Overview
EN ISO 14130:1997 (ISO 14130:1997) defines a standardized short-beam test for determining the apparent interlaminar shear strength (ILSS) of fibre‑reinforced plastic composites. The method uses a three‑point bending (short-span) configuration to promote interlaminar shear failure and is intended primarily for screening, quality control and material comparison, not for deriving design allowables.
Key topics and technical requirements
- Scope: Applies to thermoset and thermoplastic fibre‑reinforced composites (unidirectional and textile reinforcements, prepregs, hybrids) provided interlaminar shear failure can be produced.
- Specimen geometry (standard size): rectangular bars; typical nominal dimensions given are thickness h = 2 ± 0.2 mm, width b = 10 ± 0.2 mm, overall length l = 20 ± 1 mm. Alternative sizes must preserve the ratios l = 10h and b = 5h.
- Span setting: span L = 5h − 0.3 mm (short span to emphasize shear).
- Test setup: three‑point loading with specified loading nose/support radii (loading member r = 5 mm, supports r = 2 mm) and loading centered between supports. Test speed typically 1 mm/min unless otherwise specified.
- Calculation: apparent ILSS is calculated from the maximum load F using the formula:
t = 3F / (4 b h) (expressed in MPa).
- Failure modes: only single or multiple interlaminar shear failures are acceptable. Mixed or non‑shear failures (tension, compression, plastic shear) must be reported and the calculated values flagged as not true ILSS.
- Specimen preparation & conditioning: machining per ISO 2818 and preparation guidance per ISO 1268; conditioning and test atmosphere per ISO 291.
- Reporting: includes specimen ID, dimensions, span, loading radii, test speed, failure mode, individual and mean ILSS values, and any deviations from the method.
- Precision: interlaboratory precision was not established in the 1997 edition.
Applications and who uses it
- Composite materials laboratories and test houses conducting quality control, batch acceptance and comparative screening of fibre‑reinforced plastics.
- R&D teams comparing resin systems, reinforcement types or processing variants where quick ranking of interlaminar shear resistance is needed.
- Manufacturers and suppliers of composite laminates who require a standardized, repeatable short‑beam method (ILSS) for internal QC and material data sheets.
- Note: this method is not intended as a design property for structural calculations.
Related standards
- ISO 14125 - flexural properties of fibre‑reinforced plastics (three‑point bending)
- ISO 291 - conditioning/plastic standard atmospheres
- ISO 5893 - test machine requirements
- ISO 1268, ISO 2818 - specimen preparation and machining
- ISO 2602 - statistical treatment of results
Keywords: EN ISO 14130, ISO 14130:1997, interlaminar shear strength, ILSS, short‑beam method, composite testing, fibre‑reinforced plastic composites.
