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.