Atomizer/hq/hq/projects/lightweight-bracket/CONTEXT.md

Lightweight Bracket — Project Context

Created: 2026-02-16
Status: Design Phase
Owner: Technical Lead

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Material Decision

Property	Value
Selected Material	Al 7075-T6
Decision Date	2026-02-16
Decision By	Antoine (CEO)
Rationale	Prioritize structural performance / weight savings

7075-T6 Key Properties

• Density: 2.81 g/cm³
• UTS: 572 MPa
• Yield: 503 MPa
• Elongation: ~11%
• Thermal conductivity: 130 W/m·K
• CTE: 23.2 µm/m·°C

Rejected Alternative

• 6061-T6 — better thermal conductivity, weldability, and cost, but lower strength-to-weight

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Design Requirements

(To be defined — awaiting detailed requirements from CEO/Manager)

• Load cases (magnitude, type, direction)
• Geometric envelope / mounting constraints
• Displacement / stiffness targets
• Fatigue / cycle life requirements
• Manufacturing constraints (machining vs. additive)
• Weight target

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Next Phase: Preliminary Design & Analysis Plan

Phase 1 — Requirements & Baseline

1. Define load cases — static, dynamic, thermal (if any)
2. Establish geometric envelope — mounting points, clearances, interfaces
3. Set performance targets — max displacement, stress margins, weight budget
4. Create baseline CAD geometry in NX

Phase 2 — FEA Baseline Analysis

1. Mesh — CQUAD4/CHEXA (mesh convergence study required)
2. Boundary conditions — match physical mounting (bolted? welded? pinned?)
3. SOL 101 linear static — baseline stress & displacement
4. SOL 103 modal — check natural frequencies vs. excitation environment
5. Validate — analytical hand-calcs for sanity check

Phase 3 — Design Optimization

1. Identify design variables — wall thickness, rib placement, fillet radii, topology
2. Formulate optimization — minimize mass, constrain stress (σ_y / FOS) and displacement
3. Topology optimization (if applicable) — SOL 200 or Simcenter topology
4. Parametric study — LAC pattern via Atomizer framework
5. Iterate to converged optimum

Phase 4 — Validation & Deliverables

1. Mesh convergence confirmation on final design
2. Margin of safety report (yield, ultimate, buckling if thin-walled)
3. Fatigue assessment if cyclic loading present
4. Note on 7075-T6 ductility — 11% elongation is moderate; flag any high-strain regions
5. Final report with full documentation

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Open Questions / Gaps

• G1: Bracket function — what does it support? What assembly?
• G2: Load cases — not yet defined
• G3: Geometric constraints — no envelope defined
• G4: Manufacturing method — machining assumed, confirm
• G5: Factor of safety requirements
• G6: Any thermal loads? (7075-T6 lower conductivity noted as accepted trade-off)
• G7: Fatigue/cycle life requirements

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Superseded Decisions

• None