for the diagrams of both load cases separately.

In resume my question would be: is there a way to get envelope diagrams for moving load case including static load cases?.

And last but not least, when creating the manual combination which moving load should i use?: the one i created or the automatico (+) and (-) that RS creates?.

Thanks for your help!!!.

[Artur.Kosakowski]

Hi @Anonymous 

Could zip and you attach your model?

And last but not least, when creating the manual combination which moving load should i use?: the one i created or the automatico (+) and (-) that RS creates?.

The (+) and (-) are just the filters to see the top and bottom envelopes of the results from every positions of a vehicle.

[Anonymous]

Hi Artur, i didn´t attach the model because it was an imaginary example.

I know that creating a different case from each component of a moving load generates single static loads according to the discretization i seted. Then i can envelope the diagramas for all those static loads and the rest of the static cases in the model, but that is something i can do manually without having to configure and apply a Moving Load. The whole point seems a bit silly to me, i would suppose that RS can automatically overlap (and envelope) the two fenomenums: moving loads and static loads, and build a unique diagram.

¿Is my question clear?, maybe i´m not self expressing correctly.

[Artur.Kosakowski]

Hi @Anonymous 

My assumption is that you ae looking at the wrong combination number. You need to find the automatically created one with the name being the same as you used for the combination you defined (4 COMB1 and 8  COMB1 in the example below):

 

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[Anonymous]

Artur, i´m not getting the same behaviour in my model (see attached). When you ask for diagrams of the combinations it don´t show the envelopes as in your example. Also, when running the model the combination with the same number is not automatically created.

Hope you can understand me.

Thanks,

Leonardo.