Computation Of Temperature Distribution On A Composite Aircraft Skin Protection Grid Due To Induced Electric Current During Flight under Thunderstorm Conditions

The use of composite materials in aircraft manufacturing is more and more extended. Despite the considerable empty weight penalty savings, this kind of material are vulnerable to lightning strikes due to their poor electrical and thermal conductivity. This problem is solved by using full or partial metallic spray or a metallic grid imbedded into the composite material. A lightning spark from a thundercloud to the ground can be considered as a wire traversed by an electric current with a peak intensity of several hundred of Ampères. This way an ambient magnetic field is created which in turn, according to Lenz law, creates an electric current circulating along the wires of the grid, producing heat. In this paper, a approach for computing the temperature distribution inside a composite aircraft skin due to the presence of an ambient magnetic field is presented. The goal is to compute the temperature rise inside the composite material so as to define areas of possible long term damage.