Structural rib/beam with holes

Hi guys,

I am an absolute Grasshopper noob, but hey, no pain no gain, so I'm trying to work it out. Most likely, I'm making a begginer mistake or my logic is completely wrong.

I have been working on a rib structure for a design studio project. I have some sets of planar curves, drawn in Rhino from interpolated points. I'd like to create the ribs along these lines, with a depth of 1/x of the length of each curve. Then, I want to creat two struts that branch from the rib to hold a cable/wire. Finally, I want to array some holes along the central axis of the rib.

So, aiming to this, I started working on Grasshopper with a random Rhino curve. You'll find the .gh file attached, but I will try to sum up my logic:

Original Rhino curve 1, with a L length
Setting curve 1 L/x off, curve 2
Creating an axis curve, setting curve 1 L/2x
Creating arcs 1 and 2 at both ends of axis curve, r= L/2x
Setting axis curve L/y off, curve 3
Dividing axis curve and curve 3 in 3 segments
Creating lines between division points, strut axis
Creating circle at the start of strut axis and arc 3 at the end
Creating tangen lines between circle and arc 3
Creating strut (as edge surface) with tangent lines, arc 3 and curve 2
Creating a circle with a L/Ax radius (smaller than L/2x) on the rib plane
Arraying the circle along axis curve
Joining curve 1, curve 2, arc 1 arc 2, rib contour
Boundary surface with rib contour and circles, to create rib with holes

Ii kind of worked out with the sample curve... I was so happy.. (IMG 1). But then I tried with a simple set of curves and it totally failed to create the rib (IMG 2). It looks like my approach was wrong... I attach my Grasshopper file, I've tried clarify it as much as I can.

The geometry resulting from my first attempt (IMG 1) is actually what I'm looking for, any advice?

Thank you very much for your attention and your time.

Attachments:

Cuadernas 02.gh, 27 KB
IMG 1-Baked rib - original curve selected.JPG, 69 KB
IMG 2.JPG, 278 KB

Replies to This Discussion

Permalink Reply by Carlos Chamorro on December 12, 2016 at 1:09pm

Update!

I've kept on working on my GH file and I think I've been able to fix most of my problems:

The issue with the rotated arcs at the ends of the ribs was due to a wrong definition of the plane which was used as an input for those arcs. I've changed it to a 3-points-defined plane, making sure the X-axis is perpendicular to the curve tangent and I think it works for any curve.
After fixing the arcs at the ends, the substraction of the circles works OK
I've changed the definition of the struts to be a surface, instead of a psurf. By doing so, I can join the rib and the struts to bake the together, making the rhino model simpler and easier to manage

So, the only problem remaining is this one: I can only set one curve at the time as initial curve. If I choose "set multiple curves", the geometry collapses. I could still do my project setting one curve, baking the geometry and then choosing the next, but if anyone has any idea on how to allow for multiple curves to be set, I'd be very glad to hear about it.

You'll find the modified file attached. IMG 3 shows what happens when multiple curves are set.

Thanks!

Attachments: