Lightning Currents on Fastening Assemblies of an Aircraft Fuel Tank, Part I: Uncertainties Assessment With Statistical Approach

This paper proposes a statistical approach in order to assess the fastening resistances uncertainties in aircraft assemblies. This method relies on the use of the maximum likelihood estimation method, several statistical tests, and/or statistical criteria. Using the Dassault-Aviation measurement database, distribution laws are established in order to characterize uncertainties in the lightning impact on the fasteners. A simple finite-difference time-domain (FDTD) fastener model is proposed with a wire and a resistance. This generic model can represent any fasteners. The statistical model established from the fastener resistances state after a lightning shot is used to define the stochastic distribution values in the fastener electric model. This model is added to a 3-D FDTD parallelepiped generic fuel tank model. In this paper, we compare the current distributions between a composite and metallic fuel tank. The results highlight not only the model uncertainties effects on the statistical approach but also the fuel tank material choice impact.