An assumed mode method and finite element method investigation of the coupled vibration in a flexible-disk rotor system with lacing wires

2017 ◽  
Vol 31 (2) ◽  
pp. 577-586 ◽  
Author(s):  
Shui-Ting Zhou ◽  
Yi-Jui Chiu ◽  
Guo-Fei Yu ◽  
Chia-Hao Yang ◽  
Hong-Wu Huang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rotor System ◽  
Coupled Vibration ◽  
Assumed Mode Method ◽  
Mode Method ◽  
Flexible Disk ◽  
Assumed Mode ◽  
Element Method

The Discretization Methods of a Rotating Flexible Cantilever Beam

2012 ◽  
Vol 226-228 ◽  
pp. 697-707
Author(s):  
Ji Hua Fan ◽  
Ding Guo Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cantilever Beam ◽  
Interpolation Method ◽  
Flexible Beam ◽  
Transverse Deformation ◽  
Longitudinal Deformation ◽  
Assumed Mode Method ◽  
Mode Method ◽  
Assumed Mode

The dynamics of a rotating flexible cantilever beam is investigated by using assumed mode method, finite element method and Bezier curve interpolation method in this paper. The longitudinal deformation and the transverse deformation of the flexible beam are considered and the coupling term of the deformation which is caused by transverse deformation is included in the expression of longitudinal deformation. The assumed mode, finite element and Bezier interpolation are used to discretize the deformation of the flexible beam, and then the dynamics equations are built by Lagrange equation, and a software package for the dynamic simulation of the rotating cantilever beam is developed. Two cases are considered in the simulations. One is the dynamics study which the external rotating torque is known, another one is that a rotating fixed axis flexible beam falls with gravity. According to the simulation results, assumed mode, finite element and Bezier interpolation method can be well used for discretizing the deformation of the flexible beam; the computational efficiency of finite element method is the lowest, and Bezier interpolation method is the highest; the calculation accuracy of the assumed mode method is lower than the Bezier interpolation method.

Squeal Analysis of a Disc Brake Considering Damping between a Disc and a Pad Lining

2012 ◽  
Vol 157-158 ◽  
pp. 1000-1003
Author(s):  
Ke Wei Zhou ◽  
Cheol Kim ◽  
Min Ok Yun ◽  
Ju Young Kim
Keyword(s):  
Finite Element ◽  
Equations Of Motion ◽  
Element Model ◽  
Disc Brake ◽  
Vibration Modes ◽  
Assumed Mode Method ◽  
Frictional Damping ◽  
System Components ◽  
Mode Method ◽  
Assumed Mode

The improved equations of motion for a friction-engaged brake system have been newly derived on the basis of the assumed mode method and frictional damping. The equations of motion with a finite element model were constructed by a set of vibration modes found from FE modal analysis on all system components. Consequently, the modal information of system components are combined with equations of motion derived from the analytical model. Numerical analysis showed the mode which was unstable in an undamped case became stable in a damped case.

Coupled Vibration Analysis of Vehicle-Bridge System for Yujiang River Bridge on Nanning-Guangzhou Railway Line

2011 ◽  
Vol 255-260 ◽  
pp. 1790-1794
Author(s):  
De Shan Shan ◽  
Shen Gai Cui
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
System Dynamics ◽  
Vibration Analysis ◽  
Coupled Vibration ◽  
Railway Line ◽  
Cable Stayed Bridge ◽  
Set Up ◽  
Bridge System ◽  
Element Method

Taking Yujiang River Bridge on Nanning-Guangzhou railway line as study background, the refined numerical simulation model of whole vehicle and whole bridge system for coupled vibration analysis is set up. The dynamic analysis model of the cable-stayed bridge is established by finite element method, and the natural vibration properties of the bridge are analyzed. The German ICE Electric Multiple Unit (EMU) train refined three-dimensional space vehicle model is set up by multi-system dynamics software SIMPACK, and the multiple non-linear properties are considered. The space vibration responses are calculated by co-simulation based on multi-body system dynamics and finite element method when the ICE EMU train passes the long span cable-stayed bridge at different speeds. In order to test if the bridge has the sufficient lateral or vertical rigidity and the operation stability is fine. The calculation results show: The operation safety can be guaranteed, and comfort index is “excellent”. The bridge has sufficient rigidity, and vibration is in good condition.

Complex Modal Analysis of a Non-Modally Damped Continuous Beam

2013 ◽  
Author(s):  
Xing Xing ◽  
Brian F. Feeny
Keyword(s):  
Finite Element ◽  
Eigenvalue Problem ◽  
Separation Of Variables ◽  
Mode Shapes ◽  
Modal Assurance Criterion ◽  
Assumed Mode Method ◽  
State Variable ◽  
Mode Method ◽  
Cantilevered Beam ◽  
Assumed Mode

This work represents an investigation of the complex modes of continuous vibration systems with nonmodal damping. As an example, a cantilevered beam with damping at the free end is studied. Traditional separation of variables for this problem leads to a differential eigenvalue problem which requires a numerical solution. In this paper, assumed modes are applied to discretize the eigenvalue problem in state-variable form, to then obtain estimates of the frequencies and modes. The finite-element method (FEM) is also utilized to get the mass, stiffness, and damping matrices and further to solve a state-variable eigenproblem. A comparison between the assumed-mode and finite-element eigenvalues and modal vectors shows that the methods produce consistent results. The comparison of the modes was done visually and also by using the modal assurance criterion (MAC) on the modal vectors. The assumed-mode method is then used to study the effects of the damping coefficient on mode shapes and modal damping.

Simplified dynamic analysis of stepped thickness rectangular plate structures by the assumed mode method

2016 ◽  
Vol 231 (1) ◽  
pp. 177-187
Author(s):  
Dae-Seung Cho ◽  
Byung Hee Kim ◽  
Jin-Hyeong Kim ◽  
Nikola Vladimir ◽  
Tae-Muk Choi
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Dynamic Analysis ◽  
Rectangular Plate ◽  
Forced Response ◽  
Plate Structures ◽  
Assumed Mode Method ◽  
Frequency Responses ◽  
Mode Method ◽  
Assumed Mode

In this article, the assumed mode method is applied to simplified dynamic analysis of stepped thickness rectangular Mindlin plates and stiffened panels with arbitrary boundary conditions. The natural and frequency responses of stepped thickness plate structures subjected to harmonic point excitation force and enforced acceleration at boundaries, respectively, are considered. Potential and kinetic energies of the system are formulated and used to derive eigenvalue problem utilizing Lagrange’s equation of motion, and mode superposition method is further used for forced response assessment. Characteristic orthogonal polynomials having the property of Timoshenko beam functions are used for the assumed modes. Numerical examples analysing vibration of stepped thickness plate structures with different topologies and various sets of boundary conditions are provided. Numerical results are compared with the results from the relevant literature and finite element solutions obtained by a general finite element tool, and a very good agreement is achieved. Hence, it is expected that stepped rectangular plate structures satisfying the prescribed criteria regarding natural and frequency responses can be efficiently designed based on the proposed method.

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