Need help about using Kangaroo for form finding

Dear all the experts in Kangaroo,

I newly learned to use Kangaroo to do form finding.

However, the tutorial is not clear and I met an error in my practice.

The .3dm and .gh documents are attached. Can anyone help me to solve this error?

Much thanks,

Xue Zhengyu

Attachments:

error document.gh, 19 KB
error.3dm, 73 KB

Replies to This Discussion

Permalink Reply by Zhengyu Xue on November 25, 2015 at 9:39am

Dear Lord SardineLand,

I started with Bend V1A.gh and tried to use Visual Basic to build the component with C#....... Everything seems well but the result is a gh file containing one component of no use...Empty..

To translate C# code in gh to VS I need to redefine the type of the strings .. Need some instructions here...

#I never expect you to do give me a turn key solution.. I need to fight my own way through.. But, it is beyond perfect that you are here . I even feel that you are one of my graduation committee..:)

Best,

Duke Illy with countless bottles of Champagne.

Attachments:

MyProject2.zip, 38 KB

Permalink Reply by peter fotiadis on November 25, 2015 at 11:13am

Dear King of Hopelessness

I confess that I can't follow you:

1. Did I explicitly said to STOP doing the relaxation thingy and START doing some serious thingy? (the $%$% truss, that is).

2. Since you have V1B why bother with V1A?

3. What has VS to do with such simple scripts? Truth is that the build in C# editor is a bit of a crap ... but IF you count all the beans (and having in mind a myriad of mini scripts that a true man does day in day out) I would suggest to take the plunge and ... er ...suffer. Now ... if that was some serious project with "some" lines and this and that ... then yes ... VS could be a logical choice.

See this? well ... it's not you, he he (but victory and world domination are on sight; it's just a matter of months [or years, or decades or centuries]).

4. Who invited VB to the party? Not me anyway.

5. What means "and tried to use Visual Basic to build the component with C#" ?? > BUT all the stuff attached are written in C# (intro Level but long is the path - and hilly). But wait a minute: let me check again, he he (blame advancing Alzheimer).

6. Are you under the influence of spirits? (literally). If so ... I want some.

best, The Merciless SardineLord

Permalink Reply by Zhengyu Xue on November 25, 2015 at 11:27am

Dear SardineLand ?like Champagne,

1.Sorry about the typo "Visual Basic"..I mean , I use Visual Studio to build the component and make it part of a plug-in in GH..

2.V1A is better for me to start my C# learning compared to the relatively more complex V1B.... I first absorb V1A then go to V1B.. Sorry I am numb to computational language.. But luckily I can understand your code, at least code in V1A.

3.I like your high-spirit rabbit...Mushroom..I am full of energy. So are you..But remember to have enough rest.

Best,

Eros never go Seppuku

Permalink Reply by peter fotiadis on November 25, 2015 at 1:45pm

Be prepared > tomorrow I'll post something for you (the promised multi variable system for a T truss > ultra complex + ultra expensive > ideal for Kings and men who know no fear).

Permalink Reply by peter fotiadis on November 28, 2015 at 10:03am

Dear King of Intractability,

I do hope that you've abandoned by now ALL your form finding explorations and you are in the path for greatness (+ some optional tears): the tensegrity truss itself.

Here's a T XFrame type system (but for large scale AEC stuff) that can adapt pretty much to any surface (at the cost of relatively small torsional forces hence the beefy M25/250 used to connect the adapters).

Now ... can you tell me what parts of it you want to send to FEA? he ,he (meaning the obvious: forget FEA and all that freaky stuff: too complex - for the moment > stick to things that are achievable).

Original:

Translated to Rhino (all intelligence lost + all assembly/component structure lost > only geometry survived):

Moral: another amoral case, what else?

he, he

Permalink Reply by Zhengyu Xue on November 30, 2015 at 5:27am

Dear Lord of amazing connections,

oke, form finding has been thrown to the corner at this moment..

I have three points:

1) first is an elaboration of my idea about optimisation which can answer your question above.

All I do now is to realize the optimisation process in Grasshopper by clicking one button. As I described in the pdf file ,I will make the parametric model in GH, define loads and prestress, nodes, elements, material, property, section size in GH[Write] and send these information to FEA. Make a component "analyse in FEA". Then read the analysis result like node displacement(stiffness check), normal force in each element(unit check), total self weight(fitness) from FEA to GH[Read]. ----------------------- Apart from these, I need C# to make a loop for my optimisation procedure and for unit check[Later steps].

2) About programming.

Last week I tried to make some components in GH about math and list. However, I am stuck in my self-study of C#, no progress in Write GH information to FEA. About V1B you sent to me, I understand the essential part about how it works to make the rectangular grid and anchors , but got confused with LexerOps and U V (I know they are intervals, need to read another time to absorb how they works and why the code looks like that). I've made an appointment with my university supervisor on this Wednesday to get a start.

3) About system type (you asked in our former discussion)

First is the one I sent you in email. I choose this type as a start point. The other options are Buckminster Fuller tensegrity dome , David Geiger tensegrity dome and tensegrity truss system (see in attach jpg file).

These pics you posted are very nice connections. I do not understand why you give me these pics at this moment? And do you have any advice about my next step?

Best,

Price never Surrender.

Attachments:

General idea about Optimisation.pdf, 114 KB
164-SolarPavilionModelInterior3_fs.jpg, 91 KB

Permalink Reply by peter fotiadis on November 30, 2015 at 6:14am

Dear King Of NeverGiveUp

1. Pics: The reason that I've provided these pics is ... to convince you ... er ... NOT to do it (because the Path is long and hilly).

2. Programming: well ... unless the Time wrapper is invented (I'm working on it) getting the gist of it requires more than, say, a week (maybe a decade, maybe a century who can tell?).

3. Galapagos: What exactly Galapagos can serve in these freaky situations? In trusses our problem NUMERO uno is clash situations between the components of a real-life system. For instance and in relation with the system outlined above:

Of course the system is designed by allowing you to manage such stuff (by using a 2nd "coaxial" cable/strut adapter) but I do hope that you get(?) the gist of my meaning.

4. Advise: Marry a rich girl, forget all that.

5. Fun time: Anyway get this 3dPDF (animated + an authentic [static] pic of the Sardine Lord) and have faith ... to things that will come (this week or this month or this decade).

best, Lord of Darkness, King of SardineLand, Prince of Simplicity (kinda)

Attachments:

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

Permalink Reply by Zhengyu Xue on November 30, 2015 at 8:05am

Dear Lord of Darkness,

Don't be sad..This is my graduation work and I will find a way through.

Here I want to ask some questions about construction ..There is very few information available on the Internet . I already know prestress is added by rotating the toggle between two cables(then cables will be pulled together). But how to precisely control how much pretension will be added to the cables? Please have a look at the attached pdf file which is from a journal paper. I am confused about the negative magnitude of prestress. Plus, take group 9 as an example, to apply prestress should we divide this group into two cables and add a toggle in between? How to add different prestress in group 5 and group 8?

Best ,

Star of Hope.

Attachments:

geiger dome.pdf, 145 KB

Permalink Reply by peter fotiadis on November 30, 2015 at 8:59am

Dear King of FarAndAwayFromTarget

1. Pre-stress is achieved by rotating a tension regulator (see Norsman stuff in PDF) that has clock/anti clock wise threads and thus rotation means "bring the 2 ends closer". 2 ends means a kind of "terminal" (massif east/ hollow west) SS 316/304 stuff that east has the threads and west is pressed around the cable. Classic structural analysis dictates the forces AND then (if the things are NOT commercially available) comes FEA that validates the nuts and the bits of any bespoke/custom system (if bits they can't sustain the forces > change country ASAP > Brazil + plastic surgery is highly recommended).

Spam on:

Wait a minute: WHAT are you after? Design some WOW truss or computing the forces of it? Because these 2 are different animals that are treated by different kind of disciplines: The Architect designs something and the Structural Engineer (in parallel) evaluates that something ... whilst the idiot (the Architect) does some other variant (since the first was crap).

In the old days that "I design" + "you compute" combo was a bit of a token ... since the "I-re-design" part was out of question. But these days it's not nuclear science provided that you can mastermind a fully parametric system that is adaptable enough to what the structural department could possibly dictate (that does this ^@$%$@ thing provided as an "indication" of these freaky systems).

Spam off.

2. That thing shown is not tensegrity in the classic sense (i.e. simplex, W, Xtruss etc etc) where the out boundaries of a given module they DON'T carry any member (cable or "thin" massif extrusion) that is NOT under tension. For instance a simplex module IS "pure" tensegrity since ... blah, blah. But on your thing the upper members are under pressure ... blah, blah.

3. That brings us to the 1M question: pure tensegrity (in the Name of Science) or a "bastardized" one? (in the Name of Something). If the latter ... why bother and not using a classic MERO KK system that costs 10 times less? (or carbon MERO [almost thin air] or a membrane or synthetic goat skin or solidified air (C)(tm)).

Permalink Reply by peter fotiadis on November 30, 2015 at 9:28am

WARNING: a system that is "bastardized" MAY behave as expected in normal conditions ... but seismic activities have other things in mind and thus havoc is assured at least with what the structure supports (the skin, that is : if it's glass rather stay 1 mile away).

Moral: the ideal world is only found in planet Utopia.

Permalink Reply by peter fotiadis on November 30, 2015 at 9:19am

PS: I have a terrible idea: what about forgetting all that stuff and make the (C#, what else?) definition that does this attached? (designed by The Lord for NASA [Mars attacks project etc etc']).

I'm talking about the notorious GonzoDuck-Millipede (all-terrain) modular vehicle that could (with a few minor mods) serve as a truss as well.

best, Lord of Mars

Attachments: