Overview
ISO 1099:2017 - Metallic materials - Fatigue testing - Axial force-controlled method - defines conditions for conducting axial, constant‑amplitude, force‑controlled fatigue tests on metallic specimens at ambient temperature. The standard is intended to generate fatigue‑life data (stress vs. number of cycles to failure) for materials in a given condition (e.g., hardness, microstructure) and at various stress ratios (R‑ratios). Tests are typically sinusoidal and performed with the applied force along the specimen’s longitudinal axis. Component testing and specially notched specimens are excluded from the standard’s scope.
Key topics and technical requirements
- Test type: Axial, constant‑amplitude, force‑controlled fatigue tests (sinusoidal waveform unless otherwise specified).
- Environmental conditions: Ambient testing recommended (ideally 10 °C to 35 °C); atmospheric control guidance referenced (ISO 554).
- Specimens: Forms and preparation for circular and rectangular cross‑sections are described (including geometry, machining, surface condition, marking and storage). Notched or component‑level test pieces are not standardized here.
- Test planning: Agreement on specimen form, R‑ratios, test objectives (fatigue life at a given stress, fatigue strength at a given life, or full S‑N/Wöhler curve), specimen counts, test sequence and termination cycle.
- Instrumentation & verification: Requirements for test machines, alignment checks, force transducers, grip methods, recording systems and cycle counting. Relevant verification standards are cited.
- Data presentation: Use of Wöhler (S‑N) curves, mean‑stress diagrams and clear reporting of test conditions, failure criteria and termination.
- Failure criterion/termination: Defined criteria for specimen failure and when to stop tests (including predetermined maximum cycle counts).
Practical applications and users
ISO 1099:2017 is used to produce reliable fatigue‑life data for material characterization, design inputs and comparative material assessment. Typical users include:
- Materials engineers and metallurgists characterizing alloy fatigue behavior.
- Mechanical designers needing S‑N data for fatigue life prediction.
- Test laboratories performing standardized uniaxial fatigue testing.
- Quality and R&D teams validating heat treatments, surface finishes or process changes that affect fatigue performance.
Keywords: ISO 1099:2017, fatigue testing, axial force‑controlled, metallic materials, S‑N curve, Wöhler curve, stress ratio, fatigue life, specimen preparation.
Related standards
- ISO 4965‑1 - Dynamic force calibration for uniaxial fatigue testing (Part 1: Testing systems)
- ISO 7500‑1 - Verification of static uniaxial testing machines (force‑measuring system)
- ISO 23788 - Verification of the alignment of fatigue testing machines
- ISO 554 - Environmental conditions for testing (referenced for controlled atmospheres)
For implementation, consult the full ISO 1099:2017 text for detailed geometries, machining procedures, instrumentation tolerances and reporting requirements.