ISO 12817:2025

Overview - ISO 12817:2025 in brief

ISO 12817:2025 specifies a standardized test method to determine the open-hole compression strength of laminated fibre‑reinforced plastic composites. It applies to balanced/symmetrical or otherwise thickness‑homogeneous laminates made from textile‑diameter fibres (carbon, glass, aramids, etc.) and thermoset or thermoplastic matrices. The standard defines specimen preparation, apparatus, test procedures and reporting so results are repeatable and comparable for composites testing and material qualification.

Key technical topics and requirements

• Three test methods:
  • Method 1 - short specimen with support fixture (L‑shaped base plate and two end fixtures compressed between platens).
  • Method 2 - short specimen without support fixture (end supports similar to ISO 14126:2023, useful for cyclic and reversed loading with hydraulic grips).
  • Method 3 - long specimen with support fixture, including 3A (stabilization fixture clamped by hydraulic grips) and 3B (stabilization fixture end‑loaded by platens); methods reference ASTM D6484/D6484M‑09 procedures.
• Principle: a rectangular strip with a central open hole is compressed; the maximum load divided by the gross cross‑section (width × thickness) defines open‑hole compressive strength.
• Apparatus and measurement:
  • Test machines to conform with ISO 5893 requirements; load indication and load cell precision ≤ ±1% full scale.
  • Specific fixtures/supports to prevent buckling and control force introduction; material and dimensional details are provided.
• Specimens & conditioning:
  • Detailed specimen shapes/dimensions, preparation, inspection (including hole roundness measurement) and conditioning per ISO 291.
• Procedure & reporting:
  • Test speed, preliminary loading, loading and recording procedures, failure‑mode classification, calculation of open‑hole compressive strength and precision statements.
  • Test reports must include key items such as specimen configuration, hole roundness and chosen method; note that results from methods 1, 2 and 3 may not be equivalent.

Practical applications and typical users

• Applications:
  • Material qualification and comparative performance testing for aerospace, automotive, marine, wind‑energy, sporting goods and other composite structures where notches/holes are stress concentrators.
  • Design validation, quality control, production acceptance and failure analysis for notched composite components.
• Who uses ISO 12817:2025:
  • Test laboratories, composite manufacturers, R&D teams, structural and materials engineers, certification bodies and suppliers of fibres/matrices.

Related standards

• ASTM D6484/D6484M‑09 (procedures A and B referenced for method 3)
• ISO 14126:2023 (fixtures referenced for method 2)
• ISO 291 (conditioning), ISO 5893 (test machines), ISO 472 (vocabulary), ISO 1268 (test plate production), ISO 12815 (pin‑bearing)
• ASTM D5766 (open‑hole tension) - related open‑hole test methods

Keywords: ISO 12817:2025, open‑hole compression strength, fibre‑reinforced plastic composites, composites testing, ASTM D6484, ISO 14126.