BS EN 15857:2010 pdf free download Non-destructive testing — Acoustic emission — Testing of fibre- reinforced polymers — Specific methodology and general evaluation criteria
This European Standard describes the general principles of acoustic emission (AE) testing of materials,components and structures made of FRP with the aim of:
materials characterisation;
proof testing/manufacturing quality control;retesting/in-service inspection;
health monitoring.
When AE testing is used to assess the integrity of FRP materials, components or structures or identify criticalzones of high damage accumulation or damage growth under load this standard further describes the speciicmethodology (e.g.suitable instrumentation, typical sensor arrangements, location procedures, etc.).
lt also describes available,generally applicable evaluation criteria for AE testing of FRP and outlinesprocedures for establishing such evaluation criteria in case they are lacking.
NOTE The structural significance of the AE may not in all cases definitely be assessed based on AE evaluationcriteria only but may require further inspection and assessment (e.g. with other non-destructive test methods or fracturemechanics calculations).
This standard also recommends formats for the presentation of AE test data that allow the application ofqualitative and quantitative evaluation criteria, both on-line during testing and by post test analysis, and thatsimplify comparison of AE test results obtained from different test sites and organisations.
2Normative references
The following referenced documents are indispensable for the application of this document. For datedreferences,only the edition cited applies. For undated references,the latest edition of the referenceddocument (including any amendments) applies.
EN 473,Non-destructive testing —Qualification and certification of NDT personnel—General principlesEN 1330-1:1998,Non destructive testing —Terminology- Part 1: List of general terms
EN 1330-2:1998,Non-destructive testing —Terminology — Part 2:Terms common to the non-destructivetesting methods
EN 1330-9:2009,Non-destructive testing —Terminology— Part 9:Terms used in acoustic emission testingEN 13477-1,Non-destructive testing — Acoustic emission – Equipment characterisation — Part 1:Equipment description
EN 13477-2,Non-destructive testing — Acoustic emission – Equipment characterisation — Part 2:Verification of operating characteristic
EN 13554,Non-destructive testing — Acoustic emission – General principles
EN 14584,Non-destructive testing — Acoustic emission — Examination of metallic pressure equipmentduring proof testing — Planar location of AE sources
EN 15495,Non-destructive testing — Acoustic emission — Examination of metallic pressure equipmentduring proof testing —Zone location of AE sources
3Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1330-1:1998,EN 1330-2:1998 andEN 133o-9:2009 and the following apply.
3.1
fibre
slender and greatly elongated solid material
NOTE Typically with an aspect ratio greater than 5 and tensile modulus greater than 20 Gpa.The fibres used forcontinuous (filamentary) or discontinuous reinforcement are usually glass, carbon or aramide.
3.2
polymer matrix
surrounding macromolecular substance within which fibres are embedded
NOTE Polymer matrices are usually thermosets (e.g. epoxy, vinylester polyimide or polyester) or high-performancethermoplastics (e.g. poly(amide imide), poly(ether ether ketone) or polyimide). The mechanical properties of polymermatrices are significantly affected by temperature,time, ageing and environment.
3.3
fibre laminate
two-dimensionally element made up of two or more layers (plies of the same material with identicalorientation) from fibre-reinforced polymers
NOTE They are compacted by sealing under heat and/or pressure. Laminates are stacked together by plane (orcurved) layers of unidirectional fibres or woven fabric in a polymer matrix.Layers can be of various thicknesses andconsist of identical or different fibre and polymer matrix materials. Fibre orientation can vary from layer to layer.
3.4
fibre-reinforced polymer materialFRP
polymer matrix composite with one or more fibre orientations with respect to some reference direction
NOTE Those are usually continuous fibre laminates. Typical as-fabricated geometries of continuous fibres includeuniaxial, cross-ply and angle-ply laminates or woven fabrics.FRP are also made from discontinuous fibres such as short-fibre, long-fibre or random mat reinforcement.
3.5
delamination
intra- or inter-laminar fracture (crack propagation) in composite materials under different modes of loading
NOTE Delamination mostly occurs between the fibre layers by separation of laminate layers with the weakestbonding or the highest stresses under static or repeated cyclic stresses (fatigue), impact,etc. Delamination involves alarge number of micro-ractures and secondary effects such as rubbing between fracture surtaces. It develops inside ofthe composite, without being noticeable on the surface and it is often connected wih significant loss of mechanicalstiffness and strength.
3.6
micro-fracture (of composites)
occurrence of local failure mechanisms on a microscopic level, such as matrix failure (crazing,cracking),fibre/matrix interface failure (debonding) or fibre pull-out as well as fibre failure(breakage, buckling)