BS ISO 12106:2017 pdf download

BS ISO 12106:2017 pdf download.Metallic materials — Fatigue testing — Axial-strain- controlled method
1 Scope
This document specifies a method of testing uniaxially deformed specimens under strain control at constant amplitude, uniform temperature and fixed strain ratios including at R e = −1 for the determination of fatigue properties. It can also be used as a guide for testing under other R-ratios, as well as elevated temperatures where creep deformation effects may be active.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 23788, Metallic materials — Verification of the alignment of fatigue testing machines
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 engineering stress
instantaneous force divided by the initial cross-sectional area of the gauge length
Note 1 to entry: At strains to approximately 10 %, the true stress is approximated by the engineering stress, F/A o . It is also important to note that at strains to approximately 10 %, it is the engineering strain that is actually measured by the extensometer and it is the controlled parameter in a test.
Note 1 to entry: At true strain values to approximately 10 %, ε is approximated by the engineering strain e = ΔL/L.It is also important to note that at strains to approximately 10%, it is the engineering strain that is the quantity measured by the extensometer and the controlled parameter in a strain-controlled fatigue test.
3.6 cycle
smallest segment of the strain-time function that is repeated periodically
3.7 maximum
greatest algebraic value of a variable within one cycle
3.8 minimum
least algebraic value of a variable within one cycle
3.9 mean
one-half of the algebraic sum of the maximum and minimum values of a variable
3.10 range
algebraic difference between the maximum and minimum values of a variable
3.11 amplitude
half the range of a variable