中文摘要：

纵扭复合型超声电机独特的工作机理决定了该类电机的定子往往是一个非常复杂的结构。基于拉格朗日方程、压电材料的机电耦合方程以及模态叠加理论，建立了纵扭复合型超声电机定子的解析模型，并且通过实例验证了该模型的可行性。该模型能方便地实现对电机定子各阶模态的计算，可用于电机系统的性能预测和参数优化设计，对电机整机性能的研究提供了一定的理论基础。

英文摘要：

The stator of longitudinal and torsional hybrid type ultrasonicmotor （TLHUSM） was always designed as complicated configuration because of its particular principle of operation. TLHUSM＇s analytical model was educed detailedly herein based on Lagrange equation, electromechanical coupled equation and mode superposition principle. The mathematics model can be applied to calculate varying modal parameters of the stator easily. Finally the computational results of the model were compared against those from the finite element method and experiments. Thus a high computational efficiency of the model are demonstrated and it proves that the proposed model can be used in the performance simulation and optimization design of the motor systems.