This dtveto1><d In 心,onto nee with lnternollonolly ,ec叨.如I p,lndl)le, on stondo"lf研 Ion 句的 II 亚d in the D础Ion on r,1,叶)阳 fo, the ur lultrnallon"I SIQud 盯心, Gukl 心的d Rt<0mm,n心心“'泌,心J by the Wo,td Tu,de 0屯皿iu,, ;on 11心如I 61.,rie,s to'lhld, (TBT) Commill... in ten田lo 仆o l SI加 cl血叩s De、,,lop mtnl 矗 Designation: 03039/ 03039M-17 •utL 劓r•RHATIOH.U Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials 1 ·111is standard is issued under lhc fixed dcsi 沪出 ion 03039103039M; lhc number immediately following lhc dcsignarion indica1cs lhc year of original adoption or. in the case of revision. the year of last 代visi or,. A number in parentheses i nd 心tes die year of I 邸 reapproval. Asuperscript epsilon (e) indicates an editorial change sin 忱 t he last 代visio n or reapproval. Thfr s1turdtud has 妇en nJ平m,·ed for me by agende.r 叶 1Jre U.S. D叩arlmenl I. Scope 02734 Test Methods for Void Content of Reinforced Plastic-s D31 7 1 Test Methods for Constituent Content of Composite Materials 03878 Terminology for Composite Materials D5229/D5229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite Materials E4 Practices for Force Verification of Testing Machines E6 Tenninolo!,')'Relating to Methods of Mechanical Test mg E83 Practice for Verification and Classification o f Extensometer Systems E 111 Test Method for Young's Modulus, Tangent Modulus, and Chord Modulus E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process E 132 Test Method for Po isson's Ratio at Room Tempernture El 77 Practice for Use of the Tenns Precision and Bias in ASTM Test Methods E25 I Test Methods for Perfonnance Characteristics of Me叫lic Bonded Resistance Strain Gages E456 Tenninology Relating to Qual ity and St.1tist1cs E 10 12 Practice for Verification o f Testing Frame and Spec, 一 men Alignment Under Tensile and Compressive Axial Force Application E 1237 Guide for Install ing Bonded Resistance Strain Gages 1.1 This test method determines the in-plane tensi le properties of polymer matrix composite materials reinforced by high-modulus fibers. The composite material fonns are limited to continuous fiber or discontinuous fiber-reinforced composites in which the lamina比 is balanced and symmetric with respect to the test direction 1.2 The values stated in e ither SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; 加refore, each system must be used independently of the other. Combining values from the nvo systems may result in nonconformance with the st.mdard. 1.3 This sra1uk11rl does ,wt p111po11 ro acid心:s all of the 呻ry concems, if auy, associated wi1h its use. Ir is the 心po心如lity of the user of th凸 standard 10 esrciblish app,vpriate safety, health, and e1111ironmenJa/ practices and determiue the applicability of regulatory limi,ations prior to use 1.4 This i11teriwtio11al stan归 was developed in accor如ce wi1h illlenwtionally recognized principles on standard叩ion established in the Decision 011 Principles for the Developmem of lnremational Sta11da1本, 如des and Recommendatim1s issued by rhe World Trade Organizarion Technical 彻rriers to Trade (TBT) Commiflee. 2. Referenced Documents 2.1 ASTM Stan如心.2 0792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement D883 Terminology Relating to Plastics D2584 Test Method for Igi1ition Loss of Cured Reinforced Resins ' This t凶 ,neth od is under the jurisdiction of ASTM Co,nm i 阰e 030 on Composite Materials and is the di 的 responsib血y of Su如mmittce 030.04 on Lamina and 匕minat e Test Methods. Current edition approved Oct. 15. 201 7. P ubl isl心I November 2017. Originally spprovcd in 1971. ~•SI previous cdi1ion spprovcd in 2014•s D3039/D3039M- 14 DOI: 10.1520/03039 D3039M-17 , Fo r 咄ren 如 ASTM sci 心rds. visit the ASTM we的 te, www.as皿o rg. or cont吹 t ASTM Customer Service at scrvkc@astm 叩. Por Annual 8心kofASTM S血danl., volume in fornuition令 refer to the sta叫叫 's Docmnent Sumn,ary page on 1hc AS'l'M wcbs;tc e心,;9ht<CI ASTM ,,.(Defense. 3. Tcrminolo切 3. 1 Defi11i1io11s一Terminology D3878 defines terms re latmg to high-modulus fibers and their composites. Terminology D883 defines terms relating to plastics. Tenn inology E6 defines tenns relating to mechanical testing. Terminology £456 and Practice E 177 define terms re lating to statistics. In the event of a conflict 归ween terms, Tenninology D3878 shall have precedence over the other standards 3.2 Defi11i1io11s of Terms Specific to This S血dart/ 3.2. 1 No比一If the tenn represents a physical quantity, its analytical dimensions are stated immediately following the term (or letter symbol) in fondamental dimension fonn, using the foll owing ASTM s臼ndard symbology for fundamental dimensions, shown within square brackets: [M] for mass, [LI 伽 length, (71 for time, (0 ] for thermodynamic temperattire, lntemadonal. 100 Bau 心tbot Omo. PO Bo, C700. Wost I为nsh中oc""'. PA194蕊2函虹od S邸OS • 03039/03039M - 17 and [ nd j for nondimensional quantities. Use of these symbols is restricted to a nalytical d imensions when used with square brackets, as the symbols may have other definitions when used without the brackets 3.2.2 nominal va/11e, 11一a value, existing in name only, 妞gned to a measurable property for the p田pose of conven ient designation. Tolerances may be applied LO a nominal value to define an acceptable range for the prope1ty. 4. Summary of Tes t Method 4.1 A thin flat strip of material having a consta nt rectangular c ross section is mounted in the grips of a mechanical test ing machine and monotonically loaded in tension while recording the force. The ultimate strength of the materia l can 加 determined from the maximum force carricd before failure. If the coupon strain is monitored with strain or dis place ment transducers then the stress-strain response of the mate rial can be detennined, from which the ultimate tensile strnin, tensile modulus o f e lasticity, Poisson's ratio, a nd transition s tra in can be derived 3.2.3 tra11sitio11,它gio11, n一a strain region of a stress-strain or strain-strain curve over which a signifi cant change in the slope o f the c urve occurs within a small strain range. 3.2.4 transition strain, £,,.,,,,,;,;.,. [,对~- n一the stntin value at the mid range of the trans山 on region between the t\vo essentially linear port ions of a bi linear stress-strain or strainstrain cu,ve 3.2.4.1 Discr,ssion- Many filamentary composite mate rials s how essentially bil inear behavior during force application, such as seen in plots of either longitodinal stress versus longitudinal strain or transverses血 in versus long long血dinal strain. There are varying physical reasons for tl1e existence of a transition region. Common examples include: matrix cracking under tensile force application and ply delamination. 5. Significance and Use 5.1 This test method is designed 10 produce tensile property data for materia l specificat ions, researc h and development, quality assurance, and structural design a nd analy勺s. Factors that influence the tensile response and should therefore be repoited include the following: material, methods of material pl可paration and lay-up, specimen stacking sequence, s pecimen preparation, specimen cond山oning, environment of tes ting, s pecimen aligi1ment and g ripping, speed of testing, time at temperanire, void content, a nd volume percent reinforcement Properties, in the test direction, which may be obtained from this test method include the following: 5. l. I Ultimate tensile strength, 5. 1.2 Ultimate tensile strnin, 5.1 .3 Tensil e chord modulus of e lastic ity, 5.1.4 Poisson 's ratio, and 5.1 .5 Transition strain . 3.3 Symbols: cross-sectional area of a coupon. 8广percent bending for a unia,ual coupon of rectangular cross section about y axis o f the specimen (about the narrow d irection). 从一percent bending for a uniaxial co upon o f rectangular cross section about z axis of the specimen (about the wide direction). CV-coefficient o f variation statistic of a sample population for a given property (in percent). £-111odulus o f elasticity in the test direction 户一ultimate ' tensi le strength m the test direc tion. 尸“一ultimate shear strength in the test direction /i-cou1}0n thickness l g extensometer gage length . L,.,;,,一minimum requ ired bonded tab length II一number of coupons per sample population. P一force carried by test coupon. 杜-force carried by test coupon at fai lure !"""·' -maximum force ca1Tied by test coupon before fai lure s,. 一 /一亚ndard deviation statistic of a sample population 「i:>r a given property. W一coupon width. X;一test result for an individual coupon from the sample population for a g iven property 入r-mean or average (estimate of mean) of a sample population for a given prope,ty. <>--extensional dis placement 七、一general symbol for strain, whether normal strain or s hear strain . 产indicated normal strain from strain transducer o r extensomete r. 6一nonnal stress. v--Poisson 's ra tio. A一average 6. Interferences 6. 1 Material and Specimen 府paration-Poor material fabrication practices, lack of control of fiber alignment, and damage induced by improper coupon machini ng are known causes of high material data scatter in composites. 6.2 Gripping一A high percentage of grip-induced 伽lures, especia lly when combined with high material data scatter, is an indicawr o f specimen gripping problems. Specimen gripping methods are discussed further in 7.2 .4, 8.2, and 11 .5. — 6.3 System Alig11me111一Excessi ve bending will ca use premat ure failure, as well as highly inaccura比 modulus of e lasticity determination. Every effo1t should be made to e liminate excess bending from the test system. Bending may occur as a result of misali驴叫 grips or from specimens themselves if improperly installed in the grips or out-o f-tolerance caused by poo r specimen preparation. If there is any doubt as 10 the alignment inherent in a given test machine, then the al igrunent s hould be checked as d iscussed in 7.2.5 6.4 Edge Effects in Angle Ply Laminates一Premature f;创ure a nd lower stiffnesses are observed as a result o f edge softening in laminates containing off-axis plies. Because of this, the s trength and modulus for angle ply laminates can be drastically underestimated . For quasi-isoliopic laminates containing significant 0° plies, the effect is not as significant 7 . Apparatus 7. I Micrometers a nd Calipers一A micrometer with a 4 to 7 [0. 16 to 0.28 in] nominal diameter ball interface shal l be 111111 2 • 03039/03039M - 17 used to measure the specimen thickness when at least one surface is irregu lar (such as the bag-side of a lam inate). A micrometer with a 4 to 7 mm (0.16 to 0.28 in.] nominal diameter ball interface or with a Aat anvi l interface s hall be used to measure 1he specimen thickness when both surfaces are s mooth (such as tooled sur你tees). A micrometer or caliper, with a Rat anvi l interface, shall be used to measure the w idlh of the specimen. The accuracy of the instruments s hall be su心ble for reading to w ithin I % of the sample dimensions. For typical specimen geometries, an ins订ument w ilh an accuracy of 土 0.0025 mm [ 土 0.000 1 in.) is adequate for thickness measurement, while an instrument w ith an accuracy of :!:0.025 mm (:!:0.001 in.] is adequate for width measurement. during tensile testing. In addition to Practice EIOl2, the degree of bending in a tensile system can also be evaluated using the 甸 lowing related procedure. Specimen bending is considered separately in 11.6.1. 7.2.5 .1 A rectangular alignment coupon, preferably similar in size and stiftness to tl1e test specimen of interest, is instn1mented w ith a minimum o f three longin,dinal strain gages of similar type, two on the front face across the w idth and one on the back face of the specimen, as s hown in Fig. I. Any d 曲rence in indicated s train between these gages during loading provides a measure of the amount of bending in the 曲ckness plane (B,.) and width plane (8.) of the coupon. The strain gage location s hould normally be located in the middle of the coupon gage section (if modulus determination is a concern), near a grip (if preman,re grip failures are a problem), or any combination of these areas. 7.2.5 .2 W hen evaluating system aligi1111ent, it is advisable to perfonn the alignment check with the same coupon inserted in each of the fo ur possible installation permutations (described relative to the initia l position) : initial (top-front facing observer), rotated back to front 01tly (top back facing observer), rotated e nd for end only (加ttom front facing observer), and rotated 沁th front to back and end to end (bottom back facing obse1ver). T hese four data sets provide an indication of whether the bending is due to the syste m itsel f or to tolerance in the alignment check coupon or gaging. 7.2.5.3 T he zero strain point may be taken e ither before gripping or after gripping. The strain response of the al ignment coupon is subsequently monitored duri ng the gripping process, the tensi le loading process, or both. Eq I and Eq 2 use these ind邸ted s t.t·ains to calculate the ratio of the percen吨ge of bending strain to average extens iona l strain for each bending plane of the a lignment coupon. Plotting percent bending versus 扭ial average stra in is useful in understanding trends in tbe ben中 ng behavior of the system 7.2 .5.4 Problems with fai lures duiing gripping wou ld be reason to examine bending strains during the gripping process 7.2 Testing Machine一The testing machine shalI be in conformance with Practices £4 and shall satisfy the following require ments: 7.2.1 7切ing Machine Heads一The testing machine sha ll have both an essentia lly stationary head and a movable head 7.2.2 Drive Mechanism-The testing mac hine 如 ve mechan,sm shall be capable of imparting to the movable head a contrnlled velocity w ith respect to the stationary head. The velocity of the movable head shall be capable of being regulated as specified in 11.3. 7.2.3 Fo心 Indicator一The testing machine force-sens ing device s hall be capable of indicating the tota l force being carried by the tesl s1>ecimen. T his device s hall be essentially free from inertia lag at the s pecified ra1e of tes ting and sha ll 呻cate the force with an accuracy over the force range(s) of interest of w ithin :!: I % of the indicated value. The force range(s) of interest may be fairly low for modulus evaluation, much higher for stre ngth evaluation, or both, as required No冗 l 一Ob1aiaiag precision 勋rce darn over a large ronge or inter邸 in the same tcsl, such as when both elastic modulus and ultimalc force arc 比 ing deiermined、 place extrellle requirelllenis on the load cell and i1s calibration. For some equipment. a special cal ibr汕on may 比 required. For some combinations of material and load cell, simultaneous precision measure111eo1 of both elastic modulus and ultimate sirength may 1101 加 沁ssible and measurement of modul 心 and s1reng1h may have to 比 performed in 立parate tests using a differenl load cell range for each test 7.2.4 Grips一巨ch head of the testing machine shall carry one grip for holding the test specimen so that the direction of force applied to the specimen is coincident with the longitudinal ax.is of1he specimen. The grips shall apply s ufficient lateral pressure to prevent s lippage between the grip face and the coupon. If tabs are used 1he grips should be long enough that they overhang the beveled portion of the tab by approximately IO to 15 mm (0.5 in .]. It is highly desirable to use grips that are rolationally self-aligning to minim ize bending slresses in the coupon. -l w tSG2 SGI No亢 2一Grip surfa心s 1ha1 are ligh1ly serrated, approxima1ely I serra1ion/mm [25 serra1ionslin,J, have been found sa1islac10ry for use in wedge-aclion gri p、 when kepi clean and sharp; coarse serrations may produce grip如 duced failures in untab加d coupons. Smoo1h gripping surfaces have been used successfully with either hydraulic grips or aa emery cloth interface, or bo小 -l 7.2.5 System Alig1111比11/一Poor system alignment can be a major contributor to premature 伽lme, to e lastic property data scatter, or both. Practice E IO12 describes bending evaluation guidelines and describes pote111ial sources of misalignment FIG.1 3 5G3 □ 一 ....r.. SGl&SGl g w/8 汀YP 2.Pl) Front Stde Gage Locations for System Alignment Check Coupon • 03039/03039M - 17 weave. Some guidelines on the use of strn111 gages on composites follow. A general reference on the subj ect is Tuttle and Brinson. 4 7.3. 1. 1 Surface preparation of fiber-reinforced composites in accordance with Practice £1237 can penetrate the matrix material and cause damage to the reinforcing fibers resulting in improper coupon fail ures. Reinforcing fibers should not 加 exposed or damaged during the surface preparation process. The strain gage manufacturer should be consulted regarding surface preparation guidelines and recommended bonding agents for composites pending the development of a set of standard practices for strain gage installation surface preparation of fiber-reinforced compos,te materials. 7.3. 1.2 Consideration should be given to the selection of gages having larger resistances to reduce heating etfects on low-conductivity materials. Resistances of350 nor higher are preferred. Additional consideration should be g iven to the use of the minimum 吵ssible gage excitation voltage consistent with the desired accuracy (I to 2 V is recommended) to reduce further the power consumed by the gage. Heating of the coupon by the gage may affect the performance of the material d irectly, or it may affect the indicated strain as a result of a 础erence 加tween the gage temperature compensation factor and the coefficient of thennal expansion of the coupon material. 7.3. 1.3 Consideration of some fonn of temperawre compensation is recommended, even when testing at standard laboratory atmosphere. Temperature compensation is required when testing in nonambient temperature environments 7.3. 1.4 Consideration should be given to the transverse sensitivity of the selected strain gage. The strain gage manufacturer should be consulted for recommendations on tnmsverse sensitivity corrections and effects on composites. This is particularly important for a transversely mounted gage used to determine Poisson's ratio, as discussed in Note 14 7.3.2 Exte瓜0111啦rs一For most purposes, the extensometer gage length should be in the range of IO to 50 mm (0.5 to 2.0 in.]. Extensometers shall satisfy, at a minimum, Practice ['83. Class B-1 requirements 「or the strain range of interest and shall be calibrated over that strain range in accordance with Practice E83 . For extremely stiff materials, o r for measurement of transve岱e strains, the fixed error allowed by Class B-1 extensometel'S may be significant, in which case Class A extensometers should be considered. The extensometer shall 加 essentially free of inertia lag at the specified speed of testing, and the weight of the extensometer should not induce bending strains greater than those allowed in 6.3. 111 the location near tl1e grip. Concern over modulus data scatter would be reason to evaluate bending strains over the modulus evaluation force range for the typical transducer location Excessive fai lures near the grips wou ld be reason to eva lua比 bending strains near the grip at high loading levels. Whil e the maximum advisable amount of system misal ignment is material and location dependent, good testing practice is generally able to limit percent bending to a range of 3 to 5 % at moderate strain levels {> l000 阰) . A system showing excessive bending for the given application should be reacljusted or modified. By = 从= E 趴. t - ., ~· X 100 213 (&, - &,) •• 心 X 100 (I) (2) where: B = percent bending a加ut system y axis (about 8 = percent bending about system z ax,s (about the narrow plane), as calculated by Eq I, %; the wide plane), as calcu lated by Eq 2, %; mdicated long,tudmal strams displayed by Gages 1, 2, and 3, respectively. of Fig. 1, 匹 and 知" = ((€1 +€2)/2 +€3)/2 No亢 J-£xpc,·imen tal error may be inrrodu心d by sources such as poor system alignment, specimen preparation and strain gage precision and calibration. These 幻urccs of error may result in an average calculotcd strain (s,.,,) of 0, causing H,, and IJ, (Eq I and 6q 2) ,o approach infinity as the average calculaled ·strain is 小e denominator. To minimize the 沁如11 ial for this occurrence during system alignment cval 间 ion, it is recommeoded 1ha1 fo心 be applied ,o ,he alignmemcou伈n until all 1hree strain gages measure positive strain of no less than 500 匹 wi th ans让,, of no less than 1000 1比. Ir these cond山ons can no1 be met、 the I邸 configura,ion should be adjusted prior 10 perfonning further system alignme111 evalua1ion e,. e2. and £J = 7.3 Srrai,吻(如ring Device-Force-strain data, if required, shall be determined by means of either a strain transducer or an 妞cnsomeler. Allachment of the strain-indicating device to lhe coupon shall not cause damage to the specimen surface. If Poisson's ratio is to be determined, the specimen shall be instrumented lo measure strain in both longitudinal and laleral d irections. [f the modulus of elasticity is to be determined、 1he longitudinal strain should be simultaneously measured on opposite faces of the specimen to allow for a correction as a result of any bending of the specimen (see 11.6 for further guidance). 7.3.1 8011ded Resisra11ce Strain Gage Se/ectio11—S廿ain gage selection is a compromise based on the type of material An active gage length of 6 111111 [0.25 in.] is recommended for most materials. Active gage lengths should not be less than 3 mm (0.125 in.].3 Gage calibration certification sha ll comply with Test Methods E25 I. When testing woven fabric lami nate.s、 gage selection should consider the use of an active gage length 曲t is at least as great as the characteristic repealing unit of the No·re 4一It is generolly less dillicul1 10 perform s1rain calibration on exlensometers of longer gage lenglh as less precision in displacement is required of 1he ex1ensome1er calibra1ion device. 7.4 Co11di1ioni11g Chamber-When conditioning materials at nonlaboralOry environments, a temperature/vaporlevelcontrolled environmental conditioning chamber is requ ired that shall be capable of maintaining the required temperature to ' A typical g•ge would have a 0.25-in. •ctive gage I叩创l, 350 •!1 尺sista nce. a strain rating of 3 % or beucr, and th e 叩propriatc cnvironm,n 旦I resistance and 1hem"I ooefficien1. • i;血le. M. E. a叫 Brin沁 n. H. F.. "Resis切1心和 I S血 in ,Goge Technology as Applied lo Composite Malcrials," E.叩,;,,印1111/ Medumics. \勺I 24. No. I, March 1984: pp. 54-65: erra切 ,lOted in Vol 26. No. 2. J 皿e 1986. pp. 153-154. 4 • 03039/03039M - 17 TABLE 1 Tensile Specimen Geometry Requirements Pa,ameter Reqoirement Coupon Requirements· shape constani rectangular cross-section minimum length gri印,ing + 2 times width + gage length A specimen width as 归d ed specimen width tolerance ±t %of width specimen lhi伙ness as 呤 ed specimen thi如 ess tolerance ±4 %of thickness specimen flatness Hat with light finger pre岱vre w ith in 土3 °C [ :!: 5°F] and the required relative vapor level to within :!:3 %. Chamber conditions shall be monitored either on an automated continuous basis or on a manual basis at regular intervals 7.5 E11viro11me11/a/ Test Chambe,~ An env叩mental test chamber is required for test enviro nments other than ambient testing laboratory conditions. This chamber shall be capable of maintaining the gage section of the test specimen at the required test environment during the mechanical test. 8. Sampling and'I、est TabR的 uirements (ii 因ed). Specimens lab material fiber orientation (composite tabs) as 戊兄ded lab 价ickness as needed 土 I % lab thickness as 叩eded lab 小ickness variation between labs tab bevel angle 5 10 90", inclusive tab step al bevel to 环cim的 lea归,red without damaging specimen ASee 8.2.2 or Tab比 2 forrecomm印dations, 8. l St,mpling-Test at least fi ve specimens per test cond,tion unless valid results can be gained through the use of fewer specimens, such as in the case of a designed experiment. For 妞 istically significant data, the procedures outlined in Practice E 122 should be co nsulted . Report the method of sampling. NoTE 5一If specimens arc lo undergo cnvironmcnlal conditioning to equilibrium, and are of such l)'pe or geome1ry 1hac the weigh1 change of the malerial cannol be properly measured by weighing the specimen ilsell屿 (such as a tabbed mechanical coupon), !hen use anolher lraveler coupon of 1he same nominal rbickness and appropriare size (bu1 wi1hou1 rabs) 10 如ermine when equilibrium has been reached for 1he specimens being conditioned. 8.2 Geomet,y-Desigi1 of mechanical test coupons, especiall y those using end tabs, remains to a large extent an art rather than a science, with no industry consensus on how to approach the engineering of the gripping interface. Each major composite testing laboratory has developed g ripping methods for the specific material systems and environments commonly encountered within that laboratory. Comparison of these methods shows them to differ widely, making it extremely difficult to recommend a unive飞ally usefol approach o r set of approaches. Because of this difficulty, definition of the geometry of the test coupon is broken dO\vn into the following three levels, which are discussed ftu廿1er in each appropriate section· Purpose Degree of G欢rmetry Definition result: acceptable failure mode and location. If acceptable 伽lure modes occ1u- with reasonable frequency, then there is no reason to change a given gripping method. 8.2.2 Specific Recommendations令 8.2.2.1 Width, Thick11ess, and Len砂-Select the specimen width and 曲ckness to promote failure in the gage sect ion and assure that the specimen contains a sufti cient munber of fibers in the cross section to be statisticall y representative of the bulk material. The specimen length should nonna lly be substantially longer than the minimum requirement to minimize bending stresses caused by minor grip eccentricities. Keep the gage section as for from the grips as reasonably possible and provide a signifi cant amount of material under stress and therefore produce a more statistically significant result. The minimum requirements for specimen design shown in Table I are by themselves insufficient to create a properly dimensioned and tolernnced coupon drnwing. Therefore, recommendations on other important dimensions are provided for typical material configurations in Table 2. These geometries have been found by a number of testing laboratories to produce acceptable 甸ure modes on a wide variety of material systems, but use of them does not gttanmtee success for every existing or fttture material system. 8.2.2.2 Gripping/Use of Tabs一There are many material configurations, such as multidirectiona l laminates, fabiic-based materials, or randomly reinforced sheet-molding compounds、 which can be successfully tested without tabs. However, tabs are strongly recommended when testing unidirectional materials (or strongly unidirectionally dominated laminates) to fai lure in the fiber direction. Tabs may also be requii-ed when testing unidirectional materials in the matrix direction to prevent gripping damage. 8 2.1 General R的uirements Mandatory Shape a心 To际ances 8.2.2 S郎lf,cR氏omm句心如S Nonmandatory Suggested Dimensions 8 2.3 Oet和沁d Examples Nonmandatory Typical Praciic:es 8.2. I General Requirements: 8.2.1.l Shape, Di, 成11sio11s. and Tolerances一The complete 佃 of requirements for s11ecimen shape, dimensions, and tolerances is shown in Table I 8.2. 1.2 Use of Tabs一Tabs are not required. The key factor in the selection of specimen tolerances and gri pping methods is 1he successful introduction of force into the specimen and 1he prevention of premanu-e failure as a result of a significant discontinuity. Therefore, determine the need to use tabs, and specification of the major tab design parameters, by the end TABLE 2 Tensile Specimen G的 metry RecommendationsA Wl(llh, 0哼all Lenglh, Th吐n的$, Tab Length, Tab Thickness, Tab Bevel 0如,.廿on mm pn.J mm (In.) mm (In.) mm pn.J mm (In.] Angle,• o• unidir氐tional 15 [0.5) 250 [10.0J 1.0 (0.040) 56 (2.25) 1.5 [0.062] 7o『 90 90'un;,t;rectio咄f 25 [1.0J 175 [ 7.0J 2.0 (0.080) 25 (1.0J 1.5 [0.062] 90 balanced and symmet心 25 [1.0) 250 [10.0J 2.5 (0.100) emery clolh random-discontinuous 25 fl.OJ 250 [10.0J 2.5 (0.100) emery clolh • Dimensions in 1his table and the tolerances o1 丙 2 or Fig. 3 are recommenda1ions only and may be varied so long as lhe requi rem 础s of Table I are met. Fiber 5 • 03039/03039M - 17 8.2.2.3 Tab Geomelly-Recommendations on important dimensions are provided for typical materia l config11rations in 111ble 2 . These dimensions have been found by a number of testing laboratories to produce acceptable failure modes on a wide varie1y of material systems, bu1 use of 1hem does not guarantee s uccess for every existing or future mateiial system The selection of a tab configuration that can successfully produce a gage section tens业 failure is dependent upon the coupon material, coupon ply orientation, and tl1e type of grips being used. When pressure-operated nonwedge grips are used with care, squared-off 90°tabs have been used successfully. Wedge-operated grips have been used most successfully with tabs having low bevel angles (7 to I0°) and a feathered smooth transition into the coupon. For a lignment purposes, it is essential that the tabs be of matched thic妳ess 8.2.2.4 Friction Tabs一Tabs need not a lways be bonded to the materia l under tes t to be effective in introducing the force into the specimen. Friction tabs, essentially nonbonded tabs held in place by the pressure o f the g~ip, and often used with emery cloth or some other light abrasive between the tab and the coupon, have been successfully used in some applications In specific cases, lightly serrated wedge gl'ips (see Note 2) have been successfully used with only emery c loth as the inte,和ce between the grip and the coupon. However, the abrasive used must be able to withstand si驴ificant compressive forces. Some types of emery clotl1 have been found ineffective in this application because of disintegration o f the abrasive. 8.2.2.5 Tab Material- The most consistently used bonded 呻 materia l has been continuous E-glass fiber-reinforced polymer matnx . materials (woven or unwoven) in a [0/90]ns lamrnate configuration. The tab material is com.monly applied at 45° to the force direction to provide a soft interface. Other configurations that have reportedly been success和lly used have incorporated st沈I tabs or 叫bs made of the same material as is being tested. 8.2.2.6 Bonded 励 Length-When using bonded tabs, estimate the minimum suggested tab length for bonded tabs by the following simple equation. As this equation does not account for the peaking stresses that are 知own to exist at the ends of bonded joints. The tab length calculated by this equation s hould normally be increased by some factor to reduce the c hances of joint 伽lure: L.,;. = F'"h/ 21"" c ,ent to create a pro1)erly dimensioned and toleranced coupon drawing. Dimensionally toleranced spec imen drawings for both tabbed and untabbed forms are s hown as examples in Fig. 2 (S I) and Fig. 3 (inch-pound). The tolerances on these drawings are fixed, but satisfy the requirements of Table I for all of the recommended configw11tions of Table 2. For a specific configuration, the tolerances on Fig. 2 and Fig. 3 might be able to be relaxed. 8.3 Specimen P戊paration. 8.3.1 Panel Fabrication- Control of fiber a lignmem is cri止 cal. Improper fiber alignment will reduce the measured properties. Erratic fiber a lignment wil l also increase the coefficient of variation. The specimen preparation method shall be reported. 8.3.2 Machining Melhodr一Specimen preparation is extremely important for this specimen. Mold the specimens individually to avoid edge and cutti ng eftects or cut them from plates. If they are cut from plates, take precautions to avoid no1ches, underculs, rough or uneven s urfaces, or delaminations caused by inappropriate machining methods. Obtain final d imensions by water-lubricated precision sawing, mi lling, or grinding. The use of diamond tooling has been found to be extremely e胆ctive for many material systems. Edges should be flat and para llel within the specifi叫 tolerances 8.3.3 If specific gravity, density, reinforcement volume, or void volume are to be repor1ed, then obtain these samples from the same panels being tension tested. Specific gravity and density may be evaluated by means of Test Methods 0792. Volume percent of the constinients may be evaluated by one of the matrix digestion procedures of Test Method 0317 1, or, for certain reinforcement ma比rials such as glass and ceramics, by the matrix burn-off technique of Test Method D2584. The void content equations of Test Methods 02734 are applicable t0 both Test Method D2584 and the mahix digestion procedures. 8.3.4 切be/ing一Label the coupons so that they will be distinct from each other and traceable back to the raw material and in a marn冗r that wi ll both be unaffected by the test and not influence the test. 9. Calibration 9. I The accuracy of al l measuring equipment shall have cer1ified calibrations that are current at the time of use of the equipment. (3) where. L'";" = min imum required bonded tab length, mm [in.]; f'" = ultimate tensile strength of coupon materia l, MPa [psi] ; = coupon thickness, 111111 [in.]; and h 户 = ultimate s hear strength of adhesive, coupon material, or tab material (whichever is lowest), l'vlPa (psi]. 10. Conditioning 10.1 Tl1e recommended pre-test cond111on ,s effective mo,sture equilibrium at a specific re lative humidity as establ八hed by Test Method D5229/ D5229M; however, if the test requestor does not explicitly specify a pre-test cond小oning environment, no conditioning is required and the test specimens may be tested as prepared. 8.2.2.7 Bonded Tab Adhesive一Any higl1-e longation (tough) adhesive system that meets the environmental requirements may be used when bonding tabs to the mate1ial under test. A uniform bondline of minimum thickness is desirnble to reduce unde.sirable stresses in the assembly. 8.2.3 Detailed Examples-The minimum requirements for Sp如mend邻1驴小scussed in 8.2.1 are by themselves insuf:li- I 0.2 The pre-test specimen conditioning process, to include specified environmental exposure levels and resulting moisture content, shall be reported with the test data NoTE 6-Thc tcrm moisture. as used in Tcsl Method D5229/D5229M, includes no1 only the vapor or a liquid and i1s condensate, but 1he liquid i应 I f in In屯e quan1i1ies, as ro『 i mmersion , 6