The aim of the study was to predict the accumulated corrosion damage on an aileron hinge from an F/A-18. The aileron hinge mounts to the rear and aft spars, and to a connecting rib in the outer wing section.
The CAD geometry was used to create the model of the aileron hinge and the fastener and pin-bushing material properties defined. Polarisation properties of the various materials were obtained from the BEASY POLCURVEX database. Boundary conditions based on the electrochemical kinetics (i.e. polarization curves) were applied to represent the various component materials. Lastly, the characteristics of the electrolyte film (e.g. conductivity, film thickness) were assigned.
The BEASY Corrosion Manager Service Life Model was used to predict the spatial distribution of galvanic stress under a typical environmental exposure spectrum, representative of the operational conditions of the aircraft.
The cumulative corrosion damage is predicted using the corrosion rates determined from each of the defined exposure conditions in combination with an environmental exposure spectrum. The corrosion damage is determined using Faraday’s Law and integrating the corrosion rates over specified time periods. The cumulative corrosion damage is calculated using a time-stepping approach and summing the damage from each discrete exposure period. Please note that this cumulative corrosion damage prediction is made at each element in the computer model and produces a 3D surface contour showing the spatial distribution of corrosion damage for the entire structure.