• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.775-780
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• 2010

In the machinery, the brake system is as important part as machine's working. The situation of emergency stop, the machine doesn't stopped would be occur big accident. This is common things for all of machinery, also for the ships. There are two kind of mooring devices are existed on the ship. One of them, the windlass winch, is used to anchor. The other, the mooring winch is used to moor the ship in pier use the rope tied to bitt on dock. In case of previously been used mooring winch made of a steel plate, and the bolt which was connect brake band and lining broken. In this study, prevent an accident find the position of stress concentration by finite element analysis program. And removed stress concentration. And search the optimum position of the separation angle to be more efficient.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.134-147
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• 2001

Laser cladding process accompanies phase transformations from melting (on heating) through solidifying (on cooling) at the same time within a small material volume and to final solid phase. The phase transformations are not reversible, but an irreversible thermodynamic process; they accompany either absorption or release of thermal energy (referred to latent heat) during transformation. Yet, most analyses on materials processed by laser as a heat source have been performed on models of neglecting the latent heat in the process and those did not Justify the simplification. With literatures on the laser material process, we have not place an answer to how little the assumption affects on analyses. This led us to our current study: the effects of latent heat on thermo-mechanical analysis. To this end, we developed a fairly accurate program accommodating an algorithm for enforcing the latent heat whenever necessary and ran it combining with ABAQUS$^{TM}$. The simulation techniques we used in this study were verified by directly comparing our prediction with experimental publications elsewhere; our numerical results agreed accurately with the experiments. On the effects of the latent heat, we performed two alternatives about considering the latent heat in analysis, and compared each other. As a result, we found that more accurate conclusions might come out when considering the latent heat in process analyses.s.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.2
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• pp.217-223
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• 2020

As construction work on soft ground increases, many researchers have studied to secure the stability of trafficability with interest in construction safety accidents due to reinforcement work. Although the stability of soft ground is evaluated based on the allowable bearing capacity of theoretical equations proposed in the literature such as Yamanouchi and Meyerhof formulas, further numerical verification also requires comparison of the stress increase (Δσ_z) and deformation of the distributed contact pressure on the soft ground. In this study, the deformation of the soft ground is compared with the increasing the seam tensile strength of geotextile using the finite element analysis program, and the stress increase is investigated by variation of the distributed contact pressure by appling input data of case study.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.152-160
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• 2010

In this study, cohesion of soft ground, soft ground depth and embankment height varying conditions, such as the impact of each condition after the calculation of the range, SCP was performed to evaluate the applicability of the method. Reinforcing effects of scope, and permit lateral movement of SCP 2D and 3D analysis of the program were calculated by the displacement ratio, the result follows. The height and depth of soft soil embankment with increasing and decreasing the cohesion tends to be affected were long range, SCP method applied by the finite element analysis Cu = 1.0tf/$m^2$, embankment height is 3.0m depth of soft soil can be applied in a less than 5.0m, and Cu = 3.0tf/$m^2$, embankment height, the soft soil depth is 3.0m 12.0m, Cu = 3.0tf/$m^2$, embankment height is 5.0m less than 7.0m depth of soft soil can be applied in was. And Cu = 5.0tf/$m^2$, embankment height is 3.0m below 15.0m depth rouge anti Floor, Cu = 3.0tf/$m^2$, embankment height of 5.0m 12.0m depth below the soft soil, Cu = 5.0tf/$m^2$, If the depth of soft soil embankment height of 7.0m and below 5.0m was applicable.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.203-209
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• 2012

In this paper, cross-sectional stiffnesses, static stresses, and dynamic natural frequencies are analyzed to examine the structural performance of wind turbine composite blades. The material properties of composite materials are based on room-temperature and radiation curing processes. The cross-sectional stiffnesses of composite blades are calculated by applying a beam theory with solid-profile cross sections. The wind turbine blades are modeled with a finite element program, and static analyses are carried out to check the maximum displacement and stress of the blades. In addition, dynamic analyses are performed to predict the rotating natural frequencies of the composite blades including the effects of centrifugal force. By comparing these analysis results, mainly owing to the material properties of composite materials, an improvement in the structural performance of the blades according to the curing process is investigated.

• Magazine of the Korea Concrete Institute
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• v.9 no.2
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• pp.153-161
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• 1997

In the concrete st~uctures exposed to the environmental condition, the water movement is occurred by thc moisture difilsion, and the rnoisturrt distribution in concwt.c is nonunifhrm. Such a non-unif'orm moisture distribution causes tht. diflbrent.ia1 drying shrinkage in concrete structures. From this typc. of' dif'fercntial drying shrinkagr' tensiit-1 stress is occurred in exposure surface of concrete structures. and may result in crack formation. This residual stress is significantly affected by the creep of concrete, and the differential creep is also occurred at the cross section of concrete structures due to moisture difference at each locations. In this study, based on the moisture diffusion theory, a finite element program which is capable of simulating the moisture distribution in concrete was developed. And the analysis method for the differential drying shrinkage was suggested, in which the differential creep was considered. The differential drying shrinkage strain was also measured at various positions of concrete. Finally the validity of analysis method was proved by comparing test results with analytical results.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.69-72
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• 2008

The so-called Pier-Shafts system which consists of the continuous column and shaft is often used to support the highway bridge structure because of advantages in easy construction and low cost. In the earthquake region, the Pier-Shafts system undergoes large displacements and represents a nonlinear behavior under the lateral seismic loading. The soil-pile interaction should be considered for more accurate analysis of the Pier-Shafts system. In this study, a transverse response of a reinforced concrete Pier-Shafts system inside multi-layered soil medium is predicted using a finite element program which adopts an elasto-plastic interface model for the interface behavior between the shaft and the soil. Then, seismic analysis is performed to evaluate the performance of Pier-Shafts system under strong ground motion and their results are verified with experimental data.

• Journal of the Korea Concrete Institute
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• v.28 no.6
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• pp.713-722
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• 2016

The goal of this study was to assess the seismic performance of hollow cast-in-place and precast reinforced concrete bridge columns with triangular reinforcement details. The developed material quantity reduction details are economically feasible and rational, and facilitate shorter construction periods. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. The used numerical method gives a realistic prediction of seismic performance throughout the input ground motions for several hollow column specimens investigated. As a result, triangular reinforcement details were designed to be superior to the existing reinforcement details in terms of required seismic performance.

• International Journal of Concrete Structures and Materials
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• v.11 no.2
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• pp.327-341
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• 2017

Openings in slabs are usually required for many different applications such as aeriation ducts and air conditioning. Opening in concrete slabs due to cutouts significantly decrease the member stiffness. There are different techniques to strengthen slabs with opening cutouts. This study presents experimental and numerical investigations on the use of Carbon Fiber Reinforced Polymers (CFRP) as strengthening material to strengthen and restore the load carrying capacity of R.C. slabs after having cutout in the hogging moment region. The experimental program consisted of testing five (oneway spanning R.C. flat slabs) with overhang. All slabs were prismatic, rectangular in cross-section and nominally 2000 mm long, 1000 mm width, and 100 mm thickness with a clear span (distance between supports) of 1200 mm and the overhang length is 700 mm. All slabs were loaded up to 30 kN (45% of ultimate load for reference slab, before yielding of the longitudinal reinforcement), then the load was kept constant during cutting concrete and steel bars (producing cut out). After that operation, slabs were loaded till failure. An analytical study using finite element analysis (FEA) is performed using the commercial software ANSYS. The FEA has been validated and calibrated using the experimental results. The FE model was found to be in a good agreement with the experimental results. The investigated key parameters were slab aspect ratio for the opening ratios of [1:1, 2:1], CFRP layers and the laminates widths, positions for cutouts and the CFRP configurations around cutouts.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.1
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• pp.33-42
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• 2003

This paper deals with the FEM analysis of nonlinear sloshing of incompressible, invicid and irrotational flow in two dimensional rectangular tank. We use laplace equation based on potential theory as governing equation. For large amplitude sloshing motion, kinematic and dynamic free surface conditions derived from Bernoulli equation are applied. This problem is solved by FEM using 9-node elements. For the time integration and accurate velocity calculation, we introduce predictor-corrector time marching scheme and least square method. Also, numerical stability in tracking of free surface is obtained by direct calculation of free surface location to time variation. Numerical results of sloshing induced by harmonic excitations, while comparing with those of linear theory and references, prove the accuracy and stability. After verification of our program, we analyze sloshing response characteristics to the fluid height and the excitation amplitude.