1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 14869-2:2011Structural adhesives Determination of shear behaviour of structural bondsPart 2: Thick adherends shear test (ISO 11003-2:2001, modified)BS EN 14869-2:2011 BRITI
2、SH STANDARDNational forewordThis British Standard is the UK implementation of EN 14869-2:2011. It was derived from ISO 11003-2:2001. It supersedes BS EN 14869-2:2004 and BS ISO 11003-2:2001, which are withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/52, Adhe
3、sives.A list 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. BSI 2011 ISBN 978 0 580 72244 8 ICS 83.180 Compliance wi
4、th a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2011.Amendments issued since publicationDate Text affectedBS EN 14869-2:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISC
5、HE NORM EN 14869-2 May 2011 ICS 83.180 Supersedes EN 14869-2:2004English Version Structural adhesives - Determination of shear behaviour of structural bonds - Part 2: Thick adherends shear test (ISO 11003-2:2001, modified) Adhsifs structuraux - Dtermination du comportement en cisaillement dadhsifs s
6、tructuraux - Partie 2 : Mthode dessai en traction sur prouvette paisse (ISO 11003-2:2001, modifi) Strukturklebstoffe - Bestimmung des Scherverhaltens struktureller Klebungen - Teil 2: Scherprfung fr dicke Fgeteile (ISO 11003-2:2001, modifiziert) This European Standard was approved by CEN on 10 March
7、 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtain
8、ed on application to the CEN-CENELEC 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 translation under the responsibility of a CEN member into its own language and notified to the CEN-
9、CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, M
10、alta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of ex
11、ploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14869-2:2011: EBS EN 14869-2:2011EN 14869-2:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Apparatus .66 Specimen 66.1 Specimen dimensions an
12、d configurations .66.2 Adherends 76.3 Preparation of surfaces before bonding .77 Test specimen 97.1 Preparation .97.1.1 Specimens with flat-ended adherends 97.1.2 Specimens with stepped adherends. 107.2 Number of specimens 108 Procedure 139 Calculations . 159.1 Symbols used 159.2 Average shear stres
13、s in the adhesive 159.3 Shear strain in the adhesive 159.4 Stress strain curve 179.5 Shear modulus of the adhesive . 1810 Precision 1811 Test report . 18Annex A (informative) Suitable extensometer design 20BS EN 14869-2:2011EN 14869-2:2011 (E) 3 Foreword This document (EN 14869-2:2011) has been prep
14、ared 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 November 2011, and conflicting national standards sha
15、ll be withdrawn at the latest by November 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14869-2:20
16、04. 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 safety and heal
17、th practices and to ensure compliance with any regulatory conditions. ENVIRONMENTAL STATEMENT It is understood that some of the material permitted in this standard may have negative environmental impact. As technological advantages lead to acceptable alternatives for these materials, they will be el
18、iminated from this standard to the extent possible. At the end of the test, the user of the standard should take care to carry out an appropriate disposal of the wastes, according to local regulation. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the foll
19、owing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slov
20、akia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 14869-2:2011EN 14869-2:2011 (E) 4 1 Scope This European Standard specifies a test method for determining the shear behaviour of an adhesive in a single lap joint bonded assembly when subjected to a tensile force. The test is pe
21、rformed on specimens consisting of thick, rigid adherends, with a short length of overlap, in order to obtain the most uniform distribution of shear stresses possible and to minimize other stress states which initiate failure. This test method may be used to determine: the shear-stress against shear
22、-strain curve to failure of the adhesive; the shear modulus of the adhesive; other adhesive properties that can be derived from the stress/strain curve such as the maximum shear stress and shear strain; the effect of temperature, environment, test speed, etc. on these properties. 2 Normative referen
23、ces 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) applies. EN 923:2005+A1:2008, Adhesives Terms and defi
24、nitions EN 13887, Structural Adhesives Guidelines for surface preparation of metals and plastics prior to adhesive bonding EN ISO 291, Plastics Standard atmospheres for conditioning and testing (ISO 291:2008) EN ISO 10365, Adhesives Designation of main failure patterns (ISO 10365:1992) ISO 683-11, H
25、eat-treatable steels, alloy steels and free-cutting steels Part 11: Wrought case-hardening steels ISO 1052, Steels for general engineering purposes ISO 4995, Hot-rolled steel sheet of structural quality 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN
26、923:2005+A1:2008 apply. 4 Principle An adhesively bonded test specimen (see Figure 1) is subjected to a tensile force so that the adhesive is stressed in shear. BS EN 14869-2:2011EN 14869-2:2011 (E) 5 The relative displacement of the adherends is measured using a purpose-built transducer located in
27、the central region of the specimen. Force and displacement are measured from the start of application of the load until fracture of the specimen. The shear stresses and strains are then calculated from the bond dimensions. Dimensions in millimetres Key a) Bonded adherends b) Machined adherends 1 Adh
28、esive bond b Width of adhesive l Length of adhesive Figure 1 Specimen dimensions and configuration BS EN 14869-2:2011EN 14869-2:2011 (E) 6 5 Apparatus 5.1 Tensile-testing machine, capable of producing fracture in the specimen at a tensile force between 10 % and 80 % of the full-scale range of the fo
29、rce transducer. 5.2 Device for introducing a force into the specimen, so that negligible torque develops when force (F) is applied to the specimen. For this purpose, the simple universal-joint design shown in Figure 2 is satisfactory. 5.3 Force transducer, capable of measuring the force in the speci
30、men with an accuracy of 1 % of the force at a shear strain of 0,01. 5.4 One or two extensometers (see Note 2), for measuring the shear displacement between points of known separation on each adherend in the central region of the bond (see Figure 3 and Annex A). The points of contact with the adheren
31、ds shall be within a distance of 2 mm from the bonded faces. The device(s) shall be capable of measuring the shear displacement to an accuracy of 1 m. NOTE 1 During loading, each adherend will bend slightly, leading to a small rotation of the central (bonded) region of the test specimen. In order to
32、 achieve high accuracy in displacement measurements, the extensometer(s) should rotate with the specimen. This has been achieved in the design shown in Figure 3 by double-pin contact with one of the adherends. NOTE 2 The use of two extensometers on opposing faces of the specimen is recommended to mi
33、nimize, by averaging the extensometer readings, any contribution to measurements from a twisting moment applied to the specimen. The use of two extensometers will also serve to indicate any malfunctioning of one of the extensometers as revealed by significantly different readings from the two device
34、s. 5.5 Data-logging equipment, to continuously record the relative displacement of the adherends and the applied load, from the start of application of the load until the specimen breaks. 5.6 Micrometer, having an accuracy of better than 0,002 mm, to measure the dimensions of the adherends. 5.7 Opti
35、cal microscope, having an accuracy of better than 0,002 mm, to measure the thickness of the adhesive bond when the specimen configuration shown in Figure 1a) is used. 6 Specimen 6.1 Specimen dimensions and configurations Specimens shall be prepared either by bonding metal plates or strips together t
36、o produce the configuration shown in Figure 1a) or by bonding adherends that have been machined to the shape shown in Figure 1b). The dimensions of the specimen are given in Figure 1 and are the same, within variations in the bond thickness, for both preparation methods. The bond thickness shall not
37、 be less than 0,05 mm. NOTE The adherends shown in Figure 1a) have a lower bending stiffness than the continuous geometry shown in Figure 1b). Consequently, the peel stresses at the ends of the adhesive in the specimen in Figure 1a) will be higher than those in the specimen in Figure 1b). However, t
38、hese differences in stiffness are likely to cause a trivial deviation in the comparative results. BS EN 14869-2:2011EN 14869-2:2011 (E) 7 Figure 2 Example of device for loading the specimen in a tensile-testing machine 6.2 Adherends For the purpose of the measurement of the properties of the adhesiv
39、e, steel adherends are recommended because of their high modulus. Machine the panels or bars to be used for the adherends in accordance with ISO 683-11, ISO 1052 and ISO 4995 to the dimensions given in Figure 1a) or 1b) depending on which specimen configuration is chosen. 6.3 Preparation of surfaces
40、 before bonding The surfaces to be bonded shall be prepared in accordance with EN 13887 or by any other method leading to cohesive failure within the adhesive layer. BS EN 14869-2:2011EN 14869-2:2011 (E) 8 Key 1 Mobile inner part 2 Rigid outer frame 3 Steel leaf spring 4 Transducer coil 5 Transducer
41、 core 6 Turgsten pins Figure 3 Example of extensometer positioning BS EN 14869-2:2011EN 14869-2:2011 (E) 9 7 Test specimen 7.1 Preparation 7.1.1 Specimens with flat-ended adherends 7.1.1.1 General Specimens with flat-ended adherends shall have the configuration shown in Figure 1a) and may be prepare
42、d from uncut panels, from pre-cut panels or as individual specimens from machined plates. 7.1.1.2 Uncut panels The panels from which the specimens are cut shall consist of two sheets with dimensions in accordance with Figure 4, bonded together in accordance with the adhesive manufacturers instructio
43、ns. In order to define the thickness of the adhesive, shims or spacers (metal foil) or calibrated metal wires may be incorporated outside the area which will become the overlap zone. Cut the bonded panels into specimens using a suitable tool such as a band saw. Then subject the specimens to the requ
44、ired machining. Perform the last pass on the edge of the specimen parallel to the longitudinal direction of the specimen so as to avoid any metal burrs along the bonded joint. Drill holes at the ends of each specimen for pins to hold the specimen to the tensile-testing machine. Delineate the overlap
45、 zone by milling two grooves as shown in Figure 5. When the specimens are machined, care shall be taken to ensure that the assembly is not heated above 50 C. No liquid shall be used for cooling. 7.1.1.3 Pre-cut panels Proceed as in 7.1.1.2, using two pre-cut sheets so as to obtain a panel in accorda
46、nce with Figure 6. Two holes shall be provided in each sheet so that the two sheets can be superposed correctly using an assembly with two centring lugs. Cut out and machine specimens as explained in 7.1.1.2. 7.1.1.4 Individual specimens Bond two plates of dimensions 110 mm 25 mm 6 mm in accordance
47、with the adhesive manufacturers instructions, defining the thickness of the adhesive joint as indicated in 7.1.1.2. Ensure that the sides of the adherends are parallel to the nearest 0,1 mm. Machine each specimen to the required size. Drill holes for applying the load. Make two grooves by milling to
48、 delineate the overlap. Take the same precautions as in 7.1.1.2. BS EN 14869-2:2011EN 14869-2:2011 (E) 10 7.1.2 Specimens with stepped adherends The adherends for this specimen type shall be machined to the dimensions given in Figure 1b) prior to bonding. The adherends shall be bonded whilst held se
49、curely in a frame that ensures accurate alignment of the adherends. In order to produce a bond of well-defined shape and length, strips of steel or PTFE of thickness 1,5 mm shall be inserted in the gaps between the adherends after the application of the adhesive and prior to curing. They shall be removed after the adhesive has cured. If steel strips are used, they shall be coated with a release agent. NOTE It is recommended that such strips have a 45 tapered edge so that a trian
