• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1996.09a
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• pp.95-110
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• 1996

High Tensile Steel enables to reduce the plate thickness comparing to the case when Mild Steel is used. From the economical view point this is very preferable since the reduction in the hull weight. However to use the High Tensile Steel effectively the plate thickness may become thin so that the occurrence of buckling is inevitable and design allowing plate buckling may be necessary. If the inplane stiffness of the plating decreases due to buckling, buckling may be necessary. If the inplane stiffness of the plating decreases due to buckling the flexural rigidity of the cross section of a ship's hull also decreases. this may lead to excessive deflection of the hull girder under longitudinal bending. In these cases a precise estimation of plate's behavior after buckling is necessary and nonlinear analysis of isolated and stiffened plates is required for structural system analysis. In this connection this paper discusses nonlinear behaviour of thin plate under thrust. Based on the analytical method elastic large deflection analysis of isolated plate is perform and simple expression are derived to evaluate the inplane rigidity of plates subjected to uniaxial compression.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.147-151
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• 2010

Since the kinetic energy is dissipated through plastic deformation energy generated in expanding process of the tube by a die. In order to successfully absorb the kinetic energy there should be no buckling in the expansion tube during expanding process. The buckling instability of the expansion tubes is affected by the initial boundary conditions, tube thickness and length. In this study, the effects of the tube thickness except length and initial boundary condition on the buckling instability are studied using a finite element method. In addition, Analysis procedure for nonlinear post-buckling analysis of expansion tube is established. There are three kinds of finite element analysis procedures for buckling analysis of expansion tube, quasi-static analysis, linear buckling analysis and nonlinear post-buckling analysis. The effect of the geometry imperfections defined as linear superimposition of buckling modes is considered in the nonlinear post-buckling analysis. The results of finite element analysis indicate that the buckling load increase with increase of thickness of tube and geometry imperfection. Finial buckling shapes are changed with respect to the geometry imperfection.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.1
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• pp.53-61
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• 2015

This paper presented the nonlinear behaviors of the single-layered lattice dome, which is widely used for the long-span structure system. The behaviors were analysed through the classical shell buckling theory as the single-layered lattice dome behaves like continum thin shell due to its geometric characteristics, and finite element analysis method using the software program Nastran. Shell buckling theory provides two types of buckling loads, the global- and member buckling, and finite element analysis provides the ultimate load of geometric nonlinear analysis as well as the buckling load of Eigen value solution. Two types of models for the lattice dome were analysed, that is rigid- and pin-jointed structure. Buckling load using the shell buckling theory for each type of lattice dome, governed by the minimum value of global buckling or member buckling load, resulted better estimation than the buckling load with Eigen value analysis. And it is useful to predict the buckling pattern, that is global buckling or member buckling.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.565-584
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• 2020

The nonlinear thermo-electro-elastic buckling behavior of viscoelastic nanoplates under magnetic field is investigated based on nonlocal elasticity theory. Employing nonlinear strain-displacement relations, the geometrical nonlinearity is modeled while governing equations are derived through Hamilton's principle and they are solved applying semi-analytical generalized differential quadrature (GDQ) method. Eringen's nonlocal elasticity theory considers the effect of small size, which enables the present model to become effective in the analysis and design of nano-sensors and nano actuators. Based on Kelvin-Voigt model, the influence of the viscoelastic coefficient is also discussed. It is demonstrated that the GDQ method has high precision and computational efficiency in the buckling analysis of viscoelastic nanoplates. The good agreement between the results of this article and those available in literature validated the presented approach. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as electric voltage, small scale effects, elastomeric medium, magnetic field, temperature effects, the viscidity and aspect ratio of the nanoplate on its nonlinear buckling characteristics. It is explicitly shown that the thermo-electro-elastic nonlinear buckling behavior of viscoelastic nanoplates is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of viscoelastic nanoplates as fundamental elements in nanoelectromechanical systems.

• Structural Engineering and Mechanics
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• v.60 no.4
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• pp.615-631
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• 2016

In this paper, an analytical method for the Post-buckling response of cylindrical shells with spiral stiffeners surrounded by an elastic medium subjected to external pressure is presented. The proposed model is based on two parameters elastic foundation Winkler and Pasternak. The material properties of the shell and stiffeners are assumed to be continuously graded in the thickness direction. According to the Von Karman nonlinear equations and the classical plate theory of shells, strain-displacement relations are obtained. The smeared stiffeners technique and Galerkin method is used to solve the nonlinear problem. To valid the formulations, comparisons are made with the available solutions for nonlinear static buckling of stiffened homogeneous and un-stiffened FGM cylindrical shells. The obtained results show the elastic foundation Winkler on the response of buckling is more effective than the elastic foundation Pasternak. Also the ceramic shells buckling strength higher than the metal shells and minimum critical buckling load is occurred, when both of the stiffeners have angle of thirty degrees.

• Structural Engineering and Mechanics
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• v.27 no.4
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• pp.477-499
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• 2007

The main purpose of this paper is to investigate the ultimate behavior of steel cable-stayed bridges with design variables and compare the validity and applicability of computational methods for evaluating ultimate load capacity of cable-stayed bridges. The methods considered in this paper are elastic buckling analysis, inelastic buckling analysis and nonlinear elasto-plastic analysis. Elastic buckling analysis uses a numerical eigenvalue calculation without considering geometric nonlinearities of cable-stayed bridges and the inelastic material behavior of main components. Inelastic buckling analysis uses an iterative eigenvalue calculation to consider inelastic material behavior, but cannot consider geometric nonlinearities of cable-stayed bridges. The tangent modulus concept with the column strength curve prescribed in AASHTO LRFD is used to consider inelastic buckling behavior. Detailed procedures of inelastic buckling analysis are presented and corresponding computer codes were developed. In contrast, nonlinear elasto-plastic analysis uses an incremental-iterative method and can consider both geometric nonlinearities and inelastic material behavior of a cable-stayed bridge. Proprietary software ABAQUS are used and user-subroutines are newly written to update equivalent modulus of cables to consider geometric nonlinearity due to cable sags at each increment step. Ultimate load capacities with the three analyses are evaluated for numerical models of cable-stayed bridges that have center spans of 600 m, 900 m and 1200 m with different girder depths and live load cases. The results show that inelastic buckling analysis is an effective approximation method, as a simple and fast alternative, to obtain ultimate load capacity of long span cable-stayed bridges, whereas elastic buckling analysis greatly overestimates the overall stability of cable-stayed bridges.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.185-192
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• 2002

In this study, we choose the sinusoidal shaped arch with pin-ends subjected to sinusoidal distributed excitation to investigate the fundamental mechanism of the dynamic instability. We derive the nonlinear equations of motion to investigate the instability phenomenon of arch structures and Identify the buckling characteristics of sinusoidal shaped arch structures through the nonlinear eigenvalue analysis with discreted equations of motion by Galerkin's method. We examine that phenomenons which direct snapping and indirect snapping with backbone curves to understand occurrence paths of the dynamic buckling.

• Journal of Korean Association for Spatial Structures
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• v.10 no.4
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• pp.133-140
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• 2010

This paper studies on the instability behaviour of the Seoul southwest baseball dome. The nonlinear Snapping phenomenon of the structure is investigated about the load mode by the design load of analysis structure and these combined loads. The initial imperfection obtains the buckling mode through the eigenvalue analysis of the tangential stiffness matrix and uses this for the nonlinear analysis. However, the buckling of members or the local buckling, and etc don't consider in the research range of this research task. Also it is limited the overall buckling phenomenon.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.307-317
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• 1991

A displacement-based finite element method is presented for the geometrically nonlinear analysis of eccentrically stiffened plates. The nonlinear degenerated shell and eccentric isobeam(isoparametric beam) elements are formulated on the basis of total Lagrangian and updated Lagrangian descriptions. To describe the stiffener's local plate buckling mode, some additional local degrees of freedom are used in the eccentric isobeam element. The eccentric isobeam element can be affectively employed to model the eccentric stiffener just like the case of the degenerated shell element. A detailed nonlinear analysis including the effects of stiffener's eccentricity is performed to estimate the critical load and the post buckling behaviour of an eccentrically stiffened plate. The critical buckling loads are found higher than analytic plate buckling load but lower than Euler buckling load which are the buckling strength requirements of classification society.

• Journal of Ocean Engineering and Technology
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• v.26 no.2
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• pp.79-84
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• 2012

This study aimed to analyze the nonlinear buckling of ring-stiffened circular cylinders under uniform external pressure, e.g. hydrostatic pressure, considering material nonlinearity and initial imperfection. In the present study, we analyzed the collapse pressure of pressure vessels using ANSYS Workbench, which is a framework of finite element methods. First, linear buckling analysis is performed to find collapse modes of the model. Second, scaling the first mode shape with small factor, geometric model is pre-deformed. And then, by analyzing the nonlinear buckling of the pre-deformed shape, the collapse pressure is estimated. To verify the validity of the analyses, we compared the results with Ross' experimental results. Finally, we applied it to ring-stiffened circular cylindrical shell of the pressure hull of a small submarine.