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Abstract Landing gears, which are designed to absorb impact energy in order to provide support to the aircraft during landing, take-off and ground operations, are important components of the structure. Shimmy, which is one of the causes of aircraft failures, is a vibration that occurs as a result of the interaction of tire and landing gear dynamics and can cause an accident. In this study, the shimmy behavior of a helicopter used for civil, military and air ambulance purposes are investigated at different load and taxiing velocities. A landing gear single degree of freedom mathematical model is obtained and a Von Schlippe stressed spring tire model is included. The eigenvalues of the equations of motion are analyzed and stability maps of the system for different operating conditions are obtained. Runge-Kutta method (MATLAB ode45) is used to solve the equations of motion and a viscous damper is proposed. To obtain the damping, versions of the non-Newtonian silicone oil in the damper with different kinematic viscosities were evaluated. Apparent viscosities were obtained using the rheological values of the silicone oil and the analysis was repeated. As a result of the shimmy analysis at the initial velocities and maximum loading values required for the helicopter to taxiing, it was seen that damping was achieved in all conditions by using versions of the silicone oil with higher kinematic viscosities.
Akkaya et al. (Wed,) studied this question.