Spring different Stiffness for Traction and Compression

Grasshopper Kangaroo
1

Hi,
I would like to know if it is possible, while using “LengthLine”, to get a different stiffness output if the line is under traction or compression.

Spring Striffness
Spring Striffness1118×581 11.1 KB

It is to simulate a textile structure with wind load => in traction the shell should be rigid like a wind foil, in compression the shell should be flappy like a flag.

In theory, it seams to be a little like plasticity, where the solver behaves in a different way according to the stress / deformation input during each iteration…

Any idea ?

Thanks for your help

2

You could modify the spring component to do this.

But I am not even sure if a nonlinear spring is necessary. Could you post an example file? If you have a bunch of elements, your structure will be kinematic/instable in compression anyways, no need to modify the springs.

Btw. to be mathematically correct, your left curve of your stiffness diagram has to point down (negative values)