Atomizer/projects/hydrotech-beam/CONTEXT.md

CONTEXT.md — Hydrotech Beam Structural Optimization

Client

Hydrotech (internal test fixture)

Objective

Minimize beam mass while meeting displacement and stress constraints. Single-objective: minimize mass, constrain displacement (≤ 10 mm) and stress (≤ 130 MPa).

Key Parameters — Confirmed (Gen 002 + Introspection)

Parameter	NX Expression	Current	Range	Units	DV?	Notes
beam_half_core_thickness	beam_half_core_thickness	25.162	10–40	mm	Yes (DV1)	Core half-thickness
beam_face_thickness	beam_face_thickness	21.504	10–40	mm	Yes (DV2)	Face sheet thickness
holes_diameter	holes_diameter	300	150–450	mm	Yes (DV3)	✅ G14 closed
hole_count	hole_count (→ Pattern_p7)	10	5–15	integer	Yes (DV4)	Pattern parameter link
beam_length	beam_lenght ⚠️	5,000	Fixed	mm	No	Typo in NX — no 'h'
beam_half_height	beam_half_height	250	—	mm	No	✅ G12 closed
beam_half_width	beam_half_width	150	—	mm	No	✅ G13 closed
hole_span	p6 (→ Pattern_p9)	4,000	TBD	mm	Potential (G15)	Total span for hole distribution

Constraints

• Max tip displacement: ≤ 10 mm
• Max von Mises stress: ≤ ~130 MPa (steel, conservative — Gap G9)
• Mass tracked via NX expression p173 (body_property147.mass [kg])

Baseline Performance — Confirmed (Introspection)

Metric	Value	Source	Confidence
Mass	1,133.01 kg	NX expression p173, CEO correction + binary introspection	✅ High
Tip displacement	19.56 mm (node 5161, Tz = −19.51 mm)	OP2 parse via pyNastran, SOL 101 baseline run 2026-02-10	✅ High
Max von Mises stress	117.48 MPa	OP2 parse via pyNastran, CQUAD4 shell stress	✅ High
Material	AISI Steel 1005	physicalmateriallibrary.xml	✅ High
Density	7.3 g/cm³	KBS session	✅ High

⚠️ 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.

NX Expression Map — Full Introspection

Design Variables

Expression	Value	Unit	Type
beam_face_thickness	21.504404775742785	mm	Number — continuous
beam_half_core_thickness	25.162078968746705	mm	Number — continuous
holes_diameter	300	mm	Number — continuous
hole_count	10	—	Integer (via Pattern_p7)

Fixed Geometry Parameters

Expression	Value	Unit
beam_half_height	250	mm
beam_half_width	150	mm
beam_lenght	5,000	mm

Hole Pattern Expressions

Expression	Value/Formula	Notes
p6	4,000 mm	Hole span — potential DV
Pattern_p7	→ hole_count	Count link
Pattern_p8	444.444 mm	Computed spacing (span / (count-1))
Pattern_p9	→ p6	Span link
Pattern_p10	(linked)
Pattern_p11	10 mm
Pattern_p12	0 mm

Mass Properties (Measure Body)

Expression	Formula	Unit
p170	surface_area	mm²
p171	volume	mm³
p172	center_of_mass	mm (point)
p173	mass	kg
p174	weight	N
p175	density	kg/mm³

Other

Expression	Value	Notes
p4	→ beam_lenght	Alias
p119	4,000 mm
p132	444.444 mm	Computed
p134	4,000 mm
p135	4,000 mm
p139	10 mm
p141	0 mm

Boundary Conditions — Confirmed (Gen 002)

BC	Location	Value	Source
Fixed support	Left side (full edge)	All DOF constrained	✅ KBS session
Applied force	Right side (free end)	10,000 kgf downward (−Y)	✅ KBS session — "project requirement"
Configuration	Cantilever	Left fixed, right loaded	✅ KBS session

Mesh — Confirmed (Gen 002)

Property	Value	Source
Element type	CQUAD4 (thin shell)	✅ KBS session
Element size	33.7 mm (67.4/2)	✅ KBS session
Idealization	Promote body → mid-surface extraction	✅ KBS session

Hole Geometry — Confirmed (Gen 002)

Property	Value	Notes
Span	4,000 mm (expression p6)	Total distribution length
Start offset	500 mm from beam start	Fixed requirement — not parametric
End offset	500 mm from beam end	Fixed requirement — not parametric
Computed spacing	444.444 mm (4000 / 9)	At baseline (10 holes)
Collision check	Required at DV extremes	15 × 450 mm in 4,000 mm → overlap

Model Files

• NX Part: Beam.prt
• FEM: Beam_fem1.fem
• Idealized part: Beam_fem1_i.prt
• Simulation: Beam_sim1.sim
• Solver: NX Nastran SOL 101 (static structural)
• NX Version: DesigncenterNX 2512 (Siemens rebranded NX → "DesigncenterNX")
• Install path: C:\Program Files\Siemens\DesigncenterNX2512 (on dalidou)

First Results (2026-02-11)

Metric	Value	Notes
Displacement	17.93 mm	At baseline-ish DVs
Von Mises stress	111.9 MPa	At baseline-ish DVs
Solve time	~12 s/trial	On dalidou (Windows)
Mass extraction	Via p173 expression	Journal writes _temp_mass.txt

Both constraints violated at baseline (disp > 10mm). Optimization will need to find stiffer/heavier designs or relaxed constraints.

Future Expansion

• Material alternatives: Aluminum 6061, Stainless Steel ANSI 310 (per Antoine, KBS session)
• p6 (hole span) as additional design variable (pending decision G15)
• Mesh refinement (Antoine: "Eventually we're going to be able to refine the element size")

Decisions

• 2026-02-08: Project received from Antoine
• 2026-02-10: KBS sessions processed → Gen 002 KB update. BCs confirmed.
• 2026-02-10: Binary introspection — all expression names/values confirmed. Mass = 1,133.01 kg.
• 2026-02-11: NX version fixed (DesigncenterNX 2512), path resolution bugs fixed, iteration architecture finalized (backup/restore in-place), history DB added. First real solve results.

Status

Phase: DOE execution — solver pipeline operational, first results obtained Generation: 003 Channel: #project-hydrotech-beam Last update: 2026-02-11

Solver Pipeline Status

• ✅ NX journal solve working (DesigncenterNX 2512)
• ✅ Mass extraction via p173 expression
• ✅ Displacement & stress extraction via pyNastran OP2 parsing
• ✅ Iteration archival (params, results, OP2, F06)
• ✅ History DB (SQLite + CSV, append-only, survives --clean)
• ✅ Geometric pre-checks (hole overlap, web clearance)
• 🔄 Full 51-trial DOE run pending

Development Workflow

• Git only for development (git push/pull between server and dalidou)
• Syncthing paused to avoid conflicts during active development
• Resume Syncthing for production/delivery phases