Sources: 3 KBS capture sessions (20260210-132817, 20260210-161401, 20260210-163801)
Key changes:
- Mass corrected: 974 kg (p173) → 11.33 kg (p1) — KBS ground truth
- Beam length confirmed: 5,000 mm cantilever
- BCs confirmed: left fixed, right 10,000 kgf downward
- Material confirmed: AISI Steel 1005, density 7.3 g/cm³
- Mesh confirmed: CQUAD4 thin shell, 33.7 mm elements
- Hole geometry: span 4,000 mm (p6), offsets 500 mm fixed
- 3 gaps closed (G1, G2, G8), 6 new gaps identified (G10-G15)
- New expressions: beam_half_height, beam_half_width, beam_length, p6
Files: CONTEXT.md, kb/_index.md, kb/_history.md, kb/components/sandwich-beam.md,
kb/materials/steel-aisi.md, kb/fea/models/sol101-static.md, kb/dev/gen-002.md
3.2 KiB
3.2 KiB
Steel — AISI 1005
Status: Baseline material confirmed (Gen 002) NX Material Name: "beam material" (inherited by thin shell property)
Properties
| Property | Value | Units | Source | Confidence |
|---|---|---|---|---|
| Standard | AISI / SAE | — | KBS session | ✅ Confirmed |
| Grade | 1005 | — | KBS session ("NSE steel 10 or 5" = ANSI Steel 1005) | ✅ Confirmed |
| Density | 7.3 | g/cm³ (7,300 kg/m³) | KBS session — Antoine stated directly | ✅ Confirmed |
| E (Young's modulus) | ~200 | GPa | Typical for AISI 1005 — needs NX verification | 🟡 Estimated |
| Yield strength | ~285 | MPa | Typical for AISI 1005 (cold-drawn) — needs NX verification | 🟡 Estimated |
| UTS | ~330 | MPa | Typical for AISI 1005 — needs NX verification | 🟡 Estimated |
| Poisson's ratio | ~0.29 | — | Typical for carbon steel — needs NX verification | 🟡 Estimated |
| Elongation | ~20 | % | Typical for AISI 1005 — needs verification | 🟡 Estimated |
Notes on AISI 1005
- AISI 1005 is a low-carbon plain steel (0.06% max C) in the 10xx series
- Commonly used for structural applications — good weldability, moderate strength
- NX material library designation may vary (Antoine said "NSE steel 10 or 5" which maps to ANSI/AISI Steel 1005)
- Density note: Antoine stated 7.3 g/cm³. Standard steel is 7.85 g/cm³. The 7.3 value may be the NX library default or a specific setting. This affects mass calculation directly.
Stress Allowable
| Parameter | Value | Basis | Status |
|---|---|---|---|
| Stress constraint | 130 MPa | From intake — Gap G9 | 🟡 Not yet confirmed for Gen 002 |
| Implied safety factor | ~2.2 | vs. 285 MPa yield (estimated) | Conservative |
⚠️ Need to confirm whether the 130 MPa stress limit from Gen 001 intake still applies given the mass discrepancy resolution. The 130 MPa may have been set for the ~974 kg model.
Future Material Expansion
Antoine explicitly requested future material support (KBS session 20260210-163801):
| Material | Standard | Priority | Notes |
|---|---|---|---|
| Aluminum 6061 | — | Future | Antoine: "change this type of material for aluminum, 6061" |
| Stainless Steel ANSI 310 | ANSI 310 | Future | Antoine: "stainless steel. ANSI, let's say 310" |
Antoine's instruction: "Don't start with [these]. Just add this as a future expansion for the optimization process."
Material Expansion Implications
- Multi-material optimization would change the problem fundamentally:
- Different E, ρ, σ_y for each material → different optimal geometries
- Could be handled as a categorical DV or separate optimization runs per material
- Aluminum 6061: E ≈ 69 GPa, ρ ≈ 2.7 g/cm³, σ_y ≈ 276 MPa — lighter but much less stiff
- SS 310: E ≈ 200 GPa, ρ ≈ 8.0 g/cm³, σ_y ≈ 205 MPa — heavier, similar stiffness, lower yield
History
- Gen 001 (2026-02-09): Placeholder — only knew "Steel (AISI)"
- Gen 002 (2026-02-10): Confirmed AISI 1005 from KBS session. Density confirmed 7.3 g/cm³. Future materials flagged (Al 6061, SS 310). Typical mechanical properties added (pending NX verification).