Estimation of the load produced by the electro-thermal behaviour of lightning strike protection layers on a composite panel

International audienceThe lightning damage mechanism for carbon laminate aeronautical structure is a complex multi-physical phenomenon. The lightning current entering into the surface metallic protection, called LSP (Lightning Strike Protection) and the carbon plies generates Joule’s effects and magnetic forces which both induce mechanical forces and surface explosion that has a significant mechanical impact. In this paper, the focus is made on the contribution of the surface explosion. An electro-thermal model of the vaporization profile has been first validated with lightning test results for an accurate dynamic profile. In a second step an overpressure profile combined with the vaporization front has been implemented in a mechanical model. The deflection profiles of the mechanical model are in good correlation with measurements. The contribution of the explosion is the major contributor in the loading of composite panel. A next step will consist in the determination of the contribution of the CFRP (Carbon Fiber Reinforced Plastic) explosion in the first plies which initiates the damage in the composite by breaking the fibers