• Title/Summary/Keyword: 이방성 판

Search Result 155, Processing Time 0.026 seconds

A Study on the Natural Frequency of Composite Laminated Plate Under Attached Point Mass/Masses (첨가질량이 있는 적층복합판의 고유진동수에 관한 연구)

  • 홍창우;심도식;박제선
    • Computational Structural Engineering
    • /
    • v.10 no.1
    • /
    • pp.149-158
    • /
    • 1997
  • This paper presents the illustration of application under attached point mass to the special orthotropic plates with a pair of opposite edges simply supported and the other pair of opposite edges free. Design engineers need to calculate the natural frequencies of such elements but obtaining exact solution to such problems is very much difficult. Pretlove reported a method of analysis of beams with attached masses using the concept of effective mass. This method, however, is useful only for certain simple types of beam. Therefore, considering the method has been developed by D. H. Kim(1974) is simple, accurate, and very effective for the plates with arbitrary boundary conditions and irregular sections, this paper calculates the natural frequencies of composite laminated plate under attached point mass/masses.

  • PDF

Mechanical Properties Anisotropy of Plain Weave Glass Fabric Reinforced Epoxy Resin Laminates (평직유리섬유강화 에폭시 적층판의 기계적 특성 이방성)

  • Kim, Yon-Jig
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.17 no.3
    • /
    • pp.15-21
    • /
    • 2009
  • The anisotropic mechanical properties were measured for the three orthogonal orientations of plain weave glass fabric reinforced epoxy resin laminate. In tensile and flexural tests, axial and edge type specimens failed by pull-out of warp and fill yarns, respectively. In contrast, the thickness type specimens failed by adhesive failure process. Longitudinal cracking occurred in several of the edge type specimens during tensile test. That cracking caused pop-in in the stress-strain curve. Defects induced by improper coupon machining caused that cracking.

Viscoelastic Bending, Vibration and Buckling Analysis of Laminated Composite Plates on Two-parameter Elastic Foundation (2개 매개변수를 갖는 탄성지반위에 놓인 복합재료 적층판의 점탄성적 휨, 진동 좌굴해석)

  • Han, SungCheon;Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
    • /
    • v.13 no.5
    • /
    • pp.443-455
    • /
    • 2001
  • An energy method has been used for an elastic formulation of bending vibration and buckling analysis of laminated composite plates on two-parameter elastic foundations. A quasi-elastic method is used for the solution of viscoelastic analysis of the laminated composite plates. The third-order shear deformation theory is applied by using the double-fourier series. To validate the derived equations the obtained displacements for simply supported orthotropic plates on elastic foundations are compared with those of LUSAS program Numerical results of the viscoelastic bending vibration and buckling analysis are presented to show the effects of layup sequence number of layers material anisotropy and shear modulus of foundations.

  • PDF

3D Non-linear Analysis of Interlaminar Stress around the Hole Edge of Orthotropic Laminates (직교이방성 적층판의 Hole단부의 3D 비선형 층간응력 해석)

  • SONG KWAN-HYUNG
    • Journal of Ocean Engineering and Technology
    • /
    • v.18 no.5
    • /
    • pp.36-42
    • /
    • 2004
  • Orthotropic laminates, such as [$0^{\circ}6$/$90^{\circ}6$]s and [$90^{\circ}6$/$0^{\circ}6$]s, were performed, using a commercial nonlinear finite element method. Interlaminar stress distributions, around the hole curve free-edge, were calculated. The delamination bearing strengths of pin joints were predicted, using the modified delamination failure criterion. These stress distributions were presented along the radial lines and around the free-edge of the hole. Further, three-dimensional non-linear contact analysis of orthotropic laminates was conducted to investigate the effect of friction. In this paper, laminates with a circular hole were taken to study interlaminar stresses the curved edge. This study may assist in the design of a thick composite laminate with mechanically pin joints.

A Study on Post-Tensioned Reinforced Concrete Slab by the Beam Theory (포스트텐션된 철근콘크리트 슬래브의 보 이론에 의한 연구)

  • Han, Bong-Koo;Kim, Duck-Hyun
    • Composites Research
    • /
    • v.22 no.5
    • /
    • pp.24-29
    • /
    • 2009
  • In this paper, a post-tensioned reinforced concrete slab was analyzed by the specially orthotropic laminates theory. Both the geometrical and material property of the cross section of the slab was considered symmetrically with respect to the neutral surface so that the bending extension coupling stiffness, $B_{ij}=0$, and $D_{16}=D_{26}=0$. Reinforced concrete slab behave as specially orthotropic plates. In general, the analytical solution for such complex systems is very difficult to obtain. Thus, finite difference method was used for analysis of the problem. In this paper, the finite difference method and the beam theory were used for analysis. The result of beam analysis was modified to obtain the solution of the plate analysis.

Rupture Prediction of the Rupture Disc Tests using Elastic-Plastic Analysis (탄소성해석을 이용한 파열판의 파열예측)

  • Han, Houk-Seop;Lee, Won-Bok;Koo, Song-Hoe;Lee, Bang-Eop
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.481-487
    • /
    • 2011
  • This paper provides a comparison between finite element analysis results and test data of rupture disc. Rupture disc is safety device of high pressure equipment. Rupture disc of solid rocket motor is a device to control rupture pressure. Rupture discs were made of AISI 316L. By the elastic-plastic analysis, the stress limit of rupture discs were compared to the test results. The results can be used to control the rupture pressure by the change of the disc size.

  • PDF

An Experimental Study on the Static Behavior in Weak Axis of FRP Bridge Deck Filled with a Foam (폼 충전 FRP 바닥판의 약축방향 정적거동 특성에 관한 실험적 연구)

  • Kim, Byeong Min;Zi, Goang Seup;Hwang, Yoon Koog;Lee, Young Ho
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.6A
    • /
    • pp.943-953
    • /
    • 2006
  • We investigated experimentally the static behavior of an orthotropic bridge deck which is made from glass fiber reinforced polymer (GFRP) and polyurethane foam. The bridge deck consists of many unit cells with rectangular holes which are filled with the foam to improve its structural behavior in its weak axis. It is found that although the elastic modulus of the foam compared to that of the GFRP is about the order of, the structural behaviors in the weak axis such as nominal strength, stiffness, etc. are greatly improved. Owing to the low mass density of the foam used in this study, the bridge deck is still light enough with the improved structural properties. Webs of the cells filled with the foam did not significantly contribute to the strength development of the deck. However, the propagation of a crack initiated in a cell is caught by the webs and limited to the inside of that cell only, which makes the load-displacement behavior of the foam-filled GFRP deck less brittle.

Optimization of Microwave Absorbing Performance in Polymer Matrix Composite Laminate (고분자 기기 복합재료 적층판의 전자파 흡수 최적화)

  • 김진봉;김태욱
    • Composites Research
    • /
    • v.14 no.6
    • /
    • pp.38-46
    • /
    • 2001
  • In this study, An optimization code that can design microwave absorbing composite laminates is developed, and 3-layered microwave absorbing composite laminates are developed by optimizing the thickness of each layer. The layers are 3 different composite laminates. Many variables including lay-up angles of electromagnetically orthotropic composite layer can be considered in this code. The developed laminate is composed of an impedance matching layer of glass/epoxy fabric laminate, a glass/epoxy fabric laminate layer containing aluminum filler and carbon/epoxy fabric laminate layer. Permittivities of the materials are obtained using a network analyzer and a coaxial air line.

  • PDF