ASTM A931-2018 Standard Test Method for Tension Testing of Wire Ropes and Strand.pdf

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1、Designation: A931 18Standard Test Method forTension Testing of Wire Ropes and Strand1This standard is issued under the fixed designation A931; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in p

2、arentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the tension testing of wire ropesand strand at room temperature, specifically to determine themeasured breaking force, yi

3、eld strength, elongation, and modu-lus of elasticity. Methods described in this standard are notintended for other purposes.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for informati

4、on onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability

5、 of regulatory limitations prior to use.Specific precautionary statements are given in Note 1 and Note2.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Internat

6、ional Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A586 Specification for Zinc-Coated Parallel and HelicalSteel Wire Structural StrandA603 Specification for Zinc-Coated Steel Struct

7、ural WireRopeA1023/A1023M Specification for Stranded Carbon SteelWire Ropes for General PurposesE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8 Test Methods for Tension Testing of Metallic MaterialsMetric E0008_E0008M2.2 ISO Standard3

8、ISO 17558 Specification for Steel Wire Ropes SocketingProcedures Molten Metal and Resin Socketing3. Terminology3.1 The terminology relating to tensile testing in Terminol-ogy E6 applies to this test method. In addition, the followingdefinitions for wire rope will apply:3.2 Definitions:3.2.1 abrasion

9、, nfrictional surface wear on the wires of awire rope.3.2.2 aggregate area, nsee area, metallic.3.2.3 aggregate strength, nthe strength derived by totalingthe individual breaking strengths of the elements of the strandor rope. This strength does not give recognition to thereduction in strength resul

10、ting from the angularity of theelements in the rope, or other factors that may affect efficiency.3.2.4 area, metallic, nsum of the cross-sectional areas ofall wires either in a wire rope or in a strand.3.2.5 breaking force, nthe maximum load at which atensile failure occurs in the sample of wire rop

11、e being tested.3.2.5.1 DiscussionThe term breaking force is synony-mous with actual strength.3.2.6 cable, na term loosely applied to wire rope, wirestrand, and electrical conductors.3.2.7 center, nthe axial member of a strand about whichthe wires are laid.3.2.8 classification, ngroup or family desig

12、nation basedon wire rope constructions with common strengths and weightslisted under the broad designation.3.2.9 construction, ngeometric design description of thewire ropes cross section. This includes the number of strands,the number of wires per strand, and the pattern of wirearrangement in each

13、strand.1This test method is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.03 on Steel Rod and Wire.Current edition approved Sept. 1, 2018. Published September 2018. Originallyapproved in 1994. Last previou

14、s edition approved in 2013 as A931 08 (2013).DOI: 10.1520/A0931-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM we

15、bsite.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un

16、ited StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barrie

17、rs to Trade (TBT) Committee.13.2.10 core, nthe axial member of a wire rope aboutwhich the strands are laid.3.2.11 fiber core, ncord or rope of vegetable or syntheticfiber used as the core of a rope.3.2.12 grade, nwire rope or strand classification bystrength or type of material, that is, Class 3, Ty

18、pe 302 stainless,phosphor bronze, etc. It does not apply to strength of theindividual wires used to manufacture the rope or strand.3.2.13 independent wire rope core (IWRC), na wire ropeused as the core of a larger wire rope.3.2.14 inner wires, nall wires of a strand except the outeror cover wires.3.

19、2.15 lay, n(a) the manner in which the wires in a strandor the strands in a rope are helically laid, or (b) the distancemeasured parallel to the axis of the rope (or strand) in which astrand (or wire) makes one complete helical convolution aboutthe core (or center). In this connection, lay is also r

20、eferred to aslay length or pitch.3.2.16 minimum breaking force, nspecified value that thebreaking force must meet or exceed in a prescribed test.3.2.17 modulus of elasticity, nthe slope of the elasticportion of the stress-strain curve. The ratio of stress tocorresponding strain below the proportiona

21、l limit. This value isgenerally taken between 20 and 50 % of the minimum breakingforce.3.2.18 socket, ngeneric name for a type of wire ropefitting.3.2.19 strand, na plurality of round or shaped wireshelically laid about a center.3.2.20 wire rope, nstrands helically laid around a core.3.2.21 wire str

22、and core (WSC), na wire strand used as thecore of a wire rope.3.2.22 zinc-coated (galvanized) rope, nwire rope made upof zinc coated (galvanized) wire.3.2.23 zinc coated (galvanized) strand, nstrand made upof zinc-coated (galvanized) wire.4. Significance and Use4.1 Tension tests are generally to be

23、performed on new wireropes. The use of wire rope in any application can reduceindividual wire strengths due to abrasion and nicking that willresult in the wire rope strength being reduced. Damage to theouter wires will also lower the maximum strength achievedduring tension testing.4.2 The modulus of

24、 elasticity of wire rope is not consideredto be a standard requirement at this time. The determination ofthis material property requires specialized equipment andtechniques.4.3 Rope to be tested should be thoroughly examined toverify that no external wire damage is present. If present, itshould be n

25、oted. When possible, a new undamaged sampleshould be obtained for testing.4.4 End attachments and their installation can directly affectbreaking force achieved during testing. Any attachment thatcan be used to directly achieve the required rope breaking forcecan be used. Standard testing with a pour

26、ed socket, using zinc,white metal or thermoset resin, has been considered the mostefficient. Proficiency in attachment of any fitting can have adirect effect on the final test results.5. Interferences5.1 Visual examination of the sample for any damage toouter wires should be done. If any damage is e

27、vident, thesample should not be used.5.2 Measurement of the rope or strand sample is necessaryto document the size, length between end attachments, andlength of lay of the rope if necessary. Further details regardingthis will be discussed in test results.5.3 The length of test specimen shall not be

28、less than 3 ft,(0.91 m) between sockets for wire ropes up to 1 in. (25.4 mm)diameter, inclusive, and not less than 5 ft (1.52 m) betweensockets for wire ropes 118 in. (28.6 mm) to 3 in. (77 mm)diameter. On wire ropes larger than 3 in. (77 mm), the clearlength of the test specimen shall be at least 2

29、0 times the ropediameter.6. Apparatus6.1 Testing MachinesMachines used for tension testingshall conform to the requirements of Practices E4. The loadsused in determining tensile strength and yield strength shall bewithin loading range of the tensile machine as defined inPractices E4.6.2 Gripping Dev

30、ices:6.2.1 GeneralVarious types of gripping devices may beused to transmit the measured load applied by the testingmachine to test specimens. To ensure axial tensile stress withinthe gage length, the axis of the test specimen should coincidewith the center line of the heads of the machine. Any depar

31、turefrom this requirement may introduce bending stresses that arenot included in the usual stress computation.6.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of gripping long specimens of ductile metal.If, however, for a

32、ny reason, one grip of a pair advances fartherthan the other as the grips tighten, an undesirable bendingstress may be introduced. When liners are used behind thewedges, they must be of the same thickness and their facesmust be flat and parallel. For best results, the wedges should besupported over

33、their entire lengths by the heads of the testingmachine. This requires that liners of several thicknesses beavailable to cover the range of specimen thickness. For propergripping, it is desirable that the entire length of the serratedface of each wedge be in contact with the specimen. Specially-desi

34、gned round-shaped grips may have to be used for testingrope or strand. It is essential that all wires in the rope or strandare uniformly gripped when the load is applied.6.2.3 Conical GripsConical grips are constructed so thatwhen they are fitted together, a conical-shaped cavity existswhich will ho

35、ld a cone socket wire rope or strand andattachment (fitting).A931 1827. Sample End Terminations7.1 Poured sockets or swaged sockets are typically used intensile tests. Properly prepared, they are 100 % efficient. Othertypes of end terminations may be used as long as the requiredminimum breaking forc

36、e is achieved. Refer to ISO 17558 forsocketing procedures.8. Procedure8.1 Take measurements on the sample to determine theactual rope diameter and sample length between sockets beforeloading on the test machine.NOTE 1The proper method to determine the actual diameter of a ropeis shown in Fig. 1. The

37、 method of incorrect measurement is shown in Fig.2.8.2 After the sample is placed in the test machine, completethe zeroing before testing begins for accurate results. Startapplying the load to the sample. The maximum rate of loadingshould be 0.032 in. per minute (0.032 mm per min) for each in.(mm) o

38、f test gage length when the rate is under the operatorcontrol (a typical test gage length is 60 in. (1524 mm). Applythe load until a reduction from a maximum reading occurs.This reduction will normally be accompanied by a noise whenwires and strand break. Wire and lubricant will be thrown fromthe sa

39、mple if not contained.NOTE 2It is recommended that adequate safety shields be useddirectly around the sample, as well as around the operator and observers.Uncontained wires during testing can impact and penetrate objects at agreat distance.8.2.1 The measured breaking force is reached when nofurther

40、increase in applied force is possible. After the initialfailure of some strands, the sample has reached its maximumstrength. It is not necessary to continue the test until all strandsin the sample have failed.NOTE 3Verification of meeting the required Minimum BreakingForce is achieved once the appli

41、ed force to the test specimen meets orexceeds the required Minimum Breaking Force. It is not necessary toobtain the measured breaking force of the specimen to verify confor-mance.8.2.2 The test may be discounted when the rope strandfracture occurs within a distance equivalent of 6 rope diametersor 1

42、0 strand diameters from the base of the grip or thetermination and the intended minimum breaking force has notbeen reached.8.3 If the sample being evaluated does not meet the mini-mum breaking force, additional samples may be tested. Retestinstructions are detailed in Specifications A586, A603 andA1

43、023/A1023M.8.4 Final tensile test results are normally measured inpounds.9. Precision and Bias9.1 The primary intent of testing wire ropes and strand is toensure that the wire rope or strand will meet the specifiedbreaking force. Sometimes yield strength, elongation, or modu-lus of elasticity is req

44、uired or desired. In the case of zinc coatedstructural strand and zinc coated structural rope tested to meetthe requirements in Specifications A586 and A603, the proce-dures for determining percent elongation and modulus ofelasticity and gage lengths are specified in Specifications A586and A603.9.1.

45、1 When yield strength is needed, the methods defined inTest Methods E8 are recommended.9.2 PrecisionThe precision of this test method has notbeen determined.9.3 BiasThe bias of this test method includes quantitativeestimates of the uncertainties of the dimensional measuringdevices, the calibrations

46、of testing equipment and the skill ofthe operators. At this time, the statements on bias should belimited to documented performance of particular laboratories.10. Keywords10.1 socket; thermo-set resin; wire ropeFIG. 1 Correct MeasurementFIG. 2 Incorrect MeasurementA931 183SUMMARY OF CHANGESCommittee

47、 A01 has identified the location of selected changes to this standard since the last issue(A931 08 (2013) that may impact the use of this standard. (Approved Sept. 1, 2018.)(1) Removed Specification B6 from Referenced Documents(Section 2).(2) Reworded first sentence of 4.1 to further clarify theaccu

48、racy of minimum breaking force of ropes newly manufac-tured.(3) Reworded Notes 1 and 2 to eliminate use of the term“should”.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are exp

49、ressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a me