1、October 2007DEUTSCHE NORM English price group 12No part of this standard 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 83.180!$Iqa“1387862www
2、.din.deDDIN EN 15190Structural adhesives Test methods for assessing long term durability of bonded metallicstructuresEnglish version of DIN EN 15190:2007-10Strukturklebstoffe Prfverfahren zur Bewertung der Langzeitbestndigkeit geklebter metallischer StrukturenEnglische Fassung DIN EN 15190:2007-10ww
3、w.beuth.deDocument comprises 22 pages DIN EN 15190:2007-10 2 National foreword This standard has been prepared by Technical Committee CEN/TC 193 “Adhesives” (Secretariat: AENOR, Spain). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing
4、Standards Committee), Technical Committee NA 062-04-55 AA Prfung von Konstruktions-klebstoffen, -klebverbindungen und Kernverbunden. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15190August 2007ICS 83.180English VersionStructural adhesives - Test methods for assessing long termdurability of bon
5、ded metallic structuresAdhsifs structuraux - Mthodes dessai pour valuer ladurabilit long terme des structures mtalliques collesStrukturklebstoffe - Prfverfahren zur Bewertung derLangzeitbestndigkeit geklebter metallischer StrukturenThis European Standard was approved by CEN on 24 June 2007.CEN membe
6、rs are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application
7、to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the sa
8、me status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Roma
9、nia, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedwor
10、ldwide for CEN national Members.Ref. No. EN 15190:2007: EEN 15190:2007 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle8 5 Apparatus and materials.9 6 RDCB Specimen.10 6.1 RDCB Specimen configuration and dimensions10 6.2 Specimen
11、 manufacture .10 6.2.1 Initial cleaning10 6.2.2 Control of shape and thickness of bonded area 10 6.2.3 Bonding 11 6.2.4 Cutting and drilling12 6.3 Inspection .12 7 Test procedures.13 7.1 Determination of load train compliance 13 7.2 Compliance calibration at (23 C 2C, 50 % 5 % RH)13 7.3 Determinatio
12、n of fatigue resistance and Gth at 23 C, 50% RH15 7.4 Determination of wet adhesion properties17 7.5 Determination of fatigue properties under other environmental conditions 18 8 Precision.18 9 Test report 19 Bibliography 20 EN 15190:2007 (E) 3 Foreword This document (EN 15190:2007) has been prepare
13、d by Technical Committee CEN/TC 193 “Adhesives”, the secretariat of which is held by AENOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2008, and conflicting national standards shall
14、be withdrawn at the latest by February 2008. 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, German
15、y, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 15190:2007 (E) 4 Safety statement Persons using this document should be familiar with the normal la
16、boratory practice, if applicable. This document does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any regulatory conditions Introduction Susc
17、eptibility to fatigue crack growth under hot humid conditions is one of the major concerns for the durability assessment of bonded metallic joints. Knowledge of the long-term durability of bonded joints is useful for product development and material selection. Furthermore, it has been shown that the
18、 relationship between cyclic mode I strain energy release rate and crack growth rate is independent of geometry and load application. This allows the materials characterisation data measured from RDCB testing to be applied directly to other joined metallic structures, and therefore the data are usef
19、ul for establishing design allowable criteria used in their life assessment. EN 15190:2007 (E) 5 1 Scope 1.1 This standard specifies test procedures for determining the long-term durability of an adhesive system subjected to environmental and fatigue loads. The procedures are based upon measurement
20、of the crack growth rate and the resistance to crack propagation through the adhesive layer in double cantilever beam type specimens under an applied mode I opening cycling loading. 1.2 The test specimens consist of rectangular metal substrates bonded together with a pre-starter crack in the bondlin
21、e. For testing joints consisting of relatively thin sheets of metallic substrates the specimen needs to be structurally reinforced by adding layers of compatible material to the back of each adherend substrate in order to prevent permanent deformation, usually referred to as reinforced double cantil
22、ever beam (RDCB) test specimen. 1.3 For brevity, the standard relates to testing RDCB specimens, which are essentially more complex in manufacturing than standard double cantilever beam (DCB) specimens. However, the standard allows also for use of single substrate double cantilever beam specimens wh
23、en the substrate material is available in sufficient thickness. 1.4 The test method has been proven to be particularly sensitive in finding weaknesses within certain adhesive systems and is recommended as a scientific tool to study adhesion properties. This test method may be used to determine: - Th
24、e fatigue crack growth rate as a function of the mode I strain energy release rate; - The threshold values for negligible crack growth; - The effects of other environmental factors (temperature and/or humidity cycling); - The mode I (peel or crack opening) failure mode of the adhesive joint (cohesiv
25、e, interfacial, near-surface ). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) app
26、lies. EN 923:2005, Adhesives Terms and definitions EN 13887, Structural Adhesives - Guidelines for surface preparation of metals and plastics prior to adhesive bonding EN ISO 9142, Adhesives - Guide to the selection of standard laboratory ageing conditions for testing bonded joints (ISO 9142:2003) I
27、SO 15024, Fibre-reinforced plastic composites Determination of mode I interlaminar fracture toughness, GIc, for unidirectionally reinforced materials 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 923:2005 and the following apply. EN 15190:2007 (E) 6
28、 3.1 mode I crack opening crack opening mode due to a load applied perpendicular to the plane of crack growth using a reinforced double cantilever beam specimen as shown in Figure 1 3.2 number of fatigue cycles, N (cycles) cycle count during a fatigue test 3.3 crack length, a (mm) crack length measu
29、red from the loading point to the crack tip 3.4 initial crack length, ao(mm) manufactured crack length before the test 3.5 fatigue crack growth rate, da/dN (mm/cycle) increase of the crack length per fatigue cycle 3.6 strain energy release rate, G (J/m2) loss of strain energy, dU, in the test specim
30、en per unit of specimen width for an infinitesimal increase in crack length, da, for a crack growing under a constant displacement. In mathematical form, aUbGdd0001= (1) where: U total elastic strain energy in the test specimen (mJ) b specimen width (mm) a crack length (mm) 3.7 displacement, (mm) di
31、stance between the load points 3.8 fatigue loading ratio, R ratio of the minimum load to the peak load within a load cycle 3.9 maximum mode I cyclic strain energy release rate, G(Imax)(J/m2) value of G at peak load during the fatigue cycle 3.10 strain energy release rate threshold, Gth(J/m2) value o
32、f G at which fatigue crack growth becomes negligible (approach zero). This is typically at measured crack growth rates between 10 -6mm/cycle and 10-7mm/cycle. 3.11 peak load, Pmax(N) maximum load applied during a dynamic load cycle EN 15190:2007 (E) 7 3.12 compliance, C (mm/N) displacement divided b
33、y load during the loading cycle applied to the RDCB specimen, at a given crack length 3.13 maximum displacement, max(mm) maximum test piece displacement at the peak load, i.e. Pmaxx C, for any given crack length 3.14 compliance calibration constant, m (mm-2/3. N-1/3) slope of the linear fit relation
34、ship between the cube root of the test piece compliance, C (y-axis) and crack length, a (x-axis) 3.15 compliance calibration constant, (mm) x-axis intercept, determined from the extrapolation of the linear fit (between C1/3and a) to the point where C1/3equals zero 3.16 test piece width, b (mm) 4-poi
35、nt average of test piece width, measured along the length of the RDCB test piece 3.17 Paris Law constants, A and B for the Paris Law relationship: da/dN = A(G)Bapplied to the log-log plot of G(Imax)versus da/dN 3.18 projected threshold, G|10-6(J/m2) projected value of GI(max)at a crack growth rate o
36、f 10-6mm/cycle, using the Paris Law relationship: da/dN = AGB3.19 projected threshold, G|10-7(J/m2) projected value of GImaxat a crack growth rate of 10-7mm/cycle, using the Paris Law relationship: da/dN = AGB EN 15190:2007 (E) 8 Dimensions in millimetres Metallic adherends Adhesive Reinforcement ba
37、rs PTFE inserts NOTE The 3,2 mm diameter holes are for the use with 3 mm pins to apply the load Key 1 Centre line 2 Reinforcement 3 Substrate (thickness as required) 4 Reinforcement Figure 1 RDCB Specimen dimensions and configuration 4 Principle 4.1 A reinforced double cantilever beam (RDCB) test sp
38、ecimen (see Figure 1) is tested to determine a compliance relationship with the crack length, the rate of crack growth at ambient and elevated temperature and the effect of imposing a hostile environment. For the fatigue characterisation the RDCB is cycled between a minimum and maximum displacement,
39、 min, and max, at a specified frequency. For linear elasticity and small deflections the displacement ratio, min/max, is identical to the fatigue loading ratio, R. The rate of growth of the crack per fatigue cycle is recorded along with the corresponding mode I cyclic strain energy release rate, for
40、 example the maximum value, G(Imax). The test is run until the crack growth rate reduces to a slow rate or nominally a threshold value, Gth. The test is conducted at ambient temperature, elevated temperature, and both elevated temperature and humidity to determine any degradation in wet adhesion. Co
41、mbinations of environmental factors can also be applied, to determine their effects on either crack growth behaviour or crack initiation. EN 15190:2007 (E) 9 4.2 This method can serve the following purposes: To measure adhesion properties and reveal the presence of weak-boundary layers. To compare q
42、uantitatively the relative values of fatigue crack growth rate for different adhesive systems, including failure mode. To compare quantitatively the effects of different adhesive systems on the wet adhesion durability. To develop criteria for predicting the crack growth extent in damage tolerance an
43、d durability analyses. 5 Apparatus and materials 5.1 Fatigue tensile-testing machine capable of producing crack growth in the specimen under a sinusoidal displacement producing a tensile force between 10 % and 80 % of the full-scale range of the force transducer. This should be capable of running un
44、attended for long periods during a 10 million cycle test with maintained accuracy. Good alignment must be present in the load train to enable accurate positioning of loading forks around the RDCB test piece. Rotational freedom, via the use of threaded bars and universal joints, also help with the fi
45、tting of the loading pins through the loading fork-test piece assembly. NOTE For efficiency in testing time, the cross head of this machine should enable more than one specimen to be fitted and tested concurrently. The force behaviour of each specimen will be monitored individually by using individu
46、al force transducers. 5.2 Force transducer one for each specimen capable of measuring the force applied to the specimen with an accuracy of 1 N. The transducers shall be able to withstand any applied environmental conditions without any change in their characteristics. A minimum capacity of 500 N is
47、 recommended. 5.3 Displacement transducer for the test machine capable of measuring displacement to an accuracy of 1 %, and including two places of decimal. 5.4 Environmental chamber fitted to the fatigue machine shall be used for test conditions other than room 5 % following EN ISO 9142. 5.5 Data-l
48、ogging equipment to continuously record the displacement and the applied load, for each specimen, from the start of application of the load until the end of the test. NOTE It is recommended that computer based logging systems are used which log directly to disc for conversion into results after or d
49、uring the test. 5.6 RDCB manufacturing equipment to enable the production of identical RDCB specimens. NOTE As well as adhesive and adherends, the following list of equipment is recommended: - heated press, plaque mould, reinforcement material, heated adhesive applicator, cutting device (abrasive wheel saw, water jet, band saw with milling machine to finish). 5.7 Micrometer, having an accuracy of better than 0,1 mm, to measure the external dimensions of the RDCB. 5.8 Optical measuring microscope, having an accuracy of better than 0,01
