ISO 12106:2017

Overview

ISO 12106:2017 - Metallic materials - Fatigue testing - Axial‑strain‑controlled method defines a standardized procedure for uniaxial, strain‑controlled fatigue testing of metallic specimens. The standard covers constant‑amplitude, fixed strain‑ratio tests (including R = −1) performed at uniform temperature and provides guidance for elevated‑temperature creep‑fatigue testing. ISO 12106:2017 is aimed at producing reproducible low‑cycle fatigue data, cyclic stress‑strain responses and strain‑life relationships for engineering materials.

Key topics and technical requirements

ISO 12106:2017 addresses the complete test chain from apparatus to reporting. Major technical topics include:

• Test conditions: strain‑controlled, constant amplitude cycles, fixed R‑ratios (explicitly including R = −1), uniform temperature; guidance for other R‑ratios and high‑temperature creep effects.
• Apparatus and instrumentation: requirements for test machines, force transducers, grips, alignment checks and extensometers/strain measurement systems.
• Specimen definitions: geometry options (e.g., round bars and flat sheet products), preparation, surface condition, dimensional control and handling.
• Test procedure: laboratory environment, machine control, mounting, cycle shape and strain rate/frequency, start and end criteria, data recording (stress‑strain hysteresis loops) and failure criteria.
• High‑temperature creep‑fatigue: methodology for testing where creep and cyclic deformation interact.
• Data analysis and reporting: expression of results, strain‑life and stress‑strain relationships, test report content (purpose, material, specimen, methods, conditions, and presentation of results).
• Quality & verification: calibration and alignment references, measurement uncertainty and recommended verification practices.

Applications and who uses it

ISO 12106:2017 is used by:

• Materials testing laboratories and metallurgical R&D teams to generate low‑cycle fatigue (LCF) data and cyclic stress‑strain curves.
• Design and qualification engineers in aerospace, automotive, nuclear, medical device and heavy‑engineering sectors where components undergo cyclic plastic strains.
• Quality assurance and standards compliance teams seeking reproducible, comparable fatigue data for material selection, life prediction and finite element validation. Practical outcomes include strain‑life curves for design, inputs for fatigue life models, and validated creep‑fatigue data for high‑temperature components.

Related standards

Key normative references cited in ISO 12106:2017:

• ISO 7500‑1 (calibration/verification of force systems)
• ISO 9513 (extensometer calibration)
• ISO 23788 (fatigue machine alignment)

Using ISO 12106:2017 ensures consistent axial strain‑controlled fatigue testing, reliable low‑cycle fatigue properties and clear reporting for engineering decision‑making.