Fatigue analysis simplified

Traditional standards like AS4100 use nominal stress in a member and a catalogue of detail categories for SN curves, perfect for simple connections and loading. However, for complex geometries, this method is confusing and finding an appropriate detail category becomes challenging or even impossible. The nominal stress method is not suitable for complex geometry due to its inability to account for stress concentrations - the most likely location of fatigue cracks.

Fortunately, in the offshore oil industry the hot-spot method was developed, (later codified in standards like BS7608) which addressed these limitations. It focuses on calculating stresses at stress concentrations, allowing confident fatigue life predictions for all geometries and enabling designers to leverage FEA to manage peak stresses and extend structure life.

Despite its advantages, the hot-spot method is complex, involving stress interpolations or multiple points and consideration of normal stresses at various angles, the image above shows one surface stress interpolation method. FiniteLife was created to simplify these calculations, providing engineers with the benefits of the hot-spot method without the time consuming calculations.