• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.327-334
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• 2001

This paper presents a non-linear analysis procedure for plane frame structures by finite element formulation with assumptions of Timoshenko beam theory. Finite element displacement method based on Lagrangian formulation is used and two-noded and isoparametric line element is adopted to represent finite element model. The layered approach is used for the elasto-plastic analysis of the plane frame structures with rectangular and I cross sections. A load incremental method combined with the tangent stiffness and the initial stiffness methods for each load increment is used for the solution of non-linear equations. Numerical examples are presented to investigate the behavior and the accuracy of the elasto-plastic non-linear application and the results of this study are compared with other solutions using the concept of plastic hinge.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.429-431
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• 2009

Drawability and other mechanical properties of sheet metals are strongly dependent on their crystallographic orientations. In this paper the formability of the AA 5052 Al alloy sheets was investigated after asymmetric rolling and subsequent heat treatment. In most cases, after asymmetric rolling specimens showed a fine grain size and subsequent heat treated specimens showed that the ND // <111> texture component were observed. The anisotropy of formability is often described by the plastic strain ratios (r-value) as a function of the angle to the rolling direction in sheet metal. For a good formability, a high r-value is required in sheet metals. In the asymmetry rolled and subsequent heat treated Al alloy sheet, the variation of the plastic strain ratios have been investigated in this study, The plastic strain ratios of the asymmetry rolled and subsequent heat treated AA 5052 Al alloy sheets were higher than those of the original Al sheets. These could be related to the formation of ND // <111> texture components through asymmetric rolling in Al sheet.

• Journal of International Society for Simulation Surgery
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• v.2 no.1
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• pp.10-12
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• 2015

Purpose It has been stated that patient satisfaction is the crucial factor for determining success in plastic surgery. The convergence of medical science and computer vision has made easier to satisfy patients who wants to have plastic surgery. In this paper, we try to apply 3D face modeling in plastic surgical area. Materials and Methods The author introduces a method for accurate 3D face modeling techniques using a statistical model-based 3D face modeling approach in a mirror system. Results We could successfully obtain highly accurate 3D face shape results. Conclusion The method suggested could be used for acquiring 3D face models from 2D face image and the result obtained from this could be effectively used for plastic surgical areas.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.255-256
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• 2007

A A4 size black and white reflective plastic display was developed for out door application. For document readability, high resolution of 180ppi plastic TFT backplane and high reflectance electrophoretic front panel sheet was used. Preparation of display was held near $100^{\circ}C$ process on PEN substrate.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.90-100
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• 2000

The present paper investigates the elasto-plastic buckling of ball-jointed single layer latticed domes considering the connection characteristics. The domes are composed of tubular member elements, ball joints and connectors. To judge yielding of the member, the ends and central part of tubular member elements are assumed as five elasto-plastic springs. Elasto-plastic buckling load can be identified the yielding load of estimated member As a numerical analysis technique, loading incremental method based on the Newton-Raphson method is used. The effects of connection characteristics are investigated by the following points; (1) the length of rigid zone, (2) looseness of screw, (3) diameter of connector Finally, it is emphasized that the connection characteristics as well as the material non-linearity have significant effects upon the buckling toad of domes.

• Coupled systems mechanics
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• v.6 no.4
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• pp.501-522
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• 2017

This paper introduces a numerical procedure to incorporate elasto-plastic local deformation effects in the dynamic analysis of beams. The appealing feature is that simple beam type finite elements can be used for the global model which needs not to be altered by the localized elasto-plastic deformations. An overlapping local sophisticated 2D membrane model replaces the internal forces of the beam elements in the predefined region where the localized deformations take place. An iterative coupling technique is used to perform this replacement. Comparisons with full membrane analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein. In this study, the membrane formulation is able to capture the elasto-plastic material behaviour based on the von Misses yield criterion and the associated flow rule for plane stress. The Newmark time integration method is adopted for the step-by-step dynamic analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.268-271
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• 2010

In this paper, forward and reverse analysis is introduced in order to estimate the elastic-plastic properties from a power-law hardening bulk specimen materials with one simple spherical indentation impression test. In order to verify the reliability of the reverse analysis, we have simulated about a large range of materials that essentially cover all engineering materials, using ABAQUS(6.91) program. Then, we could obtained the fitting functions and plastic parameters from the numerical analysis results. Next, through the procedure of reverse analysis we can obtain the yield stress and power-law exponent. Finally, obtain good agreement between the result from reverse analysis and initial input data from experiment.

• Structural Engineering and Mechanics
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• v.58 no.4
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• pp.641-659
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• 2016

This paper deals with the pure bending of incompressible elastic perfectly plastic two-layer sheets under plane strain conditions at large strains. Each layer is classified by its yield stress, shear modulus of elasticity and its initial percentage thickness in relation to the whole sheet. The solution found is semi-analytic. In particular, a numerical technique is only necessary to solve transcendental equations. The general solution is cumbersome because different analytic expressions for the radial and circumferential stresses should be adopted in different regions of the whole sheet. In particular, there are several alternative ways a plastic region (or plastic regions) can propagate. However, for any given set of material and process parameters the solution to the problem consists of a sequence of rather simple analytic expressions connected by transcendental equations. The general solution is illustrated by a simple example.

• Advances in materials Research
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• v.4 no.2
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• pp.87-96
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• 2015

In this paper, three-dimensional finite element method is used to analyze the J integral for repaired cracks in plates with bonded composite patch and stiffeners. For elastic the effect of cracks, the thickness of the patch ($e_r$) and properties of the patch are presented for calculating the J integral. For elastic-plastic a several calculations have been realized to extract the plasticized elements around the crack tip of repaired and un-repaired crack. The obtained results show that the presence of the composite patch and stiffener reduces considerably the size of the plastic zone ahead of the crack. The effects of crack size and the inter-distance of repaired cracks were analysed.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.6
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• pp.792-802
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• 2010

A plastic analysis method is commonly used in ship and offshore structural system to utilize the ultimate strength. In this paper, the basic principle of plastic analysis method is applied to ship grillages such as transverse oil-tight bulkheads. The main emphasis is placed on the optimum arrangement of grillage system to give minimum weight. Additional parametric study is carried out to find the effect of various arrangement of grillage system. The above methods are applied to oil-tight bulkhead design, and results are compared with the existing one.