• Title/Summary/Keyword: sandwich beam

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A Study on Material Damping of the $0^0&90^0$ Laminated Composite Sandwich Cantilever Beam inserted with Viscoelastic layer (점탄성층을 삽입한 $0^0&90^0$ 섬유강화 복합재료의 감쇠계수에 대한 연구)

  • Yim, Jong-Hee;Seo, Yun-Jong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.345-348
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    • 2004
  • In this paper it is to establish a comprehensive model for predicting damping in sandwich Laminated composites on the basis of strain energy method. In this model, the effect of transverse shear on the material damping has been considered with in-plane stresses. Results showed that the viscoelastic core thickness in the sandwich beam and the Length of a beam have a high impact on the material damping. The transverse shear appears to be highly influenced by the damping behavior in $0^0$ laminated sandwiched composites. However, it is Little influenced by that in $90^0$ laminated sandwiched composites.

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Vibration analysis of sandwich beam with nanocomposite facesheets considering structural damping effects

  • Cheraghbak, Ali;Dehkordi, M. Botshekanan;Golestanian, H.
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.795-806
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    • 2019
  • In this paper, free vibration of sandwich beam with flexible core resting on orthotropic Pasternak is investigated. The top and bottom layers are reinforced by carbon nanotubes (CNTs). This sandwich structural is modeled by Euler and Frostig theories. The effect of agglomeration using Mori-Tanaka model is considered. The Eringen's theory is applied for size effect. The structural damping is investigated by Kelvin-voigt model. The motion equations are calculated by Hamilton's principle and energy method. Using analytical method, the frequency of the structure is obtained. The effect of agglomeration and CNTs volume percent for different parameter such as damping of structure, thickens and spring constant of elastic medium are presented on the frequency of the composite structure. Results show that with increasing CNTs agglomeration, frequency is decreased.

Development of a double cantilever sandwich beam method for evaluating frequency dependence of dynamic modulus and damping factor of rubber materials (고무의 동탄성계수와 손실계수의 주파수 의존성을 평가하기 위한 양팔 샌드위치보 시험법의 개발)

  • 김광우;최낙삼
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.19-22
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    • 2001
  • This paper proposes a double cantilever sandwich-beam method for evaluating the frequency dependence of material dynamic characteristics. The flexural vibration of a double cantilever sandwich-beam specimen with a partially inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Quadratic relationships of dynamic elastic modulus and material loss factor of rubbers with frequency were quantitatively suggested employing the least square error method.

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Dynamic Characteristic of Composite Beam using the Sandwich Plate System (샌드위치 플레이트 시스템을 이용한 합성보의 동적 특성)

  • Ryu, Jae-Ho;Ju, Young-Kyu;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.14 no.4
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    • pp.65-72
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    • 2014
  • To improve the noise and vibration problems of the existing public parking systems, new floor system was proposed. This system consists of the Sandwich Plate System(SPS), steel beam and post-tensioned steel tendons. To verify the dynamic characteristics such as the natural frequency and damping ratio of the system, the free vibration test was performed. Test results showed that the natural frequency of the SPS composite beam was 23.8Hz and it was increased by 3.8% by installing the post-tensioned tendons. The damping ratio of the specimen with tendons was about 1.64%.

Flexural Vibration Analysis of a Sandwich Beam Specimen with a Partially Inserted Viscoelastic Layer

  • Park, Jin-Tack;Park, Nak-Sam
    • Journal of Mechanical Science and Technology
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    • v.18 no.3
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    • pp.347-356
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    • 2004
  • The flexural vibration characteristics of a sandwich beam system with a partially inserted viscoelastic layer were quantitatively studied using the finite element analysis in combination with the sine-sweep experiment. Asymmetric mode shapes of the flexural vibration were visualized by holographic interferometry, which agreed with those obtained by the finite element simulation. Effects of the length and the thickness of the partial viscoelastic layer on the system loss factor (η$\_$s/) and resonant frequency (f$\_$r/) were significantly large for both the symmetric and asymmetric modes of the beam system.

Bending and free vibration analysis of FG sandwich beams using higher-order zigzag theory

  • Gupta, Simmi;Chalak, H.D.
    • Steel and Composite Structures
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    • v.45 no.4
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    • pp.483-499
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    • 2022
  • In present work, bending and free vibration studies are carried out on different kinds of sandwich FGM beams using recently proposed (Chakrabarty et al. 2011) C-0 finite element (FE) based higher-order zigzag theory (HOZT). The material gradation is assumed along the thickness direction of the beam. Power-law, exponential-law, and sigmoidal laws (Garg et al 2021c) are used during the present study. Virtual work principle is used for bending solutions and Hamilton's principle is applied for carrying out free vibration analysis as done by Chalak et al. 2014. Stress distribution across the thickness of the beam is also studied in detail. It is observed that the behavior of an unsymmetric beam is different from what is exhibited by a symmetric one. Several new results are also reported which will be useful in future studies.

Mechanical behavior of composite beam aluminum-sandwich honeycomb strengthened by imperfect FGM plate under thermo-mechanical loading

  • Bensatallah Tayeb;Rabahi Abderezak;Tahar Hassaine Daouadji
    • Coupled systems mechanics
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    • v.13 no.2
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    • pp.133-151
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    • 2024
  • In this paper, an improved theoretical interfacial stress analysis is presented for simply supported composite aluminum- sandwich honeycomb beam strengthened by imperfect FGM plateusing linear elastic theory. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends, while all existing solutions neglect this effect. Remarkable effect of shear deformations of adherends has been noted in the results.It is shown that both the sliding and the shear stress at the interface are influenced by the material and geometry parameters of the composite beam. This new solution is intended for applicationto composite beams made of all kinds of materials bonded with a thin plate. Finally, numerical comparisons between the existing solutions and the present new solution enable a clear appreciation of the effects of various parameters.

A numerical study on nonlinear stability of higher-order sandwich beams with cellular core and nanocomposite face sheets

  • Ding, Ke;Jia, Hu;Xu, Jun;Liu, Yi;Al-Tamimi, Haneen M.;Khadimallah, Mohamed Amine
    • Structural Engineering and Mechanics
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    • v.83 no.4
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    • pp.465-473
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    • 2022
  • In this research, a numerical study has been provided for examining the nonlinear stability behaviors of sandwich beams having a cellular core and two face sheets made of nanocomposites. The nonlinear stability behaviors of the sandwich beam having geometrically perfect/imperfect shapes have been studied when it is subjected to a compressive buckling load. The nanocomposite face sheets are made of epoxy reinforced by graphene oxide powders (GOPs). Also, the core has the shape of a honeycomb with regular configuration. Using finite element method based on a higher-order deformation beam element, the system of equations of motions have been solved to derive the stability curves. Several parameters such as face sheet thickness, core wall thickness, graphene oxide amount and boundary conditions have remarkable influences on stability curves of geometrically perfect/imperfect sandwich beams.

Development of super convergent Euler finite elements for the analysis of sandwich beams with soft core

  • Sudhakar, V;Gopalkrishnan, S;Vijayaraju, K
    • Structural Engineering and Mechanics
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    • v.65 no.6
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    • pp.657-678
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    • 2018
  • Sandwich structures are well known for their use in aircraft, naval and automobile industries due to their high strength resistance with light weight and high energy absorption capability. Sandwich beams with soft core are very common and simple structures that are employed in day to day general use appliances. Modeling and analysis of sandwich structures is not straight forward due to the interactions between core and face sheets. In this paper, formulation of Super Convergent finite elements for analysis of the sandwich beams with soft core based on Euler Bernoulli beam theory are presented. Two elements, Eul4d with 4 degrees of freedom assuming rigid core in transverse direction and Eul10d with 10 degrees of freedom assuming the flexible core were developed are presented. The formulation considers the top, bottom face sheets and core as separate entities and are coupled by beam kinematics. The performance of these elements are validated by results available in the published literature. Number of studies are performed using the formulated elements in static, free vibration and wave propagation analysis involving various boundary and loading conditions. The paper highlights the advantages of the elements developed over the traditional elements for modeling of sandwich beams and, in particular wave propagation analysis.

Thermal, electrical and mechanical buckling loads of sandwich nano-beams made of FG-CNTRC resting on Pasternak's foundation based on higher order shear deformation theory

  • Arani, Ali Ghorbanpour;Pourjamshidian, Mahmoud;Arefi, Mohammad;Arani, M.R. Ghorbanpour
    • Structural Engineering and Mechanics
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    • v.69 no.4
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    • pp.439-455
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    • 2019
  • This research deals with thermo-electro-mechanical buckling analysis of the sandwich nano-beams with face-sheets made of functionally graded carbon nano-tubes reinforcement composite (FG-CNTRC) based on the nonlocal strain gradient elasticity theory (NSGET) considering various higher-order shear deformation beam theories (HSDBT). The sandwich nano-beam with FG-CNTRC face-sheets is subjected to thermal and electrical loads while is resting on Pasternak's foundation. It is assumed that the material properties of the face-sheets change continuously along the thickness direction according to different patterns for CNTs distribution. In order to include coupling of strain and electrical field in equation of motion, the nonlocal non-classical nano-beam model contains piezoelectric effect. The governing equations of motion are derived using Hamilton principle based on HSDBTs and NSGET. The differential quadrature method (DQM) is used to calculate the mechanical buckling loads of sandwich nano-beam as well as critical voltage and temperature rising. After verification with validated reference, comprehensive numerical results are presented to investigate the influence of important parameters such as various HSDBTs, length scale parameter (strain gradient parameter), the nonlocal parameter, the CNTs volume fraction, Pasternak's foundation coefficients, various boundary conditions, the CNTs efficiency parameter and geometric dimensions on the buckling behaviors of FG sandwich nano-beam. The numerical results indicate that, the amounts of the mechanical critical load calculated by PSDBT and TSDBT approximately have same values as well as ESDBT and ASDBT. Also, it is worthy noted that buckling load calculated by aforementioned theories is nearly smaller than buckling load estimated by FSDBT. Also, similar aforementioned structure is used to building the nano/micro oscillators.