FESADev/README.md

FESA

FESA is a C++17 finite element structural analysis solver project. The first milestone is a reference-verified linear static MITC4 shell solver with an Abaqus-compatible input subset, HDF5-oriented results, and explicit numerical conventions.

Current Phase 1 Direction

• MITC4 shell element baseline formulation.
• Linear elastic material.
• Nodal loads and fixed boundary conditions.
• Abaqus input subset with S4 mapped to FESA MITC4.
• S4R deferred.
• 6 shell DOFs per node: UX, UY, UZ, RX, RY, RZ.
• Small artificial drilling stiffness.
• Constrained DOF elimination.
• Full-vector reaction recovery.
• double precision and int64 ids/indices/equation numbering.
• Stored-reference comparison from references/*.inp and references/*_displacements.csv without requiring local Abaqus execution.

Reference Artifacts

Stored Abaqus examples live under references.

The initial accepted artifact pair is:

• quad_01.inp
• quad_01_displacements.csv

Reference CSV displacement columns use Abaqus labels Node Label, U-U1, U-U2, U-U3, UR-UR1, UR-UR2, UR-UR3, mapped to FESA UX, UY, UZ, RX, RY, RZ.

Documentation Entry Point

Start with docs/README.md.

The core project documents are:

• AGENTS.md
• docs/HARNESS_ENGINEERING.md
• docs/PRD.md
• docs/ARCHITECTURE.md
• docs/ADR.md
• docs/NUMERICAL_CONVENTIONS.md
• docs/ABAQUS_INPUT_SUBSET.md
• docs/VERIFICATION_PLAN.md
• docs/RESULTS_SCHEMA.md
• docs/MITC4_FORMULATION.md

Validation

The default repository validation command is:

python scripts/validate_workspace.py

At this planning stage, validation may report that no concrete build/lint/test commands are configured.