policy_id: MATERIAL-FALLBACK-001
recorded: '2026-10-11'
authorized_by_user: true
user_instruction: Если не можешь найти данные для современных плит, при расчётах подставляй
  старые
status: authorized_preliminary_input_policy_no_structural_calculation_performed
priority:
- current grade data if available
- historical data for same grade if available
- historical similar material with explicit analogy
- unavailable property remains unresolved until documented assumption or source
record_for_each_substitution:
- property and units
- source ID, page and year
- original grade and test method
- target candidate
- test/loading direction or unknown flag
- reason for analogy
- uncertainty and sensitivity scenarios
historical_modulus_defaults:
- target_candidate: ПЕНОПЛЭКС 45 (H16)
  source_id: H25
  source_page: 116
  source_year: 2010
  original_grade: ПЕНОПЛЭКС 45, ТУ 5767-006-56925804–2007
  published_property_label: Модуль упругости
  published_method: СОЮЗДОРНИИ
  reference_modulus_MPa: 18
  use: provisional historical substitution, not current batch measurement
  loading_direction: not specified in table
- target_candidate: CARBON SOLID 500 (H17)
  source_id: H25
  source_page: 117
  source_year: 2010
  original_grade: ТЕХНОПЛЕКС 45…500, ТУ 2244-047-17925162–2006
  published_property_label: Модуль упругости
  published_method: СОЮЗДОРНИИ
  reference_modulus_MPa: 20
  use: provisional analogy between high-compression XPS grades; not identity of products
  loading_direction: not specified in table
restrictions:
- Do not relabel published generic modulus as measured shear modulus G.
- Before using reference modulus as FEM Young modulus explicitly record a model assumption
  about method, direction and constitutive model.
- Do not infer identical density, shear, bond or fatigue from compression class.
- Historical or analog-derived values remain assumptions when reporting strength,
  masses and draft.
- Use sensitivity checks; no statistical confidence interval claimed.
- Retain complete superstructure and roof load path.
future_inputs:
- numerical historical shear modulus and shear strength for comparable foam
- bond behavior of chosen resin and skin
- creep and temperature behavior
source_reference: research/hull-materials/polystyrene-mechanics/reference-values.json