• Title/Summary/Keyword: Strip theory

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Spline finite strip method incorporating different plate theories for thick piezoelectric composite plates

  • Akhras, G.;Li, W.C.
    • Smart Structures and Systems
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    • v.5 no.5
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    • pp.531-546
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    • 2009
  • In the present analysis, the spline finite strip with higher-order shear deformation is formulated for the static analysis of piezoelectric composite plates. The proposed method incorporates Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model, Cho's higher-order zigzag laminate theory, as well as the classic plate theory and the first-order plate theory. Thus, the analysis can be conducted based on any of the above-mentioned theories. The selection of a specific method is done by simply changing a few terms in a 2 by 2 square matrix and the results, obtained according to different plate theories, can be compared to each other. Numerical examples are presented for piezoelectric composite plates subjected to mechanical loading. The results based on different shear deformation theories are compared with the three-dimensional solutions. The behaviours of piezoelectric composite plates with different length-to-thickness ratios, fibre orientations, and boundary conditions are also investigated in these examples.

Vibration and stability analyses of thick anisotropic composite plates by finite strip method

  • Akhras, G.;Cheung, M.S.;Li, W.
    • Structural Engineering and Mechanics
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    • v.3 no.1
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    • pp.49-60
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    • 1995
  • In the present study, a finite strip method for the vibration and stability analyses of anisotropic laminated composite plates is developed according to the higher-order shear deformation theory. This theory accounts for the parabolic distribution of the transverse shear strains through the thickness of the plate and for zero transverse shear stresses on the plate surfaces. In comparison with the finite strip method based on the first-order shear deformation theory, the present method gives improved results for very thick plates while using approximately the same number of degrees of freedom. It also eliminates the need for shear correction factors in calculating the transverse shear stiffness. A number of numerical examples are presented to show the effect of aspect ratio, length-to-thickness ratio, number of plies, fibre orientation and stacking sequence on the natural frequencies and critical buckling loads of simply supported rectangular cross-ply and arbitrary angle-ply composite laminates.

Leaky-waves of Metal-strip Gratings on Optical Planar Dielectric slabs

  • Ho, Kwang-Chun;Kim, June-Hwan;Kim, Yung-Kwon
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.359-362
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    • 1998
  • The electromagnetic properties of leaky-waves guided by metal-strip grating configurations can be phrased in rigorous modal theory. Such a modal solution expressed by simple electrical transmissionline networks is utilized to analyze the leakage and filtering characteristics of metal-strip gratings. In particular, the modal transmission-line theory can serve as a template for computational algorithms that systematically evaluate the radiation effects that are not readily obtained by other methods.

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Evaluation of Stress Intensity Factors for an Electrostrictive Crack with an Electric Yielding Zone (전기적 항복영역을 갖는 전왜균열에 대한 응력강도계수 계산)

  • 범현규;정은도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.469-472
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    • 2000
  • a crack with electrically impermeable surfaces in an electrostrictive material subjected to uniform electric loading is analysed. A strip yield zone model is employed to investigate the effect of electric yielding on stress intensity factor. complete forms of electric fields and elastic fields for the crack are derived by using complex function theory. /the stress intensity factors are obtained based on the strip yield zone model.

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Development of Mathematical Model for the Prediction of Roll Force and Tension Profiles in Flat Rolling (판 압연에서 압하력 및 장력 분포 예측 모델 개발)

  • Kim, Y.K.;Hwang, S.M.
    • Transactions of Materials Processing
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    • v.19 no.6
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    • pp.344-351
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    • 2010
  • This paper presents a precision on-line model for the prediction of the roll force and tension distributions across the strip in hot strip rolling. The approach is based on an approximate 3-D theory of rolling, and in particular, considers the effect of pre-deformation of the strip, which occurs near the roll entrance before the strip enters the bite zone. The prediction accuracy of the proposed model is examined through comparison with the predictions from the 3-D finite element models.

Thermal buckling analysis of thick anisotropic composite plates by finite strip method

  • Cheung, M.S.;Akhras, G.;Li, W.
    • Structural Engineering and Mechanics
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    • v.7 no.5
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    • pp.473-484
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    • 1999
  • In the present study, the thermal buckling analysis of thick anisotropic laminated composite plates is carried out using the finite strip method based on the higher-order shear deformation theory. This theory accounts for the parabolic distribution of the transverse shear strains through the thickness of the plate and for zero transverse shear stresses on the plate surfaces. Therefore, this theory yields improved results over the Mindlin plate theory and eliminates the need for shear correction factors in calculating the transverse shear stiffness. The critical temperatures of simply supported rectangular cross-ply and angle-ply composite laminates are calculated. The effects of several parameters, such as the aspect ratio, the length-to-thickness ratio, the number of plies, fibre orientation and stacking sequence, are investigated.

A Study for Process Planning of Progressive Working by the using of Fuzzy Set Theory (Fuzzy set 이론을 이용한 프로그레시브 가공의 공정설계에 관한 연구)

  • Kim, Y. M.;Kim, J. H.;Kim, C.;Choi, J. C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.735-739
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    • 2001
  • This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working os based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theorise, experimental results and the empirical knowledge of field experts. the system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of three main modules, which are input and shape treatment, flat pattern layout and strip layout modules. Strip layout of the system is designed by using fuzzy set theory. Process planning is determinated by fuzzy value according to several rules. Strip layout drawing generated in strip layout module is presented in 3-D graphic forms, including bending sequences and piercing processes with punch profiles divided into for external area. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

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A Study on The Pattern shape(Figure) of the korean Trouser, Hanbok-Baji, in the Realation to its Fabric(Ground) - Emphasized on the Topological Aspect - (한복구조에 나타난 ′옷감′(ground)과 ′옷꼴′(figure)에 관한 연구-위상기하학적 측면을 중심으로-)

  • 임영자;문공화
    • Journal of the Korean Society of Costume
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    • v.52 no.3
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    • pp.149-160
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    • 2002
  • Symbolism found in a certain object inherits characteristics from the culture that contains the objects. The purpose of this study was investigate the formative beauty of Korean trousers twisted the pieces together based on the way of Korean thinks and the Topology. The shape is formed by cutting from the fabric. From the perspective of semiology, the fabric and the pattern shape correspond to ground and figure. Ground and figure are identical with the principle of the whole and the part, which is the same in Korea, China, and the West. But In Korea, the 3-dimensional garment is made by adding a twist. This is very important and defines the difference in the way of thinking and topology. Korean trousers consist of three parts : Hury, Marupok, and Sapok. The small Sapok can be made by removing the Marupok and large Sapok (figure) from the fabric (ground) when making Korean trousers. A Mobius strip is made when the large Sapok is adjoined with the small Sapok by reversing the small Sapok, making a 180$^{\circ}$twist and then stitching together. The theory of Mobius strip can be applied in Joining Bajiburi. thus when the trousers are completed the Klein's bottle is seen because of the 2 existing Mobius strop. The theory of Mobius strip can be applied in Joining Bajiburi, thus when the trousers are completed the Klein's bottle is seen because of the 2 existing Mobius strip. Hury is cylinder while the small and large Sapok make up the Mobius strip. As a result, Mobius strip, Kleins'bottle, protective plan can be applied in cutting Hanbok used in the countryside, so I have come to see that the traditional Korean way of thinking is closely related to the theory of topological.

Finite Element Analysis and Evaluation of a Three-dimensional Plate Theory (삼차원 판이론의 유한요소해석)

  • 조한욱
    • Computational Structural Engineering
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    • v.8 no.1
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    • pp.147-160
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    • 1995
  • Based on the weighted residual concept[4], a three-dimensional plate theory is derived using a Fourier series expansion of a dependent variable and a weighted residual approximation of the basic elasticity equations. The weighted residual equilibrium equations of the plate are expressed in terms of weighted displaced quantities, and the results are then interpreted by means of a potential energy functional. The potential energy expression is used to develop a finite element implementation. For illustrative purposes, the application of the theory to a strip plate is considered and two numerical examples of a cantilever and a simply-supported strip plate are studied.

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