FESADev/phases/1-linear-static-mitc4-rebaseline/step4.md

Sprint Contract: Validation Singular Diagnostics

Objective

Strengthen domain and analysis-model validation so invalid inputs and singular-prone models fail before or during solve with actionable diagnostics.

Required Reading

• /AGENTS.md
• /docs/ARCHITECTURE.md
• /docs/NUMERICAL_CONVENTIONS.md
• /docs/ABAQUS_INPUT_SUBSET.md
• /docs/VERIFICATION_PLAN.md

Scope

• Validate missing nodes, properties, materials, sets, boundary targets, load targets, active elements, and non-positive thickness.
• Add singular-prone diagnostics for no free DOFs, untouched free DOFs, missing loads where expected, and unconstrained drilling/rotational risks.
• Keep mesh quality diagnostics out of Phase 1.

Allowed Files

• include/
• src/
• tests/
• PLAN.md
• PROGRESS.md

Explicit Non-Goals

• Do not implement mesh quality metrics such as aspect ratio, skew, or warpage.
• Do not solve the global system in this step.
• Do not hide singular checks in element kernels.

Tests To Write First

• Missing node/property/material diagnostics.
• Missing set used by shell section, boundary, or load.
• No active elements.
• No free DOFs.
• Free DOFs untouched by any active element connectivity.
• Rotational/drilling weak-constraint diagnostic smoke test.

Reference Artifacts

• Negative inline test inputs may be used.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Diagnostics include node id, element id, property id, material id, set name, DOF component, and source line where available.
• Mesh quality remains explicitly deferred.
• Validation does not mutate Domain.

Handoff Requirements

• Record validation coverage in PROGRESS.md.
• Note any remaining singular-diagnostic gaps in PLAN.md.

Do Not

• Do not classify poor element shape as a Phase 1 mesh quality failure.