topic Re: Member noding in Robot Structural Analysis Forum

Member noding

Anonymous — Tue, 21 May 2019 05:04:41 GMT

Hi there,

I was wondering if it makes any difference if a beam is modelled continuous with intermediate beams intersecting at nodes. In my case, beam 212 is continuous with beams 69 and 26 intersecting at midspan. In reality, beam 212 will be continuous i.e. a primary beam with 26 being the incoming secondary beam.

Is this the right way to model it or should I be splitting beam 212 into 2 beams with no releases? I have tested it both ways and the results are identical however, I wanted to make sure that there was nothing happening in the background that I should be aware of as some softwares require members to be split at all nodes.

Thanks!

Re: Member noding

Krzysztof_Wasik — Tue, 21 May 2019 09:27:50 GMT

Hi @Anonymous

In your case there will be no difference if you consider static analysis results only

If side beams are connected with main beam in node lying on continuous element, Robot divides main beam internally, and forces are transferred properly. Internal division is always done when node is defined in intersection point.

Differences can be in design modules

If you are going to design main beam (steel module) deflection, buckling length, lateral buckling will be defined in respect to its total length.

In Analysis> Analysis type > Structure model tab you can find options for intersected bars (when there is no node in intersection point defined - 2 continuous beam s intersects each other)

There are 3 options

- automatic force transfer for bars parallel to global axis (default)

- automatic force transfer for bars defined in arbitrary direction - diagonal (can be check on)

- manual exclusion selected bars (by numbers selection) from forces transfer when they intersect with other bars (neglected in generation)

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.

Re: Member noding

Anonymous — Thu, 23 May 2019 12:34:33 GMT

Thanks @Krzysztof_Wasik that's very helpful.