• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.653-660
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• 2012

In this paper free vibration analysis of symmetric and cross-ply elastic laminated shells based on FSDT with two different boundary conditions(C-C, S-S) was performed through discretization of equations of motion and boundary condition. Model of laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations (Faraday, Ampere, Ohm, and Lorenz equations) and thermal equations which are involved in constitutive equations. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, and stacking sequence for each boundary conditions are investigated and pertinent conclusions are derived.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.13-20
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• 1994

The effects of prebuckling on the buckling of laminated composite cylindrical shells are investigated. Both axial compression and lateral pressure are considered for laminated composite cylindrical shells with length to radius ratios usually associated with container vessels. The shell walls are made of a laminate with several symmetric ply orientations. The study was made using finite difference energy method, utilizing the nonlinear bifurcation branch with nonlinear prebuckling displacements. The results are compared to the buckling loads determined when prebuckling displacements are neglected.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.9
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• pp.797-805
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• 2013

In this paper vibration and stability analysis of laminated composite shells based on the first order shear deformation theory(FSDT) for two different boundary conditions(clamped-clamped, simply supported) are performed. Structural model of cross-ply symmetric laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations(Faraday, Ampere, Ohm, and Lorenz equations)and thermal equations which are involved in constitutive equations. Extended Galerkin method is adopted to obtain the discretized equations of motion. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, laminate thickness-ratio and radius ratio for two boundary conditions are investigated and pertinent conclusions are derived.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.458-462
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• 2005

This paper deal with the optimal lamination condition of cylindrical shell applied new composite URN300 for a study of composite empirical formula. Finite element analyses for isotropic materials considered element numbers and boundary conditions are compared with existing empirical formulas to apply FE analysis for composite. And composite tensile test is done to know the composite material applied FE analysis for composite. The results of FE analyses for isotropic materials have indicated that Optimal element number and boundary condition were 1600 and both simple support. These conditions were applied in composite FE analyses. Ply orientations and lamination patterns in FE analyses for composite were considered. Ply orientations are $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;60^{\circ},\;75^{\circ},\;and\;90^{\circ}$. Lamination patterns are $[\pm\theta/0/90]_{14s]$ and $[\pm\theta_{14}/0_{14}/90_{14}]_s$ in FE analysis. Lamination pattern $[\pm\theta_{14}/0_{14}/90_{14}]_s$ is the equivalent model of $[\pm\theta/0/90]_{14s}$. At the result of this study, the FE analyses for composite have indicated that the optimized ply orientation $75^{\circ}$ is and real model must use in FE analysis for accurate results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.410-413
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• 2005

The results of an experimental and analytical study of composite pressure hull on buckling pressure are presented for LRN 300. Composite tensile test was done to know the composite material properties applied FE analysis for URN composite. We predicted the buckling and post buckling analysis of composite laminated cylindrical panels under external compression by using ABAQUS /Standard[Ver 6.4]. To obtain nonlinear static equilibrium solutions for unstable problems, where the load-displacement response can exhibit the type of nonlinear buckling behavior, during periods of the response, the load and/or the displacement may decrease as the solution evolves, used the modified Riks method. The modified Riks method is an algorithm that allows effective solution of such cases [7]. Experiments were conducted to verify the validation of present analysis for cross-ply laminated shells. The shells considered in the study have two different lamination patterns, $[{\pm}45/0/90]_{18s\;and}\;[/0/90]_{18s}$. Cylindrical panel of experiment and analysis have the radius of 200mm, length of 210mm and 60 degree of cutting angle. The critical load from experiment is $69\%$ of that of numerical analysis, because the fracture of matrix was generated before buckling. So URN 300 is not proper to use at the condition under high external pressue.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.212-213
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• 2005

The results of an experimental and analytical study of composite pressure hull on buckling pressure are presented for URN 300. We predicted the buckling and post buckling analysis of composite laminated cylindrical shell and panel under external compression by using ABAQUS/Standard[Ver 6.4]. To obtain nonlinear static equilibrium solutions for unstable problems, where the load-displacement response can exhibit the type of nonlinear buckling behavior, during periods of the response, the load and/or the displacement may decrease as the solution evolves, used the modified Riks method. Experiments were conducted to verify the validation of present analysis for cross-ply laminated shells. The shells considered in the study have four different lamination patterns, [${\pm}{\Theta}$/0/90]$_{14s}$,[${\pm}{\Theta}_{14}$/$0_{14}$/$90_{14}$],[${\pm}$45/0/90]$_{18s}$ and [/0/90]$_{18s}$. At the result of this study, the optimized ply orientation angle is $75^{\circ}$. The critical load from experiment is 69% of that of numerical analysis, because the fracture of matrix was generated before buckling. So URN 300 is not proper to use at the condition under high external pressure.