Bars intersection without node, transfer load or not?

[Anonymous]

Hello everyone,

Here is my new daily question for you guys.

When do members that intersect, without having created a node, transfer their load to one another?

Two examples to explain what I mean:

1. Three identical frames. Load on first frame. First and third frames connected together.

The members connecting the first and third frames visually intersect the second frame, but I don't want them to really intersect and transfer the load. So I didn't create a node at the intersection, and I didn't use the option "intersect".
From the results, I can see that it's doing what I want, the second frame doesn't get any load.
I can use this with brace cables for instance.     

2. Three posts. Load on first and/or third post. First and third posts connected together.

I still didn't create a node at the intersection between the second post and the bar connecting the other ones, but this time the results show that the second post is getting some load, which is not necessarily something I want.

[Rafacascudo]

Just neglect the central bar on structure generation . See the identical frames below

[Anonymous · Accepted solution]

This was just an example, I can't really neglect bars because in reality my models are more complex.  

However unchecking "Generate nodes at intersection of vert/horiz bars" seems to prevent the load transfer.
So just to be sure, if I uncheck that, the load can go from one bar to another ONLY if I created a node myself where they intersect. Is that correct?
And in that case, end nodes would do? Like if I put a bar's end node in the middle of another bar, WITHOUT clicking "intersect" to cut the bar in two, there is still a load transfer, right?

[Rafacascudo]

Can´t see any transfer of load to the center columm in your picture.

It is working as intended . I even get a "separated structure" warning !!!

But if you want to neglect some intersections ,but no all , you can divide the bar and neglect only at some intersections

[Anonymous]

Thank you Rafael. I edited my last message just before your replied because it did work. 
I just added a couple of questions to be sure that it does what I think it does, if you want to share your knowledge one more time 🙂

[Rafacascudo · Accepted solution]

"So just to be sure, if I uncheck that, the load can go from one bar to another ONLY if I created a node myself where they intersect. Is that correct?"

Yes!!!

"And in that case, end nodes would do? Like if I put a bar's end node in the middle of another bar, WITHOUT clicking "intersect" to cut the bar in two, there is still a load transfer, right?"

Yes!!!

[Anonymous]

Great, I like that. Thank you Rafael!

So, I thought I was done with this question, but actually... I came across this on a new project:

That made me laugh, and then I got a bit scared, but as I zoomed in I realized that the diagonal bars (brace cables) don't exactly go through the node where the horizontal and vertical bars intersect.
But purely out of curiosity, if the diagonals did cross the intersection, while the node I created is only for the horizontal and vertical bars, what should be done to be sure that the diagonals don't get a load from those bars? 

[Rafacascudo]

Maybe something like this.

Original Structure to the left and " corrected" to the right . Axial force diagrams. Diagonals on original structure get part of the 10kN force . On the "corrected" model  ,diagonals don´t get any force

[Anonymous]

Nice idea.
I'll definitely always try to avoid making bracing go through nodes, but if I can't, I'll try your method.
Thank you very much. Your help is always greatly appreciated.