Correctly Applying Member Releases in Timber Frame with Pinned-Pinned Connections in Robot Structural Analysis

[roderickobeja]

Hello everyone,

I'm currently analyzing and designing a timber frame building in Robot Structural Analysis, focusing primarily on obtaining accurate section sizes. Connection checks will be done in another environment.

The structure is fully timber, and we are assembling it by nailing or screwing members together, which results in pinned-pinned connections throughout (practically).

To accurately model the flexibility of the connections, I have tried to apply pinned-pinned releases to all members. However, when I apply these releases, I encounter a large number of errors and warnings that make it impossble to proceed.

Could anyone advise on the best approach to correctly apply releases in this situation without compromising the model's stability? Any tips or alternative methods would be highly appreciated.

What is the best practice around all this?

I've included the model for reference here, https://drive.google.com/file/d/1MN0LPhydr19fH2drved5LY4a2ldQa4cA/view?usp=sharing.

@Rafacascudo @Simau @Romanich @Stephane.kapetanovic and everyone...many thanks. 

[Stephane.kapetanovic]

hi @roderickobeja 

firstly, you can't articulate a bar on a support (especially the foot of the posts), then your simple connections (one end only) must not be rx but only ry-rz. for doubly articulated bars (origin end) you can use rx-ry-rz/ry-rz. there are isolated nodes, remove them. some bars (bollards) don't go as far as the crossbars, extend them. on the roof you have bar crossings but you haven't segmented one direction more than the other, you need to choose (or activate the option to generate nodes at intersections in the calculation options).

Then you need to check that, with your system, the nodes and bars cannot turn on themselves..

your panels don't seem to be correctly defined.

Regards

[Simau]

Hi @roderickobeja 

Hi @roderickobeja 

Changed calculation model to shell
Changed pinned-pinned release (fffxff at both ends)
Changed support to fixed (to block RX at lower columns end)
Merged bars 155 154

Merged columns over supports

Deleted a bar over the roof (#39)

Seismic analyse not yet fixed (to be continued).

[Simau · Accepted solution]

RC comumns without releases

Pinned support (as in your model)

Updated model attached

[roderickobeja]

Hello @Stephane.kapetanovic and @Simau,

I appreciate your timely responses. And sorry fo rteh troubles I have caused you. 

I now better understand what you suggest. And I also now better understand releases in combination with supports and stability depending on correct definitions. I also no realise that our intersections should likely have nodes. 

Suppose our panels (wall and floor) were to have pinned linear connections, and specific stifness (elastic) parameters:

1. how would we define these stiffness values if at all or is the panel definition for FEM sufficient in this case

I also think I need to better define nodes at intersections since we have some nailing at these points to connect elements. 

Again, many thanks.