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Jaehong Lee - One of the best experts on this subject based on the ideXlab platform.

  • Flexural-torsional behavior of thin-walled composite beams
    2016
    Co-Authors: Jaehong Lee
    Abstract:

    This paper presents a flexural-torsional analysis of composite box beams. A general analytical model applicable to thin-walled box section composite beams subjected to vertical and torsional load is developed. This model is based on the Classical Lamination Theory, and accounts for the coupling of flexural and torsional responses for arbitrary laminate stacking sequence configuration, i.e. unsymmetric as well as symmetric. Governing equations are derived from the principle of the stationary value of total potential energy. Numerical results are obtained for thin-walled composites beams under vertical and torsional loading, addressing the effects of fiber angle and laminate stacking sequence

  • Free vibration of thin-walled composite box beams. Compos Struct
    2016
    Co-Authors: Jaehong Lee
    Abstract:

    Free vibration of a thin-walled laminated composite beam is studied. A general analytical model applicable to the dynamic behavior of a thin-walled composite box section is developed. This model is based on the Classical Lamination Theory, and accounts for the coupling of flexural and torsional modes for arbitrary laminate stacking sequence configuration, i.e. unsymmetric as well as symmetric, and various boundary conditions. A displacement-based one-dimensional finite element model is developed to predict natural frequencies and corresponding vibration modes for a thin-walled composite beam. Equations of motion are derived from the Hamilton’s principle. Numerical results are obtained for thin-walled composites addressing the effects of fiber angle, modulus ratio, and boundary conditions on the vibration frequencies and mode shapes of the composites

  • interaction curves for vibration and buckling of thin walled composite box beams under axial loads and end moments
    Applied Mathematical Modelling, 2010
    Co-Authors: Jaehong Lee
    Abstract:

    Interaction curves for vibration and buckling of thin-walled composite box beams with arbitrary lay-ups under constant axial loads and equal end moments are presented. This model is based on the Classical Lamination Theory, and accounts for all the structural coupling coming from material anisotropy. The governing differential equations are derived from the Hamilton’s principle. The resulting coupling is referred to as triply flexural–torsional coupled vibration and buckling. A displacement-based one-dimensional finite element model with seven degrees of freedoms per node is developed to solve the problem. Numerical results are obtained for thin-walled composite box beams to investigate the effects of axial force, bending moment, fiber orientation on the buckling loads, buckling moments, natural frequencies and corresponding vibration mode shapes as well as axial-moment–frequency interaction curves.

  • Geometrically nonlinear analysis of thin-walled open-section composite beams
    Computers & Structures, 2010
    Co-Authors: Jaehong Lee
    Abstract:

    A geometrically nonlinear model for general thin-walled open-section composite beams with arbitrary lay-ups under various types of loadings based on the Classical Lamination Theory is presented. It accounts for all structural coupling coming from the material anisotropy and geometric nonlinearity. Nonlinear governing equations are derived and solved by means of an incremental Newton-Raphson method. The finite element model that accounts for the geometric nonlinearity in the von Karman sense is developed to solve the problem. Numerical results are obtained for thin-walled composite Z-beam and I-beam to investigate effects of geometric nonlinearity, fiber orientation and warping restraint on the flexural-torsional response.

  • Geometrically nonlinear analysis of thin-walled composite box beams
    Computers & Structures, 2008
    Co-Authors: Jaehong Lee
    Abstract:

    A general geometrically nonlinear model for thin-walled composite space beams with arbitrary lay-ups under various types of loadings has been presented by using variational formulation based on the Classical Lamination Theory. The nonlinear governing equations are derived and solved by means of an incremental Newton-Raphson method. A displacement-based one-dimensional finite element model that accounts for the geometric nonlinearity in the von Karman sense is developed. Numerical results are obtained for thin-walled composite box beam under vertical load to investigate the effect of geometric nonlinearity and address the effects of the fiber orientation, laminate stacking sequence, load parameter on axial-flexural-torsional response.

Reaz A Chaudhuri - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Lamination and Boundary Constraint on the Deformation of Moderately Thick Cross-Ply Rectangular Plates
    Journal of Composite Materials, 2016
    Co-Authors: Reaz A Chaudhuri, Humayun Kabir
    Abstract:

    Hitherto unavailable analytical solutions to boundary-value problems of moderately thick general cross-ply laminated rectangular plates, subjected to various boundary conditions, are presented. A recently developed double Fourier series-based method has been utilized to solve a system of five highly coupled linear second-order par tial differential equations (with constant coefficients), that emerge from the first-order shear deformation Theory (FSDT) and the associated geometric and natural boundary con ditions. The convergence characteristics of the series solutions, especially their de pendence on Lamination and boundary constraint, are numerically investigated in detail. Other numerical results presented here include (1) verification with the available analytical solutions based on the Classical Lamination Theory (CLT) as well as FSDT, (2) investigation of the effect of length-to-thickness, length-to-width and modular ratios on the response of antisymmetric and symmetric cross-ply plates, with various...

  • beam column and tie bar effects in internally pressurized thin arbitrarily laminated cantilever cylindrical shells
    Journal of Engineering Mechanics-asce, 2015
    Co-Authors: Reaz A Chaudhuri, Sinan A Oktem, Guedes C Soares
    Abstract:

    AbstractAn arbitrarily laminated, anisotropic cantilever cylindrical shell of finite length, under uniform internal pressure, is analyzed using kinematic relations under the framework of Classical Lamination Theory. Extensive numerical results are presented for two model problems, pertaining to two-layer, asymmetrically laminated, anisotropic cantilever cylindrical shells, illustrating the influence of layer anisotropy and Lamination sequence on the beam-column/tie-bar effects, which, in turn, severely affect the free-end displacements and other response quantities of interest. Furthermore, because the beam-column effect can cause severe wrinkling in a thin asymmetrically laminated cylindrical shell, the possibility of its elimination through composite tailoring (a combination of stacking sequence and fiber orientation angle in a constituent lamina) has also been explored. Finally, the effect of length-to-radius ratio is also numerically investigated.

  • effect of thickness on buckling of perfect cross ply rings under external pressure
    Composite Structures, 2007
    Co-Authors: Deokjoo Kim, Reaz A Chaudhuri
    Abstract:

    Effect of thickness on the buckling of a perfect thick plane strain cross-ply ring (very long cylindrical shell) is investigated. A linearized version of a fully nonlinear finite element analysis, that employs a cylindrically curved 16-node layer-element, and is based on the assumption of layer-wise linear displacements distribution through thickness (LLDT), is utilized for computation of hydrostatic buckling pressure of the afore-mentioned cross-ply ring. Numerical results pertaining to the effect of thickness (interlaminar shear/normal deformation) on the hydrostatic buckling pressure of cross-ply rings and comparison with their Classical Lamination Theory (CLT) counterparts are also presented.

  • vibration of clamped moderately thick general cross ply plates using a generalized navier approach
    Composite Structures, 1993
    Co-Authors: Reaz A Chaudhuri, Humayun Kabir
    Abstract:

    A hitherto unavailable analytical solution to the free vibration problem of general cross-ply laminated rigidly clamped rectangular plates, incorporating first-order shear deformation, and rotatory and in-plane inertias into the formulation, is presented. A recently developed boundary continuous displacement-based generalized Navier solution technique is used to solve the five highly coupled linear second-order partial differential equations with constant coefficients, and the associated geometric boundary conditions. The assumed solution functions are in the form of double Fourier series, which satisfy the rigidly clamped boundary conditions a priori in a manner similar to the conventional Navier method. Convergence characteristics of the natural frequencies of both symmetric and antisymmetric cross-ply plates are numerically established. Other numerical results presented herein include (i) comparison with the corresponding available first-order shear deformation Theory-based Galerkin and Classical Lamination Theory-based boundary-discontinuous analytical solutions, and (ii) study of the effects of thickness and aspect ratio on the natural frequencies.

Humayun Kabir - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Lamination and Boundary Constraint on the Deformation of Moderately Thick Cross-Ply Rectangular Plates
    Journal of Composite Materials, 2016
    Co-Authors: Reaz A Chaudhuri, Humayun Kabir
    Abstract:

    Hitherto unavailable analytical solutions to boundary-value problems of moderately thick general cross-ply laminated rectangular plates, subjected to various boundary conditions, are presented. A recently developed double Fourier series-based method has been utilized to solve a system of five highly coupled linear second-order par tial differential equations (with constant coefficients), that emerge from the first-order shear deformation Theory (FSDT) and the associated geometric and natural boundary con ditions. The convergence characteristics of the series solutions, especially their de pendence on Lamination and boundary constraint, are numerically investigated in detail. Other numerical results presented here include (1) verification with the available analytical solutions based on the Classical Lamination Theory (CLT) as well as FSDT, (2) investigation of the effect of length-to-thickness, length-to-width and modular ratios on the response of antisymmetric and symmetric cross-ply plates, with various...

  • vibration of clamped moderately thick general cross ply plates using a generalized navier approach
    Composite Structures, 1993
    Co-Authors: Reaz A Chaudhuri, Humayun Kabir
    Abstract:

    A hitherto unavailable analytical solution to the free vibration problem of general cross-ply laminated rigidly clamped rectangular plates, incorporating first-order shear deformation, and rotatory and in-plane inertias into the formulation, is presented. A recently developed boundary continuous displacement-based generalized Navier solution technique is used to solve the five highly coupled linear second-order partial differential equations with constant coefficients, and the associated geometric boundary conditions. The assumed solution functions are in the form of double Fourier series, which satisfy the rigidly clamped boundary conditions a priori in a manner similar to the conventional Navier method. Convergence characteristics of the natural frequencies of both symmetric and antisymmetric cross-ply plates are numerically established. Other numerical results presented herein include (i) comparison with the corresponding available first-order shear deformation Theory-based Galerkin and Classical Lamination Theory-based boundary-discontinuous analytical solutions, and (ii) study of the effects of thickness and aspect ratio on the natural frequencies.

P I Gonzalezchi - One of the best experts on this subject based on the ideXlab platform.

  • scaling effect on the tensile properties of 45 0 45 0 45 polypropylene twaron laminates
    Polymer Testing, 2015
    Co-Authors: J L Menatun, C Martinbarrera, P I Gonzalezchi
    Abstract:

    Abstract The effects of scaling on the mechanical response under tension of balanced nonsymmetrical laminates were investigated for a thermoplastic composite: Polypropylene reinforced with Twaron® fibers. The composite baseline was an 8-ply laminate which consisted of unidirectional plies arranged in the sequence [±45/0/±45/0/±45]. The influence of specimen size on the tensile properties was studied for one (thickness), two (in-plane) and three (volume) dimensional scaling. The stress-strain curves suggested some variation in laminate behavior owing to the dimensional scaling; nevertheless, a further analysis with the Classical Lamination Theory demonstrated that the observed effect was due to small variations in the fiber volume fraction of the laminates. It was concluded that the mechanical properties of these thermoplastic laminates do not exhibit scaling effects. The failure mechanism of the laminates was studied at macroscopic level; a scale effect of the fracture mechanism was observed.

  • tensile properties of thermoplastic laminated composites based on a polypropylene matrix reinforced with continuous twaron fibers
    Advances in Polymer Technology, 2013
    Co-Authors: J L Menatun, P I Gonzalezchi, A Diazdiaz
    Abstract:

    The present paper focuses on a semiempirical macroscopic approach for the prediction of the tensile properties (modulus and strength) of thermoplastic laminates based on polypropylene (PP) reinforced with Twaron fibers. The influence of fiber content on the orthotropic stiffnesses and strengths of the unidirectional composite was experimentally determined; then, these orthotropic properties were the input data for the prediction, by means of the Classical Lamination Theory, of the tensile effective properties of several PP/Twaron laminates. Good agreement was found between the predicted and experimental tensile data of the laminates. A previous publication focused on the modeling of the nonlinear behavior of PP/Twaron laminates; consequently, the results from the present work proved that the whole mechanical response of thermoplastic laminates PP/Twaron can be simulated by means of macroscopic models originally developed for thermosetting composites. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E749–E759, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21318

Sami Aksoy - One of the best experts on this subject based on the ideXlab platform.