Abstract: The stability of a variable-mass flexible spinning projectile under thrust is researched. The spinning projectile is simplified as a Timoshenko beam model, considering gyroscopic effect and shear effect, motion equations are derived based on the finite element method to analyze the effects of variable-mass, follower thrust and spinning speeds on the stability of the spinning projectile. Using the self-adaptive Newmark method, the transverse vibration response of the spinning projectile is solved. The results show that the variable-mass and thrust have influence on the natural frequency, precession frequency and critical speed. When the spinning speed is equal to the critical speed, the projectile occurs a transient resonance under the influence of the mass, and the peak time of the resonance response is slightly delayed compared with the coincidence time.

Key words: Timoshenko beam, Spinning projectile, Transverse vibration, Finite element method, Self-adaptive Newmark method