Revisiting Riera's model about malevolent aircraft impinging against a rigid target

This paper revisited the Riera's model which is known as an important theoretical model of describing a malevolent aircraft impact on a rigid target for which the engineering background is against the crashworthiness design of the protecting shell in nuclear power plant subjected to terrorist attack. The relationship among the initial momentum of the aircraft, the total impulse exerted on the rigid target, the impulse of the crushing pressure, and the impulse of the dynamic pressure were studied. It was proved that the impulse exerted on the rigid target during the impact period is approximately equal to the initial momentum of aircraft. The expression of the ratio of the initial kinetic energy of the aircraft to the limit plastic strain energy that results in the crash of the aircraft was obtained. In addition, this study demonstrated that the reflection of a large number of debris increases the impulse exerted on the target and therefore the Riera's model needs to be improved by considering this effect and the modification coefficient of the dynamic force was proposed.