EN 2850:2017

Aerospace series - Carbon fibre thermosetting resin - Unidirectional laminates - Compression test parallel to fibre direction

This European Standard defines a method for the determination of stress at failure and Young's modulus in compression of carbon thermosetting resin unidirectional laminates.
The method only covers test pieces the axis of which is parallel to the fibre direction.
This method covers fibres (or fabrics) other than carbon, when the relevant technical specification explicitly mentions it.

Luft- und Raumfahrt - Unidirektionale Laminate aus Kohlenstoffasern und Reaktionsharz - Druckversuch parallel zur Faserrichtung

Série aérospatiale - Fibres de carbone/résine thermodurcissable - Stratifiés unidirectionnels - Essai de compression parallèlement au sens des fibres

Aeronavtika - Laminati iz termično utrjenih smol z enosmerno urejenimi ogljikovimi vlakni - Preskus s stiskanjem v smeri, vzporedni z vlakni

Ta evropski standard opredeljuje metodo za ugotavljanje obremenitve pri okvari in Youngov modul pri stiskanju laminatov iz termično utrjenih smol z enosmerno urejenimi ogljikovimi vlakni.
Metoda zajema samo preskušance, katerih os je vzporedna s smerjo vlaken.
Ta metoda zajema vse vlakna (ali tkanine) razen ogljikovih, kadar je to izrecno navedeno v ustrezni tehnični specifikaciji.

General Information

• Status: Published
• Publication Date: 17-Oct-2017
• Withdrawal Date: 29-Apr-2018
• ICS: 49.025.40 - Rubber and plastics
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 4/S 8 - Thermoplastics
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 18-Oct-2017
• Completion Date: 18-Oct-2017
• Ref Project: SIST EN 2850:2018 - Aerospace series - Carbon fibre thermosetting resin unidirectional laminates - Compression test parallel to fibre direction

Overview

EN 2850:2017 is a European (CEN) aerospace series standard that specifies a compression test method for carbon fibre thermosetting resin unidirectional laminates, with the test axis parallel to the fibre direction. The standard defines procedures to determine compression stress at failure (σc11) and Young’s (secant) modulus in compression (Ec11) for unidirectional composite laminates used in aerospace applications. Where referenced by a material specification, the method may also apply to other fibre types.

Key Topics and Requirements

• Scope and purpose
  • Measurement of stress at failure and secant compression modulus for test pieces with axis parallel to fibres.
• Principle
  • Record longitudinal strain vs applied load during a constant-rate compression test until failure.
  • Two loading approaches: Method A (load introduced mainly via co-cured or bonded tabs) and Method B (direct end compression).
• Test piece geometry
  • Two specimen types (A and B) with specific dimensions (example: gauge length g = 10 ± 0.25 mm; thickness h = 2 ± 0.2 mm; width b = 10 ± 0.2 mm; total thickness H ≈ 4.5 ± 0.5 mm).
  • Tabs can be bonded or integral; co-curing preferred for high-temperature or humidity-aged specimens.
• Instrumentation & apparatus
  • Accurate load frame (±1 %), strain recording device (±1 %), micrometre for dimensions (0.01 mm), and alignment fixtures to prevent buckling.
  • Temperature-controlled testing when required.
• Calculation
  • Stress at failure σc11 = PR / (b · h) where PR = load at failure.
  • Secant modulus Ec11 calculated from load/strain data over specified strain or load intervals (α/β or PR/10–PR/2 methods).
• Validity & reporting
  • Failure must occur in the free gauge length; specific criteria address acceptable buckling and strain difference between faces.
  • Test report shall include specimen ID, dimensions, preparation and tab details, conditioning history, load/strain diagrams, σc11, Ec11, individual results, mean and standard deviation, and any influencing circumstances.

Applications

• Qualification and characterization of carbon fibre thermosetting resin unidirectional laminates for aerospace structures.
• Material data generation for design, finite element modelling and structural analysis.
• Quality assurance, production control, and comparative evaluation of prepregs, laminates and tabbing methods.
• Research and development of composite materials where compression behavior parallel to fibres is critical.

Who uses this standard

• Aerospace materials engineers and composite test laboratories
• Design and structural engineers producing material allowables
• Quality managers and certification bodies involved in aerospace composite part qualification
• R&D organizations developing unidirectional carbon/thermoset systems

Related Standards (normative references)

• EN 2565 - Preparation of carbon fibre reinforced resin panels
• EN 2743 / EN 2744 - Conditioning and preferred test temperatures
• EN 2489 / EN 2823 - Conditioning after immersion or humid exposure
• EN 3783 - Normalisation of fibre-dominated mechanical properties
• EN 2859, EN 2372, EN 3228 - Fasteners and hardware referenced for gripping

Keywords: EN 2850:2017, compression test, carbon fibre thermosetting resin, unidirectional laminates, Young’s modulus, stress at failure, aerospace composites, secant modulus.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.HQLPLDNQLLuft- und Raumfahrt - Duroplast Verbundwerkstoffe - Unidirektionale Kohlenstoffaser - Druckversuch parallel zur FaserrichtungSérie aérospatiale - Fibres de carbone/résine thermodurcissable - Stratifiés unidirectionnels - Essai de compression parallèlement au sens des fibresAerospace series - Carbon fibre thermosetting resin unidirectional laminates - Compression test parallel to fibre direction49.025.40Guma in polimerni materialiRubber and plasticsICS:Ta slovenski standard je istoveten z:EN 2850:2017SIST EN 2850:2018en,fr,de01-februar-2018SIST EN 2850:2018SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 2850
October
t r s y ICS
v {ä r t wä v r English Version
Aerospace series æ Carbon fibre thermosetting resin æ Unidirectional laminates æ Compression test parallel to fibre direction thermodurcissable æ Stratifiés unidirectionnels æ Essai de compression parallèlement au sens des fibres
Luftæ und Raumfahrt æ Unidirektionale Laminate aus Kohlenstoffasern und Reaktionsharz æ Druckversuch parallel zur Faserrichtung This European Standard was approved by CEN on
t x June
t r s yä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
t z w rã t r s y ESIST EN 2850:2018

EN 2372 1), Nuts, hexagon, thin, steel, cadmium plated — Classification: 1 100 MPa/235 °C — Aerospace series 2) EN 2489, Aerospace series — Fibre reinforced plastics — Determination of the action of test fluids EN 2565, Aerospace series — Preparation of carbon fibre reinforced resin panels for test purposes 3) EN 2743, Aerospace series — Fibre reinforced plastics — Standard procedures for conditioning prior to testing unaged materials EN 2744, Aerospace series — Non-metallic materials — Preferred test temperatures
EN 2823, Aerospace series — Fibre reinforced plastics — Determination of the effect of exposure to humid atmosphere on physical and mechanical characteristics 3) EN 2859, Aerospace series — Bolts, normal hexagonal head, close tolerance normal shank, short thread, in alloy steel, cadmium plated, metric series — Classification: 1 100 MPa (at ambient temperature) / 235 °C EN 3228, Aerospace series — Nuts, hexagonal, plain, reduced height, normal across flats, in steel, cadmium plated — Classification: 900 MPa (at ambient temperature) / 235 °C EN 3783, Aerospace series — Fibre composite materials — Normalisation of fibre dominated mechanical properties
1) Inactive for new design, see prEN 3228.
2) Published as ASD-STAN Standard at the date of publication of this standard by AeroSpace and Defence industries Association of Europe - Standardization (ASD-STAN) (www.asd-stan.org) 3) Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence industries Association of Europe - Standardization (ASD-STAN) (www.asd-stan.org) SIST EN 2850:2018
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