How to simulate the bending behaviour of a spring-steel measuring tape?

Hi, guys

I’ve been trying to simulate the behaviour of the spring-steel measuring tape. One thing I observed from the real model and what I’m trying to realise is that:(as what the picture shows)

The straight part of the tape would maintain the curvature in section, but when it bends, the bending part would lose the curvature in section and become flat.

I tried to achieve the two behaviours above at the same time, but that might be too difficult. So I also tried to achieve them separately.
What I have achieved is to bend a series straight polyline(red) with the part far away from the input force maintaining straight. But I don’t know how to make sure the section(blue) is always perpendicular to the polyline(red). Now they seems to be perpendicular to the xy plane, which is the beginning state. (40.6 KB)

I will really appreciate it a lot if you can share any suggestions or thoughts!
@ Daniel Piker


I have long loved tape springs - such a fascinating behaviour.

As a student I had a lot of fun making deployable structures out of these (see the first and last ones here)

To simulate this we need to use a mesh and treat it as a shell which is curved in its rest state.
Here’s a basic example: (13.2 KB)

edit - here with the settings tweaked a bit to speed it up (20.1 KB)


Thank you so much Daniel!
I’ll check all the contents you shared, and I’m sure I would learn a lot.


This works fine in Rhino 7 but Rhino 8 creates an extrusion with U and V flipped.

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Hi @martinsiegrist Thanks for letting us know - this inconsistency between versions does look like a bug.

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Fixed on the next BETA.