• Title/Summary/Keyword: MULTI-LAYERED STRUCTURE

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Ritz Analysis of Rectangular MEMS Structures (I);Formulation and Its Implementation (직사각형 MEMS 판 구조의 리츠 해석 (I);수식화 및 수치해법)

  • Kim, Eun-Seok;Lee, Byeong-Chae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.2 s.173
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    • pp.421-430
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    • 2000
  • We apply the Rayleigh Ritz method to analyze multi-layered plates with residual stresses. The method is very simple, straight forward, and easily programmable, but it should be applied to structure s only in simple shapes. We derive coupled variational equations based on the principle of virtual displacement, and investigate what kind of basis functions is desirable for the analysis of rectangular plates with various boundary conditions. We demonstrate the effectiveness and usefulness of the method through several examples. The analysis results obtained with the method are in good agreement with those available in literature. A multi-layered MEMS plate example shows that the coupling effect should not be ignored and that residual stresses do influence the stiffness of the structure very much.

Implementation of the Optimized Via Structure on the Multi-Layered PCB (다층 인쇄회로 기판 (multi-layered PCB)에서의 최적 via 구조의 구현)

  • 김재원;권대한;김기혁;심선일;박정호;황성우
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.341-344
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    • 2000
  • Several new via structures in printed circuit boards are proposed, fabricated and characterized in RF regime. The new structure with a larger inductance component in the bottom layer shows 3㏈ improvement over the conventional structure. The ADS simulation with model parameters extracted from 3D fie]d solver matches with the characterization of these vias

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Thickness Assessment of Adhesive Layer in Inhomogeneous Layer by Guided Wave (유도초음파에 의한 비균질 적층의 접합층두께 평가)

  • Cho, Youn-Ho;Ham, Hyo-Sik;Choi, Heung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.4
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    • pp.391-397
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    • 2001
  • The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

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Efficient Layered Manufacturing Method of Metallic Sandwich Panel with Pyramidal Truss Structures using Infrared Brazing and its Mechanical Characteristics (피라미드 트러스형 금속 샌드위치 판재의 적외선 브레이징을 이용한 효율적 적층식 제작 및 특성에 관한 연구)

  • Lee, Se-Hee;Seong, Dae-Yong;Yang, Dong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.8
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    • pp.76-83
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    • 2010
  • Metallic sandwich panels with pyramidal truss structures are high-stiffness and high-strength materials with low weight. In particular, bulk structures have enough space for additional multi-functionalities. In this work, in order to fabricate 3-D structures efficiently, Layered Manufacturing Method (LMM) which was composed of three steps, including crimping process, stacking process and bonding process using rapid infrared brazing, was proposed. The joining time was drastically reduced by employing infrared brazing of which heating rate and cooling rate were faster than those of conventional furnace brazing. By controlling the initial cooling rate slowly, the bonding strength was improved up to the level of strength by conventional vacuum brazing. The observation of infrared brazed specimens by optical microscope and SEM showed no defect on the joining sections. The experiments of 1-layered pyramidal structures and 2-layered pyramidal structures subject to 3-point bending were conducted to determine structural advantages of multilayered structures. From the results, the multi-layered structure has superior mechanical properties to the single-layered structure.

Study on the electric properties of layered $BaTiO_3$ films prepared new stacking method (새로운 방법으로 제조된 적층구조 $BaTiO_3$ 박막의 전기적 특성에 관한 연구)

  • Song, Man-Ho;Lee, Yun-Hi;Hahn, Taek-Sang;Oh, Myung-Hwan;Yoon, Ki-Hyun
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1129-1132
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    • 1995
  • In the preparation of the layered $BaTiO_3$ thin films with high performance, the new stacking method using the continuous cooling of the substrate was introduced. Amorphous/polycrystalline $BaTiO_3$ layered structure was confirmed by SEM and index of refraction. The layered $BaTiO_3$ thin films formed by the new stacking method showed such a high dielectric constant that the layered structure could not be explained by a stacking structure of the two defined layers but could only be explained by multi-layered structure, i.e. amorphous/micro crystalline/polycrystalline structure. The layered $BaTiO_3$ thin film with a thickness of 240 nm showed higher capacitance per unit area and breakdown strength than the double layered $BaTiO_3$ thin film prepared by the conventional stacking method. And well defined ferroelectric hysteresis leer was observed in the layered $BaTiO_3$ thin film with a thickness of 200 nm.

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Effective Compression Technique of Multi-view Image expressed by Layered Depth Image (계층적 깊이 영상으로 표현된 다시점 영상의 효과적인 압축 기술)

  • Jee, Inn-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.29-37
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    • 2014
  • Since multi-view video exists a number of camera color image and depth image, it has a huge of data. Thus, a new compression technique is indispensable for reducing this data. Recently, the effective compression encoding technique for multi-view video that used in layered depth image concepts is a remarkable. This method uses several view point of depth information and warping function, synthesizes multi-view color and depth image, becomes one data structure. In this paper we use actual distance for solving overlap in layered depth image that reduce required data for reconstructing in color-based transform. In experimental results, we confirmed high compression performance and good quality of reconstructed image.

Cuboidal Infinite Elements for Soil-Structure-Interaction Analysis in Multi-Layered Half-Space (3차원 지반-구조물 상호작용해석을 위한 입방형 무한요소)

  • Seo, Choon-Gyo;Yun, Chung-Bang;Kim, Jae-Min
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.1
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    • pp.39-50
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    • 2007
  • This paper presents 3D infinite elements for the elastodynamic problem with multi-layered half-space. Five different types of infinite elements are formulated by using approximate expressions of multiple wave components for the wave function in multi-layered soil media. They are horizontal, horizontal-corner, vortical, vertical-corner and vertical-horizontal-comer infinite elements. The elements can effectively be used for simulating wane radiation problems with multiple wave components. Numerical example analyses are presented for rigid disk, square footings and embedded footing on homogeneous and layered half-space. The numerical results show the effectiveness of the proposed infinite elements.

Simulations of Frequency-dependent Impedance of Ground Rods Considering Multi-layered Soil Structures

  • Lee, Bok-Hee;Joe, Jeong-Hyeon;Choi, Jong-Hyuk
    • Journal of Electrical Engineering and Technology
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    • v.4 no.4
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    • pp.531-537
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    • 2009
  • Lightning has a broad frequency spectrum from DC to a few MHz. Consequently, the high frequency performance of grounding systems for protection against lightning should be evaluated, with the distributed parameter circuit model in a uniform soil being used to simulate grounding impedances. This paper proposes a simulation method which applies the distributed parameter circuit model for the frequency-dependent impedance of vertically driven ground rods by considering multi-layered soil structures where ground rods are buried. The Matlab program was used to calculate the frequency-dependent ground impedances for two ground rods of different lengths. As a result, an increase of the length of ground rod is not always followed by a decrease of grounding impedance, at least at a high frequency. The results obtained using the newly proposed simulation method considering multi-layered soil structures are in good agreement with the measured results.

A Study on the Characteristics of Circular Piezoelectric Transformner which has Multi-layered Crescent-Shaped Input Electrode (적층형 Crescent-Shaped Input Type 원형 압전변압기의 특성)

  • Jeong, Seong-Su;Park, Tae-Gone
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.223-224
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    • 2006
  • This paper present a new disk-type piezoelectric transformer. The input side of the transformer has a crescent-shaped electrode and the output side has a focused poling direction. This transformer has multi-layered structure. The piezoelectric transformers operated m each transformer's resonance vibration mode. The electrodes and poling directions on commercialy available piezoelectric ceramic disks were designed so that the planar or shear mode coupling factor ($k_p,\;k_{15}$) becomes effective rather than the transverse mode coupling factor ($k_{31}$). The Resonance frequency is 65.22[kHz] and maximum voltage step-up ratio is 149. Multi-layered transformer has better efficiency and step-up ratio than the single-layered transformer.

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An Estimation of the Sound Insulation Performance of the Multi-layered Panel for a Tilting Train (틸팅 차량용 적층재의 차음성능 평가)

  • Seo, Tae-Gun;Lim, Bong-Gi;Kim, Seock-Hyun;Kim, Jae-Chul
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.597-600
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    • 2009
  • Sound transmission loss (TL) is experimently investigated on the multi-layered panel used for the floor of a tilting train. Measurement of the intensity transmission loss is performed according to ASTM E 2249-02. The floor structure consists of corrugated steel panel, glass wool, plywood and cover. On the corrugated steel panel, TL drop by local resonance is considered and the TL improvement effect by damping treatment is estimated. Total sound transmission loss of the entire floor structure is obtained and the contribution of each layer is examined.

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