FESADev/phases/linear-static-mitc4-shell/step3.md

Step 3: MITC4 Kinematics and Constitutive Law

담당 역할과 필수 스킬

• 담당 역할: implementation-agent
• 필수 스킬: harness, fesa-cpp-msvc-tdd

읽어야 할 파일

• /.agents/skills/harness/SKILL.md, /.codex/skills/fesa-cpp-msvc-tdd/SKILL.md
• /AGENTS.md, /docs/PRD.md, /docs/ARCHITECTURE.md, /docs/ADR.md
• /docs/HARNESS.md, /docs/HARNESS_WORKFLOW.md, /.codex/hooks.json
• /docs/linear-static-mitc4-shell/implementation-plan.md
• /docs/linear-static-mitc4-shell/requirements.md Requirements 031-038/050-052
• /docs/linear-static-mitc4-shell/research.md
• /docs/linear-static-mitc4-shell/formulation.md Sections 3-11, 17
• /docs/linear-static-mitc4-shell/numerical-review.md Sections 5.1-5.6, 6.1-6.2
• /docs/linear-static-mitc4-shell/io.md
• /docs/linear-static-mitc4-shell/reference-model.md
• phase indexes, step3.md, Step 2 geometry paths/summary
• /include/fesa/elements/euler_beam_3d.hpp와 cpp는 concrete value-kernel style 참고용
• Candidate new /include/fesa/elements/mitc4_shell.hpp
• Candidate new /src/fesa/elements/mitc4_shell.cpp
• Candidate new /tests/unit/elements/mitc4_shell_test.cpp
• source/test CMakeLists

작업

1. MITC4-KIN-001..005 tests를 먼저 작성한다.
2. Public common Element hierarchy 없이 concrete Mitc4Shell value type을 만든다.
3. Candidate creation seam은 four nodes, four initial directors, ShellSection, LinearElasticMaterial을 받아 validated Result<Mitc4Shell>을 반환한다.
4. Shape/derivative identities, local frames, T_p/T_d channel maps, direct membrane/bending columns, four covariant MITC edge-midpoint tying samples와 interpolation weights, engineering shear factors를 구현한다.
5. C_ps, C_5, A, D, A_s의 exact coefficients, dimensions, symmetry, positive definiteness와 unit rescaling을 구현한다.
6. 2x2x2 Gauss point/weight order를 고정하고 intermediate physical matrices는 20 DOF contract를 유지한다.

Acceptance Criteria

$requiredBuildPaths=@("C:/git/googletest","C:/Program Files (x86)/Intel/oneAPI/mkl/2026.1/lib/cmake/mkl","C:/Program Files (x86)/Intel/oneAPI/tbb/2023.1/lib/cmake/tbb","C:/Program Files/HDF_Group/HDF5/2.1.1/cmake")
foreach($p in $requiredBuildPaths){if(-not(Test-Path -LiteralPath $p)){throw "Missing $p"}}
cmake --fresh -S . -B .harness/build -G "Visual Studio 18 2026" -A x64 `
  "-DFESA_GTEST_SOURCE_DIR=C:/git/googletest" `
  "-DMKL_DIR=C:/Program Files (x86)/Intel/oneAPI/mkl/2026.1/lib/cmake/mkl" `
  "-DTBB_DIR=C:/Program Files (x86)/Intel/oneAPI/tbb/2023.1/lib/cmake/tbb" `
  "-DHDF5_DIR=C:/Program Files/HDF_Group/HDF5/2.1.1/cmake"
cmake --build .harness/build --config Debug --target fesa_unit_tests
ctest --test-dir .harness/build -C Debug -R "Mitc4ShellKinematics|Mitc4ShellConstitutive" --output-on-failure

Expected missing kernel/kinematics RED를 기록한 뒤 minimal GREEN. 이후:

cmake --build .harness/build --config Debug --target fesa_unit_tests
ctest --test-dir .harness/build -C Debug -R "Mitc4ShellKinematics|Mitc4ShellConstitutive|Mitc4Geometry" --output-on-failure
cmake --build .harness/build --config Debug
ctest --test-dir .harness/build -C Debug --show-only=json-v1
ctest --test-dir .harness/build -C Debug --output-on-failure

검증 및 상태 갱신

현재 Step의 RED와 focused/full evidence만 기록하고 상태 payload만 갱신한다.

금지사항

• Global assembly, drilling stiffness, recovery/HDF5를 구현하지 마라.
• S4R source type으로 quadrature를 분기하지 마라.
• Nonlinear state/residual/tangent를 구현하지 마라.
• Vendor type을 public header에 노출하거나 직접 commit/hook 실행을 하지 마라.