ASTM A931-1996(2002) Standard Test Method for Tension Testing of Wire Ropes and Strand《金属丝绳和绞线拉伸试验的标准试验方法》.pdf

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1、Designation: A 931 96 (Reapproved 2002)Standard Test Method forTension Testing of Wire Ropes and Strand1This standard is issued under the fixed designation A 931; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev

2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the tension testing of wire ropesand strand at room temperature, specifically to determine theminimum

3、 acceptance strength or nominal strength, yieldstrength, elongation, and modulus of elasticity.1.2 The values stated in inch-pound units are to be regardedas the standard. The SI units given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concern

4、s, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Note 1, Note 2, Note 3, andNote 5.2.

5、 Referenced Documents2.1 ASTM Standards:A 586 Specification for Zinc-Coated Parallel and HelicalSteel Wire Structural Strand and Zinc-Coated Wire forSpun-In-Place Structural Strand2A 603 Specification for Zinc-Coated Steel Structural WireRope2B 6 Specification for Zinc3E 4 Practices for Force Verifi

6、cation of Test Machines4E 6 Terminology Relating to Methods of Mechanical Test-ing4E 8 Test Methods for Tension Testing of Metallic Materials43. Terminology3.1 The terminology relating to tensile testing in Terminol-ogy E 6 applies to this test method. In addition, the followingdefinitions for wire

7、rope will apply:3.2 Definitions:3.2.1 abrasionfrictional surface wear on the wires of awire rope.3.2.2 aggregate areasee area, metallic.3.2.3 aggregate strengththe strength derived by totallingthe individual breaking strengths of the elements of the strandor rope. This strength does not give recogni

8、tion to thereduction in strength resulting from the angularity of theelements in the rope, or other factors that may affect efficiency.3.2.4 area, metallicsum of the cross-sectional areas of allwires either in a wire rope or in a strand.3.2.5 breaking strengththe ultimate load at which a tensilefail

9、ure occurs in the sample of wire rope being tested.3.2.6 DiscussionThe term breaking strength is synony-mous with actual strength.3.2.7 cablea term loosely applied to wire rope, wirestrand, and electrical conductors.3.2.8 centerthe axial member of a strand about which thewires are laid.3.2.9 classif

10、icationgroup or family designation based onwire rope constructions with common strengths and weightslisted under the broad designation.3.2.10 constructiongeometric design description of thewire ropes cross section. This includes the number of strands,the number of wires per strand, and the pattern o

11、f wirearrangement in each strand.3.2.11 corethe axial member of a wire rope about whichthe strands are laid.3.2.12 fiber corecord or rope of vegetable or syntheticfiber used as the core of a rope.3.2.13 galvanized ropewire rope made up of galvanizedwire.3.2.14 galvanized strandstrand made up of galv

12、anizedwire.3.2.15 gradewire rope or strand classification by strengthor type of material, that is, Class 3, Type 302 stainless,phosphor bronze, etc. It does not apply to strength of theindividual wires used to manufacture the rope or strand.3.2.16 independent wire rope core (IWRC)a wire ropeused as

13、the core of a larger wire rope.3.2.17 inner wiresall wires of a strand except the outer orcover wires.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 ed

14、ition approved March 10, 1996. Published May 1996. Originallypublished as A 931 94. Last previous edition A 931 94.2Annual Book of ASTM Standards, Vol 01.06.3Annual Book of ASTM Standards, Vol 02.04.4Annual Book of ASTM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Bo

15、x C700, West Conshohocken, PA 19428-2959, United States.3.2.18 lay(a) the manner in which the wires in a strand orthe 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 about

16、the core (or center). In this connection, lay is also referred to aslay length or pitch.3.2.19 minimum acceptance strengththat strength that is 21/2 % lower than the catalog or nominal strength. Thistolerance is used to offset variables that occur during samplepreparation and actual physical test of

17、 a wire rope.3.2.20 modulus of elasticitythe slope of the elastic portionof the stress-strain curve. The ratio of stress to correspondingstrain below the proportional limit. This value is generallytaken between 20 and 50 % of the nominal strength.3.2.21 nominal strengththe published (catalog) streng

18、thcalculated by a standard procedure that is accepted by the wirerope industry. The wire rope manufacturer designs wire rope tothis strength, and the user should consider this strength whenmaking design calculations.3.2.22 socketgeneric name for a type of wire rope fitting.3.2.23 stranda plurality o

19、f round or shaped wires heli-cally laid about a center.3.2.24 wire ropestrands helically laid around a core.3.2.25 wire strand core (WSC)a wire strand used as thecore of a wire rope.4. Significance and Use4.1 Wire rope tests are generally to be performed on newrope. The use of wire rope in any appli

20、cation 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 elasticity of wire rope is not consideredto be a standard re

21、quirement 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 noted. When possible, a new undamaged sampleshould be obtained

22、 for testing.4.4 End attachments and their installation can directly affectbreaking strength achieved during testing. Any attachment thatcan be used to directly achieve the required rope breakingstrength can be used. Standard testing with a poured socket,using zinc, white metal or thermoset resin, h

23、as been consideredthe most efficient. Proficiency in attachment of any fitting canhave a direct 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 evident, thesample should not be used. The purpose of th

24、is test method isto verify the nominal or maximum strength the wire rope orstrand can achieve.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 t

25、est results.5.3 The length of test specimen shall not be 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),

26、 the clearlength of the test specimen shall be at least 20 times the ropediameter.6. Apparatus6.1 Testing MachinesMachines used for tension testingshall conform to the requirements of Practices E 4. The loadsused in determining tensile strength and yield strength shall bewithin loading range of the

27、tensile machine as defined inPractices E 4.6.2 Gripping Devices: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 coincide

28、with the center line of the heads of the machine. Any departurefrom 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

29、gripping long specimens of ductile metal.If, however, for any 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 para

30、llel. For best results, the wedges should besupported over 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

31、 each wedge be in contact with the specimen. Specially-designed 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 f

32、itted together, a conical-shaped cavity existswhich will hold a cone socket wire rope or strand andattachment (fitting).7. Sample Preparation and Preparation of EndAttachments7.1 Poured sockets are considered to be the most efficientand should be used due to their ability to distribute the loadevenl

33、y in the wire rope when installed properly. Procedures forthe proper installation of poured end attachments can be foundin socketing procedures.7.2 Other end attachments such as grips may be usedprovided the required loading is achieved.7.3 Sample Preparation Procedures:7.3.1 SocketingZinc-Poured So

34、cketing:7.3.1.1 Measuring the Rope Ends to be SocketedThe ropeend should be of sufficient length so that the ends of the unlaidwires (from the strands) will be at the top of the socket basket(see Fig. 1(a).A 931 96 (2002)2FIG. 1 Wire Rope for SocketingA 931 96 (2002)37.3.1.2 Apply Serving at Base of

35、 SocketApply a tight wireserving band at the point where the socket base will be for alength of two rope diameters (see Fig. 1(b) and 1(c).7.3.1.3 Broom Out Strand WiresUnlay and straighten theindividual rope strands and spread them evenly so that theyform an included angle of approximately 60. Unla

36、y the wiresof each individual strand for the full length of the rope end,being careful not to disturb or change the lay of the wires andstrands under the serving band. Unlay the wires of an indepen-dent wire rope core in the same manner. A fiber core should becut out and removed as close to the serv

37、ing band as possible(see Fig. 1(c).7.3.2 Clean the Broomed-Out EndsA suggested cleaningsolvent for this step is SC-5 methyl chloroform. It is alsoknown under the names chlorothane VG and 1-1-1 trichlore-thane.NOTE 1Warning: Breathing the vapor of this solvent is harmful; itshould only be used in a w

38、ell-ventilated area. Be sure to follow the solventmanufacturers instructions, and carefully observe all instructions printedon the label.Some non-chlorinated solvents are adequate and are preferable ifavailable.7.3.2.1 Swish the broomed-out rope end in the solvent, thenbrush vigorously to remove all

39、 grease and dirt, making certainthat the wires are clean to the very bottom close to the servingband (see Fig. 1(d). Additionally, a solution of muriatic acidmay also be used. If, however, acid is used, the broomed-outends should be rinsed in a solution of bicarbonate of soda so asto neutralize any

40、acid that may remain on the rope. Care shouldbe exercised to prevent acid from entering the core; this isparticularly important if the rope has a fiber core. Where it isfeasible, the best and preferred cleaning method for rope endsprior to socketing is ultrasonic cleaning. After this cleaningstep, p

41、lace the broomed-out end upright in a vise allowing it toremain until all solvent has evaporated and the wires are dry.7.3.2.2 Solvent should never be permitted to remain on therope or on the serving band since it will run down the wireswhen the rope is removed from the vise.7.3.3 Dip the Broomed-Ou

42、t Rope Ends in FluxPrepare ahot solution of zinc-ammonium chloride flux comparable toZaclon K. Use a concentration of 1 lb. (453.6 g) of zinc-ammonium chloride to 1 gal (3.774 L) of water, maintain thisat a temperature of 180F (82C) to 200F (93C). Swish thebroomed-out end in the flux solution, then

43、place the rope endupright in the vise until such time as the wires have driedthoroughly (see Fig. 1(e).7.3.4 Close Rope Ends and Place SocketUse clean wire tocompress the broomed-out rope end into a tight bundle that willpermit the socket to be slipped on easily over the wires (seeFig. 1(f). Before

44、placing the socket on the rope, make certainthat the socket itself is clean and heated to 200F (93C) to400F (204C). This heating is necessary in order to dispel anyresidual moisture, and to prevent the zinc from coolingprematurely.NOTE 2Caution: Never heat a socket after it is placed on the rope.To

45、do so may cause heat damage to the rope.7.3.4.1 After the socket is on the rope end, the wires shouldbe distributed evenly in the socket basket so that zinc cansurround each wire. Use extreme care in aligning the socketwith the ropes centerline, and in making certain that there is aminimum vertical

46、length of rope, extending from the socket,that is equal to that specified in 6.3.7.3.4.2 Seal the socket base with fire clay or putty, but makecertain that this material does not penetrate into the socketbase. Should this occur, it would prevent the zinc frompenetrating the full length of the socket

47、 basket, therebycreating a void that would collect moisture after the socket isplaced in service.7.3.5 Pour the ZincThe zinc used should meet Specifica-tion B 6 Grade (1) High Grade. Pour the zinc at a temperatureof 950 to 970F (510 to 521C) (see Fig. 1(h); makeallowances for cooling if the zinc pot

48、 is more than 25 ft. fromthe socket.NOTE 3Caution: Do not heat zinc above 1200F (649C) or itsbonding properties will be lost, and heat damage will occur to the rope.The zinc temperature may be measured with a portable pyrometer or aTempilstik. Remove all dross before pouring. Pour the zinc in onecon

49、tinuous stream until it reaches the basket top and all wire ends arecovered; there should be no “capping” of the socket.7.3.6 Remove ServingRemove the serving band from thesocket base; check to make certain that the zinc has penetratedto the socket base (see Fig. 1(i).7.3.7 Lubricate the RopeApply wire rope lubricant to therope at the socket base and on any rope section where theoriginal lubricant may have been removed.8. Thermo-Set Socketing8.1 Before proceeding with a thermo-set resin socketingprocedure, check manu