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5.1 This test method can be used for acceptance testing of commercial shipments but comparisons should be made with caution because estimates of between-laboratory precision are incomplete.5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, use samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.5.2 Elongation is an indication of the ability of a fiber to absorb energy. The elongation of textile materials must be great enough to withstand strains experienced in processing and end use, and to absorb the energies of applied forces repeatedly.1.1 This test method covers the determination of the breaking strength and elongation of textile webbing, tape and braided materials using a split-drum type specimen clamp.1.2 This test method is limited to materials with a maximum width of 90 mm (3.5 in.) and a maximum breaking strength of no more than 89000 N (20000 lb).1.3 The values stated in either SI units or U.S. Customary units are to be regarded separately as standard. Within the text, the U.S. Customary units are given in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other.1.4 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 These test methods are to be used to determine the resistance of some types of preformed block insulation when transverse loads are normally applied to the surface. Values are measured at the maximum load or breaking point under specified conditions or specimen size, span between supports, and rate of load application. The equations used are based on the assumption that the materials are uniform and presume that the stress-strain characteristics below the elastic limit are linearly elastic. These assumptions are not strictly applicable to thermal insulations of certain types in which crushing occurs before failure is obtained in transverse bending; however, depending upon the accuracy required, these procedures are capable of providing acceptable results.5.2 Test Method I is especially useful when testing only for the modulus of rupture or the breaking load. This information is useful for quality control inspection and qualification for specification purposes.5.3 Test Method II is useful in determining the elastic modulus in bending as well as the flexural strength. Flexural properties determined by these test methods are also useful for quality control and specification purposes.5.4 The basic differences between the two test methods is in the location of the maximum bending moment, maximum axial fiber (flexural or tensile) stresses, and the resolved stress state in terms of shear stress and tensile/compression stress. The maximum axial fiber stresses occur on a line under the loading fitting in Test Method I and over the area between the loading fittings in Test Method II. Test Method I has a high shear stress component in the direction of loading, perpendicular to the axial fiber stress. Sufficient resolved shear stress is capable of producing failure by a shear mode rather than a simple tension/flexural failure. There is no comparable shear component in the central region between the loading fittings in Test Method II. Test Method II simulates a uniformly loaded beam in terms of equivalent stresses at the center of the specimen.5.5 Flexural properties are capable of varying with specimen span-to-thickness ratio, temperature, atmospheric conditions, and the difference in rate of straining specified in Procedures A and B. In comparing results it is important that all parameters be equivalent. Increases in the strain rate typically result in increased strengths and in the elastic modulus.1.1 These test methods cover the determination of the breaking load and calculated flexural strength of a rectangular cross section of a preformed block-type thermal insulation tested as a simple beam. It is also applicable to cellular plastics. Two test methods are described as follows:1.1.1 Test Method I—A loading system utilizing center loading on a simply supported beam, supported at both ends.1.1.2 Test Method II—A loading system utilizing two symmetric load points equally spaced from their adjacent support points at each end with a distance between load points of one half of the support span.1.2 Either test method is capable of being used with the four procedures that follow:1.2.1 Procedure A—Designed principally for materials that break at comparatively small deflections.1.2.2 Procedure B—Designed particularly for those materials that undergo large deflections during testing.1.2.3 Procedure C—Designed for measuring at a constant stress rate, using a CRL (constant rate of loading) machine. Used for breaking load measurements only.1.2.4 Procedure D—Designed for measurements at a constant crosshead speed, using either a CRT (constant rate of traverse) or CRE (constant rate of extension) machine. Used for breaking load measurements using a fixed crosshead speed machine.1.3 Comparative tests are capable of being run according to either method or procedure, provided that the method or procedure is found satisfactory for the material being tested.1.4 These test methods are purposely general in order to accommodate the widely varying industry practices. It is important that the user consult the appropriate materials specification for any specific detailed requirements regarding these test methods.1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information only.1.6 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section 101.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Both the loop breaking tenacity and the knot breaking tenacity, calculated from the breaking force measured under the conditions specified herein and the linear density of the fiber, are fundamental properties that are used to establish limitations on fiber-processing and upon their end-use applications. Physical properties, such as brittleness, not well defined by tests for breaking force and elongation can be estimated from the ratio of breaking tenacity measured in loop or knot tests, or both, and the normal tenacity as measured by Test Method D3822 provided both methods use the same gauge length and strain rate.5.2 This test method is not recommended for acceptance testing of commercial shipments in the absence of reliable information on between-laboratory precision (see Note 3). In some cases the purchaser and the supplier may have to test a commercial shipment of one or more specific materials by the best available method, even though the method has not been recommended for acceptance testing of commercial shipments. In such a case, if there is a disagreement arising from differences in values reported by the purchaser and the supplier when using this test method for acceptance testing, the statistical bias, if any, between the laboratory of the purchaser and the laboratory of the supplier should be determined with each comparison being based on testing specimens randomly drawn from one sample of material of the type being evaluated.1.1 These test methods cover the measurement of the breaking tenacity of manufactured textile fibers taken from filament yarns, staple, or tow fiber, either crimped or uncrimped, and tested in either a double loop or as a strand formed into a single overhand knot.1.2 Methods for measuring the breaking tenacity of conditioned and wet (immersed) fibers in loop and knot form are included.1.3 Elongation in loop or knot tests has no known significance, and is usually not recorded.1.4 The basic distinction between the procedures described in these test methods and those included in Test Methods D2101 is the configuration of the specimen, that is, either as a double loop or in the configuration of a single overhand knot.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.6 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Test Method D2524 for testing wool fibers for tenacity is considered satisfactory for acceptance testing when the participating laboratories, using a reference wool, have shown acceptable between-laboratory precision. It is recommended that any program of acceptance testing be preceded by an interlaboratory check in the laboratory of the purchaser and the laboratory of the seller on replicate specimens of samples of the material to be evaluated. In cases of dispute, the statistical bias, if any, between the laboratory of the purchaser and the seller should be determined with each comparison being based on testing randomized specimens from one sample of material of the type being evaluated.5.2 Values obtained from flat bundle tenacity show a good correlation with values obtained from single fiber tests and require much less time.5.3 The basic differences between the procedures described in Test Method D2524 and those described in Test Method D1294 lie in the manner of clamping the bundles and the shorter gage length employed. The special clamps used in this method allow quicker and easier bundle preparation; however, for Test Method D1294 no special clamps are required. Closer agreement with single fiber tenacity is also obtained with Test Method D2524 than when using the procedure in Test Method D1294.5.4 As the observed tenacity of fibers depends in part on the type of tensile testing machine used and the time required to break the specimen, results obtained with the different types of machines which may be used in this method will not necessarily agree. The machines specifically designed for bundle testing are CRL testers which operate at a loading rate of 1 kgf/s and therefore reach the breaking force at variable times in the order of 5 s. CRE and CRT type machines would be expected to produce somewhat different results not only because of the inherent difference in operation but because CRE and CRT type machines are to be operated at a rate to achieve the breaking load in 20 s.1.1 This test method covers the determination of the breaking tenacity of wool fibers as a flat bundle with a 1/8 in. (3.2 mm) clamp separation.1.2 This test method is especially adapted to the fiber bundle clamps and strength testing instruments specified, but may be used on other tensile testing machines when equipped with appropriate adapters to accommodate the prescribed clamps.1.3 This test method is applicable to wool in any form which can be hand-combed into small bundles of parallelized fibers.NOTE 1: Other test methods for measuring breaking tenacity of fiber bundles include Test Methods D1294, D1445, and D540.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM C648-20 Standard Test Method for Breaking Strength of Ceramic Tile Active 发布日期 :  1970-01-01 实施日期 : 

5.1 The test method provides means for establishing whether or not a lot of ceramic tile meets the strength requirements which may appear in tile specifications. Tile strength is the force in pounds-force (or newtons), as read from the pressure gage, necessary to cause the tile to break.1.1 This test method covers the determination of the breaking strength of ceramic tile, ceramic mosaic tile, quarry tile, porcelain tile and paver tile, having a facial area of at least 1 in.2 (6.4 cm2). Tiles may be glazed or unglazed.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The measurement of the strength of leather is often necessary in order to determine its suitability for its intended application. This test method is recommended for use on light, soft leathers, narrow strap, welt, lace and round belt leathers as well as others that cannot be accurately tested by Test Method D2209.1.1 This test method covers the determination of the breaking strength of leather by the grab method. It is intended for use on light, soft leathers; boarded, sueded, or embossed leathers tested on a specimen in the form of a rectangle piece; narrow strap, welt, lace, and round belt leathers; or other leathers that cannot be accurately tested by Test Method D2209. This test method does not apply to wet blue.1.2 The test method is not recommended for breaking loads over 500 lbf (2200 N) because of slippage of the specimen in the jaws.1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.1.4 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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