FESADev/docs/reference-models/euler-beam-3d-reference-models.md

3D Euler-Bernoulli Beam Reference Models

Metadata

• feature_id: euler-beam-3d
• source_requirement: docs/requirements/euler-beam-3d.md
• source_research: docs/research/euler-beam-3d-research.md
• source_formulation: docs/formulations/euler-beam-3d-formulation.md
• source_numerical_review: docs/numerical-reviews/euler-beam-3d-review.md
• source_io_definition: docs/io-definitions/euler-beam-3d-io.md
• status: needs-reference-artifacts
• owner_agent: reference-model-agent
• date: 2026-06-12

Reference Strategy

• verification_scope: future solver-level verification after parser, assembly, solve, HDF5 output, and comparison tooling exist.
• code_verification: current kernel unit tests cover local stiffness, transformation, and force recovery without external reference artifacts.
• solution_verification: future cantilever and skew-orientation models will compare displacement, reaction, and internal force quantities.
• benchmark_reference_comparison: future Abaqus-generated CSV files under reference/<model-id>/ are required before release readiness.
• excluded_validation_scope: physical experiment validation is not in scope.

Model Inventory

model_id	category	purpose	status	required_artifacts
eb3d-axial-cantilever	analytical	axial bar-as-beam displacement, reaction, and axial end force	needs-reference-artifacts	model.inp, metadata.json, displacement, reaction, internal force CSV, README
eb3d-torsion-cantilever	analytical	torsional rotation, reaction moment, and torsional end moment	needs-reference-artifacts	model.inp, metadata.json, displacement/rotation, reaction, internal force CSV, README
eb3d-bend-y-cantilever	analytical	bending response using EIy	needs-reference-artifacts	model.inp, metadata.json, displacement, reaction, internal force CSV, README
eb3d-bend-z-cantilever	analytical	bending response using EIz	needs-reference-artifacts	model.inp, metadata.json, displacement, reaction, internal force CSV, README
eb3d-skew-transform	regression	skew-oriented beam transform and component mapping	needs-reference-artifacts	model.inp, metadata.json, displacement, reaction, internal force CSV, README

Model Records

eb3d-axial-cantilever

• category: analytical.
• verified_requirements: EB3D-REQ-005, EB3D-REQ-007, future solver I/O requirements.
• analysis_type: linear static.
• element_type: two-node 3D Euler-Bernoulli beam, Abaqus-equivalent candidate B31.
• expected_physical_quantities: axial displacement, support reaction, element axial end force.
• artifact_status: needs-reference-artifacts.

eb3d-torsion-cantilever

• category: analytical.
• verified_requirements: EB3D-REQ-005, EB3D-REQ-007.
• analysis_type: linear static.
• expected_physical_quantities: twist, reaction moment about beam axis, torsional end moment.
• artifact_status: needs-reference-artifacts.

eb3d-bend-y-cantilever

• category: analytical.
• verified_requirements: EB3D-REQ-005, EB3D-REQ-007.
• analysis_type: linear static.
• expected_physical_quantities: transverse displacement, support reaction, bending end forces using EIy.
• artifact_status: needs-reference-artifacts.

eb3d-bend-z-cantilever

• category: analytical.
• verified_requirements: EB3D-REQ-005, EB3D-REQ-007.
• analysis_type: linear static.
• expected_physical_quantities: transverse displacement, support reaction, bending end forces using EIz.
• artifact_status: needs-reference-artifacts.

eb3d-skew-transform

• category: regression.
• verified_requirements: EB3D-REQ-006, EB3D-REQ-008, EB3D-REQ-011.
• analysis_type: linear static.
• expected_physical_quantities: transformed displacement, reaction, and internal force components.
• artifact_status: needs-reference-artifacts.

Abaqus Input Requirements

• input_file: reference/<model-id>/model.inp.
• supported_keyword_subset: must follow docs/io-definitions/euler-beam-3d-io.md when future parser work is approved.
• model_data: nodes, one or more beam elements, material, section, orientation, and units.
• history_data: linear static step, boundary conditions, concentrated loads or moments, and output requests.
• unsupported_keyword_policy: unsupported unless explicitly added by a future I/O contract.

Artifact Bundle Contract

reference/
  <model-id>/
    model.inp
    metadata.json
    <model-id>_displacements.csv
    <model-id>_reactions.csv
    <model-id>_internalforces.csv
    README.md

<model-id>_stresses.csv is not required until stress recovery is approved. No artifact in this bundle is created or modified in the current phase.

Metadata JSON Contract

Future metadata.json files must include:

• feature_id
• model_id
• artifact_status
• input_file
• Abaqus version/source and generation owner
• generation date
• source documents
• units and coordinate system
• analysis type and element types
• material and section values
• boundary and load summaries
• output requests
• reference CSV schema version
• reference CSV files
• tolerance policy
• limitations

Coverage Matrix

requirement_id	model_id	compared_quantity	fesa_hdf5_dataset	reference_csv	tolerance	verification_method	status
EB3D-REQ-005	eb3d-axial-cantilever	displacement/internal force	/steps/<step>/frames/<frame>/nodal/displacement, /element/internal_force	displacement/internal force CSV	TBD	hdf5-to-reference-csv	needs-reference-artifacts
EB3D-REQ-006	eb3d-skew-transform	displacement/reaction/internal force	displacement, reaction, internal force HDF5 datasets	displacement/reaction/internal force CSV	TBD	hdf5-to-reference-csv	needs-reference-artifacts
EB3D-REQ-007	eb3d-torsion-cantilever	rotation/reaction/internal force	displacement, reaction, internal force HDF5 datasets	displacement/reaction/internal force CSV	TBD	hdf5-to-reference-csv	needs-reference-artifacts
EB3D-REQ-008	eb3d-skew-transform	global end force	/steps/<step>/frames/<frame>/element/internal_force	internal force CSV	TBD	hdf5-to-reference-csv	needs-reference-artifacts
EB3D-REQ-011	eb3d-skew-transform	transform consistency	displacement and internal force datasets	displacement/internal force CSV	TBD	hdf5-to-reference-csv	needs-reference-artifacts

Artifact Acceptance Checklist

• No files under reference/ are created or modified in this phase.
• Every future model must document provenance before use as verification evidence.
• Required CSV files keep the model status at needs-reference-artifacts until generated through an approved reference phase.
• Stress CSV files remain out of scope until stress recovery is approved.

Open Issues and Downstream Handoff

I/O Definition Agent

• Finalize the exact beam section and orientation keyword subset before creating model.inp files.

Implementation Planning Agent

• Kernel TDD may proceed without reference artifacts because this phase only implements element-level matrix and recovery routines.

Reference Verification Agent

• Do not compare results until authoritative HDF5 output and approved CSV artifacts exist.