Predicting structural life under fretting fatigue loading conditions is a complex analysis requirement that cannot be performed using simplified methods. Issues such as crack initiation location and crack growth life under frictional contact require coupling the contact mechanics with fatigue crack growth simulations.
BEASY provided a robust new methodology developed under a NAVAIR SBIR contract that allowed users to perform fatigue crack growth
studies using frictional contact as the driving force.
The simulation was based on 3D models of the actual components which simulated not only the detailed stress and displacement history on the contact surfaces under the fretting load but also the stresses in the material near the contact surfaces. This enabled the model to simulate the growth of the cracks initiated during the fretting process and their paths, growth rate and resulting failure mode.
The software was applied to a dovetail fretting fatigue application for which results from an experimental test setup were available. Good agreement was observed which validated the approach.
This new software capability is extremely useful in analyzing the fretting fatigue crack growth behavior observed in a variety of structural components ranging from the dovetail joints in jet turbine engines to riveted connections in various airframe components.