Oil whip and resonance are the common faults of a rotor system. The faults directly affect its normal operation and can cause serious accidents. Based on the regularity of oil whip and resonance of the rotor system, a sensitivity study of the frequency reliability of the system is conducted. The technique developed utilizes random perturbation technology, reliability theory, and sensitivity technology. The reliability mode and the failure probability of the rotor systems are defined. The second-order joint failure probability is obtained using numerical integration methods. The variation regularities of the reliability are obtained and the influences of random parameters on the reliability of the rotor system are studied. The method presented provides a theoretical basis for the frequency reliability sensitivity design of the rotor system. A numerical example is analyzed to show the effectiveness of the proposed method.

Composite materials are widely used in aircraft due to their high specific strength and stiffness, superior impact resistance, and excellent fatigue performance. Bird strikes can inflict severe damage to critical aircraft components such as the fuselage, engines, and wings, thereby compromising flight safety. Aircraft certification regulations require that all components demonstrate a specified level of bird strike resistance before aircraft installation. Given these requirements, this study focused on the use of carbon fiber composite laminates in aircraft components. By varying impact velocity, impact angle, and ply orientation, the study investigated the resulting patterns of bird-strike impact behavior in composite materials. The derived patterns provide a theoretical reference for further research into the impact mechanics of composite materials subjected to bird strikes.

Composite materials are extensively employed in aircraft due to their high specific strength and stiffness, superior impact resistance, and fatigue performance. Bird strikes can inflict severe damage to critical aircraft components such as the fuselage, engines, and wings, compromising flight safety. Certification regulations mandate that all components must demonstrate a specified level of bird strike resistance prior to aircraft installation. Consequently, this study focuses on carbon fiber composite laminates. By varying impact velocity, impact angle, and ply orientation, it investigates the resulting patterns of bird strike impact behaviors in these composites. The derived patterns provide theoretical reference for further research into the impact mechanics of composite materials subjected to bird strikes.