In the product development process, to assess the risk of corrosion designs are often exposed to an outdoor environment for a long time, or corrosion acceleration tests are conducted to simulate the actual condition the vehicle or structure will be exposed to during its life. These methods however require several months to years of test time to complete. As an alternative approach computational modeling has the potential to significantly shorten and reduce the cost of testing.
The paper gives an overview of the development and experimental validation of a computational model for simulating galvanic corrosion in an aircraft environment. The numerical approach is based on a three dimensional Boundary/Finite Element Method model. Amongst the inputs of the problem are: geometrical description and physical properties of the electrolyte, as well as macroscopic polarization curves of the active electrodes. The main outcomes of the model are corrosion rates, electric current density and potential distribution. An experimental set-up has been established for validation of the computational results consisting of a co-planar bi-material combination composed of aluminum UNS A92024 and carbon fiber reinforced polymer (CFRP). The validation approach is explained and the results are shown. Very good agreement has been obtained between observed and simulated data. This basic model has been applied to different multi-material combinations relevant for aircraft structures. In particular, different cases of application of protective coatings and other corrosion protection measures are also considered. Finally how the modeling approach will be further developed to be used for simulating galvanic corrosion in more complex structural components of an aircraft will be discussed.
