1、BSI Standards PublicationMetallic materials Tensiletesting at high strain ratesPart 2: Servo-hydraulic and other testsystems (ISO 26203-2:2011)BS EN ISO 26203-2:2011 Incorporating corrigendum September 2015BS EN ISO 26203-2:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implem
2、entation of EN ISO 26203-2:2011. The UK participation in its preparation was entrusted by Technical Committee ISE/101, Test methods for metals, to A list of organizations represented on this subcommittee can be obtained on request to its secretary.This publication does not purport to include all the
3、 necessary provisions of a contract. Users are responsible for its correct application.ISBN 978 0 580 91633 5 ICS 77.040.10 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Co
4、mmittee on 31 January 2012.Amendments/corrigenda issued since publication The British Standards Institution 2015. Published by BSI StandardsLimited 2015Date Text affected30 September 2015 Implementation of ISO corrected text 15 March2012: See ISO Foreword for detailssubcommittee ISE/101/1, Uniaxial
5、testing.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 26203-2 October 2011 ICS 77.040.10 English Version Metallic materials - Tensile testing at high strain rates - Part 2: Servo-hydraulic and other test systems (ISO 26203-2:2011) Matriaux mtalliques - Essai de traction vitesses de dforma
6、tion leves - Partie 2: Systmes dessai servo-hydrauliques et autres systmes dessai (ISO 26203-2:2011) Metallische Werkstoffe - Zugversuch bei hohen Dehngeschwindigkeiten - Teil 2: Servohydraulische und andere Systeme (ISO 26203-2:2011) This European Standard was approved by CEN on 17 September 2011.
7、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 obtained on a
8、pplication 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-CENELEC
9、 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, Malta, N
10、etherlands, 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 exploitat
11、ion in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 26203-2:2011: E3 Foreword This document (EN ISO 26203-2:2011) has been prepared by Technical Committee ISO/TC 164 “Mechanical testing of metals“ in collaboration with Technical Committee ECISS/TC 101 “Test
12、methods for steel (other than chemical analysis)” the secretariat of which is held by AFNOR. 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 April 2012, and conflicting national standards shall be
13、 withdrawn at the latest by April 2012. 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. According to the CEN/CENELEC Internal Regulati
14、ons, the national standards organizations of the following 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,
15、 Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 26203-2:2011 has been approved by CEN as a EN ISO 26203-2:2011 without any modification. ISO 26203-2:2011(E)BS EN ISO 26203-2:2011ISO 26203-2:201
16、1(E) ISO 2011 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Normative references . 13 Terms and definitions . 14 Symbols . 15 Principle . 36 Apparatus 37 Test pieces 37.1 Test piece geometry 37.2 Preparation of test pieces . 48 Procedure and measurements . 58.1 Velocity sel
17、ection 58.2 Force measurement 58.3 Extension measurement 68.4 Data acquisition . 69 Evaluation of tests 69.1 Stress-strain curve 69.2 Determination of key values . 79.3 Strain rates 79.4 Determination of flow curves . 810 Test report . 9Annex A (informative) Testing equipment 10Annex B (informative)
18、 Examples of test piece geometries .12Annex C (informative) Example of an engineering stress-strain curve .14Bibliography .15BS EN ISO 26203-2:2011ISO 26203-2:2011(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bo
19、dies). 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 represented on that committee. International organizations, governmental an
20、d 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 drafted in accordance with the rules given in the ISO/IEC Directives,
21、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 Standard requires approval by at least 75 % of the member bodies casti
22、ng 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 26203-2 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Su
23、bcommittee SC 1, Uniaxial testing.ISO 26203 consists of the following parts, under the general title Metallic materials Tensile testing at high strain rates: Part 1: Elastic-bar-type systems Part 2: Servo-hydraulic and other test systemsThis corrected version of ISO 26203-2:2011 incorporates the fol
24、lowing correction: Figure A.2 a) The figure missing above Example 1 has been added.iv ISO 2011 All rights reservedBS EN ISO 26203-2:2011ISO 26203-2:2011(E)IntroductionThe deformation behaviour of many technical materials shows a positive strain-rate effect up to ductile failure, i.e. with increasing
25、 strain rate, an increase of yield stress and strain to failure can be observed. This information is of great importance for the reliable assessment of crashworthiness of automobile structures, which is increasingly determined by numerical methods to minimize the need for cost-intensive and time-con
26、suming crash tests. For the numerical simulation of crash-type loads, stress-strain curves determined at higher strain rates are required. The quasi-static values determined according to ISO 6892-1, i.e. strain rates lower than or equal to 0,008 s1,are not suitable for the description of the behavio
27、ur of the material of a component under dynamic load, i.e. at strain rates higher than those in quasi-static tests. ISO 2011 All rights reserved vBS EN ISO 26203-2:2011Metallic materials Tensile testing at high strain rates Part 2: Servo-hydraulic and other test systems1 ScopeThis part of ISO 26203
28、gives requirements for the testing of metallic materials. Only examples for testing flat geometries are given; however, other geometries can be tested. The area of application spans a range of strain rates from 102s1to 103s1. Tests are carried out between 10 C and 35 C and, unless otherwise specifie
29、d, using a servo-hydraulic-type test system.NOTE 1 Measurements at strain rates lower than 102s1can be performed using machines designed for quasi-static testing.NOTE 2 For test piece geometries other than those shown in 7.1 and Annex B, see ESIS P7 (Reference 1) and FAT Guideline (Reference 2).2 No
30、rmative referencesThe 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.ISO 6892-1, Metallic materials T
31、ensile testing Part 1: Method of test at room temperature3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 6892-1 apply.4 SymbolsFor the purposes of this document, the symbols given in ISO 6892-1 apply. Additional symbols, units and descriptions are pro
32、vided in Table 1.Table 1 SymbolsSymbol Unit DescriptionTest pieceaomm Original thickness of a flat test piecebomm Original width of the parallel length of a flat test piecebkmm Width(s) of the clamping area of the test pieceLomm Original gauge lengthLcmm Parallel lengthLemm Extensometer gauge length
33、r mm Transition radiusSomm2Original cross-sectional area of the parallel lengthSDmm2Dynamometer area: area on the fixed side of the test piece where only elastic deformations are required during the testINTERNATIONAL STANDARD ISO 26203-2:2011(E) ISO 2011 All rights reserved 1BS EN ISO 26203-2:2011IS
34、O 26203-2:2011(E)Symbol Unit DescriptionTimet s Timetfs Duration from beginning of test to moment of fracture initiationElongationA % Percentage elongation after fractureNOTE For non-proportional test pieces, the symbol A is supplemented by a subscript, which shows the original gauge length, in mill
35、imetres, e.g. A20 mm= percentage elongation after fracture with an original gauge length Lo= 20 mm.ExtensionAg% Percentage plastic extension at maximum force, Fm(plastic strain at maximum force, Fm)Agt% Percentage total extension at maximum force, Fm(total strain at maximum force, Fm)Straine(t) % Ti
36、me-dependent engineering strainepl% Plastic engineering strainet% Total engineering strainplTrue plastic straintTrue total strainRatesvomm s1Initial displacement rateenoms1Nominal engineering strain rate = vo /LcEquation (1)emeans1Mean engineering strain rate = A/tfEquation (4)et() s1Time-dependent
37、engineering strain rate = de(t)/dtepls1Mean value of the time-dependent engineering strain rate: de(t)/dt in the range between start of yield or 1 % strain and strain at maximum force Equation (5)fuHz Upper frequency limit of the relevant measuring system (force or extension)ForceFmN Maximum forceEn
38、gineering stress True stressR MPaaEngineering stress MPa True stressYield strength Proof strength Tensile strengthReLMPa Lower yield strengthRpMPa Proof strength, plastic extensionRmMPa Tensile strengthModulus of elasticity Slope of stress-strain curveE MPa Modulus of elasticitymEMPa Slope of the el
39、astic part of the stress-strain curveba1 MPa = 1 N/mm2.bIn the elastic part of the stress-strain curve the value of the slope can closely agree with the value of the modulus of elasticity if optimal conditions (high resolution, double-sided averaging extensometers, proper alignment of the test piece
40、, etc.) are used.Table 1 (continued)2 ISO 2011 All rights reservedBS EN ISO 26203-2:2011ISO 26203-2:2011(E)5 PrincipleThe stress-strain characteristics of metallic materials at specific plastic strain rates are determined.To perform tension tests at strain rates above those described in ISO 6892-1,
41、the measurement of force and elongation of the original gauge length, Lo, shall meet additional requirements in order to obtain reliable high-rate stress-strain curves. This part of ISO 26203 describes the requirements for determining and evaluating the stress and strain in force equilibrium during
42、plastic deformation at strain rates up to 103s1.6 ApparatusTesting machines in conformity with this part of ISO 26203 work on the principle that the kinetic energy required for the test is applied on the impact (or loading) side of the test piece (see Figure A.1). The load cell is located at the opp
43、osite end of the test piece, which is fixed or restrained in a clamp/grip (see Figure A.1). Loading at high strain rates is preferably impact-like and, therefore, often does not allow a fixed coupling of the test piece to the testing machine. All testing machines that permit a constant strain rate (
44、within certain bounds; see 9.3) during the entire test are suitable for testing.The most common high-rate testing machine applicable to this part of ISO 26203 utilizes a servo-hydraulic drive fitted with a slack adapter (see Reference 3). Other systems, which may include, for example, flywheel impac
45、tors and drop towers, may be used on condition that the requirements given in this part of ISO 26203 are met.An axial-symmetric parallel alignment of the test pieces in the load train shall be verified in order to prevent bending moments. The alignment of the load train elements may be performed in
46、accordance with ASTM E1012 (see Reference 4).From a mechanical point of view, the load train should be compact and easy to manage. This enables the load train to attain short acceleration times while also maintaining the natural frequency of the clamping and load cell system at as high a level as po
47、ssible.7 Test pieces7.1 Test piece geometryFlat tensile test pieces are used for the dynamic testing of sheet materials. The strain rate developed in the test piece gauge length is dependent on both the applied displacement rate and the parallel length of the reduced section in the test piece. A tes
48、t piece with a shorter parallel length enables higher strain rates. However, a parallel length, Lc, shall be maintained so that the original gauge length, Lo, is in a state of uniaxial stress (see Figure 1). Therefore, the recommended sizes of the parallel length, Lc, the width, bo, the thickness, a
49、o, and the transition radius, r, for the test piece are as follows: Lboo/ 2 LLbcoo+/2 baoo/ 2 bbok/, 05 r 10 mmHere bkis the width of the clamping area.Frequently used test piece dimensions based on ISO 6892-1 are given as examples in Annex B. Other geometries of test pieces (e.g. ISO 26203-1, ESIS P7 and FAT guideline) may be applied if agreed upon between the interested parties. ISO 2011 All rights reserved 3BS EN ISO 26203-2:2011ISO 26203-2:2011(E)Key1 strain gaugeaooriginal thic
