136 lines
5.8 KiB
Markdown
136 lines
5.8 KiB
Markdown
# CONTEXT.md — Hydrotech Beam Structural Optimization
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## Client
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Hydrotech (internal test fixture)
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## Objective
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Minimize beam mass while meeting displacement and stress constraints. Single-objective: minimize mass, constrain displacement (≤ 10 mm) and stress (≤ 130 MPa).
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## Key Parameters — Confirmed (Gen 002 + Introspection)
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| Parameter | NX Expression | Current | Range | Units | DV? | Notes |
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|-----------|--------------|---------|-------|-------|-----|-------|
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| beam_half_core_thickness | `beam_half_core_thickness` | **25.162** | 10–40 | mm | Yes (DV1) | Core half-thickness |
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| beam_face_thickness | `beam_face_thickness` | **21.504** | 10–40 | mm | Yes (DV2) | Face sheet thickness |
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| holes_diameter | `holes_diameter` | 300 | 150–450 | mm | Yes (DV3) | ✅ G14 closed |
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| hole_count | `hole_count` (→ `Pattern_p7`) | 10 | 5–15 | integer | Yes (DV4) | Pattern parameter link |
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| beam_length | `beam_lenght` ⚠️ | 5,000 | Fixed | mm | No | **Typo in NX — no 'h'** |
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| beam_half_height | `beam_half_height` | **250** | — | mm | No | ✅ G12 closed |
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| beam_half_width | `beam_half_width` | **150** | — | mm | No | ✅ G13 closed |
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| hole_span | `p6` (→ `Pattern_p9`) | 4,000 | TBD | mm | Potential (G15) | Total span for hole distribution |
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## Constraints
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- Max tip displacement: ≤ 10 mm
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- Max von Mises stress: ≤ ~130 MPa (steel, conservative — Gap G9)
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- Mass tracked via NX expression **`p173`** (`body_property147.mass` [kg])
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## Baseline Performance — Confirmed (Introspection)
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| Metric | Value | Source | Confidence |
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|--------|-------|--------|------------|
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| Mass | **1,133.01 kg** | NX expression `p173`, CEO correction + binary introspection | ✅ High |
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| Tip displacement | **19.56 mm** (node 5161, Tz = −19.51 mm) | OP2 parse via pyNastran, SOL 101 baseline run 2026-02-10 | ✅ High |
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| Max von Mises stress | **117.48 MPa** | OP2 parse via pyNastran, CQUAD4 shell stress | ✅ High |
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| Material | **AISI Steel 1005** | `physicalmateriallibrary.xml` | ✅ High |
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| Density | **7.3 g/cm³** | KBS session | ✅ High |
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> ⚠️ **Mass history:** Intake reported ~974 kg → CEO corrected to 1,133.01 kg (`p173`). Discrepancy with intake likely due to different parameter state. Binary introspection confirms `p173: body_property147.mass` in kg.
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## NX Expression Map — Full Introspection
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### Design Variables
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| Expression | Value | Unit | Type |
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|-----------|-------|------|------|
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| `beam_face_thickness` | 21.504404775742785 | mm | Number — continuous |
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| `beam_half_core_thickness` | 25.162078968746705 | mm | Number — continuous |
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| `holes_diameter` | 300 | mm | Number — continuous |
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| `hole_count` | 10 | — | Integer (via `Pattern_p7`) |
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### Fixed Geometry Parameters
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| Expression | Value | Unit |
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|-----------|-------|------|
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| `beam_half_height` | 250 | mm |
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| `beam_half_width` | 150 | mm |
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| `beam_lenght` | 5,000 | mm |
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### Hole Pattern Expressions
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| Expression | Value/Formula | Notes |
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|-----------|--------------|-------|
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| `p6` | 4,000 mm | Hole span — potential DV |
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| `Pattern_p7` | → `hole_count` | Count link |
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| `Pattern_p8` | 444.444 mm | Computed spacing (span / (count-1)) |
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| `Pattern_p9` | → `p6` | Span link |
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| `Pattern_p10` | (linked) | |
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| `Pattern_p11` | 10 mm | |
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| `Pattern_p12` | 0 mm | |
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### Mass Properties (Measure Body)
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| Expression | Formula | Unit |
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|-----------|---------|------|
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| `p170` | surface_area | mm² |
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| `p171` | volume | mm³ |
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| `p172` | center_of_mass | mm (point) |
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| **`p173`** | **mass** | **kg** |
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| `p174` | weight | N |
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| `p175` | density | kg/mm³ |
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### Other
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| Expression | Value | Notes |
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|-----------|-------|-------|
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| `p4` | → `beam_lenght` | Alias |
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| `p119` | 4,000 mm | |
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| `p132` | 444.444 mm | Computed |
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| `p134` | 4,000 mm | |
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| `p135` | 4,000 mm | |
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| `p139` | 10 mm | |
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| `p141` | 0 mm | |
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## Boundary Conditions — Confirmed (Gen 002)
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| BC | Location | Value | Source |
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|----|----------|-------|--------|
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| Fixed support | Left side (full edge) | All DOF constrained | ✅ KBS session |
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| Applied force | Right side (free end) | 10,000 kgf downward (−Y) | ✅ KBS session — "project requirement" |
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| Configuration | Cantilever | Left fixed, right loaded | ✅ KBS session |
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## Mesh — Confirmed (Gen 002)
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| Property | Value | Source |
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|----------|-------|--------|
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| Element type | CQUAD4 (thin shell) | ✅ KBS session |
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| Element size | 33.7 mm (67.4/2) | ✅ KBS session |
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| Idealization | Promote body → mid-surface extraction | ✅ KBS session |
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## Hole Geometry — Confirmed (Gen 002)
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| Property | Value | Notes |
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|----------|-------|-------|
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| Span | 4,000 mm (expression `p6`) | Total distribution length |
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| Start offset | 500 mm from beam start | Fixed requirement — not parametric |
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| End offset | 500 mm from beam end | Fixed requirement — not parametric |
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| Computed spacing | 444.444 mm (4000 / 9) | At baseline (10 holes) |
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| Collision check | Required at DV extremes | 15 × 450 mm in 4,000 mm → overlap |
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## Model Files
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- NX Part: `Beam.prt`
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- FEM: `Beam_fem1.fem`
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- Idealized part: `Beam_fem1_i.prt`
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- Simulation: `Beam_sim1.sim`
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- Solver: NX Nastran SOL 101 (static structural)
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## Future Expansion
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- Material alternatives: Aluminum 6061, Stainless Steel ANSI 310 (per Antoine, KBS session)
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- `p6` (hole span) as additional design variable (pending decision G15)
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- Mesh refinement (Antoine: "Eventually we're going to be able to refine the element size")
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## Decisions
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- 2026-02-08: Project received from Antoine
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- 2026-02-10: KBS sessions processed → Gen 002 KB update. BCs confirmed.
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- 2026-02-10: Binary introspection — all expression names/values confirmed. Mass = 1,133.01 kg.
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## Status
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Phase: Baseline characterized — proceeding to optimization strategy finalization
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Generation: 002 (+ introspection corrections)
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Channel: #project-hydrotech-beam
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Last KBS session: 2026-02-10T16:38:01
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