1、Designation: D 3916 02Standard Test Method forTensile Properties of Pultruded Glass-Fiber-ReinforcedPlastic Rod1This standard is issued under the fixed designation D 3916; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method describes a proced
3、ure for determiningthe tensile properties of pultruded, glass-fiber-reinforced ther-mosetting plastic rod of diameters ranging from 3.2 mm (18 in.)to 25.4 mm (1 in.). Little test specimen preparation is required;however, reusable aluminum tab grip adapters (Fig. 1)ofappropriate size are required to
4、prevent premature failure of thespecimens at the grips.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespo
5、nsibility 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 hazardsstatements are given in Note 3 and Note 4.NOTE 1There is no known ISO equivalent to this test method.2. Referenced Doc
6、uments2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2D 638 Test Method for Tensile Properties of Plastics2E4 Practices for Force Verification of Testing Machines3E83 Practice for Verification and Classification of Exten-someters33. Significance and Use3.1 The high axial-tens
7、ile strength and the low transverse-compressive strength of pultruded rod combine to present someunique problems in determining the tensile strength of thismaterial with conventional test grips. The high transverse-compressive forces generated in the conventional method ofgripping tend to crush the
8、rod, thereby causing prematurefailure. In this test method, aluminum-alloy tabs contoured tothe shape of the rod reduce the compressive forces imparted tothe rod, thus overcoming the deleterious influence of conven-tional test grips.3.2 Tensile properties are influenced by specimen prepara-tion, str
9、ain rate, thermal history, and the environmental condi-tions at the time of testing. Consequently, where precisecomparative results are desired, these factors must be carefullycontrolled.3.3 Tensile properties provide useful data for many engi-neering design purposes. However, due to the high sensit
10、ivityof these properties to strain rate, temperature, and otherenvironmental conditions, data obtained by this test methodshould not, by themselves, be considered for applicationsinvolving load-time scales or environmental conditions thatdiffer widely from the test conditions. In cases where suchdis
11、similarities are apparent, the sensitivities to strain rate,including impact and creep, as well as to environment, shouldbe determined over a wide range of conditions as dictated bythe anticipated service requirements.4. Apparatus4.1 Water-Cooled Diamond or Tungsten-Carbide Saw, forcutting rod to si
12、ze.4.2 Micrometer, reading to at least 0.025 6 0.000 mm(0.001 6 0.000 in.), for measuring the width and thickness ofthe test specimens. The thickness of nonrigid plastics should bemeasured with a dial micrometer that exerts a pressure of 25 6kPa (3.6 6 0.7 psi) on the specimen and measures the thick
13、nessto within 0.025 mm (0.001 in.). The anvil of the micrometershall be at least 30 mm (1.4 in.) in diameter and parallel to theface of the contact foot.4.3 Universal Testing Machine, verified in accordance withPractices E4, having a capacity of at least 530 kN (120 000lbf) to permit the testing of
14、25.4 mm (1 in.) diameter rod.Smaller-diameter rod may be tested on lower-capacity equip-ment, commensurate with the anticipated tensile strength ofsuch rod.4.4 ExtensometerA suitable instrument for determiningthe distance between two designated points located within the1This test method is under the
15、 jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.18 on Reinforced Thermoset-ting Plastics.Current edition approved March 10, 2002. Published May 2002. Originallypublished as D 3916 80. Last previous edition D 3916 94.2Annual Book of ASTM Standards,
16、Vol 08.01.3Annual Book of ASTM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.gage length of the test specimen as the specimen is stretched.It is desirable, but not essential, that this instrument automati-cally
17、 record this distance (or any change in it) as a function ofthe load on the test specimen or of the elapsed time from thestart of the test, or both. If only the latter is obtained, load-timedata must also be taken. This instrument shall be essentiallyfree of inertia lag at the specified speed of tes
18、ting and shall beaccurate to 61 % of strain or better.NOTE 2Reference is made to Practice E83.4.5 One Pair of 6061 T6 Aluminum-Alloy Tab Grip Adapt-ers, as described in Fig. 1 and Table 1, to fit in split wedge-typeaction jaws of the testing machine.4.6 Solvent, such as methylene chloride, for clean
19、ing thegripping surfaces of the aluminum-alloy tab grip adapters toremove any mold release, oil, or other foreign material thatmight act as a lubricant. The improper use of solvents canpresent hazardous conditions. Use of proper equipment, ven-tilation, and training of personnel in proper techniques
20、 shouldbe practiced to minimize hazards associated with the use of anyvolatile solvent.5. Test Specimens5.1 At least five specimens shall be cut from the rod sampleof interest. Specimen length shall be as great as possible,commensurate with the physical limitations of the testingmachine.NOTE 3Cautio
21、n: When fabricating composite specimens by machin-ing operations, a fine dust consisting of particles of fibers or the matrixmaterial, or both, may be formed. These fine dusts can be a health or safetyhazard, or both. Adequate protection should be afforded operating person-nel and equipment. This ma
22、y require adequate ventilation or dustcollecting facilities, or both, at a minimum.6. Conditioning6.1 Standard conditioning shall be in accordance with Pro-cedure A of Practice D 618.6.2 Tests at other than standard laboratory atmosphericconditions should be described, including time (hours), tem-pe
23、rature, and test environment, such as watersoak, and so forth.Tests should be made as near to these conditions as possible.7. Number of Test Specimens7.1 At least five specimens shall be tested for each sample.When specimens are preconditioned (for example, water-boiled or oven-aged) prior to test,
24、five specimens per sampleshall be tested for each condition employed.8. Procedure8.1 Measure and record the diameter of the rod specimen atseveral points along its length with a micrometer, noting boththe minimum and average values of these measurements.8.2 Wipe the ends of the specimen and the grip
25、ping surfacesof the aluminum tabs with a cloth saturated with a suitablesolvent to remove any foreign material that might act as alubricant.8.3 Assemble the aluminum tabs to the ends of the speci-men, allowing 10 to 20 mm (0.4 to 0.8 in.) of the specimen toextend beyond the tabs at each end, and mou
26、nt this assembly inNOTE 1Sandblast Clamp Face with 100-mesh Carbide at 100 psi.FIG. 1 General Schematic of Tab Grip AdaptersD3916022the grips of the testing machine, taking care to align the longaxis of the specimen with that of the grips of the machine.8.4 If values of the modulus of elasticity are
27、 being deter-mined, proceed as follows:8.4.1 Attach the extensometer.8.4.2 Start the machine and operate it at a nominal cross-head speed of 5 mm (0.20 in.)/min.8.4.3 Unless an automatic recorder is used, record loads andcorresponding extensions at uniform intervals of extension orload so that not l
28、ess than ten load-extension readings areobtained prior to the termination of the test.NOTE 4Caution: When testing composite materials, it is possible tostore considerable energy in the test specimen which can be released withconsiderable force on rupture. This can release small high velocityparticle
29、s and dust consisting of fractured fibers and matrix materials. Theparticles and fine dust can potentially be a health or safety hazard, or both.Adequate protection should be afforded operating personnel, bystanders,and the equipment. This may require shielding or dust collection facilities,or both,
30、 at a minimum.8.5 Determine the tensile strength and the elongation (ifrequired) by the following procedure:8.5.1 Start the machine and operate it at a nominal cross-head speed of 5 mm (0.20 in.)/min.8.5.2 Allow the test to continue until the specimen breaks,and record the breaking load and the exte
31、nsion. If elongation isdesired, measure by an extensometer or strain gage at themoment of break.8.5.3 Only failures which initiate in the free length of thespecimen shall be considered valid for the determination oftensile strength.9. Calculation9.1 Tensile StrengthCalculate the tensile strength in
32、MPa(psi) by dividing the breaking load in newtons (pounds-force)by the original minimum cross-sectional area of the specimenin square millimetres (square inches). Report the result to threesignificant figures.Tensile strength, S 5 4P/pD2where:S = tensile strength in MPa (or psi),P = maximum load in
33、N (or lbf), andD = minimum diameter of rod in mm (or in.).9.2 Modulus of ElasticityCalculate the modulus of elas-ticity by extending the initial linear portion of the load-extension curve and dividing the difference in stress, corre-sponding to a segment of this line, by the correspondingTABLE 1 Dim
34、ensions of Tab Grip Adapters for Rods of Various DiametersSI UnitsDimensionA(see Fig. 1)Rod Diameter3.2 6.4 12.7 19 22.2 25.4R 1.6+0.103.2+0.106.4+0.109.5+0.1011.1+0.1012.7+0.10D 1.4 3.0 6.1 9.0 10.1 11.4L(min) 50 50 152 152 178 229W(min) 25 25 50 57 64 67T 4 6.4 19 19 19 19E 5.6 5.6 9.5 9.5 9.5 9.5
35、2E 11.1 11.1 19.5 19.5 19.5 19.5S 14.3 14.3 31.8 38.1 44.4 47.6Pin diameter 3.2 3.2 6.4 6.4 6.4 6.4Hole diameter 3.6 3.6 6.7 6.7 6.7 6.7Typical maximumload, kN8 to 10 30 to 40 135 to 160 300 to 360 400 to 500 530 to 675Minimumspecimen length305 457 914 1070 1170 1220Inch-Pound UnitsDimensionB(see Fi
36、g. 1)Rod Diameter1814123478 1R 0.062+0.0040.0000.125+0.00040.0000.250+0.00040.0000.375+0.00040.0000.438+0.00040.0000.500+0.00040.000D 0.057 0.120 0.240 0.355 0.415 0.475L(min) 2 2 6 6 7 9W(min) 1 1 2 214 212 258T 0.1551434343434E732732383838382E71671634343434S916916 114 112 134 178Pin diameter181814
37、141414Hole diameter9649641764176417641764Typical maximumload, lbf1800 to 2200 7000 to 8000 30 000 to 35 000 65 000 to 80 000 90 000 to 110 000 120 000 to 150 000Minimumspecimen length12 18 36 42 46 48AAll dimensions in millimetres, except where noted.BAll dimensions in inches, except where noted.D39
38、16023difference in strain. This calculation shall be performed usingthe average initial cross-sectional area within the gage lengthof the test specimen. Express the result in gigapascals (or psi)and report to three significant figures.Modulus of elasticity, E 5 4mg/pD2where:E = modulus of elasticity
39、 in GPa (or psi),m = slope of the tangent to the initial straightline portion ofthe load-extension curve in kN/mm (or lbf/in.) ofextension,g = original gage length in mm (or in.), andD = average diameter of rod in mm (or in.).9.3 Percent ElongationCalculate the percent elongationby dividing the exte
40、nsion at rupture of the specimen by theoriginal gage length and multiplying by 100. Report thepercentage elongation to two significant figures as percentageelongation at break.elongation % 5 D/g!# 100where:D = extension at maximum load in mm (or in.), andg = original gage length in mm (or in.).9.4 F
41、or each series of tests, calculate the arithmetic mean ofall values obtained and report it as the “average value” for theparticular property determined.9.5 Wet-Strength RetentionCalculate the wet-strength re-tention (if specimens are tested after water boil or soak) bydividing the average wet streng
42、th by the average dry strengthof the specimens for each sample. Report the wet-strengthretention as a percent to two significant figures.9.6 Coeffcient of VariationCalculate the coefficient ofvariation (COV) for each set of test values by dividing therespective standard deviations by the correspondi
43、ng arithmeticmean. Report the result to two significant figures as “percentCOV” by multiplying by 100. The formula for standarddeviation is in 11.5 of Test Method D 638.10. Report10.1 Report the following information:10.1.1 Complete identification of the material tested, includ-ing type, source, man
44、ufacturers code numbers, form, principaldimensions, previous history, etc.,10.1.2 Dimensions of test specimens,10.1.3 Conditioning procedure used,10.1.4 Atmospheric conditions in test room,10.1.5 Number of specimens tested,10.1.6 Speed of testing,10.1.7 Tensile strength: average value and percent co
45、effi-cient of variation,10.1.8 Modulus of elasticity (if required): average value andpercent coefficient of variation,10.1.9 Percentage elongation at break (if required): averagevalue and percent coefficient of variation,10.1.10 Wet-strength retention (if applicable), expressed asa percent, and10.1.
46、11 Date of test.11. Precision and Bias11.1 Precision:11.1.1 Precision Repeatability (Single Laboratory)Testing in a single laboratory of a sample of 1in. diameterpultruded rod resulted in a within-laboratory coefficient ofvariation of 4.0% for strength and 2.9% for modulus. Thewithin-laboratory crit
47、ical interval (cr) between two test resultsis 11.2% for strength and 8.1% for modulus (2.8 3 Vr). Tworesults obtained within one laboratory on the same materialshall be judged not equivalent if they differ by more than thecritical interval (cr). Attempts to develop a full precision andbias statement
48、 for this test method have not been successfuldue to the limited number of machines of the needed capacityto perform this test. For this reason, data on precision and biascannot be given. Because this test method does not contain around robin based numerical precision and bias statement, itshall not
49、 be used as a referee method in case of dispute.Anyone wishing to participate in the development of precisionand bias data should contact the Chairman, SubcommitteeD20.18 (Section 20.18.02), ASTM, 100 Barr Harbor Drive,West Conshohocken, PA 19428.11.2 BiasA statement of bias cannot be made for this testmethod since no standard or control material exists.12. Keywords12.1 glass reinforced plastic; pultruded rods; tensilepropertiesASTM International takes no position respecting the validity of any patent rights
