Use pipe elements (PIPE289) to model polymer tube structures as line bodies. Currently, none of the hyperelastic material models can be modeled by beam elements (BEAM188, BEAM189).

Some contact element settings (KEYOPTs) are not available in the Mechanical user interface but can be easily set via command snippets, as demonstrated in this example.

When internal beam contact is involved, set KEYOPT(3) = 2 for the contact elements to capture any internal crossing and parallel beam-to-beam contact. In this example, the crossing contact type dominates between the coil and the tube; the parallel contact type may potentially occur during Newton-Raphson iterations.

Set KEYOPT(14) = 2 for the contact elements to allow each contact detection point to interact with multiple target segments simultaneously.