ISO 12817:2013

Overview

ISO 12817:2013 - "Fibre-reinforced plastic composites - Determination of open-hole compression strength" defines a standardized test method to determine the open-hole compressive strength of laminated fibre‑reinforced plastic (FRP) composites. Applicable to balanced, symmetric or otherwise homogeneous laminates, the standard covers textile‑diameter fibres (carbon, glass, aramids, etc.) and both thermoset and thermoplastic matrices. The test uses the maximum load on a centrally holed specimen to calculate open‑hole compressive strength (expressed in MPa). ISO 12817:2013 incorporates three test methods with different fixtures and loading setups, including references to ASTM D6484/D6484M‑09 for method 3.

Key Topics

• Scope and applicability: Laminated FRP composites with balanced/symmetric layups; all common fibre and matrix types meeting the standard’s requirements.
• Three test methods:
  • Method 1: Short specimen with support fixture (L‑shaped base and out‑of‑plane support).
  • Method 2: Short specimen without support fixture (suitable for hydraulic grips and cyclic loading).
  • Method 3: Long specimen with support fixture (follows ASTM D6484/D6484M-procedures 3A and 3B).
• Specimen geometry and dimensions: Standard specimen width typically 36 mm; thickness and lengths vary by method (e.g., method 1 length ~118 mm, method 2 ~125 mm; hole diameter typically 6 mm). Alternative specimens must maintain a width‑to‑hole diameter ratio of 6.
• Apparatus and measurement: Requirements for test machines (conforming to ISO 5893), fixtures, hydraulic grips, micrometers and calipers with specified precision, and load measurement accuracy (≤ ±1%).
• Procedure elements: Conditioning (ISO 291 atmospheres), dimension measurement, mounting, test speed, preliminary loading, recording of load and failure mode.
• Calculations and reporting: Open‑hole compressive strength calculated from maximum load and gross cross‑section; precision and required test report content are specified.

Applications and Users

ISO 12817:2013 is used by:

• Composite materials test laboratories and quality control teams
• Aerospace, automotive, marine and sporting goods manufacturers validating structural performance around fastener holes or cutouts
• R&D and material selection engineers evaluating damage tolerance and notch sensitivity
• Certification bodies and suppliers preparing technical data sheets

Practical uses include informing design safety factors, comparing materials and layups, validating repair methods, and supporting structural certification where open‑hole (notched) compression behaviour is critical.

Related Standards

• ASTM D6484 / D6484M‑09 (procedures referenced for method 3)
• ISO 14126 (in‑plane compressive properties)
• ASTM D5766 (open‑hole tension)
• ISO 12815 (pin‑bearing)
• Supporting references: ISO 291, ISO 472, ISO 1268, ISO 2818, ISO 5893

For accurate implementation, consult the full ISO 12817:2013 text for detailed drawings, tolerances, fixture dimensions and reporting requirements.