1、BS ISO25217:2009ICS 83.180NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAdhesives Determination ofthe mode 1 adhesivefracture energy ofstructural adhesivejoints using doublecantilever beamand tapered doublecantilever beamspecimensThis British Standardwas publi
2、shed under theauthority of the StandardsPolicy and StrategyCommittee on 31 October2009 BSI 2009ISBN 978 0 580 56823 7Amendments/corrigenda issued since publicationDate CommentsBS ISO 25217:2009National forewordThis British Standard is the UK implementation of ISO 25217:2009.The UK participation in i
3、ts preparation was entrusted to TechnicalCommittee PRI/52, Adhesives.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct applicat
4、ion.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 25217:2009Reference numberISO 25217:2009(E)ISO 2009INTERNATIONAL STANDARD ISO25217First edition2009-05-01Adhesives Determination of the mode 1 adhesive fracture energy of structural adhesive joints using doubl
5、e cantilever beam and tapered double cantilever beam specimens Adhsifs Dtermination de lnergie de fracture adhsive en mode 1 des adhsifs structurels utilisant des prouvettes de rayon de cantilever double et des prouvettes de rayon de cantilever double effiles BS ISO 25217:2009ISO 25217:2009(E) PDF d
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9、ROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO
10、s member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 25217:2009ISO 25217:2009(E) ISO 2009 All rights re
11、served iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Symbols and abbreviated terms . 1 4 Principle. 3 5 Apparatus 3 6 Specimens . 3 6.1 Number of specimens 3 6.2 Conditioning 4 6.3 Manufacture of adhesive joint specimens .4 6.4 Measurement of specimen dimensions6 6.4.1 DCB su
12、bstrates . 6 6.4.2 TDCB substrates. 6 6.4.3 DCB and TDCB substrates 6 6.5 Preparation of specimens 7 7 Procedure 7 7.1 Test set-up and data recording . 7 7.2 Initial loading (the precracking stage) 7 7.3 Re-loading: Testing from the mode I precrack 8 7.4 Measurement of machine compliance 9 8 Data an
13、alysis . 9 8.1 Determination of the raw data from the load-displacement trace . 9 8.1.1 General. 9 8.1.2 Initiation values. 9 8.1.3 Propagation values. 10 8.2 Determination of GIC. 10 8.2.1 General. 10 8.2.2 Double cantilever beam (DCB) 10 8.2.3 Tapered double cantilever beam (TDCB) . 12 9 Test repo
14、rt . 13 9.1 Test report for the DCB test. 13 9.2 Test report for the TDCB test 14 Annex A (informative) Measurement of test system compliance 16 Annex B (normative) Procedure to follow when unstable or “stick-slip” crack growth is observed during the fracture test. 18 Annex C (normative) Procedure t
15、o detect the occurrence of plastic deformation during a DCB or TDCB adhesive joint test . 19 Annex D (informative) Summary of background theory. 20 Bibliography . 24 BS ISO 25217:2009ISO 25217:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is
16、 a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represen
17、ted on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are dr
18、afted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International S
19、tandard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 25217 was prepare
20、d by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2, Mechanical properties. BS ISO 25217:2009INTERNATIONAL STANDARD ISO 25217:2009(E) ISO 2009 All rights reserved 1Adhesives Determination of the mode 1 adhesive fracture energy of structural adhesive joints using double cantilever beam an
21、d tapered double cantilever beam specimens 1 Scope This International Standard specifies a method, based upon linear elastic fracture mechanics (LEFM), for the determination of the fracture resistance of structural adhesive joints under an applied mode I opening load, using double cantilever beam (D
22、CB) and tapered double cantilever beam (TDCB) specimens. 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 (incl
23、uding any amendments) applies. ISO 291, Plastics Standard atmospheres for conditioning and testing ISO 10365, Adhesives Designation of main failure patterns 3 Symbols and abbreviated terms For the purposes of this International Standard, the following symbols and abbreviated terms apply: A insert fi
24、lm length (mm), i.e. the distance between the end of the specimen and the tip of the insert film (see Figure 1) a crack length (mm), i.e. the distance between the load-line (intersection of plane through pin-hole centres or centres of the hinge axes and plane of crack) and the tip of the precrack or
25、 crack on the edge of the specimen (see Figure 1) apprecrack length (mm), measured from the load-line to the tip of the mode I precrack a0insert film length (mm) between the load-line and the tip of the insert film (see Figure 1) B width of the specimen (mm) C compliance /P of the specimen (mm/N) Cc
26、scompliance of the calibration specimen used to measure the system compliance (mm/N) Cmaxcompliance of the specimen at maximum load (mm/N) Csycompliance of the tensile-loading system (mm/N) Ctotalcompliance of the tensile-loading system and the calibration specimen used to measure this (mm/N) (see A
27、nnex A) BS ISO 25217:2009ISO 25217:2009(E) 2 ISO 2009 All rights reservedC0initial compliance of the specimen, neglecting start-up effects, e.g. due to play in the specimen fixture (mm/N) (see Figure 2) C0+5 %initial compliance of the specimen, C0, raised by a factor 1,05 (mm/N) (see Figure 2) Effle
28、xural modulus of the arms of the substrate beam, calculated from the DCB mode I crack propagation test (GPa) Esindependently measured flexural or tensile modulus of the arms of the substrate beam (GPa); if the substrate is a fibre composite, Esis the longitudinal modulus of the material in the direc
29、tion of fibre alignment F large-displacement correction GICcritical strain energy release rate, or adhesive fracture energy, for the applied mode I opening load (J/m2) H thickness of the load-block (mm) h thickness of the substrate beam at a crack length a (mm) hathickness of the adhesive layer (mm)
30、 l total length of the specimen (mm) l1distance from the centre of the loading pin or of the piano hinge axis to the mid-plane of the arm of the substrate beam to which the load-block or the piano hinge is attached (mm) (see Figure 1) l2distance between the centre of the pin-hole in the load-block a
31、nd the edge of the load-block, measured towards the tip of the insert (starter film) or the tip of the mode I precrack (mm) (see Figure 1) l3total length of the load-block (mm) (see Figure 1) MAX/5 % either the maximum load on the load-displacement curve or the point of intersection of a straight li
32、ne with the load-displacement curve with the slope of the straight line corresponding to C0+5 %(see Figure 2) m specimen geometry factor see Equation (1) N load-block correction NL onset of non-linearity on the load-displacement curve (see Figure 2) n slope of a plot of log10C versus log10a, or log1
33、0(C/N) versus log10a if load-blocks are being used P load measured by the load-cell of the test machine (N) PROP increments of the crack length during stable crack growth (propagation) that are marked on the load-displacement curve (see Figure 2) r2correlation coefficient of linear fits r.h. relativ
34、e humidity during the test (%) VIS onset of visually recognizable crack growth at the edge of the specimen that is marked on the load-displacement curve (see Figure 2) BS ISO 25217:2009ISO 25217:2009(E) ISO 2009 All rights reserved 3 crack-length correction for a beam that is not perfectly built-in
35、(mm) displacement of the cross-head of the test machine (mm) cordisplacement of the cross-head, corrected for system compliance effects (mm) 4 Principle A double cantilever beam (DCB) specimen or a tapered double cantilever beam (TDCB) specimen is used to determine the adhesive fracture energy, GIC,
36、 of structural adhesive joints. Resistance to both crack initiation and propagation is determined. The resistance to crack initiation is determined from both a non-adhesive insert placed in the adhesive layer and from a mode I precrack. The resistance to crack propagation is determined from the mode
37、 I precrack. The adhesive fracture energy, GIC, (also termed the critical strain energy release rate) for applied mode I loading is calculated and a resistance-curve (R-curve), i.e. a plot of the value of GICversus crack length, is determined. 5 Apparatus 5.1 Tensile-testing machine, capable of prod
38、ucing a constant cross-head displacement rate between 0,1 mm/min and 5 mm/min in displacement control. The test machine shall be equipped with a) either a fixture to introduce the load to the pins inserted into the load-blocks or directly into the substrate beams; b) or grips to hold the piano hinge
39、s that allow rotation of the specimen end (see Figure 1). The test machine shall incorporate a load-cell that shall be calibrated and be accurate to within 1 % in the chosen load-range. NOTE Loads are typically expected to be in the range of 100 N to 5 000 N. The opening displacement of the test spe
40、cimen shall be deduced from the position of the cross-head. The test machine shall be equipped with means for recording the complete load versus displacement curves (loading and unloading) during the test. 5.2 Travelling microscope or video camera, with suitable magnification, capable of measuring t
41、he crack length along the edge of the specimen to an accuracy of at least 0,5 mm. 5.3 Micrometer or vernier calipers, capable of measuring the thickness of the substrate arms and bonded joints with an accuracy of at least 0,02 mm. 5.4 Micrometer or vernier calipers, capable of measuring the width of
42、 the joints with an accuracy of at least 0,05 mm. 5.5 Typewriter correction fluid (“white ink”) or white spray-paint. 6 Specimens 6.1 Number of specimens A minimum of four joints shall be tested. BS ISO 25217:2009ISO 25217:2009(E) 4 ISO 2009 All rights reserved6.2 Conditioning Most adhesives will ab
43、sorb small quantities of water from the atmosphere which may have a significant influence on the measured properties. Following specimen preparation, the adhesive will generally be dry. If testing is carried out within a few days of specimen manufacture, then it is not necessary to condition the spe
44、cimen under controlled humidity since negligible absorption of water will take place in the thin adhesive layer. However, if the specimen is tested after longer times or if the influence of absorbed water on the properties is of interest, then the humidity shall be controlled by conditioning and the
45、 properties will depend on the conditioning time. In addition, if composite substrates are used, then it may be important to dry these prior to manufacture of the joint. The properties of some adhesives are very sensitive to the presence of small amounts of moisture in a substrate prior to curing. T
46、he drying out of the substrates prior to cure will ensure that the integrity of the adhesive joint is not influenced by pre-bond moisture effects. 6.3 Manufacture of adhesive joint specimens The DCB specimen shall be as shown in Figures 1 a), 1 b) or 1 c). The TDCB specimen shall be as shown in Figu
47、re 1 d). The thickness of the film to be inserted in the adhesive layer during manufacture shall be less than 13 m. The film shall be non-stick. A PTFE film is recommended. If aluminium foil is used, the foil shall be coated with a release agent prior to use. Appropriate surface treatments for metal
48、lic substrates can be found in ISO 172121. The thickness of the adhesive layer shall be carefully controlled and shall be less than 1 mm (see Notes 1 and 2). The thickness of the layer shall not vary by more than 20 % within a joint, nor shall the average thickness of the layer in one joint differ b
49、y more than 20 % from that in another joint in the sample. When fully cured, remove any excess adhesive by mechanical means that do not weaken the bond, so as to leave the joint with smooth sides. It should be recognized that the value of GICmeasured from these tests will depend upon the thickness of the adhesive layer in the joint. The value of the layer thickness shall be determined by the user, based upon the adhesive manufacturers recommendations or upon consideration of the intended application. It is not within
