A Semi-Active Landing Gear with Variable Stiffness and Damping for Vibration Mitigation in VTOL Aircraft

4 th International Conference on Pioneer and Innovative Studies, Konya, Türkiye, 18 - 19 Ocak 2026, ss.79, (Özet Bildiri)

Vertical Takeoff and Landing (VTOL) aircraft offer high operational flexibility; however, severe

transient loads and vibrations caused by landing gear–ground interaction during vertical landing remain a

critical issue for structural integrity and flight safety. Most existing studies address this problem using active

force-based controllers or classical landing gear models with fixed stiffness and damping. These

assumptions become inadequate under ground uncertainty, asymmetric contact, and sudden load transfer

conditions inherent in VTOL landing dynamics. To address this limitation, this study proposes a semi-

active landing gear approach based on variable stiffness and damping. A multi-degree-of-freedom dynamic

model is developed to represent the coupled fuselage and landing gear dynamics. The landing gear

parameters are adjusted online according to the vibration response during landing, focusing on physical

parameter adaptation rather than active force generation. This strategy reduces control complexity and

energy demand. The proposed semi-active system is numerically compared with a conventional fixed-

parameter landing gear model using peak fuselage displacement, maximum vertical acceleration, settling

time, and RMS acceleration as performance metrics. The results demonstrate clear performance

improvements. Compared to the conventional model, peak fuselage vertical displacement is reduced by up

to 30%, maximum vertical acceleration decreases by more than 35%, vibration settling time is shortened

by approximately 40%, and RMS acceleration values are reduced by nearly 25%. Frequency-domain results

further show effective suppression of high-frequency vibration components at initial ground contact. The

main novelty of this study lies in addressing VTOL landing dynamics through online adaptation of landing

gear physical parameters, providing an energy-efficient and structurally safer alternative to classical active

control approaches.