应用机电耦合模型定义全模态型及扭振模态型；推导扭矩线性解，并根据扭矩解定义扭矩模态型及扭矩模态贡献因子。这些物理概念可直接分析轴系扭振动态，并获得更丰富的信息，这是以往定义的模态型无法做到的。此外，还分析自由振动模型和受迫轴系模型的理论基础和物理意义，并从机电耦合模型与自由振动模型的区别，解释固有扭振频率及模态型的计算值与测量值存在偏差的原因；应用解析解分析机电耦合模型与受迫振动模型的动态特性差别。

The electromechanical coupling model is employed to define the all-mode shape and torsional mode shape, and deduce the linear solutions of torques. Based on the solutions of torques, mode shapes of torques and mode contribution factors of torques are defined. The above physical concepts can directly describe shaft torsional dynamics, and get more insights than the mode shapes previously defined. Moreover, the theoretical basis and the physical implications of free vibration and forced vibration models are analyzed in detail. In light of the difference between the electromechanical coupling model and the free vibration model, the deviations between the calculated and measured values are explained for mode shapes and natural torsional frequencies. The difference between the dynamics of the electromechanical coupling and forced vibration models is analyzed as well.

新世纪优秀人才支持计划项目(NCET-05-0216)；长江学者和创新团队发展计划项目(IRT0515)；高等学校学科创新引智计划项目(B08013)。