1、Designation: D 3916 08Standard 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. Scope*1.1 This test method describes a proce
3、dure 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 theresp
5、onsibility 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 Do
6、cuments2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 638 Test Method for Tensile Properties of PlasticsE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exten-someter Systems3. Significance and Use3.1 The high axial
7、-tensile 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
8、 the 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
9、, strain 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 s
10、ensitivityof 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 su
11、chdissimilarities 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
12、to size.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 (rein-forced pultruded products are rigid) should be measured with adial micrometer that exerts a pressure of 25 6 kPa (3.6
13、6 0.7psi) on the specimen and measures the thickness to within0.025 mm (0.001 in.). The anvil of the micrometer shall be atleast 30 mm (1.4 in.) in diameter and parallel to the face of thecontact foot.4.3 Universal Testing Machine, verified in accordance withPractices E4, having a capacity of at lea
14、st 530 kN (120 000lbf) to permit the testing of 25.4 mm (1 in.) diameter rod.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 March 1, 2008. Published Ma
15、rch 2008. Originallyapproved in 1980. Last previous edition approved in 2002 as D3916 - 02.2For 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 Su
16、mmary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Smaller-diameter rod may be tested on lower-capacity equip-ment, commensurate with the an
17、ticipated tensile strength ofsuch rod.4.4 ExtensometerA suitable instrument for determiningthe distance between two designated points located within thegage length of the test specimen as the specimen is stretched.It is desirable, but not essential, that this instrument automati-cally record this di
18、stance (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 testing and shall
19、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 cleaning thegripping
20、 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 shouldbe pract
21、iced 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 3Caution: When fabrica
22、ting 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 may require adequ
23、ate 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-perature, and tes
24、t 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, five specimens
25、per sampleshall be tested for each condition employed.NOTE 1Sandblast Clamp Face with 100-mesh Carbide at 100 psi.FIG. 1 General Schematic of Tab Grip AdaptersD39160828. Procedure8.1 Measure and record the diameter of the rod specimen atseveral points along its length with a micrometer, noting botht
26、he minimum and average values of these measurements.8.2 Wipe the ends of the specimen and the gripping 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, a
27、llowing 10 to 20 mm (0.4 to 0.8 in.) of the specimen toextend beyond the tabs at each end, and mount this assembly inthe 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 being deter-mi
28、ned, 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 less than ten lo
29、ad-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 velocityparticles and dust cons
30、isting 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, at a minimum.8
31、.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 extension. If elong
32、ation isdesired, measure by an extensometer or strain gauge 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 MPa(psi) by di
33、viding 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.TABLE 1 Dimensions of Tab Grip Adapters for Rods of Various DiametersSI UnitsDimensionA(see Fig. 1)Rod Di
34、ameter3.2 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 9.52E 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.
35、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 Fig. 1)Rod Diameter1814123478 1R 0.062+0.0040.0000.125+0.00040.0000.250+0.00040.0000.375+0.00040
36、.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 diameter181814141414Hole diameter9649641764176417641764Typical maximumload, lbf1800 to 2200 7000 to 8000 30
37、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.D3916083Tensile strength, S 5 4P/pD2where:S = tensile strength in MPa (or psi),P = maximum load i
38、n 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 correspondingdifferenc
39、e 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 in GPa (or ps
40、i),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 extension at ruptu
41、re 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 For each series
42、 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 strength by the aver
43、age 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 corresponding arithmeticm
44、ean. 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, manufacturers cod
45、e 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 coeffi-cient of
46、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, and10.1.11 Date of tes
47、t.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 critical interval
48、(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 for this test
49、 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 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 Conshoh
