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Journal ArticleDOI

Nonlinear Free Flexural Vibration of Curvilinear Fibre Composite Laminates Using a Higher-Order Element

09 Nov 2018-International Journal of Structural Stability and Dynamics (World Scientific Publishing Company)-Vol. 18, Iss: 12, pp 1850147
TL;DR: In this paper, the nonlinear free flexural vibration of thick curvilinear fiber composite laminates is investigated using a higher-order shear flexible eight-noded quadrilateral element.
Abstract: In the present work, the nonlinear free flexural vibration of thick curvilinear fiber composite laminates is investigated using a higher-order shear flexible eight-noded quadrilateral element devel...
Citations
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Journal ArticleDOI
TL;DR: In this article, the influence of material and fabrication uncertainties on the natural frequencies of curvilinear fiber laminate is addressed, and material properties and fiber orientation are considered uncertain.
Abstract: This paper addresses the influence of material and fabrication uncertainties on natural frequencies of curvilinear fiber laminate. Material properties and fiber orientation are considered uncertain...

25 citations


Cites methods from "Nonlinear Free Flexural Vibration o..."

  • ...Ply Orientation Present Houmat [14] Ganapathi [16] 1⁄2< 40=10 >, < 40= 10 > sym 0....

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  • ...Table 2 shows a comparison of nondimensional fundamental frequencies obtained using the present FE code with Houmat [14] and Ganapathi [16]....

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Journal ArticleDOI
TL;DR: In this paper, the thermo-elastic buckling characteristics of variable stiffness composite shells, viz., cylindrical and spherical shell panels, subjected to uniform/non-uniform thermal fields are investigated based on finite element approach introducing higher-order theory accounting through thickness effect.

22 citations

Journal ArticleDOI
TL;DR: In this article, the effect of uncertain composite properties that could arise due to complex manufacturing and fabrication process to the buckling temperature is investigated using polynomial neural network (PNN).

20 citations

Journal ArticleDOI
TL;DR: In this article , the free and forced vibration analysis of variable stiffness composite laminated (VSCL) and sandwich shell panels having curvilinear fibres was conducted based on a higher-order theory.
Abstract: The nonlinear free and forced vibration analyses of variable stiffness composite laminated (VSCL) and sandwich shell panels having curvilinear fibres, not yet reported in literature, are conducted based on a higher-order theory. The present structural model considers a third-order shear deformation theory incorporating Murakami zig-zag effects. The analyses are performed using C 0 nine-noded isoparametric element with thirteen degrees of freedom and geometrical nonlinearity is included through von Kármán nonlinear strain–displacement relations. The free and forced vibrational responses of the VSCL are established using the eigenvalue solutions and Newmark’s time integration technique, respectively. The results obtained using the present finite element formulation are compared with the available three-dimensional exact and two-dimensional analytical and numerical solutions for establishing the validity of the model. The fundamental frequencies and nonlinear transient deflections of VSCL and sandwich spherical and cylindrical shell panels are evaluated considering the effects of curvilinear fibre path, curvature ratio, number of layers and lamination configuration. • Analysed nonlinear vibration behaviour of composite laminated and sandwich shell panels with curvilinear fibres. • A finite element formulation based on Murakami zig-zag theory with thirteen degrees of freedom per node is considered. • Nonlinear dynamic behaviour of VSCL and sandwich shell panels investigated for the first time. • Dynamic response is affected by the curvilinear fibre orientation for VSCL structures.

15 citations

Journal ArticleDOI
TL;DR: In this paper, the dynamic stability characteristics of variable stiffness composite rectangular panels subjected to non-conservative compressive or shear follower loads are investigated using the shear-deformable finite element method.

14 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a new laminated composite plate theory was developed based upon a new variational principle proposed by Reissner (1984), which was achieved by including a zigzag-shaped C 0 function to approximate the thickness variation of in-plane displacements.
Abstract: In order to improve the accuracy of the in-plane response of the shear, deformable laminated composite plate theory, a new laminated plate theory has been developed based upon a new variational principle proposed by Reissner (1984). The improvement is achieved by including a zigzag-shaped C 0 function to approximate the thickness variation of in-plane displacements. The accuracy of this theory is examined by applying it to a problem of cylindrical bending of laminated plates which has been solved exactly by Pagano (1969). The comparison of the in-plane response with the exact solutions for symmetric three-ply and five-ply layers has demonstrated that the new theory predicts the in-plane response very accurately even for small span-to-depth ratios.

723 citations

Journal ArticleDOI
TL;DR: In this paper, a solution to the plane elasticity problem for a symmetrically laminated composite panel with spatially varying fiber orientations has been obtained, and the effects of the variable fiber orientation on the displacement fields, stress resultants and global stiffness are analyzed.
Abstract: A solution to the plane elasticity problem for a symmetrically laminated composite panel with spatially varying fiber orientations has been obtained. The fiber angles vary along the length of the composite laminate, resulting in stiffness properties that change as a function of location. This work presents an analysis of the stiffness variation and its effects on the elastic response of the panel. The in-plane response of a variable stiff ness panel is governed by a system of coupled elliptic partial differential equations/Solving these equations yields the displacement fields, from which the strains, stresses, and stress resultants can be subsequently calculated. A numerical solution has been obtained using an iterative collocation technique. Corresponding closed-form solutions are presented for three sets of boundary conditions, two of which have exact solutions, and therefore serve to validate the numerical model. The effects of the variable fiber orientation on the displacement fields, stress resultants, and global stiffness are analyzed.

474 citations

Journal ArticleDOI
TL;DR: In this paper, the fiber orientation variation for flat rectangular composite laminates that possess variable stiffness properties is described, which employs a unidirectional variation based on a linear function for fiber orientation angle of individual layers.
Abstract: Descriptions of fiber orientation variation for flat rectangular composite laminates that possess variable stiffness properties are introduced. The simplest definition employs a unidirectional variation based on a linear function for the fiber orientation angle of the individual layers. Analyses of variable stiffness panels for in-plane and buckling responses are developed and demonstrated for two distinct cases of stiffness variations. The first case assumes a stiffness variation in the direction of the loading, and numerical results indicate small improvements in buckling load for some panel configurations due to favorable distribution of the transverse stresses over the panel planform. The second case varies the stiffness perpendicular to the loading, and provides a much higher degree of improvement due to the re-distribution of the applied loads. It is also demonstrated that the variable stiffness concept provides a flexibility to the designer for trade-offs between overall panel stiffness and buckling load, in that there exist many configurations with equal buckling loads yet different global stiffness values, or vice versa.

399 citations

Journal ArticleDOI
Michael W. Hyer1, H.H. Lee1
TL;DR: In this article, the authors explored the gains in buckling performance that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point.

349 citations

M. W. Hyer1, H. H. Lee
01 Mar 1990
TL;DR: In this paper, the authors explored the gains in buckling performance that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point.
Abstract: The gains in buckling performance are explored that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point. The particular situation studied is a simply supported square plate with a centrally located hole loaded in compression. By using both a sensitivity analysis and a gradient-search technique, fiber orientation in a number of regions of the plate are selected so as to increase the buckling load relative to baseline straightline designs. The sensitivity analysis is used to determine which regions of the plate have the most influence on buckling load, and the gradient search is used to find the design that is believed to represent the absolute maximum buckling load for the conditions prescribed. Convergence studies and sensitivity of the final design are discussed. By examining the stress resultant contours, it is shown how the curvilinear fibers move the load away from the unsupported hole region of the plate to the supported edges, thus increasing the buckling capacity. The tensile capacity of the improved buckling design is investigated, and it is shown that both tensile capacity and buckling capacity can be improved with the curvilinear fiber concept.

312 citations