Part VI
Verification
B. Elements and loads · Mixed support boundary
A small model has three supports. Node 0 has a full anchor. Node 1 has a translational spring of 250.0 N/m in Y. Node 2 has an imposed rotation of 0.015 rad about Z. How many degrees of freedom are rigidly restrained? Does the spring retain its elastic behavior instead of becoming a rigid restraint?
This page preserves a recorded benchmark and its expected values. The dated run below is not a new run of the current product.
This benchmark prepares boundary entries without solving a moving spring base. The current load/reference-state route supports explicit rigid boundary translations and rotations. It refuses spring base motion, device preload and device reference states.
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.
| Quantity | Symbol | Value |
|---|---|---|
| Node 0 anchor | — | 6 restrained freedoms |
| Node 1 spring stiffness in Y | k | 250.0 N/m |
| Node 2 imposed rotation about Z | θz | 0.015 rad |
2.Method.
The anchor holds all six freedoms at its node. The imposed rotation fixes one more freedom at a known value. The spring resists movement elastically and does not join the list of rigid restraints.
3.Results.
| Quantity | Expected |
|---|---|
| Restrained freedoms | 7 |
| Spring stiffness | 250.0 N/m |
| Imposed rotation | 0.015 rad |
The case record describes these checks:
- Boundary preparation completes without blocking.
- Seven freedoms are rigidly restrained.
- Exactly one spring is recorded, with a stiffness of 250.0 N/m.
- Exactly one imposed displacement is recorded, with a value of 0.015 rad.
What it shows. Checks the loads or boundary conditions prepared for the solver against a hand calculation. No system is solved.
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. Each computed value must match the reference within an absolute difference of 1.0 × 10−9 in the case’s own units. Counts and structural outcomes must match exactly. 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 linked case record and its recorded execution path. This website update did not rerun it. A historical command or result does not establish current product support.
cd projects/chirality-piping cargo test --manifest-path validation/benchmarks/mechanics/Cargo.toml support_boundary_fixture_prepares_mixed_supports
Hand calculation:
validation/hand_calcs/mechanics/support_boundary_mixed.md.
Test record, with the recorded run of 2026-07-10:
mech-support-boundary-mixed.md.