A dual-rotor system is a core component of an aero-engine, and it is very important to study the nonlinear vibrational characteristics for the aero-engine’s development. Based on analyzing structural characteristics of aero-engine’s rotors, a novel and more practical dual-rotor dynamic coupling model with nonlinear restoring forces of high-pressure and low-pressure rotors is first proposed. In the linear dynamic coupling model, the coupling critical speed, natural frequencies and vibration responses of the low-pressure rotor are analyzed systematically. In the nonlinear dynamic coupling model, the vibrational characteristics of the dual-rotor system with different nonlinear parameters are simulated numerically based on the nonlinear dynamic theory. The improved shooting method combined the harmonic balance method, and the genetic algorithm is proposed to calculate theoretical solutions of the nonlinear dynamic coupling model. The stability of theoretical solutions is investigated by the Floquet theory. The research results show that the dual-rotor system appears very complicated nonlinear vibrations such as nonlinear multitudinal solutions, double period motions, almost periodic motions and chaotic motions. The transition between nonlinear vibrations occurs suddenly.

双转子系统是航空发动机的核心组成部分，研究非线性振动特性对于航空发动机的发展非常重要。在分析航空发动机转子结构特性的基础上，提出了一种新颖，实用的具有高压和低压转子非线性恢复力的双转子动态耦合模型。在线性动态耦合模型中，系统地分析了低压转子的耦合临界速度，固有频率和振动响应。在非线性动力耦合模型中，基于非线性动力学理论，对具有不同非线性参数的双转子系统的振动特性进行了数值模拟。改进的射击方法结合了谐波平衡法，提出了遗传算法来计算非线性动力耦合模型的理论解。Floquet理论研究了理论解的稳定性。研究结果表明，双转子系统会出现非常复杂的非线性振动，例如非线性多解解，双周期运动，几乎周期运动和混沌运动。非线性振动之间的过渡突然发生。