• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.25-35
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• 2018

Resisting strength of ring-stiffened cylindrical steel shell under uniform external pressure was evaluated by geometrically and materially nonlinear finite element method. The effects of shape and amplitude of geometric initial imperfection, radius to thickness ratio, and spacing of ring stiffeners on the resisting strength of ring-stiffened shell were analyzed. The resisting strength of ring-stiffened cylindrical shells made of SM490 obtained by FEA were compared with design strengths specified in Eurocode 3 and DNV-RP-C202. The shell buckling modes obtained from a linear elastic bifurcation FE analysis were introduced in the nonlinear FE analysis as initial geometric imperfections. The radius to thickness ratios of cylindrical shell in the range of 250 to 500 were considered.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.349-355
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• 2004

The material such as steel or concrete has used to civil structures such as drainage pipes , but many problems such as corrosion in using steel and concrete pipes have happened. So, Necessity of developing new materials with high strength and anti-corrosion has been topic recently. One of this topics is study about ERP pipe. The strength of orthotropic FRP tends to be higher than it of isotropic FRP, the buckling problems can be significant in materials with high strength. thus, the study about bucking of orthotropic FRP-pipe is needed. In this study, buckling analysis of laminated cylindrical composite structures subjected In ply angle change under external uniform pressure was performed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.865-873
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• 2013

This paper proposes a theoretical solution of elastic critical buckling load of infinitely long pipelines with non-uniform thickness under external pressure. The non-uniform cross section of pipelines can be considered as corroded or stiffened pipelines so that this paper can be a fundamental research of pipelines that are essential technology for offshore industries. The theoretical solution of pipelines with non-uniform thickness is derived with an assumption that a cylindrical shell under external pressure can be considered as a simple ring. The eigenfunctions are derived to obtain the critical buckling load. The reduced thickness and the reduced range are considered as variables in parametric analysis. The finite element analysis is performed to verify the theoretical solutions and the results of the analytic method and the finite element method are in good agreement.

• Journal of Mechanical Science and Technology
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• v.19 no.11
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• pp.2053-2060
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• 2005

The unsteady Couette flow of an electrically conducting, V1SCOUS, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer taking the Hall effect into consideration. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the ion slip and the uniform suction and injection on both the velocity and temperature distributions is examined.

• Structural Engineering and Mechanics
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• v.72 no.5
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• pp.557-568
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• 2019

Accurate modeling of contact interface in bolted joints is crucial in predicting the dynamic behavior for bolted assemblies under external load. This paper presents a contact pressure distribution based non-uniform virtual material method to describe the joint interface of assembly structure, which is connected by sparsely distributed multi-bolts. Firstly, the contact pressure distribution of bolted joints is obtained by the nonlinear static analysis in the finite element software ANSYS. The contact surface around bolt hole is divided into several sub-layers, and contact pressure in each sub-layer is thought to be evenly. Then, considering multi-asperity contact at the micro perspective, the relationship between contact pressure and interfacial virtual material parameters for each sub-layer is established by using the fractal contact theory. Finally, an experimental platform for the dynamic characteristics testing of a beam lap structure with double-bolted joint is constructed to validate the efficiency of proposed method. It is found that the theoretical results are in good agreement with experimental results by impact response in both time- and frequency-domain, and the relative errors of the first four natural frequencies are less than 1%. Furthermore, the presented model is used to examine the effect of rough contact surface on dynamic characteristics of bolted joint.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.569-579
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• 2006

In the present study, the unsteady Couette flow with heat transfer of a dusty viscous incompressible electrically conducting fluid under the influence of an exponential decaying pressure gradient is studied without neglecting the Hall effect. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below while the fluid is acted upon by an external uniform magnetic field is applied perpendicular to the plates. The governing equations are solved numerically using finite differences to yield the velocity and temperature distributions for both the fluid and dust particles.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1232-1239
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• 2006

In the present study, the unsteady Hartmann flow with heat transfer of a viscous incompressible electrically conducting fluid under the influence of an exponentially decreasing pressure gradient is studied. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below while the fluid is acted upon by an external uniform magnetic field applied perpendicular to the plates. The equations of motion are solved analytically to yield the velocity distributions for both the fluid and dust particles. The energy equations for both the fluid and dust particles including the viscous and Joule dissipation terms, are solved numerically using finite differences to get the temperature distributions.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.163-172
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• 2000

The postbuckling behavior and progressive damage of composite laminated cylindrical shell under uniform external pressure were investigated by nonlinear finite element method programming. For the finite element analysis, nine-node 3-D degenerated elements were utilized, and arc-length method including line search was adopted for the iteration and load-increment along postbuckling equilibrium path. As results. buckling load, postbucking behavior, and progressive failure f3r various composite laminated cylindrical shells were discussed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.321-325
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• 2006

Because strong wind is one of the few forces that, although considered in container crane design, still cause significant damage, a container crane was tested to investigate wind load characteristic in uniform flows. So, this study measured an external point pressure at the each members of a container crane according to a wind direction and a shape of members in a wind-tunnel test. The result of this test was compared to those of computation fluid dynamics using a CFX 10. The scale of a container crane model for wind tunnel test applied similarity scales to consider the size of the wind tunnel test section and the boundary condition for CFD is like wind tunnel test.

• Journal of Mechanical Science and Technology
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• v.19 no.5
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• pp.1148-1157
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• 2005

In the present study, the unsteady Hartmann flow of a dusty viscous incompressible electrically conducting fluid under the influence of an exponentially decreasing pressure gradient is studied without neglecting the ion slip. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below. The fluid is acted upon by an external uniform magnetic field which is applied perpendicular to the plates. An analytical solution for the governing equations of motion is obtained to yield the velocity distributions for both the fluid and dust particles.