• Advances in nano research
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• v.13 no.2
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• pp.113-120
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• 2022

In this paper, a finite element (FE) simulation has been developed in order to examine the nonlinear stability of reinforced sandwich beams with graphene oxide powders (GOPs). In this regard, the nonlinear stability curves have been obtained asuming that the beam is under compressive loads leading to its buckling. The beam is considered to be a three-layered sandwich beam with metal core and GOP reinforced face sheets and it is rested on elastic substrate. Moreover, a higher-order refined beam theory has been considered to formulate the sandwich beam by employing the geometrically perfect and imperfect beam configurations. In the solving procedure, the utalized finite element simulation contains a novel beam element in which shear deformation has been included. The calculated stability curves of GOP-reinforced sandwich beams are shown to be dependent on different parameters such as GOP amount, face sheet thickness, geometrical imperfection and also center deflection.

• Korea-Australia Rheology Journal
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• v.16 no.1
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• pp.1-15
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• 2004

The computation of viscoelastic flow using neural networks and stochastic simulation (CVFNNSS) is developed from the point of view of Eulerian CONNFFESSIT (calculation of non-Newtonian flows: finite elements and stochastic simulation techniques). The present method is based on the combination of radial basis function networks (RBFNs) and Brownian configuration fields (BCFs) where the stress is computed from an ensemble of continuous configuration fields instead of convecting discrete particles, and the velocity field is determined by solving the conservation equations for mass and momentum with a finite point method based on RBFNs. The method does not require any kind of element-type discretisation of the analysis domain. The method is verified and its capability is demonstrated with the start-up planar Couette flow, the Poiseuille flow and the lid driven cavity flow of Hookean and FENE model materials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.207-212
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• 1999

A computational method based on the three-dimensional finite element method is developed for the deformation analysis of roll forming process. the method approximates the process as a kinematically steady state deformation of strip. For industrial usefulness of the simulation method several rolls with arbitrary shapes in one stand can be considered. The shapes and the thickness distributions of strip after roll forming were examined by comparing computation results with experiments It is concluded that the tool is useful enough to predict the process. The overall simulation method was integrated into a sorftware package to help the industrial roll-design.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.67-72
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• 2008

The objective of this study is to design a laboratory specimen for simulating residual stress of circumferential butt welding of pipe. Specimen type and method for residual stress generation were proposed based on the review of prior studies and parametric finite element simulation. To prove the proposed specimen type and loading method, the residual stress was generated using the designed specimen by applying proposed method and was measured. The measured residual stress using X-ray diffraction reasonably agreed with the results of finite element simulation considered in the specimen design. Comparison of residual strains measured at several locations of specimen and given by finite element simulation also showed good agreement. Therefore, it is indicated that the designed specimen can reasonably simulate the residual stress of circumferential butt welding of pipe.

• Transactions of Materials Processing
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• v.8 no.2
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• pp.216-221
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• 1999

In this paper, an application-oriented approach to piercing analysis in automatic forging simulation by the rigid-viscoplastic finite element mehtod is presented. In the presented approach, the accumulated damage is traced and the piercing instant is determined when the accumulated damage reaches the critical damage value. A method of obtaining the critical damage value by comparing the tensile test result with the analysis one is given. The presented approach is verified by experiments and applied to automatic simulation of a sequence of 6-stage forging processes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.119-122
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• 2005

In this study, the design simulation for optimal wire batch around service line was made to improve the dielectric strength at the primary winding using Finite Element Method. The automatic convergence algorithm for finding of limit object value using loop circulation method was developed to make the optimal design simulator. The modulation method was suggested to make division time faster which was very important for full simulation efficiency. As a result, the simulation time was reduced and the optimal wire batch design was obtained.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.252-255
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• 2008

We conduct finite element simulation of a cross-wedge rolling process using AFDEX 3D. The die is realistically modeled with emphasis on the hatched plicate over the slope or forming region. Coulomb frictional law is used to prevent slip between material and die. Constant shear frictional law is also investigated and it is esmphasized that the constant shear frictional law is improper for cross-wedge rolling simulation.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.86-87
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• 2011

In this paper, a conjugate heat transfer around cylinder with heat generation was investigated. Both forced convection and conduction was considered in the present finite element simulation. A finite element formulation based on SIMPLE type algorithm was adopted for the solution of the incompressible Navier-Stokes equations. We compared the finite element solution with that of Ansys fluent 12.0, in which finite volume method was employed for spatial discretization. It was found that the finite element method gave more accurate solution than Ansys fluent 12.0. Further, it was found that the maximum temperature inside cylinder is positioned at the rear side due to the flow separation.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.1
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• pp.36-43
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• 2015

Since the crack generation and its propagation caused by welding defects is one of the main hull damage patterns, the simulation of crack propagation process has an important significance for ship safety. Based on interface element method, a finite element model to simulate crack propagation is studied in the paper. A Lennard-Jones type potential function is employed to define potential energy of the interface element. Tensile tests of steel flat plates with initial central crack are carried out. Surface energy density and spring critical stress that are suitable for the simulation of crack propagation are determined by comparing numerical calculation and tests results. Based on a large number of simulation results, the curve of simulation correction parameter plotted against the crack length is calculated.

• Transactions of Materials Processing
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• v.12 no.3
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• pp.194-201
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• 2003

An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.