Full-aircraft landing ground load and influencing factors for transport aircraft

The full-aircraft landing ground load is one of the basic inputs for transport aircraft design and performance optimization. In order to study the characteristics of the ground load and its influencing factors during the full-aircraft landing, we take the typical single-channel simplified aircraft test piece as the object, designs the full-aircraft landing test scheme, and establishes the full-aircraft landing simulation analysis model which considers the flexibility of the fuselage. Through experimental and simulation analysis, the influence laws of landing conditions, fuselage weight, and fuselage flexibility on its ground load are discussed. The results show that the aircraft ground load obtained from the full-aircraft landing experiment can effectively consider influence of fuselage flexibility. The full-aircraft landing simulation model has a good prediction accuracy, the error between the curve peak and the ground load experimental result is within 5%, and the correlation coefficient is greater than 0.967. The landing velocity has the most significant effect on the aircraft landing load, and the sensitivity coefficient is 1.084. The effect of the pitch angle is the weakest, and the sensitivity coefficient is only 0.030. With the increase of landing weight, the ground load and the energy absorption amount of the buffer increase significantly, the buffer efficiency gradually decreases, and the sensitivity of the ground load peak, the buffer absorption energy, and buffer efficiency to the landing weight are 0.918, 1.131, and 0.086, respectively. With the decrease of the stiffness of the fuselage, the flexibility effect of the fuselage is significantly enhanced, and the ground load peak, the buffer absorption energy, and the efficiency gradually decrease. The influence of the fuselage flexibility on the transport aircraft landing load cannot be ignored.