KB: document simple vs assembly FEM workflow, automation notes

projects/hydrotech-beam/kb/fea/models/sol101-static.md

@@ -78,3 +78,29 @@
 
 - **Gen 001** (2026-02-09): Initial documentation from technical breakdown. All solver details pending gap resolution.
 - **Gen 002** (2026-02-10): Confirmed from KBS session — CQUAD4 thin shell, 33.7 mm element size, cantilever BCs (left fixed, right 10,000 kgf down), mass via `p1`. Material: AISI 1005.
+
+## NX Automation Workflow
+
+**This model uses the SIMPLE workflow** (single-part, no assembly FEM).
+
+### Simple Workflow Chain
+```
+Beam.prt (geometry) → Beam_fem1_i.prt (idealized/mid-surface) → Beam_fem1.fem (mesh) → Beam_sim1.sim (solve)
+```
+
+Steps:
+1. Open `.sim` file (loads chain)
+2. Switch to `Beam.prt` — import `.exp` file, update expressions, rebuild geometry
+3. Switch to `Beam_fem1.fem` — update FE model (remesh)
+4. Switch back to `.sim` — solve SOL 101
+
+### Assembly FEM Workflow (NOT used here)
+For multi-part models with `.afm` files (e.g., SAT3 mirror):
+- Additional steps: load all components, update each FEM, merge duplicate nodes, resolve label conflicts
+- Detected automatically by presence of `.afm` files in working directory
+
+### Key Automation Notes
+- `hole_count` expression unit = `Constant` (not MilliMeter)
+- All length DVs = `MilliMeter`
+- FEM part is `Beam_fem1` — NOT `Beam_fem1_i` (idealized)
+- Journal: `solve_simulation.py` handles both workflows