Atomizer/projects/hydrotech-beam/studies/01_doe_landscape/atomizer_spec_draft.json

{
  "meta": {
    "version": "2.0",
    "created": "2026-02-09T12:00:00Z",
    "modified": "2026-02-09T12:00:00Z",
    "created_by": "optimizer-agent",
    "modified_by": "optimizer-agent",
    "study_name": "01_doe_landscape",
    "description": "Hydrotech Beam — DoE landscape mapping + TPE optimization. Minimize mass subject to displacement and stress constraints.",
    "tags": ["hydrotech-beam", "doe", "landscape", "tpe", "single-objective"]
  },
  "model": {
    "sim": {
      "path": "models/Beam_sim1.sim",
      "solver": "nastran"
    },
    "part": "models/Beam.prt",
    "fem": "models/Beam_fem1.fem",
    "idealized": "models/Beam_fem1_i.prt"
  },
  "design_variables": [
    {
      "id": "dv_001",
      "name": "beam_half_core_thickness",
      "expression_name": "beam_half_core_thickness",
      "type": "continuous",
      "bounds": {
        "min": 10,
        "max": 40
      },
      "baseline": 20,
      "units": "mm",
      "enabled": true,
      "description": "Core half-thickness. Stiffness scales ~quadratically via sandwich effect (lever arm). Also adds core mass linearly."
    },
    {
      "id": "dv_002",
      "name": "beam_face_thickness",
      "expression_name": "beam_face_thickness",
      "type": "continuous",
      "bounds": {
        "min": 10,
        "max": 40
      },
      "baseline": 20,
      "units": "mm",
      "enabled": true,
      "description": "Face sheet thickness. Primary bending stiffness contributor AND primary mass contributor. Key trade-off variable."
    },
    {
      "id": "dv_003",
      "name": "holes_diameter",
      "expression_name": "holes_diameter",
      "type": "continuous",
      "bounds": {
        "min": 150,
        "max": 450
      },
      "baseline": 300,
      "units": "mm",
      "enabled": true,
      "description": "Lightening hole diameter. Mass reduction scales with d². Stress concentration scales with hole size. Geometric feasibility depends on beam web length."
    },
    {
      "id": "dv_004",
      "name": "hole_count",
      "expression_name": "hole_count",
      "type": "integer",
      "bounds": {
        "min": 5,
        "max": 15
      },
      "baseline": 10,
      "units": "",
      "enabled": true,
      "description": "Number of lightening holes in the web. Integer variable (11 levels). Interacts strongly with holes_diameter for geometric feasibility."
    }
  ],
  "extractors": [
    {
      "id": "ext_001",
      "name": "Mass Extractor",
      "type": "expression",
      "config": {
        "expression_name": "p173",
        "description": "Total beam mass from NX expression"
      },
      "outputs": [
        {
          "name": "mass",
          "metric": "total",
          "units": "kg"
        }
      ]
    },
    {
      "id": "ext_002",
      "name": "Displacement Extractor",
      "type": "displacement",
      "config": {
        "method": "result_sensor_or_op2",
        "component": "magnitude",
        "location": "beam_tip",
        "description": "Tip displacement magnitude from SOL 101. Preferred: NX result sensor. Fallback: parse .op2 at tip node ID.",
        "TODO": "Confirm displacement sensor exists in Beam_sim1.sim OR identify tip node ID"
      },
      "outputs": [
        {
          "name": "tip_displacement",
          "metric": "max_magnitude",
          "units": "mm"
        }
      ]
    },
    {
      "id": "ext_003",
      "name": "Stress Extractor",
      "type": "stress",
      "config": {
        "method": "op2_elemental_nodal",
        "stress_type": "von_mises",
        "scope": "all_elements",
        "unit_conversion": "kPa_to_MPa",
        "description": "Max von Mises stress (elemental nodal) from SOL 101. pyNastran returns kPa for NX kg-mm-s units — divide by 1000 for MPa.",
        "TODO": "Verify element types in model (CQUAD4? CTETRA? CHEXA?) and confirm stress scope"
      },
      "outputs": [
        {
          "name": "max_von_mises",
          "metric": "max",
          "units": "MPa"
        }
      ]
    }
  ],
  "objectives": [
    {
      "id": "obj_001",
      "name": "Minimize beam mass",
      "direction": "minimize",
      "weight": 1.0,
      "source": {
        "extractor_id": "ext_001",
        "output_name": "mass"
      },
      "units": "kg"
    }
  ],
  "constraints": [
    {
      "id": "con_001",
      "name": "Tip displacement limit",
      "type": "hard",
      "operator": "<=",
      "threshold": 10.0,
      "source": {
        "extractor_id": "ext_002",
        "output_name": "tip_displacement"
      },
      "penalty_config": {
        "method": "deb_rules",
        "description": "Deb's feasibility rules: feasible always beats infeasible; among infeasible, lower violation wins"
      },
      "margin_buffer": {
        "optimizer_target": 9.5,
        "hard_limit": 10.0,
        "description": "5% inner margin during optimization to account for numerical noise"
      }
    },
    {
      "id": "con_002",
      "name": "Von Mises stress limit",
      "type": "hard",
      "operator": "<=",
      "threshold": 130.0,
      "source": {
        "extractor_id": "ext_003",
        "output_name": "max_von_mises"
      },
      "penalty_config": {
        "method": "deb_rules",
        "description": "Deb's feasibility rules: feasible always beats infeasible; among infeasible, lower violation wins"
      },
      "margin_buffer": {
        "optimizer_target": 123.5,
        "hard_limit": 130.0,
        "description": "5% inner margin during optimization to account for mesh sensitivity"
      }
    }
  ],
  "optimization": {
    "phases": [
      {
        "id": "phase_1",
        "name": "DoE Landscape Mapping",
        "algorithm": {
          "type": "LHS",
          "config": {
            "criterion": "maximin",
            "integer_handling": "round_nearest_stratified",
            "seed": 42
          }
        },
        "budget": {
          "max_trials": 50,
          "baseline_enqueued": true,
          "total_with_baseline": 51
        },
        "purpose": "Map design space, identify feasible region, assess sensitivities and interactions"
      },
      {
        "id": "phase_2",
        "name": "TPE Optimization",
        "algorithm": {
          "type": "TPE",
          "config": {
            "sampler": "TPESampler",
            "n_startup_trials": 0,
            "warm_start_from": "phase_1_best_feasible",
            "seed": 42,
            "constraint_handling": "deb_feasibility_rules"
          }
        },
        "budget": {
          "min_trials": 60,
          "max_trials": 100,
          "adaptive": true
        },
        "convergence": {
          "stall_window": 20,
          "stall_threshold_pct": 1.0,
          "min_trials_before_check": 60
        },
        "purpose": "Directed optimization to converge on minimum-mass feasible design"
      }
    ],
    "total_budget": {
      "min": 114,
      "max": 156,
      "estimated_hours": "4-5"
    },
    "baseline_trial": {
      "enqueue": true,
      "values": {
        "beam_half_core_thickness": 20,
        "beam_face_thickness": 20,
        "holes_diameter": 300,
        "hole_count": 10
      },
      "expected_results": {
        "mass_kg": 974,
        "tip_displacement_mm": 22,
        "max_von_mises_mpa": "UNKNOWN — must measure"
      }
    }
  },
  "error_handling": {
    "trial_timeout_seconds": 600,
    "on_nx_rebuild_failure": "record_infeasible_max_violation",
    "on_solver_failure": "record_infeasible_max_violation",
    "on_extraction_failure": "record_infeasible_max_violation",
    "max_consecutive_failures": 5,
    "max_failure_rate_pct": 30,
    "nx_process_management": "NEVER kill NX directly. Use NXSessionManager.close_nx_if_allowed() only."
  },
  "pre_flight_checks": [
    {
      "id": "pf_001",
      "name": "Baseline validation",
      "description": "Run Trial 0 with baseline parameters, verify mass ≈ 974 kg and displacement ≈ 22 mm"
    },
    {
      "id": "pf_002",
      "name": "Corner tests",
      "description": "Test 16 corner combinations (min/max for each DV). Verify NX rebuilds and solves at all corners."
    },
    {
      "id": "pf_003",
      "name": "Mesh convergence",
      "description": "Run baseline at 3 mesh densities. Verify stress convergence within 10%."
    },
    {
      "id": "pf_004",
      "name": "Extractor validation",
      "description": "Confirm mass, displacement, and stress extractors return correct values at baseline."
    },
    {
      "id": "pf_005",
      "name": "Geometric feasibility",
      "description": "Determine beam web length. Verify max(hole_count) × max(holes_diameter) fits. Add ligament constraint if needed."
    }
  ],
  "open_items": [
    "Beam web length needed for geometric feasibility validation (holes_diameter × hole_count vs available length)",
    "Displacement extraction method: result sensor in .sim or .op2 node ID parsing?",
    "Stress extraction scope: whole model or specific element group?",
    "Verify NX expression name 'p173' maps to mass",
    "Benchmark single SOL 101 runtime to refine compute estimates",
    "Confirm baseline stress value (currently unknown)",
    "Clarify relationship between core/face thickness DVs and web height where holes are placed"
  ]
}