• Title/Summary/Keyword: In-plane displacement

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Finite Element Analysis for Free Vibration of Laminated Plates Containing Multi-Delamination (다층 층간분리된 적층 판의 유한요소 자유진동해석)

  • Taehyo Park;Seokoh Ma
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.37-44
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    • 2003
  • In this proposed work, computational, finite element model far multi-delaminated plates will be developed. In the current analysis procedures of multi-delaminated plates, different elements are used at delaminated and undelaminated region separately. In the undelaminated region, plate element based on Mindlin plate theory is used in order to obtain accurate results of out-of-plane displacement of thick plate. And for delaminated region, plate element based on Kirchhoff plate theory is considered. To satisfy the displacement continuity conditions, displacement vector based on Kirchhoff theory is transformed to displacement of transition element. Element mass and stiffness matrices of each region (delaminated, undelaminated and transition region) will be assembled for global matrix.

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Free Vibration Analysis of Multi-delaminated Composite Plates (다층간분리된 적층판의 자유진동해석)

  • Taehyo Park;Seokoh Ma;Yunju Byun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.25-32
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    • 2004
  • In this proposed work new finite element model for multi-delaminated plates is proposed. In the current analysis procedures of multi-delaminated plates, plate element based on Mindlin plate theory is used in order to obtain accurate results of out-of-plane displacement of thick plate. And for delaminated region, plate element based on Kirchhoff plate theory is considered. To satisfy the displacement continuity conditions, displacement vector based on Kirchhoff theory is transformed to displacement of transition element. The numerical results show that the effect of delaminations on the modal parameters of delaminated composites plates is dependent not only on the size, the location and the number of the delaminations but also on the mode number and boundary conditions. Kirchhoff based model have higher natural frequency than Mindlin based model and natural frequency of the presented model is closed to Mindlin based model.

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A Study on the Rotating Displacement Measurement of Rigid Body by ESPI Method (ESPI법에 의한 강체 회전 변위 측정에 관한 연구)

  • 김경석;홍명석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.2
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    • pp.125-133
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    • 1993
  • Electronic Speckle Pattern Interferometry(ESPI) using a CW laser, a video system and image processor was applied to the rotating displacement of rigid body. ESPI require no special surface preparation or attachments and displacements between any two arbitrary points on the surface can be measured. The characteristic speckle pattern formed when imaging a scattering surface illuminated by laser light retains phase information, which can be used for interferometric measurement of surface displacement. The application of this principle to measuring in-plane displacement resolved in one direction is described, together with the novel use of television equipment to detect and process the information contained in the speckle pattern. This is faster, and more convenient and versatile than customary photographic methods.

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Analytical solutions for density functionally gradient magneto-electro-elastic cantilever beams

  • Jian, Aimin;Ding, Haojiang
    • Smart Structures and Systems
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    • v.3 no.2
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    • pp.173-188
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    • 2007
  • The general solution for two-dimensional magneto-electro-elastic media in terms of four harmonic displacement functions is proposed analytically. The expressions of specific solutions of magneto-electro-elastic plane problems with specific body forces are derived. Finally, based on the general solution in the case of distinct eigenvalues and the specific solution for density functionally gradient media, two kinds of beam problems with body forces depending only on the z or x coordinate are solved by the trial-and-error method.

홀로그래픽 간섭무늬에 의한 변형률 측정

  • 권혁흥;조동현;김흥석;박승옥;조대근;권영하
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.529-533
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    • 1994
  • Atrains in microstain range are measured accurately by means of holographic interometric technique. Holographic fringes of the cantilever beam subjected to out-of-plane deflection and in-plane deflection respectively are obtained experimentally. Form these fringe patterns, 3rd order polynomial of displacements is induced using polynomial regression method. And strain stress distribution could be determined from the secound derivative of this polynomial. These results agree well with FEM.

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A multimodal adaptive evolution of the N1 method for assessment and design of r.c. framed structures

  • Lenza, Pietro;Ghersi, Aurelio;Marino, Edoardo M.;Pellecchia, Marcello
    • Earthquakes and Structures
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    • v.12 no.3
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    • pp.271-284
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    • 2017
  • This paper presents a multimodal adaptive nonlinear static method of analysis that, differently from the nonlinear static methods suggested in seismic codes, does not require the definition of the equivalent Single-Degree-Of-Freedom (SDOF) system to evaluate the seismic response of structures. First, the proposed method is formulated for the assessment of r.c. plane frames and then it is extended to 3D framed structures. Furthermore, the proposed nonlinear static approach is re-elaborated as a displacement-based design method that does not require the use of the behaviour factor and takes into account explicitly the plastic deformation capacity of the structure. Numerical applications to r.c. plane frames and to a 3D framed structure with inplan irregularity are carried out to illustrate the attractive features as well as the limitations of the proposed method. Furthermore, the numerical applications evidence the uncertainty about the suitability of the displacement demand prediction obtained by the nonlinear static methods commonly adopted.

Calculation of stress intensity factor considering out-of-plane bending for a patched crack with finite thickness (유한두께를 가지는 보강된 균열평판에 대한 면외굽힘을 고려한 응력강도계수 계산)

  • Kim, Jong-Ho;Lee, Soon-Bok
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.165-169
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    • 2000
  • A simple method was suggested to calculate the stress intensity factor for a one-sided patched crack with finite thickness. To consider out-of-plane bending effect resulting from the load-path eccentricity, the spring constant as a function of the through-thickness coordinate z was calculated from the stress distribution in the un-cracked plate, ${\sigma}_{yy}(y=0,\;z)$, and the displacement for the representative single strip Joint, $u_y(y=0,\;z)$. The stress Intensity factors were obtained using Rose's asymptotic solution approach and compared with the finite element results. In short crack region, two results had a little difference. However, two results were almost same in long crack region. On the other hand, the stress intensity factor using plane stress assumption was more similar to finite element result than plane strain condition.

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Mode III Dynamic Interfacial Crack in Bonded Anisotropic Strip Under Anti-Plane Deformation (이방성재료 접합 띠판에 대한 면외 동적계면균열)

  • Park, Jae-Wan;Choi, Sung-Ryul
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.111-116
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    • 2000
  • A semi-infinite interfacial crack propagated with constant velocity in two bonded anisotropic strip under out-of-plane clamped displacements is analyzed. The asymptotic stress and displacement fields near the crack tip are obtained, where the results get more general expressions applicable not only to isotropic/orthotropic materials but also to the extent of the anisotropic material having one plane of elastic symmetry for the interfacial crack. The dynamic stress intensity factor is obtained as a closed form, which is decreased as the velocity of crack propagation increases. The critical velocity where the stress intensity factor comes to zero is obtained, which agrees with the lower value between the critical values of parallel crack merged in the material 1 and 2 adjacent to the interface. The dynamic energy release rate is also obtained as a form related to the stress intensity factor.

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The Curved Interfacial Crack Analysis between Foam and Composite Materials under Anti-plane Shear Force (반평면 전단하중력하에서 곡면형상 접합면을 가지는 폼과 복합재료 접합부의 계면크랙에 관한 연구)

  • 박상현;전흥재
    • Composites Research
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    • v.13 no.4
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    • pp.67-74
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    • 2000
  • The general solution of the anti-plane shear problem for the curved interfacial crack between viscoelastic foam and composites was investigated with the complex variable displacement function. Kelvin-Maxwell three parameter model is used to present viscoelasticity and the Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The stress intensity factor near the interfacial crack tip was predicted by considering both anisotropic and viscoelastic properties of two different materials. The results showed that the stress intensity factor increased with increasing the curvature of the curved interfacial crack and it also increased and eventually converged to a specific value with increasing time. The stress intensity factor increased with increasing the ratio of stiffness coefficients between foam and composites and the effect of fiber orientation on the stress intensity factor decreased with increasing the ratio of stiffness coefficients between foam and composites.

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Deformation Analysis of Composits-Patched Concrete Using Moire Interferometry (무아레 간섭계를 이용한 복합재 보강 콘크리트의 변형해석)

  • Ju, Jin-Won;Chae, Su-Eun;Sin, Dong-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.160-170
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    • 2002
  • Many of aged and damaged concrete structure have been revitalized with composite reinforcement. Flexural behaviors of composite-patched concrete specimens are characterized by high-sensitivity moire interferometry. The three-mirror, four-beam interferometry system and a compact loading system are used for obtaining singe patterns representing whole-field contour maps of in-plane displacements. It is seen from the calibration test for the loading system that the measured bending displacement is in excellent agreement with the displacement calculated by the beam theory. The crack opening displacement as well as the bending and the horizontal displacement fur the notched and unnotched specimen are investigated. The results also show that the notched specimen reinforced by a composite sheet has sufficient stiffness and strength compared to the original concrete specimen.