2.5 KiB
2.5 KiB
Sandwich Beam
Type: Primary structural component Material: Steel (AISI) — see steel-aisi.md Status: Baseline documented, optimization pending
Description
Sandwich I-beam serving as primary load-bearing member in a test fixture assembly. Cross-section features a core layer flanked by face sheets on top and bottom flanges. Web contains a pattern of lightening holes (circular cutouts) to reduce mass.
Specifications
| Parameter | Value | Units | Source |
|---|---|---|---|
| Mass (baseline) | ~974 | kg | NX expression p173 |
| Tip displacement (baseline) | ~22 | mm | SOL 101 result |
| Half-core thickness | 20 (baseline) | mm | DV range: 10–40 |
| Face thickness | 20 (baseline) | mm | DV range: 10–40 |
| Hole diameter | 300 (baseline) | mm | DV range: 150–450 |
| Hole count | 10 (baseline) | — | DV range: 5–15 (integer) |
| Beam length | ❓ TBD | mm | Gap G1 |
| Support conditions | ❓ TBD | — | Gap G1 |
Structural Behavior
From Technical Breakdown (Gen 001):
The beam is bending-dominated:
| Behavior | Governing Parameters | Notes |
|---|---|---|
| Bending stiffness (EI) | Face thickness, core thickness | Faces carry bending stress, core carries shear. Stiffness scales ~quadratically with distance from neutral axis |
| Mass | All four variables | Core and face add material; holes remove material from web |
| Stress concentrations | Hole diameter, hole spacing | Larger holes → higher SCF at edges. Closely spaced holes can interact |
| Shear capacity | Core thickness, hole count, diameter | Holes reduce shear-carrying area |
Design Variable Interactions
- Core × Face — classic sandwich interaction. Optimal stiffness balances core depth (lever arm) vs face material (bending resistance)
- Hole diameter × Hole count — both remove web material. Large + many could leave insufficient ligament width
- Face × Hole diameter — thicker faces reduce nominal stress, allowing larger holes
- Core × Hole diameter — core thickness determines web height, constrains max feasible hole diameter
Key Risk
⚠️ Baseline FAILS displacement constraint (22 mm vs 10 mm target). Optimizer must increase stiffness by >50% while reducing mass. Feasible region may be tight.
History
- Gen 001 (2026-02-09): Initial documentation from intake + technical breakdown