Constant Tension mesh implodes

I created a capillary network, meshed it, and used the edges inside a constant tension component. I drew anchor points, first inside the mesh, and then on verticies on the mesh.

The mesh shrinks, rips, and shrinks to the left and right sides of the model, going past the anchor points.

What is wrong with the model? Would you help me troubleshoot?capillary_kangaroo_test_sharing.gh (961.2 KB)

See my attached definition.

The constant tension elements are exactly that - their tension force is not elastic and does not depend on their length (unlike a spring or length goal, where the force goes to zero as it reaches its rest length).

This is an inherently unphysical behaviour because it does not preserve energy, and networks of these constant tension elements aren’t guaranteed to converge to a static equilibrium.
It is still a useful one to have for some form-finding purposes (for example finding Steiner trees), but needs to be used with care - either selecting initial conditions from which it will converge, or including additional goals to regularize it.

If you are just looking for constant elastic stiffness across a mesh, then Length goals is probably what you are after.

OK thank you for the insight.

I am still experiencing a dissolving mesh with the Lenght(Line) goal. Attached is my updated definition. I am not using any other goals besides the line goal. I also simplified my mesh I was working with.capillary_kangaroo_test.gh (382.1 KB)

Part of the problem was the geometry was small relative to the tolerance of the solver, and some short edges of the mesh were getting collapsed into a single particle. Changing to the tolerance avoids this:
capillary_kangaroo_test.gh (331.9 KB)
I’ve also included a slightly improved version of the mesh.
I switched it back to pressure instead of Volume. There was something else strange going on with the volume mesh component though - I haven’t figured out what yet.