Dynamic Analysis and Parameter Estimation of Bladed Rotor Bearing System

BackgroundThis study presents a dynamic model of a Bladed Rotor Bearing System (BRBS) with different blade configurations, taking into account the coupled vibration characteristics of the blades and rotor. Consideration is given to the blade configuration, such as the pre-twist, taper, and that connects the blades with lacing wires.MethodologyBlade dynamics includes simultaneously considering axial, chordwise, and flapwise dynamics in the presence of rotordynamic effects such as gyroscopic, centrifugal stiffening, and softening effects. The disk is assumed to be rigid, and its mass is lumped at a node on the flexible shaft, which is modelled as a first-order shear deformable beam. The bladed-rotor is supported on a set of spring-damper model-based linear bearings, whose effect is also considered during the evaluation of results. Displacement kinematics is developed based on the forementioned characteristics, and Lagrangian's equation of motion is used to develop the governing dynamic equations. Further, the model is discretized based on the Galerkin Finite Element Method.Results and ConclusionThe natural frequencies of the model are compared with the existing literature to understand the numerical efficiency of the model. Under a combination of aerodynamic and external excitations, forced response investigations are performed on BRBS under different blade configurations. Finally, using a hybrid-genetic neuroscheme, the efficacy of the presented model to identify parameters such as twist angle, taper ratio, lacing wire stiffness, and locations is discussed.