Tensile membrane on struts

My tensegrity demo works very well in kangaroo before I add this membrane fabric(16 mesh) on top of it, my goal is I want all these mesh following the movement of my tensegrity structure when I'm doing the simulation in kangaroo, can someone help me fix this definition? thank you

Siyu

Attachments:

Testing Version Peter.gh, 59 KB
5x5 Peter.3dm, 755 KB

Replies to This Discussion

Permalink Reply by Nik Willmore on December 1, 2015 at 9:00pm

Good work.

Just adding screen shots:

Permalink Reply by peter fotiadis on December 2, 2015 at 12:47am

Yikes + Yikes (+Yikes).

If you want to go from this (100% academic since it doesn't assure rigidity of the X: as shown it's just an "indication" of the topology" ):

to that:

well - as I replied to another similar thread (by the King of HopelessEfforts) - this requires a policy for achieving rigidity (and that's 100% impossible without having a fully adaptable system for the scope).

BTW: the system that I've provided (STEP214) to you IT DOESN'T work for non planar X members (that are the norm if you use surface for the XTruss) since the X linkage is ... er .. planar. It may require (depending on the size/loads etc etc) "simple" stuff like this:

Anyway I have about 10 different systems like the above. I'll try to translate for Rhino the simplest one and I'll mail to you.

AFTER fully understanding what the whole issue is (and studying the system) you should modify your definition in order to comply with the system (but THAT is not a task for a novice by any means).

BTW: deploying a T truss on a "tensile" membrane like surface is 120% BAD engineering approach (kinda like tuning a Harley Davidson: 1M miles off topic). A tensile membrane is the obvious choice and about 12 times more economical.

more soon

Permalink Reply by peter fotiadis on December 2, 2015 at 1:01am

Anyway ... before that translation (NOT that easy: CATIA talks to Rhino? what this actually means? he he), here's 2 3dPDF that MAY convince you ... er ... to change plans (never is too late, he he).

One is animated for an non planar large scale XTruss system and the other is a static demo for a (highly suggested - NOTE: use the available saved views on that one) far more simpler and economical double tetra thingy.

Moral: never is too late.

Attachments:

265_UAE_Tenseg_STR_B3-DoubleTetra-000.pdf, 1.8 MB
265_UAE_Tenseg_STR_B3-265_Master_XCombo-000.pdf, 1.1 MB

Permalink Reply by peter fotiadis on December 2, 2015 at 1:20am

BTW: By "double" tetra I mean this classic "pure" tensegrity truss. Of course this (as shown) is also academic since cables et all they don't meet at "star" points (see PDF above)... but this is 100 times more simple to do with GH than a proper XFrame variant.

BTW: Of course non of the above uses any "relaxation" via Kangaroo (utterly pointless to use it since this is not our scope at all).

Permalink Reply by SIYU GUO on December 2, 2015 at 1:38am

Last time when you sent me the "stp" file was works well in rhino, the only tiny issue was some block I can not explode. (Which is fine they are easy to remake )

Can I see the GH file you made for the first two pictures?

I'm curious about why the non-planar X module can work in GH

Permalink Reply by peter fotiadis on December 2, 2015 at 2:19am

1. GH file: well ... er ... hmm ... this is classified as internal (sorry about that) since ... er ... hmm ... is internal. Additionally it uses solely C# and not a single native component.

2. Non planar X: the reason that it doesn't work is that you need 4+++ members composing that #$#^$ X (instead of 2) AND some way to assure that they stay "rigidly" connected (that's the ultra hard part, "cheapo" as well in real-life): the whole XTruss T thingy assumes that the X is "solid" (as a whole).

3. STEP214 issues: Well CATIA doesn't really care about the rest of the world: is the master of all things known to man ... and therefor ... if something is not working > so what? (life sucks).

Permalink Reply by peter fotiadis on December 2, 2015 at 2:43am

BTW: Here's a rather simple demo (T on a cylinder) that outlines rather clearly the non planar situation: white ones are non planar since they "follow" the skin and blues are non planar since ... hmm ... follow the white ones.

Permalink Reply by peter fotiadis on December 2, 2015 at 3:05am

WHAT an idiot: blues ARE planar but their member angles ARE not the same.

please accept my apologies.

Permalink Reply by peter fotiadis on December 2, 2015 at 3:00am

BTW: here's a comparison (T on a tube) between 3 T modes (double tetra is far more easier to make in real-life not to mention some GH def of some sort):

and this is what happens when mixing Vodka with Tequila:

Permalink Reply by SIYU GUO on December 2, 2015 at 3:13am

double tetra is the first one or second one? third one looks like those tensegrity domes

Permalink Reply by peter fotiadis on December 2, 2015 at 6:51am

First is XTruss, second is double tetra and third is cubic (that actually requires tension "from outside" - more on that later). The fourth (Mobius) lunatic thingy is XTruss.

Permalink Reply by SIYU GUO on December 2, 2015 at 1:52am

haha, I feel like choosing the X module is actually a mistake at the begin,(because I didn't any new work come from this type).. I already spend a lot of money on the physical model of the X module which force me to keep going. I can never go this further without your help, thank you a lot peter.

For the new connection part you just sent, we need 8 struts for one "X" ?