A frame member is fixed at its root and carries tip force 1.0 N transversely. A lift-off support initially holds tip rotation about z. An initially open gap of 0.002 mm acts transversely in y. One support transition can change the other response. Does the solver follow the sequence one step at a time, and where does it settle?

This page preserves a recorded benchmark and its expected values. The dated run below is not a new run of the current product.

These recorded transitions and free-degree residuals do not establish general equilibrium or convergence for other models.

Support state check. The recorded test exercises nonlinear support state or assembled-loop behavior in its benchmark crate. It does not exercise desktop authoring.

1.Inputs.

Illustrative values, taken from no standard and chosen so the arithmetic can be followed by hand. Most do not describe a real pipe; read them in any consistent set of units.

2.Method.

On the first iteration only the rotational lift-off support changes: it releases. With the tip now free to rotate, the second iteration changes the classification of the gap, which closes. On the third iteration neither support changes, so the loop has converged. The changed-support counts run 1, 1, 0.

The reference for this group records the expected support states, changed-support counts and final residuals. It does not work out displacements or reactions, so none are tabulated here.

3.Results.

The case record describes these checks:

• The solve converges in exactly 3 iterations, with changed-support counts of 1, 1 and 0 in that order.
• The first iteration changes only the rotational lift-off support, and the second changes only the gap.
• Final states match the reference: lift-off support released, gap closed. No diagnostics are raised.
• At the final iteration the out-of-balance force, moment and work at the free degrees of freedom are all exactly 0.0.
• The changes in displacement, rotation and reaction over the last iteration stay inside the recorded envelope for this group.

What it shows. Compares final support states, the iteration count, and force balance. It does not compare movements or reactions with a hand calculation.

Path exercised. The benchmark calls the solver’s components directly: elements, loads, frame solver and stress recovery. It does not go through the program’s own model-to-solve path.

Agreement. The loop counts as converged only when no support changes state between iterations. The changed-support count must reach exactly 0 within at most 4 iterations, with no relative or absolute allowance. At the final iteration, out-of-balance force, moment and work at free degrees of freedom must be 0.0. Changes in displacement, rotation and reaction over the last iteration must stay inside the recorded envelope. Long values are shown here to seven significant figures; the tests compare the full values in the record.

4.Recorded command.

This command belongs to the archived source at 462f66975d36cd10d5b8455193ada9517d28d353. Use a checkout of that exact revision. This edition did not run the command. The recorded result does not establish current product support.

git checkout --detach 462f66975d36cd10d5b8455193ada9517d28d353
cd projects/chirality-piping
cargo test --manifest-path validation/benchmarks/nonlinear/Cargo.toml multisupport_acceptance_inventory_uses_narrow_dec_046_policy

Hand calculation: validation/hand_calcs/nonlinear/assembled_multi_support_cascade_gap_lift_off_acceptance.md. Test record, with the recorded run of 2026-07-10: nl-assembled-multi-dof-cascade-gap-lift-off-accepted-original.md.