Francisco josé caldas

Solo disponible en BuenasTareas
  • Páginas : 54 (13332 palabras )
  • Descarga(s) : 0
  • Publicado : 22 de septiembre de 2010
Leer documento completo
Vista previa del texto
Designation: D638 – 10

Standard Test Method for

Tensile Properties of Plastics1
This standard is issued under the fixed designation D638; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates aneditorial 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 covers the determination of the tensile properties of unreinforced and reinforced plastics in the form of standard dumbbell-shaped test specimens when tested under defined conditions of pretreatment, temperature, humidity, and testingmachine speed. 1.2 This test method can be used for testing materials of any thickness up to 14 mm (0.55 in.). However, for testing specimens in the form of thin sheeting, including film less than 1.0 mm (0.04 in.) in thickness, Test Methods D882 is the preferred test method. Materials with a thickness greater than 14 mm (0.55 in.) must be reduced by machining. 1.3 This test method includes theoption of determining Poisson’s ratio at room temperature.
NOTE 1—This test method and ISO 527-1 are technically equivalent. NOTE 2—This test method is not intended to cover precise physical procedures. It is recognized that the constant rate of crosshead movement type of test leaves much to be desired from a theoretical standpoint, that wide differences may exist between rate of crosshead movementand rate of strain between gage marks on the specimen, and that the testing speeds specified disguise important effects characteristic of materials in the plastic state. Further, it is realized that variations in the thicknesses of test specimens, which are permitted by these procedures, produce variations in the surface-volume ratios of such specimens, and that these variations may influence the testresults. Hence, where directly comparable results are desired, all samples should be of equal thickness. Special additional tests should be used where more precise physical data are needed. NOTE 3—This test method may be used for testing phenolic molded resin or laminated materials. However, where these materials are used as electrical insulation, such materials should be tested in accordancewith Test Methods D229 and Test Method D651. NOTE 4—For tensile properties of resin-matrix composites reinforced with oriented continuous or discontinuous high modulus >20-GPa [>3.0 3 106-psi) fibers, tests shall be made in accordance with Test Method D3039/D3039M.

1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.6 Thisstandard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards:2 D229 Test Methods for Rigid Sheet and Plate Materials Used for ElectricalInsulation D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension D618 Practice for Conditioning Plastics for Testing D651 Method of Test for Tensile Strength of Molded Electrical Insulating Material3 D882 Test Method for Tensile Properties of Thin Plastic Sheeting D883 Terminology Relating to Plastics D1822 Test Method for Tensile-Impact Energy to Break Plastics and ElectricalInsulating Materials D3039/D3039M Test Method for Tensile Properties of Polymer Matrix Composite Materials D4000 Classification System for Specifying Plastic Materials D4066 Classification System for Nylon Injection and Extrusion Materials (PA) D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens E4 Practices for Force Verification of Testing Machines E83 Practice for Verification and...
tracking img