{
  "vercy": "1.0-draft",
  "publication": {
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    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-13T22:52:39Z",
    "providers": [
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    "pass": 2,
    "wave": 4,
    "engine": "claude",
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      "engine": "claude",
      "producedAt": "2026-10-06T11:00:00Z",
      "ingestedAt": "2026-10-06T07:45:27+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "owners"
      ]
    },
    "revisions": [
      {
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          "definition"
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        "review by codex: pass"
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  },
  "metaModel": {
    "id": "THING-Q1500907",
    "registryId": "vr.tr.membrane-structure",
    "name": "membrane structure",
    "version": "0.2.0-wave.4",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "PHY.BLT"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q1500907/",
  "model": {
    "registry_id": "vr.tr.membrane-structure",
    "name": "membrane structure",
    "purpose": "Let an agent explain membrane structures, relay forms, materials, design principles and notable examples from architecture and structural engineering sources, and distinguish membrane structures from shells of rigid concrete, tents as temporary shelters, cable-stayed bridges and inflatable products.",
    "definition": "A building structure whose form and load-bearing capacity come from a thin, flexible membrane, usually a coated fabric such as PTFE-coated glass fibre or PVC-coated polyester, or a foil such as ETFE, kept in tension by cables, masts, arches or air pressure, including tensile structures and air-supported domes; examples include the Millennium Dome in London and the ETFE cushions of the Eden Project. Membrane structures need design for wind, snow and fire performance under building codes.",
    "what_it_is_for": "Covering large spans with lightweight surfaces.",
    "affordances": [
      "explain forms and materials",
      "relay design principles",
      "describe notable examples",
      "distinguish related structures"
    ],
    "distinguishing_features": [
      "Tension-based form",
      "Lightweight",
      "Double-curved surfaces",
      "Translucency"
    ],
    "appearance": "Curved, taut fabric or foil surfaces supported by masts, cables or air, often white or translucent.",
    "visual_identification": [
      "Tensioned membrane building structure",
      "Tensile structure, fabric structure, air-supported structure, ETFE cushion roof",
      "Concrete shells are rigid; tents are temporary; cable-stayed bridges carry decks; inflatable products are not buildings"
    ],
    "physical_properties": [
      {
        "quantity": "Munich Olympic Stadium roof",
        "typical_range": "1972",
        "unit": "year",
        "note": "Frei Otto and Behnisch"
      },
      {
        "quantity": "PTFE-coated glass fibre lifespan",
        "typical_range": "about 25 or more",
        "unit": "years",
        "note": "typical estimates"
      },
      {
        "quantity": "ETFE foil weight",
        "typical_range": "about 1 percent of glass",
        "unit": "note",
        "note": "often cited comparison"
      }
    ],
    "families_and_kinds": [
      "tensile fabric structures",
      "cable net structures",
      "air-supported structures",
      "air-inflated ETFE cushions",
      "retractable membrane roofs"
    ],
    "related_models": [
      {
        "relation": "is a kind of",
        "target": "built structure",
        "why": "in registry terms"
      },
      {
        "relation": "includes",
        "target": "tensile structure",
        "why": ""
      },
      {
        "relation": "uses",
        "target": "ETFE",
        "why": ""
      },
      {
        "relation": "is contrasted with",
        "target": "thin-shell structure",
        "why": ""
      }
    ],
    "identifiers": [],
    "standards_and_regulation": [
      "EN 1990 series and CEN/TS 19102 membrane design",
      "ASCE 55 tensile membrane structures",
      "Fire safety building codes"
    ],
    "failure_modes_and_hazards": [
      "Wind and snow load failure",
      "Deflation of air-supported domes",
      "Material ageing and fire"
    ],
    "in_scope": [],
    "out_of_scope": [],
    "characteristics": [],
    "agent_conduct": {
      "may": [
        "Describe membrane structures, their materials and support systems.",
        "Report damage, sagging or loss of pressure to the structure's operator."
      ],
      "must_not": [
        "Allow people into an air-supported dome during deflation or after a pressure alarm.",
        "Ignore wind or snow load warnings for a membrane roof.",
        "Bring open flames or heat sources near a membrane not rated for them.",
        "Change pressure, cable tension or support settings without the operator's instruction."
      ],
      "requires_human": [
        "Evacuating or closing a membrane structure in severe weather."
      ]
    },
    "ethics": {
      "considerations": [
        "Membrane roofs cover crowds, so a failure can hurt many people at once."
      ],
      "affected_parties": [
        "Occupants and spectators",
        "Maintenance workers",
        "Owners and operators"
      ]
    },
    "owners": {
      "steward": "The owner or operator of the building, under building control authorities.",
      "master_systems": []
    }
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q1500907: membrane structure",
      "url": "https://www.wikidata.org/wiki/Q1500907",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: Membrane structure",
      "url": "https://en.wikipedia.org/wiki/Membrane_structure",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "understand",
        "name": "Understand",
        "description": "What a membrane structure is.",
        "rationale": "Definition.",
        "layers": [
          {
            "id": "definition",
            "name": "Definition",
            "description": "Definition.",
            "findings": [
              {
                "id": "definition-finding",
                "name": "Definition",
                "description": "Definition.",
                "questions": [
                  {
                    "text": "What is a membrane structure, and how does it differ from concrete shells, tents, cable-stayed bridges and inflatables?",
                    "kind": "definition"
                  },
                  {
                    "text": "Is the question about design, a specific building or safety?",
                    "kind": "boundary"
                  }
                ]
              }
            ]
          },
          {
            "id": "forms",
            "name": "Forms",
            "description": "Forms.",
            "findings": [
              {
                "id": "forms-finding",
                "name": "Forms",
                "description": "Forms.",
                "questions": [
                  {
                    "text": "What are tensile fabric, cable net, air-supported and ETFE cushion structures?",
                    "kind": "definition"
                  },
                  {
                    "text": "Which entry fits the specific form?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "engineering",
        "name": "Engineering",
        "description": "Engineering.",
        "rationale": "Science.",
        "layers": [
          {
            "id": "formfinding",
            "name": "Form finding",
            "description": "Form finding.",
            "findings": [
              {
                "id": "formfinding-finding",
                "name": "Form finding",
                "description": "Form finding.",
                "questions": [
                  {
                    "text": "How do engineers find stable tensioned shapes, from soap film models to software?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which references are standard?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          },
          {
            "id": "materials",
            "name": "Materials",
            "description": "Materials.",
            "findings": [
              {
                "id": "materials-finding",
                "name": "Materials",
                "description": "Materials.",
                "questions": [
                  {
                    "text": "How do PTFE, PVC and ETFE membranes differ?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which sources are cited?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "safety",
        "name": "Safety",
        "description": "Codes.",
        "rationale": "Regulation.",
        "layers": [
          {
            "id": "loads",
            "name": "Loads",
            "description": "Wind and snow.",
            "findings": [
              {
                "id": "loads-finding",
                "name": "Loads",
                "description": "Loads.",
                "questions": [
                  {
                    "text": "How are membranes designed for wind, snow and ponding?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits structural load?",
                    "kind": "action"
                  }
                ]
              }
            ]
          },
          {
            "id": "fire",
            "name": "Fire",
            "description": "Fire performance.",
            "findings": [
              {
                "id": "fire-finding",
                "name": "Fire",
                "description": "Fire.",
                "questions": [
                  {
                    "text": "How do building codes treat membrane fire performance?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits fire safety?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "context",
        "name": "Context",
        "description": "Examples.",
        "rationale": "Context.",
        "layers": [
          {
            "id": "otto",
            "name": "Frei Otto",
            "description": "Frei Otto.",
            "findings": [
              {
                "id": "otto-finding",
                "name": "Frei Otto",
                "description": "Frei Otto.",
                "questions": [
                  {
                    "text": "How did Frei Otto shape lightweight architecture?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits Frei Otto?",
                    "kind": "action"
                  }
                ]
              }
            ]
          },
          {
            "id": "eden",
            "name": "Eden Project",
            "description": "ETFE domes.",
            "findings": [
              {
                "id": "eden-finding",
                "name": "Eden Project",
                "description": "Eden Project.",
                "questions": [
                  {
                    "text": "How do the Eden Project biomes use ETFE cushions?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits Eden Project?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Should air-supported structures be a separate entry?",
    "How should design standards be linked?",
    "Should notable examples be linked as instances?"
  ],
  "statistics": {
    "bundles": 4,
    "layers": 8,
    "findings": 8,
    "questions": 16
  }
}