  This work is concerned with the development of a numerical modelling approach
for studying the time-accurate response of aerospace fasteners subjected to
high electrical current loading from a simulated lightning strike. The
electromagnetic, thermal and elastoplastic response of individual fastener
components is captured by this method allowing a critical analysis of fastener
design and material layering. Under high electrical current loading, ionisation
of gas filled cavities in the fastener assembly can lead to viable current
paths across internal voids. This ionisation can lead to localised pockets of
high pressure plasma through the Joule heating effect. The multi-physics
approach developed in this paper extends an existing methodology that allows a
two-way dynamic non-linear coupling of the plasma arc, the titanium aerospace
fastener components, the surrounding aircraft panels, the internal supporting
structure and internal plasma-filled cavities. Results from this model are
compared with experimental measurements of a titanium fastener holding together
carbon composite panels separated by thin dielectric layers. The current
distribution measurements are shown to be accurately reproduced. A parameter
study is used to assess the internal cavity modelling strategy and to quantify
the relation between the internal cavity plasma pressure, the electrical
current distribution and changes in the internal cavity geometry.
