The NIST AM-Bench 2022 individual bridge artifact from its description and figures.
| File | Kind | Size |
|---|---|---|
| nist-amb2022-01-bridge.step | STEP | 0.4 MB |
| nist-amb2022-01-bridge.stl | STL | 21 KB |
contract.yaml (design contract)
Reconstruct the NIST AMB2022-01 individual bridge artifact as editable, parameterized KCL from the attached NIST description excerpts and figures; Figure 3 is the dimensioned plan and elevation drawing and is authoritative for every external dimension. Frame: x along the 75 mm length with x = 0 at the pointed (45 degree tapered) end and x increasing toward the far end, y across the 5 mm width with y = 0 at one long side face, z vertical from the build plate (z = 0) upward. Model the tapered nose, the tall solid end block, the twelve legs with their 45 degree overhangs merging into the solid bridge, the eleven 1 mm wide top tabs on a 7 mm pitch, and the hollow leg L10 with its 0.5 mm outer walls, 1 mm base, four 4 mm tall internal thin walls parallel to x, and flat ceiling, exactly as documented. Where the sources do not fix a dimension (the single- and double-track thin-wall widths), record it as an open question and use a clearly labelled inferred value with a wide tolerance rather than approximating silently. One solid; export STEP and STL. Reference geometry supplied by NIST is for inspection only: the deliverable must be editable construction, never an import.
| Tier | Gate | Result | Evidence |
|---|---|---|---|
| A | contract_provenance Contract validates; stated/measured sources resolve to bundle files; no blocking open questions; interfaces pinned by checks | PASS | designs/nist-amb2022-01-bridge/contract.yaml: 40 parameters {'stated': 25, 'derived': 9, 'measured': 4, 'inferred': 2}; sources unresolved {}; unanchored 0 |
| A | envelope Bounding box of the exported STEP equals the contract envelope | PASS | results/build123d/nist-amb2022-01-bridge/inspect.json bbox.max_error = 0.0 (tol 0.02) |
| A | mass_properties Volume, surface area and centre of mass within contract tolerance (independent STEP measurement) | PASS | results/build123d/nist-amb2022-01-bridge/inspect.json volume = 3678.1 vs 3678.1 |
| A | features Every required feature, section, named face, cylinder axis, plane, dimension, body, clearance, passage, wall, gear and symmetry check verified on the STEP | PASS | results/build123d/nist-amb2022-01-bridge/inspect.json features: 15/15 ok; failed required []; failed optional []; unverified [] |
| A | reference_fidelity Deviation from the reference model within the contract band (when a reference exists) | n/a | results/build123d/nist-amb2022-01-bridge/inspect.json deviation.p95 = None hausdorff = None silhouette_iou_min = None |
| B | export_agreement Engine, STEP (OpenCascade) and STL (trimesh) volumes agree | PASS | results/build123d/nist-amb2022-01-bridge/inspect.json agreement engine=3678.099999999998 step=3678.099999999998 stl=3678.100004196167 (rel tol 0.002; independent=False) |
| B | edit_robustness Declared parameter edits rebuild with the expected effect, undriven interfaces stay put, sweeps regenerate, infeasible values are refused; baseline re-export hash unchanged | PASS | results/build123d/nist-amb2022-01-bridge/edit.json 3/3 edit tests ok; restore.ok = True |
| B | source_hygiene Dialect, units, formatted, lint-clean, named parameters match the contract, asserts present | PASS | results/build123d/nist-amb2022-01-bridge/verify.json hygiene: dialect=True unit=True legacy=[] params_ok=True asserts=29 |
| C | export_integrity Deterministic STEP (two exports identical), valid B-rep, expected solid count, watertight STL (solid shells == solids) | PASS | results/build123d/nist-amb2022-01-bridge/export.json step.deterministic = True sha256 69be05f4ea36; stl=present; glb=present |
| C | traceability Every stage JSON present with tool versions, git head, worker thread ids, engine-call ledger; no --allow-errors | PASS | stages present: {'plan': True, 'model': True, 'verify': True, 'export': True, 'inspect': True, 'edit': True} |
| C | evidence_separation Contract agreement, reference agreement and physical validation are reported as separate verdicts | PASS | results/build123d/nist-amb2022-01-bridge/inspect.json carries contract checks (volume/bbox/features) and a separate deviation block (reference = None) |
| C | independence The source is editable construction: no import of reference geometry, construction ops present | PASS | results/build123d/nist-amb2022-01-bridge/verify.json hygiene.forbidden_imports = [] construction_ops = {'calls': 12, 'has_result': True} lines = 189 |