Tensile Testing

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Tensile Testing Of Metallic Materials
概要: Tensile testing of metallic materials is specified according to European EN 10002 standard. In this article the terms, definitions and designation for tensile test made at ambient temperature is described. The test involves straining a test piece in tension, generally to fracture, for the purpose of determining mechanical properties. Tensile testing of metallic materials is specified according to European EN 10002 standard. This standards consists of five parts: •EN 10002-1 - Method of testing at ambient temperature

EN 10002-2 - Verification of the force measuring system of the tensile testing machine •EN 10002-3- Calibration of force proving instruments used for the verification of uniaxial testing machines •EN 10002-4 - Verification of extensometers used in uniaxial testing •EN 10002-5 - Method of testing at elevated temperatures

In this article the terms, definitions and designation for tensile test made at ambient temperature is described. The test involves straining a test piece in tension, generally to fracture, for the purpose of determining mechanical properties. Terms and definitions

For the purpose of this European Standard, the following terms and definitions apply: •gauge length (L) - length of the cylindrical or prismatic portion of the test piece on which elongation is measured. In particular, a distinction is made between: ooriginal gauge length (Lo) - gauge length before application of force ofinal gauge length (Lu) - gauge length after rupture of the test piece oparallel length (Lc) - parallel portion of the reduced section of the test piece •elongation - increase in the original gauge length (Lo) at any moment during the test •percentage elongation - elongation expressed as a percentage of the original gauge length (Lo) •percentage permanent elongation - increase in the original gauge length of a test piece after removal of a specified stress, expressed as a percentage of the original gauge length (Lo) •percentage elongation after fracture (A) - permanent elongation of the gauge length after fracture (Lu - Lo), expressed as a percentage of the original gauge length (Lo). In the case of proportional test pieces, where original gauge length is other than 5.65√So, the symbol A should be supplemented by an index indicating the coefficient of proportionality used (A11,3 for Lo=11.3√ So) or by an index indicating the original gauge length (A80 mm for Lo=80 mm) •percentage elongation at maximum force - increase in the gauge length of the test piece at maximum force, expressed as a percentage of the original gauge length (Lo) •extensometer gauge length (Le) - length of the parallel portion of the test piece used for the measurement of extension by means of an extensometer •extension - increase in the extensometer gauge length (Le) at a given moment of the test •percentage permanent extension - increase in the extensometer gauge length, after removal from the test piece of a specified stress, expressed as a percentage of the extensometer gauge length (Le) •percentage yield point extension (Ae) - in discontinuous yielding materials, the extension between the start of yielding and the start of uniform work hardening •percentage reduction of area (Z) - maximum change in cross-sectional area which has occurred during the test (So - Su) expressed as a percentage of the original cross-sectional area (So) •maximum force (Fm) - the greatest force which the test piece withstands during the test once the yield point has been passed. For materials, without yield point, it is the maximum value during the test •stress - force at any moment during the test divided by the original cross-sectional area (So) of the test piece •tensile strength (Rm) - stress corresponding to the maximum force (Fm) •yield strength - when the metallic material exhibits a yield phenomenon, stress corresponding to the point reached during the test at which plastic deformation occurs...
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