Research and Development
Multiaxial Fatigue Analysis of Interference Fit

Al 2024-T3 Specimens
Summary: Fatigue failure of interference-fit aluminum joints has been investigated by testing several specimens geometries, conducting numerical simulations and using multiaxial fatigue theories. The experiments included center crack, edge crack and uncracked specimens, fitted with a zero load-transfer interference-fit fasteners and tested to failure at different cyclic loads. Thermal imaging system was used to observe initiation of cracks during the fatigue tests. This has shown promising prospects for an early detection of small surface cracks.
An elastic-plastic contact finite element (EPFE) analysis was carried out to simulate the local combined interference and cyclic stress distribution in the specimens near the fastener's hole. The simulation and test results were used in a multiaxial fatigue analysis that examined several theories including the critical plane approach and the octahedral stress parameter. The experimental lives were correlated by calculating the multiaxial fatigue parameters at different locations along the hole edge.