ISO 12110-1:2013

Overview

ISO 12110-1:2013 - Metallic materials - Fatigue testing - Variable amplitude fatigue testing - Part 1: General principles, test method and reporting requirements - defines general principles and test/reporting requirements for laboratory fatigue tests where the load amplitude varies from cycle to cycle. The standard addresses deterministic loading time histories (derived from service measurements) and focuses on force-controlled, single-actuator (commonly uniaxial) test modes. Its goal is to improve consistency and comparability of variable amplitude fatigue data so designers and engineers can better correlate models and experimental results.

Key topics and requirements

• Loading time history: definition, preparation and description of the sequence of cycles used to reproduce service-like loads.
• Control signal generation: practical methods to convert measured time histories into machine control signals - principally programmed blocks and signal reconstruction from a transition matrix (random draw).
• Cycle counting and data handling: use of cycle counting to extract cycles from a time history and to build cumulative frequency diagrams or transition matrices (note: ISO 12110-2 covers cycle counting and data reduction in detail).
• Signal filtering and omission: guidance on removing electronic noise or non‑damaging small cycles, with warnings about inappropriate filtering that may remove damaging cycles or affect mean stress considerations.
• Test conduct and reporting: required reporting elements for each specimen - original loading description, testing conditions, preliminary analysis (individual specimen and series), and other metadata to allow comparison between tests.
• Scope and limits: applies to deterministic variable amplitude loading under force-control, excludes random-loading descriptions, multiaxial tests, large structural components, environmental effects (corrosion, creep), and constant-amplitude tests with isolated overloads/underloads.

Practical applications

• Reproducing representative service loadings for metallic specimen fatigue tests.
• Generating control signals for fatigue test rigs to evaluate material durability under realistic load sequences.
• Producing comparable fatigue datasets for model validation, design life estimation, and reliability assessment.
• Useful in sectors with complex service loadings (automotive, aerospace, rail) where variable amplitude fatigue governs component life.

Who should use this standard

• Materials and fatigue test laboratories
• Mechanical and structural engineers performing durability testing
• OEM test engineers (aerospace, automotive, transport)
• R&D teams validating fatigue models and life‑prediction methods
• Quality and certification bodies requiring standardized reporting

Related standards

• ISO 12110-2 (Cycle counting and related data reduction methods)
• ISO 1099, ISO 12106, ISO 12107, ISO 12108, ISO 23788 (referenced standards covering specific fatigue methods, statistical analysis, crack growth, and test machine alignment)

Keywords: ISO 12110-1, variable amplitude fatigue testing, loading time history, transition matrix, programmed blocks, cycle counting, force-controlled fatigue, metallic materials, fatigue test reporting.