• Title/Summary/Keyword: Stretching bending

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A new hybrid HSDT for bending, free vibration, and buckling analysis of FGM plates (2D & quasi-3D)

  • Belkhodja, Y.;Ouinas, D.;Fekirini, H.;Olay, J.A. Vina;Achour, B.;Touahmia, M.;Boukendakdji, M.
    • Smart Structures and Systems
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    • v.29 no.3
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    • pp.395-420
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    • 2022
  • A new hybrid quasi-3D and 2D high-order shear deformation theory is studied in this mathematical formulation, for an investigation of the bending, free vibrations and buckling influences on a functionally graded material plate. The theoretical formulation has been begun by a displacement field of five unknowns, governing the transverse displacement across the thickness of the plate by bending, shearing and stretching. The transverse shear deformation effect has been taken into consideration, satisfying the stress-free boundary conditions, especially on plate free surfaces as parabolic variation through its thickness. Thus, the mechanical properties of the functionally graded plate vary across the plate thickness, following three distributions forms: the power law, exponential form and the Mori-Tanaka scheme. The mechanical properties are used to develop the equations of motion, obtained from the Hamilton principle, and solved by applying the Navier-type solution for simply supported boundary conditions. The results obtained are compared with other solutions of 2D, 3D and quasi-3D plate theories have been found in the literature.

A sinusoidal plate theory with 5-unknowns and stretching effect for thermomechanical bending of functionally graded sandwich plates

  • Hamidi, Ahmed;Houari, Mohammed Sid Ahmed;Mahmoud, S.R.;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.235-253
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    • 2015
  • In this research, a simple but accurate sinusoidal plate theory for the thermomechanical bending analysis of functionally graded sandwich plates is presented. The main advantage of this approach is that, in addition to incorporating the thickness stretching effect, it deals with only 5 unknowns as the first order shear deformation theory (FSDT), instead of 6 as in the well-known conventional sinusoidal plate theory (SPT). The material properties of the sandwich plate faces are assumed to vary according to a power law distribution in terms of the volume fractions of the constituents. The core layer is made of an isotropic ceramic material. Comparison studies are performed to check the validity of the present results from which it can be concluded that the proposed theory is accurate and efficient in predicting the thermomechanical behavior of functionally graded sandwich plates. The effect of side-to-thickness ratio, aspect ratio, the volume fraction exponent, and the loading conditions on the thermomechanical response of functionally graded sandwich plates is also investigated and discussed.

Fabrication or Bending Actuator Using Shape Memory Alloy and Basic Experiment or Control (형상기억합금을 이용한 bending 액츄에이터의 제작 및 컨트롤을 위한 기초실험)

  • Kim, M.S.;Choi, N.B.;Kim, D.W.;Lee, S.H.;Lee, S.K.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.497-500
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    • 1997
  • In this paper, we proposes a bending actuator using shape memory alloy coil-type springs. By the heating of two shape memory alloy coil-type springs sequentially, the bending and stretching motion of the actuator is possible. We measure the bending angle and repeated bending motion with the various currents. Furthermore, we control the bending angle of the 1 directional bending actuator with sensors. The performance of the actuator has been characterized or the possible application for catheter.

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RBF-POD reduced-order modeling of DNA molecules under stretching and bending

  • Lee, Chung-Hao;Chen, Jiun-Shyan
    • Interaction and multiscale mechanics
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    • v.6 no.4
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    • pp.395-409
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    • 2013
  • Molecular dynamics (MD) systems are highly nonlinear and nonlocal, and the conventional model order reduction methods are ineffective for MD systems. The RBF-POD method (Lee and Chen, 2013) employed a radial basis function (RBF) approximated potential energies and inter-atomic forces of MD systems under the framework of the proper orthogonal decomposition (POD) method for the reduced-order modeling of MD systems. In this work, we focus on the numerical procedures of the RBF-POD method and demonstrate how to apply this approach to the modeling of ds-DNA molecules under stretching and bending conditions.

In-plane Vibration Analysis of Rotating Cantilever Curved Beams

  • Zhang, Guang-Hui;Liu, Zhan Sheng;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1045-1050
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    • 2007
  • Equations of motion of rotating cantilever curved beams are derived based on a dynamic modeling method developed in this paper. The Kane's method is employed to derive the equations of motion. Different from the classical linear modeling method which employs two cylindrical deformation variables, the present modeling method employs a non-cylindrical variable along with a cylindrical variable to describe the elastic deformation. The derived equations (governing the stretching and the bending motions) are coupled but linear. So they can be directly used for the vibration analysis. The coupling effect between the stretching and the bending motions which could not be considered in the conventional modeling method is considered in this modeling method. The natural frequencies of the rotating curved beams versus the rotating speed are calculated for various radii of curvature and hub radius ratios.

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Press Formabilities of Aluminum Sheets for Autobody Application (차체용 알루미늄 판재의 프레스 성형성)

  • Kim, Y.S.;Kim, K.S.;Kwon, N.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.73-83
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    • 1994
  • Press formabilities of aluminum sheets for automobile body were investigated. Plane strain stretching test (called RIST-PSST), cupping test and U bending test were performed to assess the press formability of aluminum sheets respectively. The results showed that aluminum sheets are generally inferior to cold-rolled steel sheet of deep drawing quality (CSP3N) in press formability. The limiting punch height (LPH) and limiting plane strain (FLCo) of aluminum sheets are 50%-70% level compared to that of CSP3N. Moreover, the limiting drawing ratios(LDR) of aluminum sheets are ranged between 1.95 and 2.1. The poor press formability of aluminum sheets is responsible for low values of total elongation and plastic anisotropy parameter in tensile characteristic. The shape fixability of aluminum sheets evaluated in U bending test is very poor due to its low elastic modulus compared to CSP3N.

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Robust quasi 3D computational model for mechanical response of FG thick sandwich plate

  • Achouri, Fatima;Benyoucef, Samir;Bourada, Fouad;Bouiadjra, Rabbab Bachir;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.70 no.5
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    • pp.571-589
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    • 2019
  • This paper aims to develop a quasi-3D shear deformation theory for the study of bending, buckling and free vibration responses of functionally graded (FG) sandwich thick plates. For that, in the present theory, both the components of normal deformation and shear strain are included. The displacement field of the proposed model contains undetermined integral terms and involves only four unknown functions with including stretching effect. Using Navier's technique the solution of the problem is derived for simply supported sandwich plate. Numerical results have been reported, and compared with those available in the open literature were excellent agreement was observed. Finally, a detailed parametric study is presented to demonstrate the effect of the different parameters on the flexural responses, free vibration and buckling of a simply supported sandwich plates.

Influence of clamped-clamped boundary conditions on the mechanical stress, strain and deformation analyses of cylindrical sport equipment

  • Yuhao Yang;Mohammad Arefi
    • Geomechanics and Engineering
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    • v.35 no.5
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    • pp.465-473
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    • 2023
  • The higher order shear deformable model and an exact analytical method is used for analytical bending analysis of a cylindrical shell subjected to mechanical loads, in this work. The shell is modelled using sinusoidal bivariate shear strain theory, and the static governing equations are derived using changes in virtual work. The eigenvalue-eigenvector method is used to exactly solve the governing equations for a constrained cylindrical shell The proposed kinematic relation decomposes the radial displacement into bending, shearing and stretching functions. The main advantage of the method presented in this work is the study of the effect of clamping constraints on the local stresses at the ends. Stress, strain, and deformation analysis of shells through thickness and length.

A nonlocal quasi-3D theory for bending and free flexural vibration behaviors of functionally graded nanobeams

  • Bouafia, Khadra;Kaci, Abdelhakim;Houari, Mohammed Sid Ahmed;Benzair, Abdelnour;Tounsi, Abdelouahed
    • Smart Structures and Systems
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    • v.19 no.2
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    • pp.115-126
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    • 2017
  • In this paper, size dependent bending and free flexural vibration behaviors of functionally graded (FG) nanobeams are investigated using a nonlocal quasi-3D theory in which both shear deformation and thickness stretching effects are introduced. The nonlocal elastic behavior is described by the differential constitutive model of Eringen, which enables the present model to become effective in the analysis and design of nanostructures. The present theory incorporates the length scale parameter (nonlocal parameter) which can capture the small scale effect, and furthermore accounts for both shear deformation and thickness stretching effects by virtue of a hyperbolic variation of all displacements through the thickness without using shear correction factor. The material properties of FG nanobeams are assumed to vary through the thickness according to a power law. The neutral surface position for such FG nanobeams is determined and the present theory based on exact neutral surface position is employed here. The governing equations are derived using the principal of minimum total potential energy. The effects of nonlocal parameter, aspect ratio and various material compositions on the static and dynamic responses of the FG nanobeam are discussed in detail. A detailed numerical study is carried out to examine the effect of material gradient index, the nonlocal parameter, the beam aspect ratio on the global response of the FG nanobeam. These findings are important in mechanical design considerations of devices that use carbon nanotubes.

A refined quasi-3D hybrid-type higher order shear deformation theory for bending and Free vibration analysis of advanced composites beams

  • Meradjah, Mustapha;Bouakkaz, Khaled;Zaoui, Fatima Zohra;Tounsi, Abdelouahed
    • Wind and Structures
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    • v.27 no.4
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    • pp.269-282
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    • 2018
  • In this paper, a new displacement field based on quasi-3D hybrid-type higher order shear deformation theory is developed to analyze the static and dynamic response of exponential (E), power-law (P) and sigmoïd (S) functionally graded beams. Novelty of this theory is that involve just three unknowns with including stretching effect, as opposed to four or even greater numbers in other shear and normal deformation theories. It also accounts for a parabolic distribution of the transverse shear stresses across the thickness, and satisfies the zero traction boundary conditions at beams surfaces without introducing a shear correction factor. The beam governing equations and boundary conditions are determined by employing the Hamilton's principle. Navier-type analytical solutions of bending and free vibration analysis are provided for simply supported beams subjected to uniform distribution loads. The effect of the sigmoid, exponent and power-law volume fraction, the thickness stretching and the material length scale parameter on the deflection, stresses and natural frequencies are discussed in tabular and graphical forms. The obtained results are compared with previously published results to verify the performance of this theory. It was clearly shown that this theory is not only accurate and efficient but almost comparable to other higher order shear deformation theories that contain more number of unknowns.