Experimental Investigations of the Flexible Rotor System by Introducing Parametric Excitations into Both Ends of the Rotating Shaft Axially

2022 ◽  
pp. 287-296
Author(s):  
L. Atepor ◽  
F. Davis ◽  
P. M. Akangah
Keyword(s):  
Rotor System ◽  
Experimental Investigations ◽  
Flexible Rotor ◽  
Rotating Shaft

scholarly journals Effect of the Supports’ Positions on the Vibration Characteristics of a Flexible Rotor Shafting

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Miaomiao Li ◽  
Zhuo Li ◽  
Liangliang Ma ◽  
Rupeng Zhu ◽  
Xizhi Ma
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Vibration Characteristics ◽  
Rotor System ◽  
Experimental Investigations ◽  
Flexible Rotor ◽  
Bending Vibration ◽  
First Order ◽  
Element Simulation

In this study, we evaluated the effect of changing supports’ position on the vibration characteristics of a three-support flexible rotor shafting. This dependency was first analyzed using a finite element simulation and then backed up with experimental investigations. By computing a simplified rotor shafting model, we found that the first-order bending vibration in a forward whirl mode is the most relevant deforming mode. Hence, the effect of the supports’ positions on this vibration was intensively investigated using simulations and verified experimentally with a house-made shafting rotor system. The results demonstrated that the interaction between different supports can influence the overall vibration deformation and that the position of the support closer to the rotor has the greatest influence.

A Virtual Bearing Method for Optimal Bearing Placement of Flexible Rotor Systems

2017 ◽  
Author(s):  
Shibing Liu ◽  
Bingen Yang
Keyword(s):  
Optimization Problem ◽  
Optimization Method ◽  
Rotor System ◽  
Problem Solution ◽  
Flexible Rotor ◽  
Rotor Systems ◽  
Real Coded Genetic Algorithm ◽  
Minimum Number ◽  
Distributed Transfer Function ◽  
Flexible Rotor Systems

Flexible multistage rotor systems have a variety of engineering applications. Vibration optimization is important to the improvement of performance and reliability for this type of rotor systems. Filling a technical gap in the literature, this paper presents a virtual bearing method for optimal bearing placement that minimizes the vibration amplitude of a flexible rotor system with a minimum number of bearings. In the development, a distributed transfer function formulation is used to define the optimization problem. Solution of the optimization problem by a real-coded genetic algorithm yields the locations and dynamic coefficients of bearings, by which the prescribed operational requirements for the rotor system are satisfied. A numerical example shows that the proposed optimization method is efficient and accurate, and is useful in preliminary design of a new rotor system with the number of bearings unforeknown.

Optimization of Nonlinear Unbalanced Flexible Rotating Shaft Passing Through Critical Speeds

2021 ◽  
Author(s):  
Sadegh Amirzadegan ◽  
Mohammad Rokn-Abadi ◽  
R. D. Firouz-Abadi
Keyword(s):  
Degrees Of Freedom ◽  
Nonlinear Oscillations ◽  
Nonlinear Differential Equations ◽  
Equations Of Motion ◽  
Angular Acceleration ◽  
Beam Theory ◽  
Rotor System ◽  
Rotating Shaft ◽  
Critical Speeds ◽  
Applied Torque

This work studies the nonlinear oscillations of an elastic rotating shaft with acceleration to pass through the critical speeds. A mathematical model incorporating the Von-Karman higher-order deformations in bending is developed to investigate the nonlinear dynamics of rotors. A flexible shaft on flexible bearings with springs and dampers is considered as rotor system for this work. The shaft is modeled as a beam and the Euler–Bernoulli beam theory is applied. The kinetic and strain energies of the rotor system are derived and Lagrange method is then applied to obtain the coupled nonlinear differential equations of motion for 6 degrees of freedom. In order to solve these equations numerically, the finite element method (FEM) is used. Furthermore, for different bearing properties, rotor responses are examined and curves of passing through critical speeds with angular acceleration due to applied torque are plotted. Then the optimal values of bearing stiffness and damping are calculated to achieve the minimum vibration amplitude, which causes to pass easier through critical speeds. It is concluded that the value of damping and stiffness of bearing change the rotor critical speeds and also significantly affect the dynamic behavior of the rotor system. These effects are also presented graphically and discussed.

Research of Strength of Rotor System about Containing Blade Crackle Based on Nonlinear Dynamics

2010 ◽  
Vol 44-47 ◽  
pp. 1158-1162
Author(s):  
Xiao Bo Liu ◽  
Kai Qin Li
Keyword(s):  
Nonlinear Dynamics ◽  
Stress Distribution ◽  
Rotor System ◽  
Ansys Software ◽  
Rotating Shaft ◽  
Alloy Material ◽  
Interior Stress ◽  
Nonlinear Dynamics Model ◽  
Nonlinear Dynamic Stability ◽  
Intensity Stress

As the condition of a certain blade cracked of rotor system of fans, limited short-axletree nonlinear dynamics model is used ,the vibration frequency and nonlinear dynamic stability single-disc rotor is discussed, interior stress distribution and size of rotating shaft after loaded is analyzed concretely by ANSYS software. Through contrast X, Y, X-Y three directions stress distribution of rotating shaft interior, for entity model of near support disc and shaft, it is observed that its field of stress distribution compare dense is near--support field，also stress concentration is relatively bigger after load is added. Meanwhile ANSYS software is used to calculate by simulation this relation of the blade cracking spread width-temporal of four different alloy material and to count the intensity、stress distributing and the axial displacement of the axletree. The best numerical value about elastic modulus and hardness of the material is found by analysis the curve of crackle width- time function.

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