FESADev/phases/1-linear-static-mitc4/step10.md

Step 10: mitc4-formulation-closure

Sprint Contract

Objective

Close the MITC4 formulation decisions required before element implementation: transverse shear tying, local basis, integration ordering, drilling stiffness default, and Phase 1 output scope.

Required Reading

• /AGENTS.md
• /PROGRESS.md
• /PLAN.md
• /docs/README.md
• /docs/HARNESS_ENGINEERING.md
• /docs/PRD.md
• /docs/NUMERICAL_CONVENTIONS.md
• /docs/RESULTS_SCHEMA.md
• /docs/MITC4_FORMULATION.md
• /docs/VERIFICATION_PLAN.md

Scope

• Update docs/MITC4_FORMULATION.md with the exact baseline formulas and implementation checklist needed for coding.
• Resolve or explicitly defer R-004, R-005, R-006, and R-007.
• Record literature/source basis and benchmark expectations without requiring local Abaqus execution.
• Update ADR or PLAN only when a durable design decision changes.

Allowed Files

• docs/MITC4_FORMULATION.md
• docs/RESULTS_SCHEMA.md
• docs/VERIFICATION_PLAN.md
• docs/ADR.md
• PLAN.md
• PROGRESS.md
• phases/1-linear-static-mitc4/index.json

Explicit Non-Goals

• Do not implement C++ MITC4 code in this step.
• Do not invent formulas from memory without documenting the source or derivation.
• Do not expand Phase 1 outputs beyond resolved R-007.

Tests To Write First

• No C++ tests are required unless executable formulation checks already exist.
• Add documentation checklist items or review notes that can be evaluated before Step 11.

Reference Artifacts

• None required. Existing references/quad_01* may inform future benchmark planning but is not a Phase 1 MITC4 acceptance case.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Transverse shear tying equations are explicit enough to implement.
• Local shell basis construction is explicit for flat and non-flat quads.
• Drilling stiffness default scale and parameter name are finalized.
• Integration ordering and output scope are finalized or explicitly deferred with downstream blockers.
• Step 11 remains blocked if any required formulation item is unresolved.

Handoff Requirements

• Record closed decisions and remaining risks in PROGRESS.md.
• Remove or update resolved readiness tasks in PLAN.md.
• Update the matching phase index entry: use completed with a one-line summary, or blocked with blocked_reason, or error with error_message.

Verification

1. Run the acceptance command.
2. Review docs for implementable formulas and unresolved placeholders.

Do Not

• Do not let implementation begin on undocumented MITC4 formulas.