1、Designation: E2954 15Standard Test Method forAxial Compression Test of Reinforced Plastic and PolymerMatrix Composite Vertical Members1This standard is issued under the fixed designation E2954; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 This test method covers the evaluation of verticalmembers in axial compression for “full-sized”
3、 specimens withvarious end conditions with constant cross-sections throughoutthe length.1.2 This test method is limited to reinforced plastic andpolymer matrix composite materials and covers the determina-tion of the compressive properties of structural members. Themethod is intended primarily for m
4、embers of rectangular crosssection, but is also applicable to irregularly shaped studs, roundposts, or special sections.1.3 This test method covers short-term axial load testingunder standard indoor atmospheric conditions. It does notaddress: sampling, the ability of the material to carry asustained
5、 long-term load, design load derivations, temperatureeffects, performance under freeze/thaw or salt spray exposureconditions, chemical/UV exposure effects, or engineeringanalysis/modeling needed to extrapolate the results to condi-tions other than those tested. Each of these factors, andpotentially
6、others, need to be considered by the design profes-sional or product standard development committee beforeusing the information generated by this test method to assessstructural adequacy.1.4 Short sections are not covered in this test method andshould be tested using a material test standard such as
7、 TestMethod D6108 or Test Methods D198.1.5 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 information onlyand are not considered standard.1.6 This standard does not purport to address
8、all of thesafety concerns, 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.2. Referenced Documents2.1 ASTM Standards:2D198 Test Methods
9、of Static Tests of Lumber in StructuralSizesD883 Terminology Relating to PlasticsD2915 Practice for Sampling and Data-Analysis for Struc-tural Wood and Wood-Based ProductsD3878 Terminology for Composite MaterialsD6108 Test Method for Compressive Properties of PlasticLumber and ShapesE4 Practices for
10、 Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE575 Practice for Reporting Data from Structural Tests ofBuilding Constructions, Elements, Connections, and As-sembliesE631 Terminol
11、ogy of Building Constructions3. Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto high-modulus fibers and their composites. TerminologyD883 defines terms relating to plastics. Terminology E6 definesterms relating to mechanical testing. In the event of a conflictbetween terms, Term
12、inology D3878 shall have precedenceover the other standards.3.1.1 For definitions of terms in this standard, see Termi-nology E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 full-sized specimenfull-sized specimens (meaningfull cross-sectional area) tested with standard lengths withvari
13、ous end conditions and bracing conditions about the weakand strong member axes. The end conditions addressed in-clude: eccentricity, fixed, pinned.3.2.2 short sections (not considered in this test method)compressive test sections having a maximum length, L, lessthan 17 times the least radius of gyra
14、tion, r, where r = (I/A).1This test method is under the jurisdiction of ASTM Committee E06 onPerformance of Buildings and is the direct responsibility of Subcommittee E06.11on Horizontal and Vertical Structures/Structural Performance of Completed Struc-tures.Current edition approved May 1, 2015. Pub
15、lished July 2015. DOI: 10.1520/E2954-152For 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 Interna
16、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.3 Symbols:3.3.1 = compressive strength.3.3.2 = compressive stress at proportional limit.3.3.3 E = compressive modulus of elasticity.3.3.4 E = apparent modulus of elasticity.3.3.5 A = cross-sectional area.3.
17、3.6 L= change in length from original gage length atproportional limit.3.3.7 LG= gage length of compression column.3.3.8 Pmax= maximum load borne by column loaded tofailure.3.3.9 P = applied load at proportional limit, lbf (N).4. Summary of Test Method4.1 The structural member is subjected to a comp
18、ressiveforce distributed on the contact surface of the specimen in adirection generally parallel to the longitudinal axis. The speci-mens are either loaded to failure or proof loaded. The testmethod is intended to determine the axial compressive strengthof standard full-size specimens tested with va
19、rious end condi-tions including: built-in eccentricity, pinned, fixed, or asrequired to accomplish the experimental objective. Lateralbracing may be installed as required to accomplish the experi-mental objective.5. Significance and Use5.1 The compressive properties obtained by axial compres-sion wi
20、ll provide information such as: modulus of elasticity,stress at proportional limit and compressive strength for theend support, and lateral bracing condition tested.5.2 This test method addresses only full-sized specimens fordetermination of compressive strength and compressive modu-lus of elasticit
21、y intended for application to actual lengthmembers with end conditions and lateral bracing as intended.NOTE 1The effective length of the column with respect to buckling isaffected by the end conditions.Afixed end condition results in an effectivelength for buckling that is less than the actual lengt
22、h of the column, by asmuch as 50 %.6. Apparatus6.1 Drive MechanismA drive mechanism for imparting toa movable loading head a uniform controlled velocity withrespect to the stationary base.6.2 Load IndicatorA load-indicating mechanism capableof showing the total compressive force on the specimen. Thi
23、sforce-measuring system shall be calibrated to ensure accuracyin accordance with Practices E4. A schematic representation ofthe typical test set up is shown in Fig. 1.6.3 End ConditionsThe end conditions used for the testshall be chosen to satisfy the experimental objectives. Optionsinclude:6.3.1 Fi
24、xedWith a fixed end condition as conceptuallydepicted in Fig. 2(a), a spherical bearing block may be used ateither end of the column to ensure uniform contact. Whenspherical bearing blocks are used, the radius of the sphere shallbe as small as practicable, in order to facilitate adjustment ofthe bea
25、ring plate to the specimen, and yet large enough toprovide adequate spherical bearing area. This radius is usuallyone to two times the greatest cross-section dimension. Thecenter of the sphere shall be on the plane of the specimencontact surface. The size of the compression plate shall belarger than
26、 the contact surface. It has been found convenient toprovide an adjustment for moving the specimen on its bearingplate with respect to the center of spherical rotation to ensureaxial loading.6.3.2 PinnedAs conceptually depicted in Fig. 2(b), apinned end condition shall use a fixture capable of rotat
27、ingabout an axis perpendicular to the column length. The size ofthe compression plate shall be larger than the column contactsurface. The pivot point of the fixture shall be aligned with theFIG. 1 Test Set-UpE2954 152centerline of the test column. Depending upon the experimen-tal objectives, the piv
28、ot(s) shall be positioned to permit rotationabout the weak column axis, the strong column axis, or both.The pivot locations shall be positioned as close to the columnbearing surface as practical, but at a distance of not more thantwo times the smallest column cross-sectional dimension. Thepivot poin
29、ts of the fixtures shall consist of greased bolts, knifeedges, ball-bearings, or other details that minimize the fric-tional rotation restraint of the fixture. Retainer blocks, angles,clamping fixtures, or other attachments may be used to ensurethat the column does not slide off the bearing fixtures
30、 underload. However, these devices shall not protrude along thecolumn length a distance greater than the minimum cross-sectional dimension of the column.6.3.3 EccentricAn eccentric load may be applied by usinga pinned end condition that is not aligned with the membercenterline as depicted in Fig. 2(
31、c). The degree of eccentricityabout each member axis shall be selected to satisfy theexperimental objectives and recorded.6.3.4 OtherAn alternate end condition may be chosen tospecifically replicate a field application condition or otherexperimental objective. The details of the non-standard endcond
32、itions shall be fully described and reported.6.4 BracingAs conceptually illustrated in Fig. 2(d), lateralbracing shall be installed as required to satisfy the experimentalobjectives. The bracing fixtures employed for the test shall usea roller or other detailing to minimize friction to provide later
33、alrestraint without imparting axial resistance to the column. Thenumber, position, and details of the braces about each axis shallbe reported.NOTE 2Bracing may be installed about the weak axis, the strong axis,or both.6.5 CompressometerAcompressometer as shown in Fig. 1shall be used. The measuring i
34、nstruments shall conform toclass D (or better) of Practice E83.6.5.1 Gage LengthFor modulus of elasticity calculations,a device shall be provided by which the deformation of thespecimen is measured with respect to specific paired gagepoints defining the gage length. To obtain test data represen-tati
35、ve of the test material as a whole, such paired gage pointsshall be located symmetrically on the lengthwise surface of thespecimen as far apart as feasible, yet at least one times thelarger cross-sectional dimension from each of the contactsurfaces. At least two pairs of such gage points on diametri
36、-cally opposite sides of the specimen shall be used to measurethe average deformation.6.6 DeflectometerA suitable device to measure out-of-plane deflection of the member as shown in Fig. 1.NOTE 3A dial gage or electronic displacement transducer mounted tothe frame of the machine reacting at mid-heig
37、ht of the specimen is asatisfactory method.7. Test Specimen and Sampling7.1 The test specimen shall consist of a structural membercommercially used in structural applications, that is, in sizesgreater than 2 by 2-in. (51 by 51-mm) cross section.7.2 IdentificationMaterial or materials of the test spe
38、ci-men shall be identified as fully as possible by including theorigin or source of supply, composition, manufacturing processand conditioning, chemical treatment, fabrication, and otherpertinent physical or mechanical details that may affect thestrength. Details of this information shall depend on
39、thematerial or materials in the member.7.3 The material being tested shall be representative ofproduction. Where prototypes (non-production) are tested, thespecimens shall be specifically identified as such.7.4 The number of replicates shall be chosen to satisfy theexperimental objectives.As a guide
40、line, Practice D2915 can beused to determine the number of samples.7.5 Specimen DimensionsThe weight and dimensions, aswell as moisture content (if applicable) of the specimen, shallbe measured before test. Weights and dimensions (length andcross section) shall be measured to three significant figur
41、es.Sufficient measurements of the cross section shall be madealong the length of the specimen to describe shape character-istics and to determine the smallest section. Document anyinitial curvature of full sized specimens about each axis.7.6 Specimen LengthEffective buckling length shall becalculate
42、d as 0.5 times the actual specimen length for testconducted with fixed end conditions, and the distance betweenFIG. 2 Various Loading ConditionsE2954 153pivot locations for pinned end conditions, with this lengthdetermined separately for each possible buckling directionwhen unidirectional pins are u
43、sed.NOTE 4For example, when pins are used to enable buckling in theweak axis direction but not in the strong axis direction, the effectivebuckling length for the weak axis shall be the actual specimen length(distance to pivot points) and the effective buckling length for the strongaxis shall be 0.5
44、times the actual specimen length.8. Procedure8.1 ConditioningUnless otherwise indicated in the mate-rial specification, condition and perform testing on specimensexposed to standard laboratory temperature and humidity(72 6 5F and 65 6 10 % R.H.).8.2 Test Procedure:8.2.1 Test Set-upCut the specimen t
45、o the proper length sothat the contact surfaces are plane, parallel to each other, andnormal to the long axis of the specimen. Position the specimenin the test machine using the end condition and bracing fixturesselected for the test.NOTE 5A sharp fine-toothed saw of either the crosscut or “novelty”
46、crosscut type has been used satisfactorily for obtaining the proper endsurfaces for some materials. Accurate and square cuts help to ensureuniform load distribution. Power equipment with accurate table guides areespecially recommended for this work. Use of shims to achieve fullbearing is acceptable.
47、8.2.2 CenteringCenter the specimens within the frameand relative to the fixtures as required to either induce oreliminate any desired eccentricity.8.2.3 Initial CurvatureThe specimen shall typically beinstalled and tested with its natural initial curvature presentabout each member axis and with the
48、braces and supportconditions adjusted as necessary to accommodate it. If the endfixtures or braces are used to induce or limit the curvatureabout any axis, then it shall be documented in the report andthe curvature of the specimen at the time of testing shall bereported.8.3 Speed of TestingSet the s
49、peed of testing to a nearlyconstant strain rate in the gage section. The strain rate shall beselected so as to produce failure within 1 to 10 min. The loadmay be paused as necessary to remove any deformationmeasurement equipment prior to failure.8.4 DitheringIf lateral braces or rotational end restrainsare employed, then the specimen shall be repeatedly “dithered”during the test using a hammer, pole, or other device sufficientto break any friction in the braces and end restraints. Thefrequency of the dithering shall be at least once every fivese
