FESADev/phases/1-linear-static-mitc4-rebaseline/step0.md

Sprint Contract: Rebaseline Audit

Objective

Audit the existing Phase 1 implementation against the paper-based docs/MITC4_FORMULATION.md and produce a concrete rework map before changing solver behavior.

Required Reading

• /AGENTS.md
• /PROGRESS.md
• /PLAN.md
• /docs/README.md
• /docs/HARNESS_ENGINEERING.md
• /docs/PRD.md
• /docs/ARCHITECTURE.md
• /docs/ADR.md
• /docs/NUMERICAL_CONVENTIONS.md
• /docs/MITC4_FORMULATION.md
• /phases/1-linear-static-mitc4/index.json

Scope

• Inspect existing C++ implementation and tests only enough to classify what can be retained, rewritten, or deleted in later steps.
• Produce or update planning notes in PLAN.md and PROGRESS.md.
• If useful, add a short audit artifact under phases/1-linear-static-mitc4-rebaseline/.

Allowed Files

• PLAN.md
• PROGRESS.md
• phases/1-linear-static-mitc4-rebaseline/

Explicit Non-Goals

• Do not change production C++ behavior.
• Do not rewrite MITC4 formulas.
• Do not unblock stored-reference regression by accepting unsupported Abaqus syntax.

Tests To Write First

• None. This is a planning and audit sprint.

Reference Artifacts

• references/quad_01.inp
• references/quad_01_displacements.csv
• references/quad_02.inp
• references/quad_02_displacements.csv

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• The audit identifies conflicts with docs/MITC4_FORMULATION.md, especially old averaged-edge basis, 1.0e-6 drilling scale, analytic thickness integration, and direct shear evaluation risks.
• Future work is assigned to later rebaseline steps instead of being fixed here.
• PLAN.md and PROGRESS.md describe the new state without treating the old P1-01 through P1-14 implementation as authoritative.

Handoff Requirements

• Record completed audit work in PROGRESS.md.
• Keep next implementation tasks in PLAN.md or later step files.

Do Not

• Do not merge this audit with implementation.
• Do not remove old phase history.