多支承变截面转子轴系模型求解及有限元验证技术

Model solution on multi-supports nonprismatic rotor shafting and its finite element verification technique

以200WM汽轮发电机组模拟轴系为例,运用模态综合法建立了动力学模型。采用二分法和LU分解法分别获得系统的固有频率和主模态,并采用Nastran软件进行有限元分析验证上述理论和方法的正确性。最后,根据工程实际中出现的激励方式,采用Newmark时间差分法和五点空间差分法联合求解强迫弯曲振动动力学响应,该工作不仅对于这类多支承变截面转子轴系的理论分析具有重要的研究意义,还对其结构优化设计具有十分重要的指导作用。

Taking the simulative shafting of 200WM steam-turbine generator set as an example and utilizing the modality synthetic method to establish its dynamics model. The natural frequency of system and the principle modality were obtained respectively by adopting the dichotomy and the LU decomposition method, and using Nastran software to carrying out finite element analysis to testifying the correctness of the above stated theory and method. Finally, on the basis of the excitation manner presented in engineering practice, by adopting the combination of Newmark time difference method and five-point space difference method to solve the dynamics response of the forced bending vibration. This operational work not only possesses important researching significance to the theoretical analysis of this kind of multi-supports nonprismatic rotor shafting but also possesses quite significant guiding effect on the optimization design of its structure.