Modeling Method and Vibration Analysis of Dovetail Jointed Blade Set With Underplatform Damper by Considering Thermal Effect

Considering the thermal environment of rotating blades, this paper calculated the predeformation caused by thermal strain and centrifugal strain using the pseudo-static analysis method. The finite element model of the structural dynamics of blades was constructed by applying the predeformation. Then, this paper solved the nonlinear forces acting on the contact interface considering the pressure distribution and contact characteristics under different thermal conditions. Under the excitation order of the blade, the vibration results of the blade under the influence of temperature and rotational velocity are discussed, respectively. The main discussion focused on the amplitude-frequency characteristic curve of the blade and the frictional hysteresis curve under resonance conditions. Results show that the blade set's vibration response will significantly increase with the temperature increase. This is mainly related to the influence of temperature on the material and contact characteristics. The vibration behavior of the platform is more intense than that of the tenon. The platform's position has a greater influence on the vibration of the blade set.