• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.693-694
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• 2010

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.149-157
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• 2000

Computer simulations of the mechanical behavior of a three point bend specimen with a quarter notch under impact load are performed. The case with a load application point at the side is considered. An elastic-plastic von Mises material model is chosen. Three phases such as impact bouncing and bending phases are found to be identified during the period from the moment of impact to the estimated time for crack initiation. It is clearly shown that no plastic deformation near the crack tip is appeared at the impact phase. However it is confirmed that the plastic zone near the crack tip emerges in the second phase and the plastic hinge has been formed in the third phase. Gap opening displacement crack tip opening displacement and strain rate are compared with rate dependent material(visco-plastic material). The stability during various dynamic load can be seen by using the simulation of this study.

• Bulletin of the Society of Naval Architects of Korea
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• v.18 no.4
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• pp.21-29
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• 1981

In this paper, plastic behavior and plastic strength of cruciform fillet welded joint under tension is investigated by finite element method. Attension is focussed, in particular, on the effect of geometry of fillet weld including its contour, size and penetration. And the approximate analysis of welded joint have been carried out from a simple model constructed by three zone, ie, base metal, heat affected zone, and weld metal.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.3
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• pp.227-235
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• 2004

Tunneling in rock mass produces two types of damages in the vicinity of a tunnel: structural and constructional damages. Structural damage represents the damage induced by the unbalance of geostatic stress caused by the tunneling, and constructional damage is the damage produced during the construction. In this study, formulations of tangential and radial stresses in the elastic and plastic zones near a tunnel, and the calculation of radius of plastic zone surrounding a tunnel are introduced by modifying the Hoek-Brown criterion of 2002 edition, which has capability of considering in situ rock mass characteristics and construction damage. From the parametric study, influences of rock mass quality, uniaxial compressive strength of intact rock, and the dimension of the tunnel on the plastic zone are investigated. The accuracy of the proposed approach is evaluated by comparing with results from the previous study.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.202-208
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• 1991

Hand injury in children was increased due to multiple environmental risks and failed attention of parents to children in rapidly developing society. By the results of this evaluation in 37 cases, it was summarized as follows. First, hand injuries in children most commonly occurs in spring, and occurs more commonly in the children at the age of high activity. The most common level of injury is zone I by microreplantation zone, and zone II by tendon injury zone. The more desirable results were obtained by full thickness skin graft and composite graft if it were possible. For the better functional results compare to adults, the methods and procedures must be constructed after more evaluation with more clinical cases. In the cases of pediatric hand injury, the most important fact is prevention of injury, with the close attention by parents, and the second is appropriate diganosis and treatment for more functional results.

• Steel and Composite Structures
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• v.20 no.3
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• pp.487-500
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• 2016

In order to investigate the flexural bearing capacity of panel zone of diaphragm-through joint between concrete filled square steel tubular column and steel beam, four specimens were tested under static tension loads to study the mechanical properties and bearing capacity of diaphragm-through joints with a failure mode of panel zone. Finite element models of these specimens were developed to simulate the test and compare the predicted failure modes, load-displacement curves and bearing capacities with the experimentally observed. It was found that the tensile load from the steel beam flange is mainly shared by the square steel tube and the diaphragm. The diaphragm plastic zone appears along the cross-section lines enclosed by the square steel tube and the influence of steel beam web on the plastic zone of the steel tube is significant and cannot be neglected. Computational models of yield lines on square steel tube and diaphragm are established based on the distribution pattern of the plastic zone, and an analytical method for the evaluation of the bearing capacity of the joint is proposed. The theoretical results and the experimental data are compared and found in good agreement.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.2
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• pp.243-251
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• 1989

Assuming plastic zones spreading out on each slip plane of the two materials under out-of-plane shear loading, the size of each plastic zone is computed. The effect of the different frictional shear stresses in the two materials on the size of each plastic zone and the relative displacement at the crack tip are investigated. The relation between the J-integral in this model and the relative displacement at the crack tip is also obtained.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1989-1995
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• 2004

Finite element analysis(FEA) is the most popular numerical method to simulate plasticity-induced fatigue crack closure and can predict fatigue crack closure behavior. Finite element analysis under plane stress state using 4-node isoparametric elements is performed to investigate the detailed closure behavior of fatigue cracks and the numerical results are compared with experimental results. The mesh of constant size elements on the crack surface can not correctly predict the opening level for fatigue crack as shown in the previous works. The crack opening behavior for the size mesh with a linear change shows almost flat stress level after a crack tip has passed by the monotonic plastic zone. The prediction of crack opening level presents a good agreement with published experimental data regardless of stress ratios, which are using the mesh of the elements that are in proportion to the reversed plastic zone size considering the opening stress intensity factors. Numerical interpolation results of finite element analysis can precisely predict the crack opening level. This method shows a good agreement with the experimental data regardless of the stress ratios and kinds of materials.

• Geomechanics and Engineering
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• v.16 no.1
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• pp.97-104
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• 2018

The finite difference software Flac3D is used to study the influence of tunnel burial depth, tunnel diameter and lateral pressure coefficient of original rock stress on the stress and deformation of tunnel surrounding rock under sandstone condition. The results show that the maximum shear stress, the radius of the plastic zone and the maximum displacement in the surrounding rock increase with the increase of the diameter of the tunnel. When the lateral pressure coefficient is 1, it is most favorable for surrounding rock and lining structure, with the increase or decrease of lateral pressure coefficient, the maximum principal stress, surrounding displacement and plastic zone range of surrounding rock and lining show a sharp increase trend, the plastic zone on the lining increases with the increase of buried depth.

• Archives of Craniofacial Surgery
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• v.21 no.4
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• pp.249-252
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• 2020

A marginal zone B-cell lymphoma is a type of B-cell lymphoma which is normally located at the margins of the secondary lymph node follicles. According to 2008 World Health Organization (WHO) classification, there are three main types classified according to the location of invasion: nodal lymphoma in the lymph nodes, splenic lymphoma in the spleen, and extranodal lymphoma in other locations. Recently, we have experienced a rare case of primary nodal marginal zone lymphoma that arose in the lower eyelid. Therefore, we report this case with a review of literature.