Methodology for Multiaxial Fatigue Assessment of 2024‐T351 Aluminum Alloy Under Load Paths Representative of Aeronautical Structures

ABSTRACT Bolted assemblies are widely used in aerospace, automotive, and railway industries, where they experience complex multiaxial loadings. Understanding the multiaxial fatigue behavior of materials in such joints is essential for ensuring structural durability. However, selecting an appropriate fatigue criterion under realistic loading conditions remains challenging. This study proposes a methodology to assess the fatigue response of 2024‐T351 aluminum alloy (AA) under loading paths representative of those in metallic bolted joints of aeronautical structures. The approach involves three steps: identifying a multiaxial cyclic elastic–plastic behavior law, defining and calibrating a suitable multiaxial fatigue criterion, and validating fatigue life predictions for different load paths. An extensive experimental campaign on cruciform specimens under combined axial and shear cyclic loading reproduces typical in‐service conditions. Among the evaluated fatigue criteria, the Combilinear model provides the most accurate life predictions, showing good agreement with experimental results and validating the proposed methodology.