1、May 2010 Translation by DIN-Sprachendienst.English price group 18No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 19
2、.100!$bG“1636136www.din.deDDIN EN 15857Non-destructive testing Acoustic emission Testing of fibre-reinforced polymers Specific methodology and generalevaluation criteriaEnglish translation of DIN EN 15857:2010-05Zerstrungsfreie Prfung Schallemissionsprfung Prfung von faserverstrkten Polymeren Spezif
3、ische Vorgehensweise und allgemeineBewertungskriterienEnglische bersetzung von DIN EN 15857:2010-05Essais non destructifs mission acoustique Essai des polymres renforcs par des fibres Mthodologie spcifique et critresdvaluation gnrauxTraduction anglaise de DIN EN 15857:2010-05www.beuth.deDocument com
4、prises pagesIn case of doubt, the German-language original shall be considered authoritative.4705.10 DIN EN 15857:2010-05 National foreword This standard has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing” (Secretatariat: AFNOR, France). The responsible German body involved
5、 in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-08-23 AA Ultraschallprfung. 2 A comma is used as the decimal marker. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15857 January 2010 ICS 19.100 English Version Non-des
6、tructive testing Acoustic emission Testing of fibre-reinforced polymers Specific methodology and general evaluation criteria Essais non destructifs mission acoustique Essai des polymres renforcs par des fibres Mthodologie spcifique et critres dvaluation gnrauxZerstrungsfreie Prfung Schallemissionspr
7、fung Prfung von faserverstrkten Polymeren Spezifische Vorgehensweise und allgemeine Bewertungskriterien This European Standard was approved by CEN on 4 December 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStan
8、dard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, Frenc
9、h, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia,
10、Cyprus, Czech Republic, Denmark, Estonia,Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION
11、 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15857:2010: EEN 15857:2010 (E) 2 Contents Page Foreword 3Intro
12、duction . 41 Scope 52 Normative references 53 Terms and definitions . 64 Personnel qualification . 75 AE sources and acoustic behaviour of FRP . 75.1 AE source mechanisms 75.2 Wave propagation and attenuation characterisation . 85.3 Test temperature 85.4 Source location procedures . 85.5 Analysis of
13、 AE from FRP 96 Instrumentation and monitoring guidelines .106.1 General 106.2 Sensors .106.3 Sensor location and spacing 106.4 Sensor coupling and mounting 106.5 Detection and evaluation threshold .116.6 Application of load 116.7 Graphs for real-time monitoring.117 Specific methodology .127.1 Gener
14、al 127.2 Testing of specimens 137.3 Testing of components and structures .137.3.1 Preliminary information 137.3.2 Test preparation .147.3.3 Load profiles 147.3.4 Written test instruction .167.3.5 Evaluation criteria 177.3.6 Stop criteria 207.4 Health monitoring 208 Interpretation of AE results / sou
15、rce mechanisms.209 Documentation .21Annex A (informative) Recommended standard formats for presentation of AE data (examples) 22A.1 AE testing of specimens .22A.1.1 Example 1: AE data from static tensile testing of UD Carbon-fibre/Epoxy composite 22A.1.2 Example 2: AE data from mode I DCB delaminati
16、on test of UD Glass-fibre/Epoxy composite .27A.2 AE testing of components and structures, example 3: AE data from pressure testing.34A.3 Advanced analysis methods 41A.3.1 General 41A.3.2 Waveform/wave mode analysis 41A.3.3 Frequency spectrum (FFT) analysis 41A.3.4 Pattern recognition of AE sources 4
17、1A.3.5 Modelling of AE sources .42Bibliography 43DIN EN 15857:2010-05 EN 15857:2010 (E) 3 Foreword This document (EN 15857:2010) has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing”, the secretariat of which is held by AFNOR. This European Standard shall be given the status
18、of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2010, and conflicting national standards shall be withdrawn at the latest by July 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of p
19、atent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
20、Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15857:2010-05 EN
21、15857:2010 (E) 4 Introduction The increasing use of fibre-reinforced polymer materials (FRP) in structural (e.g. aerospace, automotive, civil engineering) and infra structural applications (e.g. gas cylinders, storage tanks, pipelines) requires respective developments in the field of non-destructive
22、 testing. Because of its sensitivity to the typical damage mechanisms in FRP, AE testing is uniquely suited as a test method for this class of materials. It is already being used for load test monitoring (increasing test safety) and for proof-testing, periodic inspection and periodic or continuous,
23、real-time monitoring (health monitoring) of pressure vessels, storage tanks and other safety-relevant FRP structures. AE testing shows potential where established non-destructive test methods (e.g. ultrasonic or water-jacket tests) are not applicable (e.g. “thick“ carbon-fibre reinforced gas cylinde
24、rs used for the storage and transport of compressed natural gas (CNG), gaseous hydrogen, etc.). The general principles outlined in EN 13554 apply (as stated) to all classes of materials but the document in fact emphasises applications to metal components (see Clause 6 “Applications of the acoustic e
25、mission method“). However, the properties of FRP relevant to AE testing are distinctly different from those of metals. FRP structures are inherently inhomogeneous and show a certain degree of anisotropic behaviour, depending on fibre orientation and stacking sequence of plies, respectively. Material
26、 composition and properties, and geometry affect wave propagation, e.g. mode, velocity, dispersion, and attenuation, and hence the AE signals recorded by the sensors. Composites with a distinct viscoelastic polymer matrix (e.g. thermoplastics) possess a comparatively high acoustic wave attenuation w
27、hich is dependent on wave propagation parallel or perpendicular to direction of fibre orientation, plate-wave mode, frequency and temperature dependent relaxation behaviour. Therefore, successful AE testing of FRP materials, components and structures requires a specific methodology (e.g. storage of
28、complete waveforms, specific sensors and sensor arrays, specific threshold settings, suitable loading patterns, improved data analysis, etc.), different from that applied to metals. Most evaluation criteria for AE tests on FRP components and structures to date are either empirical (derived from comp
29、arative tests on a limited number of specimens) or else classified (proprietary, unpublished data banks). The time and effort to establish qualified evaluation criteria for specific AE test applications may be too costly to make it worthwhile. Generally applicable evaluation criteria for a class of
30、materials FRP will help to pave the way for the development of new applications. There are recent developments in AE testing, e.g. “modal AE“ (wave and wave mode analysis in time and frequency domain) and “pattern recognition analysis“. In particular, feature extraction and pattern recognition techn
31、iques seem promising for achieving, among others, improved source location and damage mechanism discrimination in materials that show complex wave propagation behaviour and signals originating from multiple mechanisms acting simultaneously, such as FRP. DIN EN 15857:2010-05 EN 15857:2010 (E) 5 1 Sco
32、pe 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 testi
33、ng is used to assess the integrity of FRP materials, components or structures or identify critical zones of high damage accumulation or damage growth under load this standard further describes the specific methodology (e.g. suitable instrumentation, typical sensor arrangements, location procedures,
34、etc.). It also describes available, generally applicable evaluation criteria for AE testing of FRP and outlines procedures 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 evaluation
35、 criteria only but may require further inspection and assessment (e.g. with other non-destructive test methods or fracture mechanics calculations). This standard also recommends formats for the presentation of AE test data that allow the application of qualitative and quantitative evaluation criteri
36、a, both on-line during testing and by post test analysis, and that simplify comparison of AE test results obtained from different test sites and organisations. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only
37、 the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 473, Non-destructive testing Qualification and certification of NDT personnel General principles EN 1330-1:1998, Non destructive testing Terminology Part 1: List o
38、f general terms EN 1330-2:1998, Non-destructive testing Terminology Part 2: Terms common to the non-destructive testing methods EN 1330-9:2009, Non-destructive testing Terminology Part 9: Terms used in acoustic emission testing EN 13477-1, Non-destructive testing Acoustic emission Equipment characte
39、risation 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 Examinat
40、ion of metallic pressure equipment during proof testing Planar location of AE sources EN 15495, Non-destructive testing Acoustic emission Examination of metallic pressure equipment during proof testing Zone location of AE sources DIN EN 15857:2010-05 EN 15857:2010 (E) 6 3 Terms and definitions For t
41、he purposes of this document, the terms and definitions given in EN 1330-1:1998, EN 1330-2:1998 and EN 1330-9:2009 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 us
42、ed for continuous (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-performan
43、ce thermoplastics (e.g. poly(amide imide), poly(ether ether ketone) or polyimide). The mechanical properties of polymer matrices 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 mate
44、rial with identical orientation) from fibre-reinforced polymers NOTE They are compacted by sealing under heat and/or pressure. Laminates are stacked together by plane (or curved) layers of unidirectional fibres or woven fabric in a polymer matrix. Layers can be of various thicknesses and consist of
45、identical or different fibre and polymer matrix materials. Fibre orientation can vary from layer to layer. 3.4 fibre-reinforced polymer material FRP polymer matrix composite with one or more fibre orientations with respect to some reference direction NOTE Those are usually continuous fibre laminates
46、. Typical as-fabricated geometries of continuous fibres include uniaxial, 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)
47、 in composite materials under different modes of loading NOTE Delamination mostly occurs between the fibre layers by separation of laminate layers with the weakest bonding or the highest stresses under static or repeated cyclic stresses (fatigue), impact, etc. Delamination involves a large number of micro-fractures and secondary effects such as rubbing between fracture surfaces. It develops inside of the composite, without being noticeable on the surface and it is often connected with significant loss of mechanical stiffness and strength. 3.6 micro-fracture (of composit
