• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.234-244
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• 2017

Natural frequencies of immersed square sections decrease due to a contribution of added mass to the movement of square sections. In this study, natural frequencies of square sections are obtained as a function of gap size between the square section and a rigid square wall using the finite element method. Additionally, they are used to extract the added mass effect on translational and rotation motions. Published information and studies on the translational and torsional vibration of square beams are also examined for practical use. D coupling of a square section is also investigated for multiple square sections. The suggested added mass estimation can be applicable to the spent fuel storage design of a pressurized light water modulated nuclear power plant.

• Journal of Mechanical Science and Technology
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• v.19 no.7
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• pp.1424-1431
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• 2005

In this study, head injury by impact force was evaluated by numerical analysis with 3-dimensional finite element (FE) model. Brain deformation by frontal head impact was analyzed to evaluate traumatic brain injury (TBI). The variations of head acceleration and intra-cranial pressure (ICP) during the impact were analyzed. Relative displacement between the skull and the brain due to head impact was investigated from this simulation. In addition, pathological severity was evaluated according to head injury criterion (HIC) from simulation with FE model. The analytic result of brain damage was accorded with that of the cadaver test performed by Nahum et al.(1977) and many medical reports. The main emphasis of this study is that our FE model was valid to simulate the traumatic brain injury by head impact and the variation of the HIC value was evaluated according to various impact conditions using the FE model.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.529-543
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• 2021

Inevitable source-uncertainties in geometry configuration, boundary condition, and material properties may deviate the structural dynamics from its expected responses. This paper aims to examine the influence of these uncertainties on the vibration of functionally graded beams. Finite element procedures are presented for Timoshenko beams and utilized to generate reliable datasets. A prerequisite to the uncertainty quantification of the beam vibration using Monte Carlo simulation is generating large datasets, that require executing the numerical procedure many times leading to high computational cost. Utilizing artificial neural networks to model beam vibration can be a good approach. Initially, the optimal network for each beam configuration can be determined based on numerical performance and probabilistic criteria. Instead of executing thousands of times of the finite element procedure in stochastic analysis, these optimal networks serve as good alternatives to which the convergence of the Monte Carlo simulation, and the sensitivity and probabilistic vibration characteristics of each beam exposed to randomness are investigated. The simple procedure presented here is efficient to quantify the uncertainty of different stochastic behaviors of composite structures.

• Journal of the Korean Wood Science and Technology
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• v.42 no.1
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• pp.20-26
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• 2014

This paper represented the finite element analysis to estimate structural performance of stress-laminated deck, which is determined by deflection, stress, and aging characteristics of tensioning. After loading, the deflected shape showed plate behavior because pre-stressing make frictional force between each member. Compared between initial post-tension and the results, pre-stressing forces were decreased with deck deflection. This is because deflection occurred in the deck so that pre-stressing decreased due to load reduction. However, material plasticity was not considered so that advanced researches should be performed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.3
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• pp.18-23
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• 2009

This paper focuses on development of new conveyer directly driven by the contact-less energy transmission system. The effect of the resonant circuit and the flux linkage characteristics caused from that are analyzed by using 3D finite element analysis. From the result it is shown that the resonant circuit needs to transfer energy from the primary core to the secondary core. Also the influence of the linear induction motor on the contact-less energy transmission system is presented. New conveyer and the experimental apparatus was manufactured by using the contact-less energy transmission system and the linear induction motor. Possibility of realization of the conveyer is proved by comparison the simulation result which is obtained by using 2D finite element analysis with experimental one and the characteristic of the voltage and resonant current.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.115-121
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• 2006

Geometries, boundary renditions, loading renditions and mechanical properties are essential for finite element analysis. However it is a very difficult task to obtain In-vivo geometry and mechanical properties of human body. In this study totally 38 kinds of inner organs are segmented using MRI of young male with Korean standard body shape to make a finite element model. And RUS has been used to acquire anisotropic elasticity matrix of the femoral head.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.197-204
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• 2009

It bas been hypothesized that foot ulceration might be internally initiated. Current instruments which merely allow superficial estimate of plantar loading acting on the foot, severely limit the scope of many biomechanical/clinical studies on this issue. Recent studies have suggested that peak plantar pressure may be only 65% specific for the development of ulceration. These limitations are at least partially due to surface pressures not being representative of the complex mechanical stress developed inside the subcutaneous plantar soft-tissue, which are potentially more relevant for tissue breakdown. This study established a three-dimensional and nonlinear finite element model of a human foot complex with comprehensive skeletal and soft-tissue components capable of predicting both the external and internal stresses and deformations of the foot. The model was validated by experimental data of subject-specific plantar foot pressure measures. The stress analysis indicated the internal stresses doses were site-dependent and the observation found a change between 1.5 to 4.5 times the external stresses on the foot plantar surface. The results yielded insights into the internal loading conditions of the plantar soft-tissue, which is important in enhancing our knowledge on the causes of foot ulceration and related stress-induced tissue breakdown in diabetic foot.

• Analytical Science and Technology
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• v.13 no.1
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• pp.96-100
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• 2000

The adsorption of heavy-elements to zeolite has been investigated at various adsorptional condition for purification of waste water. Four heavy elements, Cd, Cr, Cu and Pb, were examined, because they are concerned to the major heavy-element contamination. The adsorption efficiencies are measured at the different conditions such as adsorption times and pHs. The practical adsorption was achived and reaches to maximum within 30 minute by using of 2-g zeolite for 50 mL of heavy-element solution. The overall adsorption efficiencies for Cr and Cu are high and become better at low pH. Cd and Pb have 95% of adsorption ratio and this is lower than other two elements. Cadmium shows an abnormally low adsorption at low pH.

• Journal of Ocean Engineering and Technology
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• v.22 no.1
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• pp.22-29
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• 2008

A numerical investigation is made on the effects of the location and shape of the front wall of an OWC(Oscillating Water Column) chamber on the hydroelastic response of a VLFS. Most of the studies on the effects of an OWC chamber on the response of a VLFS have assumed the location of the OWC chamber to be at the front of the VLFS. In the present study, an OWC-chamber is introduced at an arbitrary position in relation to a VLFS to determine the influence of the location and shape of the OWC chamber on the hydroelastic response of the VLFS. A finite element method is adopted as a numerical scheme for the fluid domain. or the finite element method, combined with a mode superposition method, is applied in order to consider the change of mass and stiffness The OWC chamber in a piecewise constant manner. or the facilitated anefficient analysis of The hydroelastic response of the VLFS, as well as the easy modeling of different shape and material properties for the structure. Reduction of hydroelastic response of the VLFS is investigated for various locations and front wall shapes of the owe chamber.

• Steel and Composite Structures
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• v.39 no.1
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• pp.109-123
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• 2021

This research endeavor intends to use the implicit finite element method to investigate the structural response of steel shear walls with partial plate-column connection. To this end, comprehensive verification studies are initially performed by comparing the numerical predictions with several reported experimental results in order to demonstrate the reliability and accuracy of the implicit analysis method. Comparison is made between the hysteresis curves, failure modes, and base shear capacities predicted numerically using ABAQUS software and obtained/observed experimentally. Following the validation of the finite element analysis approach, the effects of partial plate-column connection on the strength and stiffness performances of steel shear wall systems with different web-plate slenderness and aspect ratios under monotonic loading are investigated through a parametric study. While removal of the connection between the web-plate and columns can be beneficial by decreasing the overall system demand on the vertical boundary members, based on the results and findings of this study such detachment can lower the stiffness and strength capacities of steel shear walls by about 25%, on average.