Vibration Modal Analysis of the Full-Sized Medium Density Fiberboard

2014 ◽  
Vol 620 ◽  
pp. 268-273 ◽  
Author(s):  
Cheng Guan ◽  
Lu Jing Zhou ◽  
Hou Jiang Zhang ◽  
Kang Hua Li
Keyword(s):  
Modal Analysis ◽  
Medium Density Fiberboard ◽  
Experimental Modal Analysis ◽  
Vibration Modes ◽  
Medium Density ◽  
Bending Vibration ◽  
Modal Frequency ◽  
Width Direction ◽  
Length Direction ◽  
Vibration Modal

To determine modulus of elasticity (MOE) of the whole full-sized medium density fiberboard (MDF) by using vibration method in the future, this paper studies MDF vibration characteristics. To solve modal parameters of full-sized MDF in the condition of free vibration, the writers conducted calculation modal analysis and experimental modal analysis of the full-sized MDF with three different thicknesses respectively, compared and analyzed the first three order modal shapes and frequencies. It is found that the full-sized MDF with three different thicknesses showed the same vibration modal forms: the first and second vibration modes had bending vibration along the length direction, while the third one had bending vibration along the width direction; the frequency obtained through calculation modal analysis and experimental modal analysis had a certain difference—the first calculation modal frequency was slightly lower than the first experimental modal frequency, and the second and third calculation modal frequencies higher than the corresponding experimental modal frequencies. However, there is a good correlation between calculation modal frequency and test experimental modal frequency with the determination coefficient reaching 0.9816.

The Study on Experimental Modal Analysis of High-Speed Rotational Shaft

2012 ◽  
Vol 605-607 ◽  
pp. 1253-1256
Author(s):  
Jun Zhao ◽  
Jian Chang Yuan
Keyword(s):  
Modal Analysis ◽  
High Speed ◽  
Excitation Frequency ◽  
Dominant Frequency ◽  
Experimental Modal Analysis ◽  
Vibration Modes ◽  
Response Signal ◽  
Modal Frequency ◽  
Frequency Components ◽  
Vibration Problems

Centering on the chuck shaft vibration problems in high speed operation of the high-speed winder, experimental modal analysis was used to identify the modal frequency and vibration modes of the chuck shaft different cross-section in the constraint, found out the sensitive point of the response signal ,and the excitation point was found by Relationship between the modal frequency and the input excitation frequency, the results show determined dominant frequency components in the response signal can provide a reliable basis for determining the vibration characteristics of the chuck shaft, analysis of distinguishing the output response signal and selecting response signal point.

The Use of Modan 3D in Experimental Modal Analysis

2013 ◽  
Vol 486 ◽  
pp. 36-41 ◽  
Author(s):  
Róbert Huňady ◽  
František Trebuňa ◽  
Martin Hagara ◽  
Martin Schrötter
Keyword(s):  
Modal Analysis ◽  
Vibration Analysis ◽  
High Speed ◽  
Mechanical Vibration ◽  
Steel Sample ◽  
Experimental Modal Analysis ◽  
Image Correlation ◽  
Optical Methods ◽  
Mode Shapes ◽  
Vibration Modes

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.

scholarly journals Experimental modal analysis in research

2017 ◽  
Vol 16 (3) ◽  
pp. 005-012 ◽  
Author(s):  
Mariusz Żółtowski ◽  
Krzysztof Napieraj
Keyword(s):  
Parameter Estimation ◽  
Modal Analysis ◽  
Civil Engineering ◽  
Experimental Modal Analysis ◽  
Impact Testing ◽  
Engineering Industry ◽  
Vibration Modes ◽  
Modal Parameter ◽  
Excitation Techniques ◽  
Modal Parameter Estimation

Experimental modal analysis has grown steadily in popularity since the advent of the digital FFT spectrum analyser in the 1970’s. This days impact testing has become widespread as a fast and economical means of finding the vibration modes of a machine or structure. Its significantly use ascending roles can be seen also in the civil engineering industry [6]. This paper reviews the main topics associated with experimental modal analysis including making FRF measurements, modal excitation techniques, and modal parameter estimation from a set of FRFs.

Vibration of Press Based on Operational Modal Analysis

2013 ◽  
Vol 312 ◽  
pp. 273-276
Author(s):  
Ming Ming Zhao ◽  
Yi Ming Wang ◽  
Xiang Dong Shi ◽  
Jian Guo Li
Keyword(s):  
Modal Analysis ◽  
Operational Modal Analysis ◽  
Test Method ◽  
Actual Condition ◽  
Vibration Modes ◽  
Vibration Characteristic ◽  
The Finite Element Method ◽  
The Press ◽  
Frequency Identification ◽  
Vibration Modal

Press vibration characteristic is the basic of press fault diagnosis and static optimization. We get press vibration characteristics with Operational Modal Analysis .Comparing theoretical analysis of the finite element method for press with operation modal analysis of test method for press in the actual condition. We get vibration modal orders and vibration modes of press wallboard under natural excitation. The experimental results show that the test modal frequency identification value of Operational Modal Analysis for the press components is highly accurate.

Application of Statistical Methods in Experimental Modal Frequency Extraction

2015 ◽  
Vol 738-739 ◽  
pp. 569-572
Author(s):  
Jian Wei Jiang ◽  
De Jian Zhou ◽  
Bing Li ◽  
Yu Tang ◽  
Xiang Yang Xie
Keyword(s):  
Mathematical Method ◽  
Modal Analysis ◽  
Statistical Methods ◽  
Experimental Modal Analysis ◽  
General Analysis ◽  
Excitation Source ◽  
Modal Frequency ◽  
Statistical Frequency

In order to extract the experimental modal analysis of the Modal frequency accurately, measuring twelve set of data during the experiment, to use the method of statistical frequency based on mathematical method to extract modal frequencies. It is helpful to avoid frequency leakage phenomenon as the reasons of excitation source select inappropriate and quickly and efficiently for a general analysis staff to extract the modal frequency values.

scholarly journals Modal Analysis of Laminated “CAS” and “CUS” Box-Beams

2017 ◽  
Vol 64 (4) ◽  
pp. 441-454 ◽  
Author(s):  
Jarosław Gawryluk ◽  
Marcin Bocheński ◽  
Andrzej Teter
Keyword(s):  
Modal Analysis ◽  
Mode Coupling ◽  
Composite Structures ◽  
Vibration Mode ◽  
Coupling Effect ◽  
Experimental Modal Analysis ◽  
Vibration Modes ◽  
The Finite Element Method ◽  
Numerical Studies ◽  
Box Beams

Abstract In the paper, the authors discuss the numerical and experimental modal analysis of the cantilever thin-walled beams made of a carbon-epoxy laminate. Two types of beams were considered: circumferentially asymmetric stiffness (i.e., CAS) and circumferentially uniform stiffness (i.e., CUS) beams. The layer-up configurations of the laminate were chosen to get a vibration mode coupling effect in both analysed cases. The aim of the paper was to perform the numerical and experimental modal analysis of the composite structures, when a flapwise bending with torsion coupling effect or flapwise-chordwise bending coupling effect took place. Firstly, numerical studies by the finite element method was performed. The numerical simulations were carried out by the Lanczos method in the Abaqus software package. The natural frequencies and the corresponding free vibration modes were determined. Next, the experimental modal analyses of the CAS and CUS beams were performed. The test stand was consisted of a special grip, two beams with an adhered holder, the LMS Scadas III system with a modal hammer and an acceleration sensor. Finally, the results of both methods were compared.

Effect of Bass Bar Tension on Modal Parameters of a Violin's Top Plate

2015 ◽  
Vol 39 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Ewa B. Skrodzka ◽  
Bogumił B.J. Linde ◽  
Antoni Krupa
Keyword(s):  
Modal Analysis ◽  
Experimental Modal Analysis ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Normal Value ◽  
Modal Damping

Abstract Experimental modal analysis of a violin with three different tensions of a bass bar has been performed. The bass bar tension is the only intentionally introduced modification of the instrument. The aim of the study was to find differences and similarities between top plate modal parameters determined by a bass bar perfectly fitting the shape of the top plate, the bass bar with a tension usually applied by luthiers (normal), and the tension higher than the normal value. In the modal analysis four signature modes are taken into account. Bass bar tension does not change the sequence of mode shapes. Changes in modal damping are insignificant. An increase in bass bar tension causes an increase in modal frequencies A0 and B(1+) and does not change the frequencies of modes CBR and B(1-).

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.

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