107 lines
5.2 KiB
Markdown
107 lines
5.2 KiB
Markdown
# SOL 101 — Static Analysis
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**Simulation:** Beam_sim1.sim
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**Solver:** NX Nastran SOL 101 (Linear Static)
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**Status:** Setup confirmed from KBS session (Gen 002). Baseline run needed.
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---
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## Setup — Confirmed
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| Item | Value | Source | Notes |
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|------|-------|--------|-------|
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| Solution type | **SOL 101** (Linear Static) | KBS session | "Solution 1 — static subcase" |
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| Element type | **CQUAD4** (4-node quad shell) | KBS session | ✅ Confirmed — thin shell collectors |
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| Property type | Thin shell | KBS session | Material inherited from "beam material" |
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| Mesh density | Element size = **33.7 mm** (67.4 / 2) | KBS session | Subdivision-based. Future refinement planned. |
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| Idealization | Promote body → mid-surface extraction | KBS session | Pair mid-surface function |
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## Boundary Conditions — Confirmed
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| BC | Location | Type | Value | Source |
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|----|----------|------|-------|--------|
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| **Fixed constraint** | Left side of beam (full edge) | SPC (all 6 DOF) | Fixed | ✅ KBS session — "left side fixed" |
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| **Applied force** | Right side of beam (free end) | Point/edge force | **10,000 kgf downward** (−Y) | ✅ KBS session — "project requirement" |
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### Loading Details
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- Force magnitude: 10,000 kgf = **98,066.5 N** (≈ 98.1 kN)
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- Direction: Downward (−Y in model coordinates)
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- Application: Right side (free end) of beam
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- Type: This is a **cantilever beam** with end loading — classic bending problem
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## Result Extraction
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| Output | Method | Expression/Sensor | Status |
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|--------|--------|-------------------|--------|
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| Mass | NX expression | **`p1`** (NOT `p173`) | ✅ Confirmed — 11.33 kg baseline |
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| Tip displacement | ❓ Sensor or .f06 parse | TBD | Gap G3, G6 — need baseline run |
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| Von Mises stress | ❓ Sensor or .f06 parse | TBD | Gap G4, G6 — need baseline run |
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> ⚠️ **Mass expression changed:** `p1` confirmed in KBS session, replacing previous assumption of `p173`. Extractor config must be updated.
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## Mesh Details
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| Property | Value | Notes |
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|----------|-------|-------|
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| Element type | CQUAD4 | 4-node quadrilateral, first-order |
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| Element size | 33.7 mm | 67.4 / 2 — Antoine says refinement is "not for now" |
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| Mesh method | Subdivision-based | Auto-mesh with size control |
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| Shell formulation | Thin shell | Mid-surface extracted from solid |
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| Convergence | ❓ **NOT VERIFIED** | Gap G8 partially closed (type known), but convergence check still needed |
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### Mesh Estimate
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- Beam length 5,000 mm / 33.7 mm ≈ 148 elements along length
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- Perimeter of I-beam cross-section ≈ varies — but total mesh likely 10K–50K elements
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- Expected DOF: 60K–300K → SOL 101 solve time: seconds to low minutes
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## Solver Considerations
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*From Technical Breakdown (Gen 001), updated with KBS data:*
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- **Linear assumption:** With 11.33 kg beam under 98 kN load, deflections may be significant relative to beam dimensions. L/δ ratio needs verification from baseline run.
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- **Mesh sensitivity:** Stress at hole edges is mesh-dependent. CQUAD4 at 33.7 mm may not fully resolve SCF at 300 mm diameter holes (~28 elements around circumference — probably adequate but needs verification).
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- **Mesh morphing vs remesh:** Parametric NX models typically remesh on update. Need to confirm behavior across DV range (Gap G7).
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- **Runtime estimate:** Single beam, CQUAD4 thin shell → likely **seconds per evaluation**. Very fast.
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- **Unit system:** NX model uses kg-mm-s (kgf for force). Nastran output stress in kPa → divide by 1000 for MPa.
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## Validation Checklist
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- [ ] Baseline mass matches NX expression `p1` (11.33 kg)
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- [ ] Baseline displacement measured (was 22 mm at old model state — **needs re-verification** G10)
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- [ ] Baseline stress measured (never had a value — **G11**)
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- [ ] Mesh convergence verified at baseline
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- [ ] Mesh quality acceptable at DV range extremes
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- [ ] Model rebuilds cleanly at all 4 corners of design space (Gap G7)
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- [ ] Stress at hole edges resolved with current mesh density
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## History
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- **Gen 001** (2026-02-09): Initial documentation from technical breakdown. All solver details pending gap resolution.
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- **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.
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## NX Automation Workflow
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**This model uses the SIMPLE workflow** (single-part, no assembly FEM).
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### Simple Workflow Chain
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```
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Beam.prt (geometry) → Beam_fem1_i.prt (idealized/mid-surface) → Beam_fem1.fem (mesh) → Beam_sim1.sim (solve)
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```
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Steps:
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1. Open `.sim` file (loads chain)
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2. Switch to `Beam.prt` — import `.exp` file, update expressions, rebuild geometry
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3. Switch to `Beam_fem1.fem` — update FE model (remesh)
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4. Switch back to `.sim` — solve SOL 101
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### Assembly FEM Workflow (NOT used here)
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For multi-part models with `.afm` files (e.g., SAT3 mirror):
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- Additional steps: load all components, update each FEM, merge duplicate nodes, resolve label conflicts
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- Detected automatically by presence of `.afm` files in working directory
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### Key Automation Notes
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- `hole_count` expression unit = `Constant` (not MilliMeter)
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- All length DVs = `MilliMeter`
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- FEM part is `Beam_fem1` — NOT `Beam_fem1_i` (idealized)
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- Journal: `solve_simulation.py` handles both workflows
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