基于增稳协同仿真算法的拉杆转子-轴承系统动力学分析

Rod-fastened rotors are pre-tightened by circumferentially uniformly distributed tie rods or central bolts, which are widely used in gas turbines and aeroengines. The dynamic stiffness of the contact interface is affected by the pre-tightening state of the tie rod as well as the external load, thus affecting the dynamic characteristics of the rotor system. Co-simulation algorithms define the exchange rules of coupling variables, which are widely used in multiphysics analysis and solver coupling for parallel computing. Based on the stabilized co-simulation algorithms, the distributed simulation of the rod-fastened rotor bearing system is studied in this project, taking into account the non-linear characteristics of the contact interface. The contents are collected as follows: based on the contact theory and the finite element model, the relationship between the contact stiffness and dynamic loads is investigated considering several fault states. Rod-fastened rotor-bearing systems involving the stiffness of the contact interfaces, are developed as a MBS-FEM distributed model. Afterwards, the coupling interface program is created. Distributed MBS-FEM simulation of the rod-fastened rotor-bearing system is carried out that reveals a novel stabilized and efficient simulation technique. To validate the co-simulation results, modal tests and run-up experiments are carried out using the test rig of our group. The project expands the application of the stabilized co-simulation algorithm, which provides some new idea for distributed solution of complex rotor-bearing system. Furthermore, it lays a theoretical foundation for multi-field coupling analysis.

燃气轮机和航空发动机广泛采用各级轮盘通过拉杆（或螺栓）连接的组合转子，其轮盘接触界面动态刚度受拉杆预紧状态和外载荷作用，从而影响转子系统动力学特性。协同仿真算法定义耦合变量传递规则，常用于多物理域耦合分析和大规模求解器并行计算。本项目基于增稳协同仿真算法，以拉杆转子-轴承系统为研究对象，考虑接触界面非线性力学特性进行转子-轴承系统分布式协同仿真研究。具体内容为：基于接触理论和有限元模型，考虑拉杆转子故障研究接触刚度和动态载荷关系；融合界面刚度发展拉杆转子-轴承多体-有限元（MBS-FEM）分布式模型，开发数据接口程序；进行拉杆转子-轴承系统的多体-有限元模型（MBS-FEM）分布式仿真，发展增稳高效协同仿真技术；基于课题组已有试验台进行静态和动态实验验证，拓展增稳协同仿真算法应用，为复杂转子-轴承系统动力学分析提供新思路，为多物理域分布式协同仿真提供理论支持。

拉杆转子是燃气轮机和航空发动机的重要旋转部件，接触界面对动力学特性影响显著。协同仿真算法是一种模块化弱耦合方法，近年来广泛用于多物理域分析和动力学系统并行计算。本项目围绕拉杆转子界面接触参数和动力学耦合分析，开展了拉杆转子界面参数识别、增稳协同仿真算法及转子-轴承协同仿真应用研究。共发表学术论文7篇，出版学术著作一部，申请发明专利2项，主要研究成果包括：1）建立了融合节点单元法和薄层单元法的多盘拉杆转子接触界面参数识别方法，针对带止口的拉杆转子接触界面发现并阐明了接触阻尼随预紧力变化的“突跳”现象；2）提出了界面雅克比近似的协同仿真增稳算法，通过定量稳定性分析和误差分析证明了算法的有效性；3）基于Matlab和COMSOL开发了拉杆转子-轴承协同仿真计算程序，开展转子-轴承系统主从耦合时域积分和增稳技术验证；4）搭建了拉杆转子-滑动轴承动力学分析试验台，可实现转速闭环精确控制下的拉杆转子动力学和故障特性实验研究。相关研究工作为拉杆转子非线性参数识别和动力学分析提供了实验和数值计算平台，为动力学系统高效增稳分布式耦合分析提供了理论基础和技术支撑。