How to design unrestrained beam with Robot

[Tmanzz]

Hello,

Need some guidance please.

Currently designing a steel grillage to support point loads.

The intention is for each beam to bear on 2 columns at the ends only.

So only the bottom flange will be fixed down at the supports.

What is the best way to do this with robot?

I suppose i want to design the beams as unrestrained.

Also, if I insert intermediate beams along the length of the main beam, can those be taken as laterally restraining the main beam?

Model attached.

If there is any video that explains this, can someone please direct this to me.

Thank you.

[Romanich]

Hi @Tmanzz,

https://youtu.be/GhP9An47EKw?list=PLY-ggSrSwbZqow_60fiqJwS69mg1nQMzk

[Krzysztof_Wasik]

Hi @Tmanzz 

Restrains for beam, considered while design, are defined in steel code check parameters assigned to that beam

Please refer to

How to limit lateral buckling length (LTB) for steel code verification, and take into account adjoin....

and

How to define correctly lateral buckling length for steel beam divided in several segments in Robot ...

I would also recommend the following tutorial (Steel design parameters are discussed from time 12.00)

Steel Design - How to build the model and assign design parameters

[Simau]

Hi @Tmanzz 

After correcting some geometric errors, the divided main bars were grouped together.

What are the 4 posts for, the concentrated loads being directly applied to the beams.

It would be wise to provide horizontal bracing.

[Tmanzz]

Hi Simau,

Thank you for that.

How did you group the divided main bars together?

The 4 posts are just there to show mast sections. They are not really required for the model.

I do have 4 members tying the 2 main beams together. 

The idea is to assemble on site so bracing the way you have shown it may be difficult, but I will have a look.

Pls send me  a copy of the corrected model.

Thanks 

[Simau]

@Tmanzz 

In your model nodes 3 6 9 12 are not aligned so you can't grouped them. To do that i used an API (attched)

Model attched

[Simau · Accepted solution]

You can use at least 4 diagonals (tension compression)

[Tmanzz]

Hi @Simau 

For the bracing, where would be the best place to install them? Top flange of beam?

[Simau]

@Tmanzz 

At the neutral axis of the beam