scholarly journals Study on the Coupled Vibration Characteristics of a Two-Stage Bladed Disk Rotor System

2021 ◽  
Vol 11 (18) ◽  
pp. 8600
Author(s):  
Yinxin Yu ◽  
Xiaolong Jin ◽  
Yanming Fu ◽  
Tianyu Zhao
Keyword(s):  
Rotor System ◽  
The Finite Element Method ◽  
Coupled Vibration ◽  
Coupled Modes ◽  
Two Stage ◽  
Second Stage ◽  
Bladed Disk ◽  
Modal Synthesis ◽  
Fixed Interface ◽  
Element Method

This paper conducts a coupled vibration analysis of a two-stage bladed disk rotor system. According to the finite element method, the bladed disk rotor system is established. The substructure modal synthesis super-element method (SMSM) with a fixed interface and free interface is presented to obtain the vibration behaviors of the rotor system. Then, the free vibration results are compared with the ones calculated by the cyclic symmetry analysis method to validate the analysis in this paper. The results show that the modes of the two-stage bladed disk not only include the modes of the first- and second-stage bladed disk, but also the coupled modes of the two-stage bladed disk.

scholarly journals A Finite Element Approach to the Analysis of Rotating Bladed-Disk Assemblies Coupled With Flexible Shaft

1994 ◽  
Author(s):  
Wen Zhang ◽  
Wenliang Wang ◽  
Hao Wang ◽  
Jiong Tang
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Coupled System ◽  
Equation Of Motion ◽  
Coupled Systems ◽  
The Finite Element Method ◽  
Bladed Disk ◽  
Modal Synthesis ◽  
Element Approach ◽  
Final Equation

A method for dynamic analysis of flexible bladed-disk/shaft coupled systems is presented in this paper. Being independant substructures first, the rigid-disk/shaft and each of the bladed-disk assemblies are analyzed separately in a centrifugal force field by means of the finite element method. Then through a modal synthesis approach the equation of motion for the integral system is derived. In the vibration analysis of the rotating bladed-disk substructure, the geometrically nonlinear deformation is taken into account and the rotationally periodic symmetry is utilized to condense the degrees of freedom into one sector. The final equation of motion for the coupled system involves the degrees of freedom of the shaft and those of only one sector of each of the bladed-disks, thereby reducing the computer storage. Some computational and experimental results are given.

scholarly journals Dynamic Characteristics of Blade-Disk-Rotor System with Structural Mistuned Features

2014 ◽  
Vol 8 (1) ◽  
pp. 138-143 ◽  
Author(s):  
Chaofeng Li ◽  
Shihua Zhou ◽  
Shuhua Yang ◽  
Xiang Ren ◽  
Bangchun Wen
Keyword(s):  
Dynamic Characteristics ◽  
Rotor System ◽  
Frequency Separation ◽  
The Finite Element Method ◽  
Dynamical Models ◽  
Local Vibration ◽  
Disk Model ◽  
Bladed Disk ◽  
System Mode ◽  
Different Levels

The finite element method is adopted to establish the dynamical models of blade, bladed disk and blades-diskshaft assemblies. Based on the analysis of mistuned structure and the dynamic characteristics of model in different levels, it gives the vibration mode distribution of different models. The research shows that the characteristics of the bladed disk and shaft have a huge difference, where some modes are caused by the strongly split and coupled vibration. The mistuned effects are likely to cause different coupled vibrations of blades between the blades-disk model and the blades-disk-shaft model. Meanwhile, it shows the frequency separation and concentration, and misses the system mode and the local vibration, which bring some difficulties for designing the blade-rotor system. In this paper, the results may provide a certain reference for blade-rotor system design and diagnosis.

Theoretical and Numerical Modal Analysis for Nuclear Coolant Pump and its Scaled Rotor System

2010 ◽  
Vol 44-47 ◽  
pp. 985-991
Author(s):  
Chun Ming Gong ◽  
Hong Shen ◽  
Zheng Qiang Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Theoretical Method ◽  
Rotor System ◽  
The Finite Element Method ◽  
Coolant Pump ◽  
Similarity Law ◽  
Nuclear Coolant ◽  
Element Method

This paper presents a theoretical transfer matrix method for the modal analysis of nuclear coolant pump, and base on certain similarity law, a scaled rotor system is designed so as to simulate the characteristics of the real nuclear coolant pump, especially the vibration characteristics. Following that, the finite element method is used to verify the accuracy of the above theoretical method since there are a few simplifications in theoretical method compared with the finite element method. Finally the natural vibration frequencies and vibration modes of both nuclear coolant pump and the designed scaled rotor system are attained, which have high similarity with each other, and which confirm the accuracy of the two methods that are used in this article.

Experimental Study of Torsional-Bending Coupled Vibration of a Rotor System With a Bladed Disk

2013 ◽  
Author(s):  
Takeshi Kudo ◽  
Koki Shiohata ◽  
Osami Matsushita ◽  
Hiroyuki Fujiwara ◽  
Akira Okabe ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Torsional Vibration ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Coupled Vibration ◽  
Bending Vibration ◽  
Nodal Diameter ◽  
Rotor Systems ◽  
Bladed Disk

An experimental investigation was conducted to confirm the bending-torsion coupled vibration of a rotor system with a bladed disk. For a rotor with relatively long blades such as in the latest low-pressure steam turbines, coupled vibration with shaft torsional vibration represents the bladed disk natural frequency of a nodal diameter (k) of zero (umbrella mode). Today this well-known behavior is reflected in the design of steam turbine rotor systems to prevent the blade vibration resonance due to torque excitation caused by the electric power grid, a standard for which is proposed by ISO 22266-1. The bending-torsion coupled resonance of rotor systems occurs, however, under specific conditions due to rotor unbalance. When the rotor’s rotational speed (Ω) is equal to the sum/difference of the bending natural frequency (ωb) and torsional natural frequency (ωθ), namely, Ω = ωθ ± ωb, there is coupled resonance, which was experimentally observed with a rotor with a relatively simplified shape. In this study, the test apparatus for a flexible rotor system equipped with a shrouded bladed disk driven by an electric motor was constructed to confirm the vibration characteristics, by envisioning the bending-torsion coupled resonance as applied to actual rotor systems of turbo machinery. A radial active magnetic bearing (AMB) was employed to support the rotor by controlling bearing stiffness and damping, and applying lateral directional excitation of forward and backward whirl to the rotor. A servomotor was also equipped at the end of the rotor system to excite the torsional vibration. The resonance of a bladed disk with nodal diameter (k) of zero, which was coupled with the rotor’s torsional vibration, was observed under the above condition (Ω = ωθ − ωb) through AMB excitation of the rotor’s bending natural frequency. Conversely, the torsional excitation caused by the servomotor was confirmed as causing the coupled resonance of rotor bending vibration.

Research on Dynamic Characteristics of Bladed Disk System by Fixed Interface Prestressed-Free Interface CMS Super-Element Method

2015 ◽  
Vol 724 ◽  
pp. 218-221
Author(s):  
Liang Zhang ◽  
Xin Li ◽  
Tie Jian Liu
Keyword(s):  
Dynamic Characteristics ◽  
Complex Structure ◽  
Maximum Relative Error ◽  
Disk System ◽  
Free Interface ◽  
Bladed Disk ◽  
Substructure Analysis ◽  
Characteristics Analysis ◽  
Fixed Interface ◽  
Element Method

For the prestressed substructure analysis, the existing CMS super-element methods are only suitable for the model that relatively simple structure, less meshing and small number of nodes. Since the complex structure and more mesh division of an arbitrary large model such as a mistuned bladed disk system, it is more time-consuming for the dynamic characteristics analysis. Because of above shortcoming, an approximate analysis method is presented, it is called fixed interface prestressed-free interface CMS super-element method. The accuracy of this method is predicted by the example. The results showed that the dimensionless dynamic frequency maximum relative error of system is 3.072215%, which can be to meet the requirement of accuracy.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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