1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58durability of bonded metallic structuresThe European Standard EN 15190:2007 has the status of a Bri
2、tish StandardICS 83.180Structural adhesives Test methods for assessing long term BRITISH STANDARDBS EN 15190:2007BS EN 15190:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2007 BSI 2007ISBN 978 0 580 55201 4Amendments issued si
3、nce publicationAmd. No. Date CommentsCompliance with a British Standard cannot confer immunity from legal obligationsNational forewordThis British Standard is the UK implementation of EN 15190:2007.The UK participation in its preparation was entrusted to Technical Committee PRI/52, Adhesives.A list
4、of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15190August 2007ICS
5、83.180English VersionStructural adhesives - Test methods for assessing long termdurability of bonded metallic structuresAdhsifs structuraux - Mthodes dessai pour valuer ladurabilit long terme des structures mtalliques collesStrukturklebstoffe - Prfverfahren zur Bewertung derLangzeitbestndigkeit gekl
6、ebter metallischer StrukturenThis European Standard was approved by CEN on 24 June 2007.CEN members 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
7、 and bibliographical references concerning such nationalstandards may be obtained on application 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 responsi
8、bility 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, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland,
9、 Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart
10、, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide 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
11、 and materials.9 6 RDCB Specimen.10 6.1 RDCB Specimen configuration and dimensions10 6.2 Specimen 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
12、 load train compliance 13 7.2 Compliance calibration at (23 C 2C, 50 % 5 % RH)13 7.3 Determination 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 repo
13、rt 19 Bibliography 20 EN 15190:2007 (E) 3 Foreword This document (EN 15190:2007) has been prepared 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
14、text or by endorsement, at the latest by February 2008, and conflicting national standards shall 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 Standa
15、rd: Austria, Belgium, Bulgaria, 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. EN 15
16、190:2007 (E) 4 Safety statement Persons using this document should be familiar with the normal laboratory 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 safe
17、ty and health practices and to ensure compliance with any regulatory conditions Introduction Susceptibility 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
18、is useful for product development and material selection. Furthermore, it has been shown that the 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 te
19、sting to be applied directly to other joined metallic structures, and therefore the data are useful 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 adhesiv
20、e system subjected to environmental and fatigue loads. The procedures are based upon measurement 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 specimen
21、s consist of rectangular metal substrates bonded together with a pre-starter crack in the bondline. 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 sub
22、strate in order to prevent permanent deformation, usually referred to as reinforced double cantilever 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.
23、However, the standard allows also for use of single substrate double cantilever beam specimens when 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 a
24、s a scientific tool to study adhesion properties. This test method may be used to determine: - The 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 hu
25、midity cycling); - The mode I (peel or crack opening) failure mode of the adhesive joint (cohesive, 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
26、 undated references, the latest edition of the referenced document (including any amendments) applies. 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 t
27、he selection of standard laboratory ageing conditions for testing bonded joints (ISO 9142:2003) ISO 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 docu
28、ment, the terms and definitions given in EN 923:2005 and the following apply. EN 15190:2007 (E) 6 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
29、 cycles, N (cycles) cycle count during a fatigue test 3.3 crack length, a (mm) crack length measured 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 fat
30、igue cycle 3.6 strain energy release rate, G (J/m2) loss of strain energy, dU, in the test specimen 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 ene
31、rgy in the test specimen (mJ) b specimen width (mm) a crack length (mm) 3.7 displacement, (mm) distance 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 a
32、t peak load during the fatigue cycle 3.10 strain energy release rate threshold, Gth(J/m2) value of 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
33、 during a dynamic load cycle EN 15190:2007 (E) 7 3.12 compliance, C (mm/N) displacement divided by 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 crac
34、k length 3.14 compliance calibration constant, m (mm-2/3. N-1/3) slope of the linear fit relationship 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 line
35、ar fit (between C1/3and a) to the point where C1/3equals zero 3.16 test piece width, b (mm) 4-point 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)versu
36、s da/dN 3.18 projected threshold, G|10-6(J/m2) projected value of GI(max)at a crack growth rate of 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
37、 = AGB EN 15190:2007 (E) 8 Dimensions in millimetres Metallic adherends Adhesive Reinforcement bars 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 Specime
38、n dimensions and configuration 4 Principle 4.1 A reinforced double cantilever beam (RDCB) test specimen (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
39、. For the fatigue characterisation the RDCB is cycled between a minimum and maximum displacement, 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 fat
40、igue cycle is recorded along with the corresponding mode I cyclic strain energy release rate, for 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 tempera
41、ture, and both elevated temperature and humidity to determine any degradation in wet adhesion. Combinations 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 purpo
42、ses: To measure adhesion properties and reveal the presence of weak-boundary layers. To compare quantitatively 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 adhes
43、ion durability. To develop criteria for predicting the crack growth extent in damage tolerance and 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
44、 % and 80 % of the full-scale range of the force transducer. This should be capable of running unattended 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 pi
45、ece. Rotational freedom, via the use of threaded bars and universal joints, also help with the fitting 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 co
46、ncurrently. The force behaviour of each specimen will be monitored individually by using individual 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 env
47、ironmental conditions without any change in their characteristics. A minimum capacity of 500 N is 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 fatigu
48、e machine shall be used for test conditions other than room 5 % following EN ISO 9142. 5.5 Data-logging 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
49、 based logging systems are used which log directly to disc for conversion into results after or during 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
