Abstract: A numerical analysis is conducted to study the ground resonance of two-blade helicopter rotor on anisotropic flexible supports, in which both co-axis and uniaxis helicopters with two blades are considered. It is shown that the present method is effective and convenient with consideration of the linear stability model, especially when a symbolic reduction technique is utilized to derive analytically the corresponding governing equations, The computation reveals many interesting results, some of which are scarcely reported in previous studies and herein are discussed in detail.

Key words: helicopters, ground, resonace, stability, numerical analysis