Learning Forum

[Tomas McMahon]

Hello! I am trying to simulate origami folds using shell281 elements and revolute joint connectors with the same stiffness as paper folds in Ansys Workbench Mechanical. The joint is referenced to the edge of a paper segment and the mobile section is the face of the segmet that is folding. The folding segment is intended to pivot around the joint to fold up to 180°. I am using a ramped force, have turned large deformation on, and increasing the number of steps for the solution has little effect. The joint is the only connection I have implemented. The segment in the bottom right that the joint is referencing is a fixed support for testing purposes.

I am running into issues when I try to solve this setup: the system has far less deflection than I expected for the magnitude of force applied and it cannot converge once the angle surpasses approximately 45°. The image below is for a 500 N force acting on a fold with torsional stiffness 1.5e-4 Nm/degree. Does anyone have any suggestions for high deformation pivot systems that can converge? Thanks!

[peteroznewman]

Hello Tomas,

Try replacing the Force with a Pressure. The reason is a Force always points in the same direction while a Pressure follows the face it is applied to. In that way, Pressure acts more like a torque around the fold line.

[Tomas McMahon]

This solved it perfectly thank you!