A Numerical Method for the Dynamic Analysis of Rotating Flexible Blade-Disc-Shaft Assemblies

1995 ◽  
Author(s):  
Georges Jacquet-Richardet ◽  
Guy Ferraris ◽  
Pierre Rieutord
Keyword(s):  
Finite Element Analysis ◽  
Numerical Method ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Rotating System ◽  
Dynamic Interactions ◽  
Element Analysis ◽  
Modal Reduction ◽  
Rotating Shafts

Abstract A numerical method is proposed to compute the natural frequencies and mode shapes of rotating flexible blade-disc-shaft assemblies The formulation is based on a modal finite element analysis of the rotating system. The mode shapes used for the modal reduction are those associated to the global non-rotating undamped structure. To compute these modes, the size of the problem is reduced using both wave propagation and component mode techniques. An application is presented. The results obtained show that the chosen reductions do not reduce the quality of the model and illustrate its capability to deal with rotating shafts usually calculated using the rotordynamic approach. Finally, the possible dynamic interactions between shaft and disc components are described.

scholarly journals Numerical Analysis of Rotating Flexible Blade-Disk-Shaft Systems

1999 ◽  
Author(s):  
O. Repetski ◽  
I. Rygikov ◽  
H. Springer
Keyword(s):  
Machine Building ◽  
Structural Components ◽  
Dynamic Interactions ◽  
Element Analysis ◽  
Bladed Disk ◽  
Modal Reduction ◽  
Shaft Flexibility ◽  
Rotating Shafts ◽  
And Shifts

The theory, the algorithms and program package BLADIS (BLAded DIsk Simulation) for strength calculations of rotating flexible blade-disk-shaft assemblies have been worked out. The formulation is based on a finite element analysis of the rotating cyclic structures and modal reduction. The stresses in different zones of the structural components due to influence of centrifugal and temperature forces using static analysis and vibration are calculated. The results obtained show, how shaft flexibility influence on stresses and frequencies. Analysis of influence of blade geometric parameters on disk-shaft stresses is presented. The results obtained by dynamic analysis show that the chosen reduction does not reduce the quality of the model and illustrate its capability to deal with rotating shafts usually calculated using the rotordynamic approach. Finally, the possible dynamic interactions between shaft and disk components are described. This information is used for bladed disks and rotors optimization leading to a reduction of resonance displacements, stress levels and shifts of natural frequencies of rotating flexible blade-disk-shaft assemblies from dangerous resonances. The numerical results are carried in leading machine building companies in Russia.

scholarly journals Rapid Evaluation for Position-Dependent Dynamics of a 3-DOF PKM Module

2014 ◽  
Vol 6 ◽  
pp. 238928 ◽  
Author(s):  
Hai-wei Luo ◽  
Hui Wang ◽  
Jun Zhang ◽  
Qi Li
Keyword(s):  
Natural Frequencies ◽  
Mode Shapes ◽  
Parallel Kinematic Machine ◽  
Computationally Efficient ◽  
Element Analysis ◽  
Reduction Techniques ◽  
Modal Reduction ◽  
Governing Differential Equation ◽  
Parallel Kinematic ◽  
Analytical System

Based on the substructure synthesis and modal reduction technique, a computationally efficient elastodynamic model for a fully flexible 3-RPS parallel kinematic machine (PKM) tool is proposed, in which the frequency response function (FRF) at the end of the tool can be obtained at any given position throughout its workspace. In the proposed elastodynamic model, the whole system is divided into a moving platform subsystem and three identical RPS limb subsystems, in which all joint compliances are included. The spherical joint and the revolute joint are treated as lumped virtual springs with equal stiffness; the platform is treated as a rigid body and the RPS limbs are modelled with modal reduction techniques. With the compatibility conditions at interfaces between the limbs and the platform, an analytical system governing differential equation is derived. Based on the derived model, the position-dependent dynamic characteristics such as natural frequencies, mode shapes, and FRFs of the 3-RPS PKM are simulated. The simulation results indicate that the distributions of natural frequencies throughout the workspace are strongly dependant on mechanism's configurations and demonstrate an axial-symmetric tendency. The following finite element analysis and modal tests both validate the analytical results of natural frequencies, mode shapes, and the FRFs.

Investigation of stiffness of small wind turbine blade based on vibration analysis technique

2019 ◽  
Vol 44 (1) ◽  
pp. 49-59
Author(s):  
Nilesh Chandgude ◽  
Nitin Gadhave ◽  
Ganesh Taware ◽  
Nitin Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Element Analysis ◽  
Finite Element Software ◽  
Small Wind Turbine

In this article, three small wind turbine blades of different materials were manufactured. Finite element analysis was carried out using finite element software ANSYS 14.5 on modeled blades of National Advisory Committee for Aeronautics 4412 airfoil profile. From finite element analysis, first, two flap-wise natural frequencies and mode shapes of three different blades are obtained. Experimental vibration analysis of manufactured blades was carried out using fast Fourier transform analyzer to find the first two flap-wise natural frequencies. Finally, the results obtained from the finite element analysis and experimental test of three blades are compared. Based on vibration analysis, we found that the natural frequency of glass fiber reinforced plastic blade reinforced with aluminum sheet metal (small) strips increases compared with the remaining blades. An increase in the natural frequency indicates an increase in the stiffness of blade.

Free Vibration Analysis of PZT Glide Heads

1999 ◽  
Vol 121 (4) ◽  
pp. 984-988 ◽  
Author(s):  
Alex Y. Tsay ◽  
Jin-Hui Ouyang ◽  
C.-P. Roger Ku ◽  
I. Y. Shen ◽  
David Kuo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Laser Doppler Vibrometer ◽  
Free Vibration Analysis ◽  
Mode Shapes ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Bonding Length ◽  
Measured Displacement

This paper studies natural frequencies and mode shapes of a glide head with a piezoelectric transducer (PZT) through calibrated experiments and a finite element analysis. In the experiments, the PZT transducer served as an actuator exciting the glide head from 100 kHz to 1.3 MHz, and a laser Doppler vibrometer (LDV) measured displacement of the glide head at the inner or outer rail. The natural frequencies were measured through PZT impedance and frequency response functions from PZT to LDV. In the finite element analysis, the glide head was meshed by brick elements. The finite element results show that there are two types of vibration modes: slider modes and PZT modes. Only the slider modes are important to glide head applications. Moreover, natural frequencies predicted from the finite element analysis agree well with the experimental results within 5% of error. Finally, the finite element analysis identifies four critical slider dimensions whose tolerance will significantly vary the natural frequencies: PZT bonding length, wing thickness, slider thickness, and air bearing recess depth.

Modal Analysis of the Cabinet of a Drum Washing Machine

2011 ◽  
Vol 199-200 ◽  
pp. 1126-1129
Author(s):  
Su Fang Fu ◽  
Han Gao ◽  
Jia Xi Du ◽  
Qiu Ju Zhang ◽  
Xue Ming Zhang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Ansys Software ◽  
Washing Machine ◽  
Element Analysis ◽  
The Finite Element Model ◽  
Good Agreement

In this paper, the finite element model for the cabinet of a drum washing machine and the model for testing vibration of the cabinet were developed in ANSYS software and PULSE™, respectively. A series of tests were conducted. The natural frequencies and mode shapes were obtained by finite element analysis and modal experiment, which revealed weak parts of the cabinet. Meanwhile, the computational modes were in good agreement with experimental ones and this could provide an available method by which it was convenient to improve the design of the cabinet.

The Vibration Characteristics of a Large Flexible Vibration Isolation Structure with Finite Element Analysis and Modal Test

2011 ◽  
Vol 199-200 ◽  
pp. 858-864 ◽  
Author(s):  
Liu Bin Zhou ◽  
Tie Jun Yang ◽  
Wan Peng Yuan ◽  
Hui Shi ◽  
Zhi Gang Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Isolation ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Element Analysis ◽  
Modal Test ◽  
The Finite Element Analysis

A large flexible vibration isolation structure is presented in this thesis, and experimental modal test based on the finite element analysis is carried out in order to find out the vibration characteristics of it. Results show that the natural frequencies and mode shapes calculated by finite element method basically conform to those measured from experimental modal test. Some suggestion to vibration active control in further research is also provided.

Finite Element Analysis of the Lateral Vibration of Thin Annular and Circular Plates With Variable Thickness

1998 ◽  
Vol 120 (3) ◽  
pp. 747-752 ◽  
Author(s):  
Dian-Yun Chen ◽  
Bao-Sheng Ren
Keyword(s):  
Finite Element Analysis ◽  
Variable Thickness ◽  
Natural Frequencies ◽  
Plate Thickness ◽  
Mode Shapes ◽  
Lateral Vibration ◽  
Circular Plates ◽  
Element Analysis ◽  
Numerical Convergence ◽  
Polar Orthotropic

The method of annular finite elements with variable thickness is applied for analyzing the lateral vibration of thin annular and circular plates. The material of the plates may be of isotropic or polar orthotropic and the plate thickness may vary arbitrarily with the radius. Natural frequencies and mode shapes of the axisymmetric and nonaxi-symmetric modes are obtained. The numerical convergence of the method has been tested and comparisons have been made with the results obtained in other studies. It has been proved that the convergence of this method is very rapid and obtained results are very accurate.

scholarly journals Modal Analysis of Optimized Trapezoidal Stiffened Plates under Lateral Pressure and Uniaxial Compression

2021 ◽  
Vol 2 (4) ◽  
pp. 681-693
Author(s):  
Zoltán Virág ◽  
Sándor Szirbik
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Uniaxial Compression ◽  
Natural Frequencies ◽  
Lateral Pressure ◽  
Mode Shapes ◽  
Stiffened Plates ◽  
Elastic Model ◽  
Element Analysis

This paper deals with the modal analysis of optimized trapezoidal stiffened plates with simple supported conditions on the four edges of the base plate. The main objective of the finite element analysis is to investigate the natural frequencies and mode shapes of some stiffened structures subjected to lateral pressure and uniaxial compression in order to identify any potentially dangerous frequencies and eliminate the failure possibilities. The natural frequencies and mode shapes are important parameters in the design of stiffened plates for dynamic loading conditions. In this study, the numerical analysis is performed for such a design of this kind of welded plates which have already been optimized for lateral pressure and uniaxial compression. The objective function of the optimization to be minimized performed with the Excel Solver program is the cost function which contains material and fabrication costs for Gas Metal Arc Welding (GMAW) welding technology. In this study, the eigenvalue extraction used to calculate the natural frequencies and mode shapes is based on the Lanczos iteration methods using the Abaqus software. The structure is made of two grades of steel, which are described with different yield stress while all other material properties of the steels in the isotropic elastic model remain the same. Drawing the conclusion from finite element analysis, this circumstance greatly affects the result.

Finite Element Analysis of Crystal Furnace Based on ANSYS Workbench

2013 ◽  
Vol 842 ◽  
pp. 427-432
Author(s):  
Bing Yuan ◽  
Yun Xia Liu ◽  
Jun Liang Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimization Design ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Sapphire Crystal ◽  
Analysis Software ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Ansys Workbench

In this paper, the sapphire crystal furnace is taken as the object of research. Based on the finite element analysis software ANSYS Workbench, static and modal analysis of the key parts of the crystal furnace are completed, the static and dynamic characteristics of the parts are studied, and the natural frequencies and the mode shapes of the key parts are obtained. According to the analysis of each mode type of the vibration, the weaknesses of the structure are identified, which provides theory reference for the structure optimization design of crystal furnace.

Sign in / Sign up

Export Citation Format

Share Document