Auxetic structure manipulation - Kangaroo Bending

Hi there,

I am trying to be able to manipulate the grid 2D structure shown in figure 1.

All the segments are the same length and I want them to maintain this length, when I alter the angle between two or more curves, I would like it to affect the entire structure, as shown in figure 2.

Figure 3 shows a model of what I am attempting to achieve in two dimensions.

I have attached my grasshopper file with the grid shown in the images and my inital attempts at trying to undertstand and achieve this result.

Any help would be much appreciated,

Thanks,

Alex

Figure 1

Figure 2

Figure 3

Attachments:

151110 2D Structure - Bend angle attractor Kangaroo.gh, 22 KB

Replies to This Discussion

Permalink Reply by Arthur Mamou-Mani on November 10, 2015 at 9:31am

Hi Alex,

I would suggest adding a "bend" force between two lines imported from Rhino first and change the rest angle to see how it affects the two lines. The I would import one component, add the bend force to each connections then several components..etc... I think starting with the whole grid is a bit too challenging in terms of sorting your list..etc.. Would be good to see if you managed to use bend forces with a simpler file...

Cheers,

Arthur

Permalink Reply by Alexander Somerville on November 10, 2015 at 9:34am

Hi Arthur,

I will give that a go to get a better understanding of how it works and build it up from there.

Thanks,

Alex

Permalink Reply by Daniel Piker on November 10, 2015 at 11:01am

Hopefully the attached definition gives an idea of how to start.

I think it helps (in reality as well as the simulation) to start with the cells slightly in this concave bow-tie shape, otherwise as soon as you pull it the rectangles open up into convex hexagons.

Attachments:

auxetic.gh, 12 KB

Permalink Reply by Alexander Somerville on November 10, 2015 at 11:13am

Hi Daniel,

Thank you for your response, it will definitely help me to start and I think starting with the cells in the slightly concave form will also help.

Thanks again

Permalink Reply by na ha on April 20, 2018 at 11:47am

Hi Daniel, I'm using this script (slightly changed) to simulate the auxetic behavior. One problem I'm having is lines crossing each other rather than exerting force and pushing each other. Is there a way to put a constraint so the lines will not cross each other?

Attachments: