FESADev/phases/1-linear-static-mitc4-rebaseline/step11.md

Sprint Contract: MITC4 Patch Benchmark Tests

Objective

Add element-level and small-mesh MITC4 patch and benchmark tests before integrating stored Abaqus references.

Required Reading

• /AGENTS.md
• /docs/MITC4_FORMULATION.md
• /docs/VERIFICATION_PLAN.md
• /docs/NUMERICAL_CONVENTIONS.md

Scope

• Add constant membrane, pure bending, pure shear, pure twist, rigid-body, and drilling sensitivity tests.
• Add a thin cantilever or plate strip test to expose shear locking.
• Add benchmark scaffolding for Scordelis-Lo after flat tests pass.

Allowed Files

• tests/
• include/
• src/ only for minimal fixes required by tests
• docs/VERIFICATION_PLAN.md only for clarifying benchmark notes
• PLAN.md
• PROGRESS.md

Explicit Non-Goals

• Do not require Abaqus execution.
• Do not add pressure loads for Scordelis-Lo in Phase 1.
• Do not hide failing element behavior by loosening tolerances without rationale.

Tests To Write First

• The patch and benchmark tests are the sprint output; write them before any fixes.
• Include at least one negative or sensitivity test for drilling scale effects.

Reference Artifacts

• Local analytic or hand-check benchmark data only.
• Stored Abaqus CSV regression is reserved for step 14.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Tests cover locking-sensitive behavior, not only shape functions.
• Tolerances are scale-aware and documented.
• Any implementation fixes remain minimal and within MITC4 scope.

Handoff Requirements

• Record benchmark coverage and remaining gaps in PROGRESS.md and PLAN.md.

Do Not

• Do not implement new load types to force a benchmark into Phase 1.