1、Designation: D1822 06D1822 13Standard Test Method forTensile-Impact Energy to Break Plastics and ElectricalInsulating Materials1This standard is issued under the fixed designation D1822; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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. Scope*1.1 This test method covers the determination of the energy required to rupture standard tension-impact s
3、pecimens of plasticor electrical insulating materials. Materials that can be tested Rigid materials are suitable for testing by this test method are thosemethod as well as specimens that are too flexible or too thin to be tested in accordance with Test Methodsother impact D256, aswell as more rigid
4、materials. test methods.1.2 The values stated in SI units are to be regarded as standard. The values given in bracketsparentheses are for informationonly.NOTE 1This test method is not equivalent to ISO 8256, and resultsand ISO 8256 cannot be directly compared between the two methods.address thesame
5、subject matter, but differ in technical content.1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regu
6、latorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod Pendulum Impact Resistance of PlasticsD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsD1822
7、Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating MaterialsD1898 Practice for Sampling of Plastics (Withdrawn 1998)3D4000 Classification System for Specifying Plastic MaterialsD4066D5947 Classification System for Nylon Injection and Extrusion Materials (PA)Test Method
8、s for Physical Dimensions ofSolid Plastics SpecimensE23E177 Test Methods for Notched Bar Impact Testing of Metallic MaterialsPractice for Use of the Terms Precision and Biasin ASTM Test Methods2.2 ISO Standards:ISO 8256 PlasticsDetermination of Tensile-Impact Strength3. Terminology3.1 DefinitionsDef
9、initions of terms applying to this test method appear in Terminology D883.4. Summary of Test Method4.1 The energy utilized in this test method is delivered by a single swing of a calibrated pendulum of a standardizedtension-impact machine. The energy to fracture a specimen, by shock in tension, is d
10、etermined by the kinetic energy extracted fromthe pendulum of anthe impact machine in the process of breaking the specimen. One end of the specimen is mounted in the1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.10
11、on Mechanical Properties.Current edition approved March 15, 2006Sept. 1, 2013. Published March 2006November 2013. Originally approved in 1961. Last previous edition approved in 19992006as D1822D1822 - 06. - 99. DOI:10.1520/D182213.2 For referencedASTM standards, visit theASTM website, www.astm.org,
12、or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website. DOI: 10.1520/D1822-06.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indic
13、ation of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be co
14、nsidered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1pendulum. The other end of the specimen is gripped by a crosshead which travels with the p
15、endulum until the instant of impactand(and instant of maximum pendulum kinetic energy,energy), when the crosshead is arrested.5. Significance and Use5.1 Tensile-impact energy is the energy required to break a standard tension-impact specimen in tension by a single swing ofa standard calibrated pendu
16、lum under a set of standard conditions (see Note 2). In order toTo compensate for the minor differencesin cross-sectional area of the specimens as they will occur in the preparation of the specimens, the energy to break can be isnormalized to units of kilojoules per square metre (or foot-pounds-forc
17、e per square inch) of minimum cross-sectional area. Analternative approach to normalizing the impact energy that compensates for these minor differences and still retains the test unitas joules foot-pounds(foot-pounds) is shown in Section 1110. For a perfectly elastic material, the impact energy mig
18、ht beisusually reported per unit volume of material undergoing deformation. However, since much of the energy to break the plasticmaterials for which this test method is written is dissipated in drawing of only a portion of the test region, such normalization ona volume basis is not feasible. The te
19、st method permits two specimen geometries so that In order to observe the effect of elongationor rate of extension, or both, upon the result can be observed. With the Type S (short) specimen the extension is comparativelylow, while with the Type L (long) specimen the extension is comparatively high.
20、 In general, the Type S specimen (with its greateroccurrence of brittle fracture) gives greater reproducibility, but less differentiation among materials. result, the test method permitstwo specimen geometries. Results obtained with different capacity machines may generally are not be comparable.5.1
21、.1 With the Type S (short) specimen the extension is comparatively low, while with the Type L(long) specimen the extensionis comparatively high. In general, the Type S specimen (with its greater occurrence of brittle fracture) gives greater reproducibility,but less differentiation among materials.NO
22、TE 2Friction losses are largely eliminated by careful design and proper operation of the testing machine. Attention is drawn to Test Methods E23for a general discussion of impact equipment and procedures.5.2 The scatter Scatter of data may be dueis sometimes attributed to different failure mechanism
23、s within a group of specimens.Some materials may exhibit a transition between different failure mechanisms; ifmechanisms. If so, the elongation will be criticallydependent on the rate of extension encountered in the test. The impact energy values for a group of such specimens will have anabnormally
24、large dispersion. Some materials retract at failure with insignificant permanent set. With such materials it may not beFIG. 1 Specimen-in-Head Tension-Impact MachineD1822 132possible to determine the type of failure, ductile, or brittle, by examining the broken pieces. A set of specimens may sometim
25、esbe sorted into two groups by observing the broken pieces to ascertain whether or not there was necking during the test.Qualitatively, the strain rates encountered here are intermediate between the high rate of the Izod test of Test Methods D256 andthe low rate of usual tension testing in accordanc
26、e with Test Method D638.5.2.1 Some materials retract at failure with insignificant permanent set. With such materials, determining the type of failure,ductile or brittle, by examining the broken pieces is difficult, if not impossible. It is helpful to sort a set of specimens into twogroups by observ
27、ing the broken pieces to ascertain whether or not there was necking during the test. Qualitatively, the strain ratesencountered here are intermediate between the high rate of the Izod test of Test Methods D256 and the low rate of usual tensiontesting in accordance with Test Method D638.5.3 The energ
28、y for fracture is a function of the force times the distance through which the force operates. Thus, two materialsmay have properties that result in equal tensile-impact energies on Therefore, given the same specimen geometry, arising in onecase from it is possible that one material will produce ten
29、sile-impact energies for fracture due to a large force associated with asmall elongation and in the other from elongation, and another material will produce the same energy for fracture result due to asmall force associated with a large elongation. It cannot shall not be assumed that this test metho
30、d will correlate with other testsor end uses unless such a correlation has been established by experiment.5.4 Comparisons among specimens from different sources can are to be made with confidence only to the extent that specimenpreparation, for example, molding history, has been precisely duplicated
31、. Comparisons between molded and machined specimensmust not be made without first establishing quantitatively the differences inherent between the two methods of preparation.5.5 Only results from specimens of nominally equal thickness and tab width shall be compared unless it has been shown thatthe
32、tensile-impact energy normalized to kilojoules per square metre or(or foot-pounds-force per square inchinch) ofcross-sectional area is independent of the thickness over the range of thicknesses under consideration.5.6 Slippage of specimens results in erroneously high values. The tabs of broken speci
33、mens should be examined for anundistorted image of the jaw faces optically, preferably under magnification, and compared against a specimen which has beensimilarly clamped but not tested. Because slippage has been shown to be present in many cases and suspected in others, the useof bolted specimens
34、is mandatory. The function of the bolt is to assure good alignment and to improve the tightening of the jawface plates.5.6 The bounce of the crosshead supplies part of the energy to fracture test specimen (see Appendix X1).5.7 For many materials, there may be a specification that requiresare specifi
35、cations that require the use of this test method, butwith some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer tothat material specification before using this test method. Table 1 of Classification System D4000 lists the ASTM mate
36、rialsstandards that currently exist.6. Apparatus6.1 The machine shall be of the pendulum type shown schematically in Fig. 1 and Fig. 2. The base and suspending frame shallbe of sufficiently rigid and massive construction to prevent or minimize energy losses to or through the base and frame. Thependu
37、lum should be released from such a position that the linear position of the pendulum holding and releasing mechanism shallbe such that the vertical height of fall of the striker shall be 610 6 2 mm (24.0 6 0.1 in.). This will produce a velocity of the centerstriker at the moment of impact (center of
38、 percussion) at the instant of impact shall be approximately 3.444 m/s 11.3 ft/s, whichcorresponds to an initial elevation of this point of 610 mm 2.00 ft.of approximately 3.5 m (11.4 ft)/second. The mechanism shallbe so constructed and operated that it will release the pendulum without imparting ad
39、ditional acceleration or vibration.FIG. 2 Specimen-in-Head Tension-Impact Machine (Schematic)D1822 1336.2 The pendulum shall be constructed of a single- or multiple-membered arm holding the head, in which the greatest mass isconcentrated.Arigid pendulum is essential to maintain the proper clearances
40、 and geometric relationships between related parts andto minimize energy losses, which always are included in the measured impact energy value. It is imperative that the center ofpercussion of the pendulum system and the point of impact can be demonstrated to be coincident are within 62.54 mm 60.100
41、in. (60.100 in.) of each other and that the point of contact occuroccurs in the neutral (free hanging) position of the pendulumwithin 2.54 mm 0.100 in.,(0.100 in.), both with and without the crosshead in place.NOTE 3The distance from the axis of support to the center of percussion may be is determin
42、ed experimentally from the period of small amplitudeoscillations of the pendulum by means of the following equation:L 5g/4pi 2!p 2 (1)where:L = distance from the axis of support to the center of percussion, mm (ft),g = local gravitational acceleration (known to an accuracy of one part in one thousan
43、d), in mm/s2 ft/s2,g = local gravitational acceleration (known to an accuracy of one part in one thousand), in mm/s2 (ft/s2),pi = 3.14159, andp = period, s, of a single complete swing (to and fro) determined from at least 50 consecutive and uninterrupted swings (known to one part in twothousand). Th
44、e angle of swing shall be less than 0.09 radians (5) each side of the center.6.3 The positions of the rigid pendulum and crosshead clamps on the specimen are shown in Fig. 2. The crosshead should isdesigned to be rigid and light in weight. The crosshead shall be supported by the pendulum so that the
45、 test region of the specimenis not under stress until the moment of impact, when the specimen shall be subjected to a pure tensile force. The clamps shall havefile-like serrated jaws to prevent slipping. Jaws should have file-like serrations andthe specimen from slipping. The edge of theserrated jaw
46、s shall have a 0.40-mm (164 the -in.) radius to break the edge of the first serrations. The size of serrations should willvary and shall be selected according to experience with hard and tough materials, and with the thickness of the specimen. The edgeof the serrated jaws in close proximity to the t
47、est region shall have a 0.40-mm 164-in. radius to break the edge of the firstserrations.6.4 Means shall be provided for determining the energy expended by the pendulum in breaking the specimen. This isaccomplished using either a pointer and dial mechanism or an electronic system consisting of a digi
48、tal indicator and sensor(typically an encoder or resolver).6.5 The indicated breaking energy is determined by detecting the height of rise of the pendulum beyond the point of impact interms of energy removed from that specific pendulum.6.5.1 Since the indicated energy must be corrected for pendulum-
49、bearing friction, pointer friction, pointer inertia, and pendulumwindage, instructions for making these corrections are found inAnnexesA1 andA2 of Test Method D256. If the electronic displaydoes not automatically correct for windage and friction, it shall be incumbent for the operator to determine the energy lossmanually. (See Note 4.)NOTE 4Many digital indicating systems automatically correct for windage and friction. The equipment manufacturer may be consulted for detailsconcerning how this is performed, or if it is necessary to determine the means fo
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1