scholarly journals Determination of Natural Frequency and Mode Shape for Hollow Thin Plates

2019 ◽  
Vol 9 (1) ◽  
pp. 2601-2606
Keyword(s):  
Finite Element ◽  
Resonance Frequency ◽  
Natural Frequency ◽  
Thin Plate ◽  
Mode Shape ◽  
Hollow Structure ◽  
Thin Plates ◽  
Mode Behavior ◽  
Analysis Experiment

The determination of natural frequency and the mode shape of structures are important in characterizing the properties or behavior of the structures. The existing hollow in solid thin plate will change the vibration behavior in term of resonance frequency and mode behavior. A lot of structure consists of hollow space such as inner panel of car hood and bonnet. However, simplifying the model from hollow structure with solid thin plates only will resulting some difference in their vibration performance. This study begins with conducting modal analysis experiment using solid thin plate under free-free boundary condition. Next, the finite element methods were performing to compare with the experimental results. The average error of 3.96% was obtain when compared which provide a good confident level with the simulation result. Next, the study continued by finding the natural frequency and the mode shape for the thin plate under various position of hole, number of holes and shape of hole by using FEM software. Finally, finite element was also being carried out on the simplified design model of the inner panel car hood based from the real product and compared the resonance frequency from the model with some vibration reference sources. Through this study, it is found that the diversity of the hole position, the increasing number of holes and the change of the hole shape play a role in changing the natural frequencies of a thin plate. Since there is a lot of hollow thin plates in the car part, designing every parts are important to make sure the NVH quality is improve and not opposite of it.

Numerical Study for Global Detection of Cracks Embedded in Beams

1999 ◽  
Author(s):  
S. A. Lipsey ◽  
Y. W. Kwon
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Natural Frequency ◽  
Mode Shape ◽  
Numerical Study ◽  
Element Model ◽  
Mode Shapes ◽  
Linear Effect ◽  
Modes Of Vibration ◽  
Damage Simulation

Abstract Damage reduces the flexural stiffness of a structure, thereby altering its dynamic response, specifically the natural frequency, damping values, and the mode shapes associated with each natural frequency. Considerable effort has been put into obtaining a correlation between the changes in these parameters and the location and amount of the damage in beam structures. Most numerical research employed elements with reduced beam dimensions or material properties such as modulus of elasticity to simulate damage in the beam. This approach to damage simulation neglects the non-linear effect that a crack has on the different modes of vibration and their corresponding natural frequencies. In this paper, finite element modeling techniques are utilized to directly represent an embedded crack. The results of the dynamic analysis are then compared to the results of the dynamic analysis of the reduced modulus finite element model. Different modal parameters including both mode shape displacement and mode shape curvature are investigated to determine the most sensitive indicator of damage and its location.

Finite Element Resonance Analysis of the Complex Structure of a Crosscut Saw Machine

2020 ◽  
Vol 70 (1) ◽  
pp. 100-106
Author(s):  
Wei-long Chen ◽  
Fang-lin Chao ◽  
Yu-hui Lin
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Mode Shape ◽  
Complex Structure ◽  
The Finite Element Method ◽  
Wood Processing ◽  
Resonance Analysis ◽  
Maximum Value ◽  
Improved Design ◽  
Saw Marks

Abstract A crosscut saw machine must be tuned to eliminate abnormal sawing marks or skewing during rapid wood processing. Once a wooden board is placed in the feed port, it is clamped and stabilized by a roller. However, the vibration amplification of the structure still causes the relative position of the blade to change and leads to the problem of saw marks on the wood surface. This article optimizes a saw machine by modal analysis based on the finite element method. The redesigned machine was compared to the original for natural frequency and mode shape. The analysis results revealed that at 31.43 Hz, stress reached the maximum value of 383.24 MPa on the frame of an alternating current motor. The mode shape showed significant deformation of the roller frame. By applying ribs on the chassis frame, vertical bending and torsion were reduced. The frequency of the sixth mode of the original machine was 43.9 Hz, which increased to 52.9 Hz after the redesign. The results showed that this was due to the addition of the ribs. A clamping roller was able to mitigate the vibration through the +y and z directions. The natural frequency of the modality was significantly improved through rib-enforced design. The structure of the improved design exhibited improvement compared to the original machine.

A Universal Finite Element of Thick and Thin Plate without Shear Locking

2011 ◽  
Vol 52-54 ◽  
pp. 1353-1357
Author(s):  
Shu Qiang Yu ◽  
Ming Zhang ◽  
Lu Lu Fan
Keyword(s):  
Finite Element ◽  
Thin Plate ◽  
Plate Thickness ◽  
High Accuracy ◽  
Thin Plates ◽  
Deep Beam ◽  
Computational Results ◽  
Shear Locking ◽  
Plate Element ◽  
Universal Element

In order to prevent shear locking, a method using theory of deep beam is proposed. A universal finite element for thick and thin plates is constructed. When the plate thickness approaches to the limit of thin plate, the universal element degenerates to the thin plate element automatically. As a results, the shear locking phenomenon will not appear. The computational results indicate that the current element has high-accuracy and good usefulness.

The Research of Drive Roll’s Dynamics Characteristics

2014 ◽  
Vol 597 ◽  
pp. 498-501
Author(s):  
Shao Hai Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Mode Shape ◽  
Vibration Mode ◽  
Element Model ◽  
Set Up ◽  
Drive Roll ◽  
Ansys Workbench

In order to research the dynamic characteristics of drive roll, finite element model of the drive roll was set up by ANSYS/Workbench. The drive roll’s natural frequency and vibration mode concerned in reality were acquired based on modal analysis, deformation trend and size of each mode shape were analysed, then deformation of the weak positions about each mode was cleared, and some measures about improving its dynamic characteristics were proposed, all of these offered a support to strengthen drive roll’s damping property.

The Application of Multiple Vibration Neutralizers for Vibration Control in Aircraft

2014 ◽  
Vol 629 ◽  
pp. 191-196 ◽  
Author(s):  
Izzuddin Zaman ◽  
Muhammad Mohamed Salleh ◽  
Bukhari Manshoor ◽  
Amir Khalid ◽  
Sherif Araby
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Control ◽  
Natural Frequency ◽  
Thin Plate ◽  
Mode Shapes ◽  
Modern Trend ◽  
Small Scale ◽  
Element Analysis ◽  
Structural Dynamic

A current challenge for researchers is the design and implementation of an effective vibration control method that reduces vibration transmission from vehicle structures such as aircraft. This challenge has arisen due to the modern trend of utilizing lightweight thin panels in aircraft structural design, which have the potential to contribute towards significant vibration in the structures. In order to reduce structural vibration, one of the common approaches is considering vibration neutralizer system attached to the structure. In this study, a vibration neutralizer is developed in a small scale size. The effectiveness of attached vibration neutralizers on a thin plate are investigated through experimental study. Prior to the experiment, a finite element analysis of Solidworks® and analytical modelling of Matlab® are produced in order to determine the structural dynamic response of the thin plate such as the natural frequency and mode shapes. The preliminary results of finite element analysis demonstrate that the first four natural frequency of clamped plate are 48Hz, 121Hz, 194Hz and 242Hz, and these results are in agreement with the plate’s analytical equations. However, there are slight discrepancies in the experiment result due to noise and error occurred during the set up. In the later stage, the experimental works of thin plate are performed with attached vibration neutralizer. Result shows that the attachment of vibration neutralizer produces better outcome, which is about 41% vibration reduction. It is expected that by adding more vibration neutralizer to the structure, the vibration attenuation of thin plate can be significant.

On Improved Thin Plate Bending Rectangular Finite Element Based on the Strain Approach

2016 ◽  
Vol 27 ◽  
pp. 76-86 ◽  
Author(s):  
Sifeddine Abderrahmani ◽  
Toufik Maalem ◽  
Djamal Hamadi
Keyword(s):  
Finite Element ◽  
Thin Plate ◽  
Degrees Of Freedom ◽  
Body Motion ◽  
Thin Plates ◽  
Elastic Behavior ◽  
Transverse Displacement ◽  
Plate Bending ◽  
Linear Elastic ◽  
Thin Plate Bending

We propose in this paper the development of a new rectangular finite element for thin plate bending based on the strain approach with linear elastic behavior. An analytical integration is used to evaluate the element stiffness matrix. The present element possesses the three main degrees of freedom (d.o.f) per node, namely, one transverse displacement (w) and two normal rotations about x and y axis respectively (Ɵx, Ɵy). The proposed displacement field represents exactly the rigid body motion and satisfies the compatibility equations. The numerical results converges rapidly to the Kirchhoff solution for thin plates, this makes the present element robust, better suitable for computations, and particularly interesting in modeling this type of structures.

Transverse Flexure of a Semi-Infinite Thin Plate Containing an Infinite Row of Circular Holes

1959 ◽  
Vol 26 (4) ◽  
pp. 661-665
Author(s):  
O. Tamate
Keyword(s):  
Thin Plate ◽  
Infinite Plate ◽  
Mutual Interference ◽  
Thin Plates ◽  
Bending Moments ◽  
Circular Holes ◽  
Kirchhoff Theory

Abstract The problem of finding stress resultants in a semi-infinite plate under plain bending and containing an infinite row of equal and equally spaced circular holes is discussed on the basis of the Poisson-Kirchhoff theory of thin plates. A method of perturbation is adopted for the determination of parametric coefficients included in the solution. The maximum bending moments occurring on the rim of the hole across the minimum section are calculated for several cases and shown in graphs, from which the mutual interference of adjacent boundaries will be informed.

Sign in / Sign up

Export Citation Format

Share Document