基于薄层单元的拉杆转子接触界面动力学建模及修正

为了研究具有复杂接触界面拉杆转子系统的动力学特性,发展了基于薄层单元的拉杆转子接触界面动力学建模及修正方法。采用线性本构关系的薄层单元模拟转子部件的复杂接触关系,基于模态试验数据,运用分层模型修正方法对预紧状态下拉杆转子部件接触面的连接刚度进行识别,通过识别的薄层连接参数建立拉杆转子动力学预测模型。将拉杆转子动力学预测模型的结果与试验数据进行对比分析,结果表明:采用线性本构关系薄层单元能够模拟拉杆预紧状态下接触界面的力学特性,修改薄层单元弹性模量能够模拟接触界面的法向刚度和切向刚度;修正后转子模型与测试结果的最大频率误差为0.6%,平均频率相对误差为0.25%,修正后模型能预测实际结构的振动响应。 

Dynamic modeling and updating for contact interface of rod fastening rotor based on thin-layer element

In order to study the dynamic characteristics of a rod fastening rotor system with complex contact interfaces, a method for dynamic modeling and updating of a rod fastening rotor system with contact interfaces is developed based on thin layer elements. The contact relationship of the rod fastening rotor parts was simulated by the thin layer element of linear constitutive relationship. Based on modal test data, the connection stiffness of contact interfaces of the rotor parts of pre-tighten status was identified by the hierarchical model updating method, and then the dynamic prediction model of the rod fastening rotor system was established via the identified connection parameters of the thin layer elements. The dynamic predictions of the rod fastening rotor were compared with the experimental data. Results show that the mechanical properties of the contact interfaces under the pre-tightening state of the tie rod can be simulated by using the thin-layer elements with linear constitutive relation, and the normal and tangential stiffness of the contact interfaces can be simulated by modifying elastic modulus of the thin-layer elements. The maximum frequency error and the average frequency relative error between the updated rotor model and the test data were 0.6% and 0.25%, respectively, and the updated model can predict the vibration responses of its actual structure.