1、Designation: D8019 15Standard Test Methods forDetermining the Full Section Flexural Modulus and BendingStrength of Fiber Reinforced Polymer CrossarmsAssembled with Center Mount Brackets1This standard is issued under the fixed designation D8019; the number immediately following the designation indica
2、tes the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the determination o
3、f theflexural modulus and bending strength of both tangent anddeadend arms bent about their minor and major axes. Onemethod covers testing of assembled tangent crossarms includ-ing the tangent bracket and relative hardware. The othermethod covers testing of assembled deadend crossarms with adeadend
4、bracket and relative phase loading hardware. Thefailure modes and associated stresses can be used for predictingthe phase load capacities of pultruded crossarms specific tocertain conductor loading scenarios.1.2 The test methods described in this standard can be usedfor predicting the vertical and h
5、orizontal component loads ofdeadend and tangent arms. Both deadend and tangent cros-sarms shall be tested in the two configurations described inFigures 1 and 2. This will permit the manufactures to publishboth vertical and horizontal design capacities for deadendcrossarm configurations so that two w
6、ay bending stresses,caused by catenary effects, can be considered when developingthe capacity of the deadend crossarms by utility designengineers and manufacturers.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system m
7、ay not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in nonconformancewith the standard.1.4 This standard will not address all factors that affect thephase loading capacity.1.5 This standard does not address the
8、use of core materialsthat are added to increase the structural capacity of thecrossarms. Core material shall not be considered in thecalculations provided in this standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
9、y 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.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D4968 Guide for Annual Review of Test Method
10、s andSpecifications for PlasticsE4 Practices for Force Verification of Testing MachinesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions of variables u
11、sed in the calculations asshown in Section 11 are as follows:a = distance from phase hardware to the center mountbolt through the crossarm, in. (m),Aw= area of the webs in shear in.2m2,E = flexural modulus, psi (Pa),I = moment of inertia about the neutral axis of thecrossarm, in.4m4,L = support span
12、, in. m,M = moment at failure, lbf-in Nm,P = ultimate or failure load acting through a single centermount bolt, lbf N,Sx= section modulus about the neutral axis of thecrossarm, in.3m3,V = in-plane shear force, lbf N, = bending stress at failure, psi Pa, = deflection relative to the applied load, in.
13、 m,max= maximum transverse shear stress, psi Pa,1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.18 on Reinforced Thermoset-ting Plastics.Current edition approved Dec. 1, 2015. Published January 2016. DOI: 10.1520/D8019
14、-15.2For 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 website.Copyright ASTM International, 100 Barr Harbor Drive, PO B
15、ox C700, West Conshohocken, PA 19428-2959. United States1Q = static moment of area in.3m3,t = thickness of region or regions under consideration in.m.4. Summary of Test Methods Including Deadend andTangent Crossarm Configurations with CommercialHardware Attached4.1 Deadend Crossarms:4.1.1 The assemb
16、led deadend crossarm, including twophase single sided position hardware and a center mountbracket fabricated to the specifications as detailed by themanufacturer, is positioned in a three point bend apparatus andloaded until failure occurs.4.1.2 A center mount bracket or a fabricated test bracket,ma
17、tching the bolt size and dimensional specifications of themanufacturers commercial bracket, is attached to the arm asdetailed by the manufacturer.4.1.3 A three point bend load is then induced into the crossarm assembly until a structural failure of the hardware orcrossarm occurs.4.1.4 The bracket is
18、 to be loaded or constrained, dependingon the load apparatus, such that no eccentric loading occurs.4.1.5 Load and deflection data are to be recorded at setintervals or continuously until failure occurs.4.2 Tangent Crossarms:4.2.1 The assembled tangent crossarm, including two phasesingle sided deade
19、nd position hardware and a center mounttangent bracket fabricated to the specifications as detailed bythe manufacturer, is positioned in a three point bend apparatusand loaded until failure occurs.4.2.2 A tangent bracket, matching the specifications, of themanufacturers commercial bracket, is attach
20、ed to the arm asdetailed by the manufacturer.4.2.3 A three point bend load is then induced into thecrossarm assembly such that the bracket and phase hardware isloaded until failure.4.2.4 The bracket is to be loaded or constrained, dependingon the load apparatus, such that the load produces eccentric
21、loading into the bracket and arm mimicking the tangentconnection to a wood, fiberglass, steel or concrete pole.4.2.5 Load and deflection data are to be recorded at setintervals or continuously until failure occurs.5. Significance and Use5.1 Determination of the flexural modulus, beam bendingstrength
22、 and full assembly strength, by this test method isespecially useful for product validation, design and specifica-tion purposes.5.2 Calculated values for flexural modulus, bendingstrength and full assembly strength will vary with specimendepth, span length, hole configurations, loading rate, andambi
23、ent test temperature. A minimum span to depth ratio of16:1 is required for establishing the flexural modulus.5.3 ValidityStress at failure, , is only valid for crossarmfailures due to local compression buckling. Other controllingmodes of failure will dictate the ultimate phase loadingcapacities. For
24、 example, in-plane shear, fastener pin bearing,position hardware, center mount failures and fastener pull outwill dictate the failure mode and ultimately the crossarmcapacity.6. Apparatus6.1 Testing MachineA properly installed and operatedload actuator, ideally one which can be operated at constantr
25、ates of load or deflection, used in combination with a properlycalibrated load cell. Error in the load measuring system shallnot exceed 61 % of the maximum load expected to bemeasured. The test setup shall also be equipped with deflectionmeasuring devices. The stiffness of the testing apparatus shal
26、lbe such that the total elastic deformation of the load frame doesnot exceed 1 % of the total deflection of the test specimenduring testing, or appropriate corrections shall be made. Theaccuracy of the testing machine shall be calibrated and verifiedin accordance with Practices E4.6.2 Loading Noses
27、and Supports:6.2.1 The manufacturers deadend crossarm shall be eitherloaded through the center mount, or through the phase hard-ware. In the event of loading through the center mount, themanufacturers deadend crossarm shall be assembled with aproduction mount or fabricated replica. Load shall be app
28、liedthrough the back of the center mount bracket. The deadendcrossarm shall be fully fabricated, representing the finishedproduct, with the phase position deadend hardware attached.The crossarm test fixture supports shall connect directly to thephase position hardware.6.2.2 For deadend crossarm test
29、ing loaded through thephase hardware, and for tangent crossarm testing, the manu-facturers center mount shall be mounted to a rigid structurethat represents a pole structure in the proper orientation. Thecrossarm shall be loaded by pulling on the phase hardware inan appropriate direction for the tes
30、t method. For tangentcrossarm testing, this would be in an apparent vertical direc-tion. For deadend crossarm testing, this would be in anapparent horizontal direction.6.3 Deadend Crossarm Test Set UpThe test fixture shallallow for various lengths of crossarms to be tested. Thecrossarm length range
31、shall be dictated by typical industryofferings. The fixture shall permit the loading of the arm in oneof two ways: such that the load is applied through the centermount bracket, into the arm and resisted by the phase loadingeyenut hardware representing a two phase single sided deadendcrossarm fabric
32、ation, or such that the load is applied throughthe phase loading eye nut hardware representing two phasesingle sided deadend crossarm fabrication, into the arm, andresisted by the secured center mount bracket. The loadingconfiguration described is shown in Fig. 1.6.4 Tangent Crossarm Test Set UpThe
33、test fixture shallallow for various lengths of tangent crossarms to be tested. Thecrossarm length range shall be dictated by typical industryrequirements. The fixture shall permit the tangent bracket to besolidly mounted to a structural member that represents a pole.6.5 In absence of specific insula
34、tor hardware requirementsfor application, the tangent crossarm shall be loaded byapplying an apparent vertical force through two eyenuts, hoistD8019 152rings, or other securing hardware connected to the loadapparatus using a threaded rod or bolt at the appropriateconductor location, in a configurati
35、on which represents typicaltangent arm usage. The load path shall propagate from theeyenut or other securing hardware, through the threaded rod orbolt, to washers which span the entire width of the crossarm.The load shall then be distributed from the washer, through thecrossarm, where it is then dis
36、tributed to the tangent bracket andinto the mount. It is critical that the mount used in thecommercial sale of the tangent arm be used in the test, as thearm strength will be influenced by the hardware or centermount. The loading configuration described is shown in Fig. 2.6.6 Deflection Measuring De
37、viceA properly calibrateddevice to measure the deflection of the crossarms shall be used.The device shall automatically and continuously record thedeflection during the test. In the absence of an automated dataacquisition system, a properly calibrated deflection dial gaugeshall be used. A minimum of
38、 ten manual recordings shall betaken at approximately the same load increments throughoutthe duration of the test. The deflection dial gauge shall beaccurate to 60.001 in. 60.0254 mm.7. Sampling and Test Specimens7.1 SamplingA minimum of five specimens, per each testmethod described in 4.1 and 4.2,
39、shall be tested for each armlength that displays a different failure mode. Alternatively, theminimum quantity as required by the agency or the appropriatecodes and standards.7.2 SpecimensSpecimens shall be full-scale samples, fab-ricated in accordance with the manufacturers specificationsand outfitt
40、ed with standard deadend or tangent crossarmhardware and tested at the desired span length.7.3 Specimen PreparationSpecimens shall be of the samematerial composition, geometric characteristics, and manufac-tured by the same process as those described in the manufac-turers specifications and as avail
41、able commercially.7.4 LabelingLabel the test specimens (date, batch number,line number) so that they will be distinct from each other andtraceable back to the specimen of origin, and will neitherinfluence the test nor be affected by it.NOTE 2Non-load bearing accessories such as identification (I.D.)
42、tags, end caps and commercial markings are not required for testspecimens.8. Calibration and Standardization8.1 The accuracy of all testing and measuring equipmentshall have certified calibrations that are current at the time ofuse of the equipment.FIG. 1 Three-Point Bend Dead End Crossarm Test Set
43、UpFIG. 2 Three-Point Bend Tangent Crossarm TestD8019 1539. Conditioning9.1 If the test requestor does not explicitly specify a pre-testconditioning environment, conditioning is not required and thetest specimens shall be tested at normal room temperature(20-25C or 68-77F).9.2 If no explicit conditio
44、ning process is performed thespecimen conditioning process shall be reported as “uncondi-tioned.”10. Procedure and Test Setup10.1 If needed, condition test specimens as required. Storethe test specimens in the conditioned environment until testtime if the test environment is different than the condi
45、tioningenvironment.10.2 Before testing, measure and record the cross-sectionalshape and dimensions as necessary. Record the dimensions tothree significant figures.10.3 Measure and record the length of the unsupported span.10.4 Rate of TestingThe load rate shall be between 1,500lbf 6,672 N and 2,500
46、lbf 11,120 N per minute.10.5 Fixture InstallationArrange the loading fixture asshown in Fig. 1 for a deadend crossarm test or as shown in Fig.2 for a tangent crossarm test.10.6 Specimen Insertion and AlignmentPlace the speci-men into the test fixture. Align the fixture and specimen so thatthe initia
47、l starting longitudinal axis of the specimen is perpen-dicular (within 1) to the longitudinal axis of the loading nose,and that the resultant load carried by the phase supports isperpendicular (within 1) of the initial starting longitudinalaxis of the specimen.10.7 LoadingApply a force while continu
48、ously recordingdata. Load the specimen until failure occurs. Load shall beapplied so that the loading axis and phase support loading axesremains perpendicular within 3.5 to the initial starting longi-tudinal axis of the specimen through the entirety of the test.10.8 Data RecordingRecord load and ver
49、tical displace-ment until failure occurs.11. Calculation of the Determination of MechanicalProperties11.1 The full section flexural modulus shall be calculated byrearranging Eq 1 and solving for E. 5Pa3L22 4a2!24EI(1)where:a = distance from phase hardware to the center mount boltthrough the crossarm. in. m,E = flexural modulus, psi Pa,I = moment of inertia about the neutral axis of the crossarm,in.4m4,L = support span, in. m,P = load acting through a single center mount bolt, lbf N,and = deflection relative to
