• 제목/요약/키워드: natural frequency of a plate

검색결과 343건 처리시간 0.032초

다점지지된 TFT-LCD 유리기판의 고유진동수 최적화 (Optimization for the Natural Frequency of the TFT-LCD Glass Plate with Multi-Support Point)

  • 이현승;이영신;김현수;이장원;이세훈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.246-249
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    • 2005
  • The TFT-LCD is extensively used from a small watch to a large TV display, and the demand is increasing rapidly. The size of R-LCD glass plate becomes more bigger, and the thickness become more thinner with high demands. As a result natural frequency of the TFT-LCD glass plate becomes more lower. The TFT-LCD glass plate will be moved by robot arm and may receive effect of vibration that occur at transfer. Natural frequency of the TFT-LCD glass plate is increased or decrease according to location that robot arm fixs glass plate. Purpose of a this study is finding support location that optimize the first natural frequency of TFT-LCD glass plate. The size optimization method of ANSYS 8.0 is used as the optimization tool search on the optimal support location of TFT-LCD glass plate. The considered number of support point is from 4 to 9.

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원공을 갖는 복합적층판 및 혼합적층판의 좌굴 및 진동해석 (Buckling and Vibration Analysis of Laminated Composite Plate and Hybrid Composite Plate with a Hole.)

  • 구경민;홍도관;김동영;안찬우;한근조
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.812-815
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    • 2002
  • This paper deals with the buckling and vibration analysis of plate with a hole. We knew that in this paper, as aspect ratio rises in design parameter, the buckling strength and the natural frequency of laminated composite plate decrease and as diameter of hole for width of plate rises, the buckling strength decrease but the natural frequency increase. Also this paper compared the CFRP laminated composit plate with the hybrid composite plate, and proposed that the hybrid composite plate is stronger than the CFRP composite plate.

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복합적층 트러스 코어형 샌드위치 판구조물의 진동특성을 고려한 최적설계 (Optimum Design of the Laminated Composite Sandwich Plate Structure of Truss Core considering Vibration Characteristics)

  • 정석모;홍도관;안찬우
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.703-709
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    • 2001
  • In this paper, we analyzed the laminated composite sandwich plate structure of truss core with changing values of the designing parameters. As a result, in designing parameters of that, the more height and thickness of the laminated composite plate's core, the more increase of natural frequency. In this type of structure, in the case of applying core of the laminated composite plate and antisymmetric stacking, natural frequency has high value and we calculated the optimum angle-ply making natural frequency maximum. Natural frequency of CFRP is higher than that of GFRP. Both are materials of the laminated composite plate. The mode shapes are various along with the angle-ply of the laminated composite plate.

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Vibration analysis of porous nanocomposite viscoelastic plate reinforced by FG-SWCNTs based on a nonlocal strain gradient theory

  • Khazaei, Pegah;Mohammadimehr, Mehdi
    • Computers and Concrete
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    • 제26권1호
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    • pp.31-52
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    • 2020
  • This paper investigates the size dependent effect on the vibration analysis of a porous nanocomposite viscoelastic plate reinforced by functionally graded-single walled carbon nanotubes (FG-SWCNTs) by considering nonlocal strain gradient theory. Therefore, using energy method and Hamilton's principle, the equations of motion are derived. In this article, the effects of nonlocal parameter, aspect ratio, strain gradient parameter, volume fraction of carbon nanotubes (CNTs), damping coefficient, porosity coefficient, and temperature change on the natural frequency are perused. The innovation of this paper is to compare the effectiveness of each mentioned parameters individually on the free vibrations of this plate and to represent the appropriate value for each parameter to achieve an ideal nanocomposite plate that minimizes vibration. The results are verified with those referenced in the paper. The results illustrate that the effect of damping coefficient on the increase of natural frequency is significantly higher than the other parameters effect, and the effects of the strain gradient parameter and nonlocal parameter on the natural frequency increase are less than damping coefficient effect, respectively. Furthermore, the results indicate that the natural frequency decreases with a rise in the nonlocal parameter, aspect ratio and temperature change. Also, the natural frequency increases with a rise in the strain gradient parameter and CNTs volume fraction. This study can be used for optimizing the industrial and medical designs, such as automotive industry, aerospace engineering and water purification system, by considering ideal properties for the nanocomposite plate.

Effect of chitosan/carbon nanotube fillers on vibration behaviors of drilled composite plates

  • Demir, Ersin;Callioglu, Hasan;Sayer, Metin;Kavla, Furkan
    • Steel and Composite Structures
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    • 제35권6호
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    • pp.789-798
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    • 2020
  • The effect of Chitosan (CS), Carbon Nanotube (CNT) and hybrid (CS-CNT) fillers on the natural frequency of drilled composite plate is investigated by experimentally in this study. The numerical validation is also made with a program based on Finite Element Method (SolidWorks). Nine types filled and one neat composite plates are used in the study. The fillers ratios are 1% CS, 2% CS, 3% CS, 0.1% CNT, 0.2% CNT, 0.3% CNT, 1% CS+0.3% CNT, 2% CS+0.3% CNT, 3% CS+0.3% CNT. The specimens cut to certain sizes by water jet from the plates 400 mm × 400 mm in dimensions. Some of them are drilled in certain dimensions with drill. The natural frequency of each specimen is measured by the vibration test set up to determine the vibration characteristic. The vibration test set up includes an accelerometer, a current source power unit, a data acquisition card and a computer. A code is written in Matlab® program for the signal processing. The study are investigated and discussed in four main points to understand the effect of the fillers on the natural frequency of the composite plate. These are the effect of fillers contents and amounts, orientation angles of fibers, holes numbers and holes sizes. As results, the natural frequency of the plate with 1% CS and 0.1% CNT hybrid filler is lower than those of the plates with other fillers ratios for 45° orientation angle. Besides, in the composite plate with 0° orientation angle, the natural frequency increases with increasing the filler ratio. Moreover, the natural frequency increases until a certain hole number and then it decreases. Furthermore, the natural frequency is not affected until a certain hole diameter but then it decreases.

합성 데크 플레이트 바닥구조의 단면환산 단순화를 통한 고유진동수 예측식의 보정에 관한 연구 (A Study on Adjustment of Prediction Equation for Natural Frequency Using the Simplification of Section Transformation Method of Composite Deck Plate Floor Systems)

  • 임지훈;김희철;홍원기
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.731-738
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    • 2001
  • The conventional techniques for the prediction of natural frequency are often used to estimate the floor vibration. However. the predicted frequency differs significantly from the measured one since the predicted equation is not able to proper1y treat various material type. Transformation of slab section is necessary to predict natural frequency of composite deck plate, and this effort is complicated due to the various shape of each deck plate. In this study, a new simplified methodology to transform slab section is proposed, which treats effective depth as the distance from the top of a concrete topping to neutral axis of each deck plate. Finally proposed equation with fairly reasonable result compared to the measured values is obtained. based on the modification of vibration equation from LRFD theory. This efforts enhance errors in predicting frequency up to 15%.

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고유진동수의 간이 추정식을 이용한 보강판 구조물의 동특성의 최적변경에 관한 연구 (A Study on Optimum Modification of Dynamic Characteristics of Stiffened Plate Using Simplified Equation of Natural Frequency)

  • 박성현;남정길
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권1호
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    • pp.48-58
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    • 2002
  • There is a purpose of this study for the proposal of the optimum technique utilized for the vibration design initial step. The stiffened plate structure for the ship hull is made for analysis model. To begin with, dynamic characteristics of stiffened plate structure is analysed using FEM. Main vibrational mode of the structure is decided in the analytical result of FEM. The simplified equation on the natural frequency of the main vibrational mode is induced. Next, sensitivity analysis is carried out using the simplified equation, and rate of change of dynamic characteristics is calculated. Then, amount of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of panel, cross section moment of stiffener and girder become a design variable. The validity of the optimization method using simplified equation is examined. It is shown that the result effective in the optimum modification for natural frequency of the stiffened plate structure.

가속을 받는 사다리꼴 외팔 평판의 동특성 해석 (Dynamic Characteristic Analysis of Trapezoidal Cantilever Plates Undergoing Translational Acceleration)

  • 임홍석;유홍희
    • 한국소음진동공학회논문집
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    • 제12권10호
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    • pp.785-791
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    • 2002
  • A modeling method for the dynamic characteristic analysis of a translationally accelerated trapezoidal cantilever plate is presented in this paper. The equations of motion for the plate are derived and transformed into a dimensionless form. The effects of the inclination angles and the acceleration on the vibration characteristics of the plate are investigated. Incidentally, natural frequency loci veering and associated mode shape variations are observed and discussed.

가속을 받는 사다리꼴 외팔 평판의 동특성 해석 (Dynamic Characteristic Analysis of Trapezoidal Cantilever Plates Undergoing Translational Acceleration)

  • 임홍석;유홍희
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.268-273
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    • 2002
  • A modeling method for the dynamic characteristic analysis of a translationally accelerated trapezoidal cantilever plate is presented in this paper. The equations of motion for the plate are derived and transformed into a dimensionless form. The effects of the inclination angles and the acceleration on the vibration characteristics of the plate are investigated. Incidentally, natural frequency loci veering and associated mode shape variations are observed and discussed

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임피던스 튜브 내에 설치된 평판의 음파투과해석 (An Analysis of the Sound Transmission through a Plate Installed inside an Impedance Tube)

  • 김현실;김봉기;김상렬;이성현
    • 한국음향학회지
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    • 제34권3호
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    • pp.219-226
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    • 2015
  • 본 논문은 단면이 정사각형인 임피던스 튜브 내에 고정된 평판의 STL(Sound Transmission Loss)을 해석적으로 구하는 방법을 다루었다. 평판의 진동과 튜브 내의 음장의 연성거동(coupled motion)을 고려하였는데 평판의 진동과 튜브 음장을 무한 급수의 합으로 전개하였으며 평면파 가정을 이용하여 처음 몇 개의 모드만 고려하여도 충분히 정확한 결과를 얻음을 보였다. 평판은 클램프(clamp) 지지로 가정하였는데 진동 모드는 단면의 가로 및 세로방향 보(beam) 진동 모드의 곱으로 전개하였고 고유진동수는 Rayleigh-Ritz 방법을 이용하여 구하였다. 평판의 STL은 가장 낮은 고유진동수에서 골(dip)을 가지며 주파수가 이보다 작아지면 STL은 커짐을 보였다. 기존 논문의 측정 및 FEM(Finite Element Method) 해석결과와 비교한 결과 잘 일치함을 확인하였다.