An Analytical-Based Lightning-Induced Damage Model for an Aircraft Wing Exposed to Pressure Loading of Lightning

Abstract

Lightning is one of the natural hazards that any aircraft may encounter while navigating. If adequate precautions are not taken against lightning, structural damage, operational disruptions, and loss of life and property can occur. Thus, studying the mechanism of damage caused by lightning strikes in an aircraft’s structural material is necessary to optimize the structure, minimize the damage, and reduce the cost caused by lightning. In the present article, the lightning-induced damage behavior of an aircraft structural material was investigated from an analytical perspective. For this purpose, two analytical-based models were developed: an improved electromagnetic pressure impact model (IEPIM) and the damage model in an aircraft wing. For the IEPIM, the findings of the article showed that the proposed pressure model is in good agreement with the experimental studies, borrowed from the open literature, for 100 and 200 kA lightning current. For the damage model, the findings of the article indicated that (i) even though lightning strikes to the regions with the same characteristics on an aircraft wing in terms of the lightning strike zone, the amount of deflection in the wing increases as the impact point approaches the wing tip and decreases as it approaches the wing root, (ii) without changing the lightning strike point ($x_0$), when the damping coefficient ($\xi$) is increased in the range of $\left[0,2\xi \right]$, the amount of deflection decreases as the amount of damping coefficient increases, and (iii) when lightning with a current of 100 kA hits to the wing root of an aircraft, the pressure impact of the lightning causes more torsion deflection than bending deflection at the wing root; however, when it hits to the mid-wing or wing tip of an aircraft, the pressure impact of the lightning causes more bending deflection than torsion deflection at the mid-wing or wing tip.