Purlins on curved beams

[Anonymous]

This is first attempt so far to draw purlins on curved beam and need some help

ref plane cant be curved so how can we set planes for purlins to follow curved path ?

[ToanDN]

Curved grids?  Reference lines?

[Anonymous]

No Luck so Far

In my section view

no option for curved grids, neither I can pick line to draw curved grids

In my Work plane pallet on ribbon no option of drawing ref lines

[Anonymous]

Used face base family. It worked

Still not sure how I can use grids and ref lines to achieve this

Any input will greatly appreciated. Always good to know more than one way to achieve the desired results 

[chrisplyler]

I've never tried this...but I'm curious what happens when you use the Beam System tool and select the curved beams as the supports?

[ToanDN]

@Anonymous

I realized now the beams are curved on elevation, not plan, so obviously curved grid lines don't work. Sorry.

[ToanDN · Accepted solution]

See the screencast.  Is it what you want?

2017.PNG

[johk02]

Hi,

That loks good - but how do you make sure the mambers are perpendicular to the curved surface - like purlins have to be?

Thanks

JH

[ToanDN]

Create one perpendicular to the curve and do a radial array.  Or draw radiating rays to align the purlins with.

[Alfredo_Medina]

If the curve is another kind of curve, not just one single arc with radius, then you can't use array. You need to use a divided path and a repetition. Something similar to this roof by Antoni Gaudi, built more than a hundred ago in Barcelona, Spain:

2018-03-11_9-59-07.jpg

If you want to read the story, follow this link to my blog: 

http://planta1.com/blog/antoni-gaudi-s-ingenious-curves-made-a-temporary-building-last-more-than-100...

[ToanDN]

Using adaptive families would be the easiest way if OP didn't need to stick with the Structural frame.  Hence the workaround. 

p/s: By the way, the picture in your post shows all purlins perpendicular to the floor, not the curvature of the roof.

[Alfredo_Medina]

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@ToanDN wrote:

Using adaptive families would be the easiest way if OP didn't need to stick with the Structural frame.  Hence the workaround. 

p/s: By the way, the picture in your post shows all purlins perpendicular to the floor, not the curvature of the roof.

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Yes, in that case the purlins were perpendicular to the top of the roof. That's how I saw them in the photographs of the building:

2018-03-11_15-33-41.jpg

[ToanDN]

Oh I realized we were talking about different things.  You were talking about the layout of the purlins and I was talking about the plumbness of those.

[johk02]

Hi,

Thanks for the replies.

To clarify my question: I meant the purlins to be perpendicular to the roof sheeting

JH

[ToanDN]

Yes that is also what my understanding.  If you don't have to use structural members then an adaptive family (not set to always vertical) can get what you want.  If you have to use structural members then you have to manually rotate them around their axis if the curvature is not an arc.