ISO 1143-2010 pdf free download.Metallic materials – Rotating bar bending fatigue testing.ISO 1143 specifies the method for rotating bar bending fatigue testing of metallic materials. The tests are conducted at room temperature or elevated temperature in air, the specimen being rotated.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 376, Metallic materials — Calibration of force-proving instruments used for the verification of uniaxial testing machines
ISO 1099, Metallic materials — Fatigue testing — Axial force-controlled method
ISO 12106, Metallic materials — Fatigue testing — Axial-strain-controlled method
ISO 12107, Metallic materials — Fatigue testing — Statistical planning and analysis of data
ISO 23718, Metallic materials — Mechanical testing — Vocabula,y
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1099, ISO 12106, ISO 12107, ISO 23718 and the following apply.
process of changes in properties which can occur in a metallic material due to the repeated application of stresses or strains and which can lead to cracking or failure
3.2 fatigue life Nf number of cycles of a specified character that a given specimen sustains before failure of a specified nature occurs
3.3 S-N diagram diagram that shows the relationship between stress and fatigue life.
4 Symbols and designations
Symbols and corresponding designations are given in Table 1, or elsewhere in this International Standard where they appear.
5 Principle of test
Nominally identical specimens are used, each being rotated and subjected to a bending moment. The forces giving rise to the bending moment do not rotate. The specimen may be mounted as a cantilever, with single-point or two-point loading, or as a beam, with four-point loading. The test is continued until the specimen fails or until a pre-determined number of stress cycles have been achieved.
6.1 Forms of the test section The test section may be
a) cylindrical, with tangentially blending fillets at one or both ends (see Figures 1,4 and 5), b) tapered (see Figure 2), or
c) hourglass-type (see Figures 3, 6 and 7).
In each case, the test section shall be of circular cross-section.
The form of test section may be dependent on the type of loading to be employed. While cylindrical or hourglass-type specimens may be loaded as beams, or as cantilevers with either single-point or double-point loading, the tapered form of specimen is used only as a cantilever with single-point loading. Figures 1 to 7 show, in schematic form, the bending moment and nominal stress diagrams for the various practical cases.
The volumes of material subjected to greatest stresses are not the same for different forms of specimen, and they may not necessarily give identical results. The test in which the largest volume of material is highly stressed is preferred.
Experience has shown that a ratio of at least 3:1 between the cross-sectional areas of the test portion and the gripping regions of the specimen is desirable.
In tests on certain materials, a combination of high stress and high speed may cause excessive hysteresis heating of the specimen. This effect may be reduced by subjecting a smaller volume of the material to the specified stress. If the specimen is cooled, the test medium should be reported.
6.2 Dimensions of specimens
All the specimens employed in a test series for a fatigue-life determination shall have the same size, shape and tolerance of diameter.
For the purpose of calculating the force to be applied to obtain the required stress, the actual minimum diameter of each specimen shall be measured to an accuracy of 0,01 mm. Care shall be taken during the measurement of the specimen prior to testing to ensure that the surface is not damaged.
On cylindrical specimens subject to constant bending moment (see Figures 4 and 5), the parallel test section shall be parallel within 0,025 mm. For other forms of cylindrical specimen (see Figure 1), the parallel test section shall be parallel within 0,05 mm. For material property determination, the transition fillets at the ends of the test section should have a radius not less than 3d. For hourglass-type specimens, the section formed by the continuous radius should have a radius not less than 5d.
Figure 8 shows the shape and dimensions of a typical cylindrical specimen. The recommended values of 1 are 6 mm, 7,5 mm and 9,5 mm. The tolerance of diameter should be 0.0O5d. Figure 9 shows a typical hourglass specimen suitable for fatigue testing at elevated temperature.ISO 1143 pdf download.