• Computers and Concrete
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• 제14권1호
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• pp.1-18
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• 2014

The addition of steel fibers in concrete mixture is recognized as a non-conventional mass reinforcement scheme that improves the torsional, flexural, and shear behavior of structural members. However, the analysis of fiber reinforced concrete beams under combined torsion, bending, and shear is limited because of the complicated nature of the problem. Therefore, nonlinear 3D finite element analysis was conducted using the "ANSYS CivilFEM" program to investigate the behavior of fiber reinforced concrete L-beams. These beams were tested at different reinforcement schemes and loading conditions. The reinforcement case parameters were set as follows: reinforced with longitudinal reinforcement only and reinforced with steel bars and stirrups. All beams were tested under two different combined loading conditions, namely, torsion-to-shear ratio (T/V) = 545 mm (high eccentricity) and T/V = 145 mm (low eccentricity). Eight intermediate L-beams were constructed and tested in a laboratory under combined torsion, bending, and shear to validate the finite element model. Comparisons with the experimental data reveal that the program can accurately predict the behavior of L-beams under different reinforcement cases and combined loading ratios. The ANSYS model accurately predicted the loads and deformations for various types of reinforcements in L-beams and captured the concrete strains of these beams.

• Structural Engineering and Mechanics
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• 제30권2호
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• pp.247-261
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• 2008

Performance of shear-deficient reinforced concrete (RC) beams strengthened with carbon fiber-reinforced polymer (CFRP) strips/sheets is analyzed through numerical simulations on four-point bending tests. The numerical simulations are carried out using the finite element (FE) program ABAQUS. A micromechanics-based constitutive model (Liang et al. 2006) is implemented into the FE program ABAQUS to model CFRP strips/sheets. The predicted results are compared with experiment data (Khalifa and Nanni 2002) to assess the accuracy of the proposed FE analysis approach. A series of numerical tests are conducted to investigate the influence of stirrup lay-ups on the shear strengthening performance of the CFRP strips/sheets, to illustrate the influence of the damage parameters on the microcrack density evolution in concrete, and to investigate the shear and flexural strengthening performance of CFRP strips/ sheets. It has been shown that the proposed FE analysis approach is suitable for the performance prediction of RC beams strengthened with CFRP strips/sheets.

• 소성∙가공
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• 제9권4호
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• pp.348-355
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• 2000

The backward tracing scheme(BWT) of the finite element method has been extended lot the design of sheet blank in three-dimensional deformation. Originally the scheme was developed for preform design in bulk forming, and applied to several forming processes successfully. Its key concept is to trace backward from the final desirable configuration to an intermediate preform or initial blocker. A program for initial blank design in sheet forming which contains the capabilities of forward loading simulation by the finite element method and backward tracing simulation, has been developed and proved the effectiveness by applying to a square cup stamping process. In the blank design of square cup stamping, the backward tracing program can produce an optimum blank configuration which forms a sound net-shape cup product without machining after forming. For the confirmation of the analytic result derived from the backward tracing simulations as well as forward loading simulations, a series of experiment were carried out. The experiments include the first trial sheet forming process with a rectangular blank, an improved process with a modified blank preform and the final process with an optimum blank resulted from the backward tracing scheme. The experiments show that the backward tracing scheme has been implemented successfully in blank design of sheet metal forming.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권2호
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• pp.87-95
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• 2010

The structural intensity analysis, which calculates the magnitude and direction of vibrational energy flow from vibratory velocity and internal force at any point of a structure, can give information on dominant transmission paths, positions of sources and sinks of vibration energy. This paper presents a numerical simulation system for structural intensity analysis and visualization to apply for ship structures based on the finite element method. The system consists of a general purpose finite element analysis program MSC/Nastran, its pre- and post-processors and an in-house program module to calculate structural intensity using the model data and its forced vibration analysis results. Using the system, the structural intensity analysis for a 4,100 TEU container carrier is carried out to visualize structural intensity fields on the global ship structure and to investigate dominant energy flow paths from harmonic excitation sources to superstructure at resonant hull girder and superstructure modes.

• 한국임상수의학회지
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• 제35권3호
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• pp.83-87
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• 2018

The aim of this study was to evaluate the biomechanical behavior of xenogenic bone plate system (equine bone) using a three-dimensional finite element ulna fracture model. The model was used to calculate the Von Mises stress (VMS) and stress distribution in fracture healing periods with metallic bone plate and xenogenic bone plate systems, which are installed while the canine patient is standing. Bone healing rate (BHR) (0%) and maximum VMS of the xenogenic plate was similar to the yield strength of equine bone (125 MPa). VMS at the ulna and fracture zones were higher with the xenogenic bone plate than with the metallic bone plate at BHRs of 0% and 1%. Stress distributions in fracture zone were higher with the xenogenic bone plate than the metallic bone plate. This study results indicate that the xenogenic bone plate may be considered more beneficial for callus formation and bone healing than the metallic bon plate. Xeonogenic bone plate and screw applied in clinical treatment of canines may provide reduced stress shielding of fractures during healing.

• 한국CDE학회논문집
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• 제10권5호
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• pp.375-379
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• 2005

Durability of rubber dust cover in the ball joint for automotive suspension parts is analyzed by FEM and compared with experimental data. Upper open area of ball joint is sealed by dust cover for preventing outflow of the lubricating oil and intrusion of send, dust, water, etc. This rubber cover undergoes repeated loadings such as tension and compression while the car is running. Analysis about rubber material needs to consider every kinds of nonlinearities arise in finite element analysis, which are geometric nonlinearity due to large displacement and small strain, materially nonlinearity and nonlinear boundary condition such as contact. The deformation behavior of dust cover is analysed by using the commercial finite element program MARC. In the study, this program could solve these kinds of nonlinear analysis accurately. Finite element model of dust cover is considered as 3-dimensional half model based on 2-dimensional axisymmetric model. Material property of rubber is modeled by Ogden model and input data for calculation takes form uniaxial tension test of rubber specimen. The final object of the study is obtaining the design specification of dust covers and the result of analysis should be a useful data to design of rubber cover.

• 대한조선학회논문집
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• 제29권3호
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• pp.149-156
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• 1992

본 연구에서는 선체 모듈강도해석을 위한 유한요소 구조해석모델링 자동화 프로그램을 개발하였다. 본 프로그램은 선체중앙부 화물창구조를 종통부재, 횡단면 부재, 횡격벽부재로 구분하여 이들 부재의 위치, 형상, 치수등에 관한 입력자료를 일관되게 처리함으로서, 요소분할, 요소-절점 위상정의, 설계하중 및 경계조건 설정등 유한요소 구조모델링에 따르는 일련의 과정을 자동화한다. 또한, 본 프로그램의 결과는 범용 구조해석 프로그램인 ANSYS와 직접 연결됨으로서 보다 효과적으로 구조해석을 수행할 수 있다. 본 연구에서는 개발된 프로그램에 대하여 실적 유조선을 대상으로 구조해석을 수행해 봄으로서 그 정도와 유용성을 검정하였다.

• Computers and Concrete
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• 제13권2호
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• pp.291-308
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• 2014

A nonlinear, three-dimensional finite element analysis was conducted on six intermediate L-shaped spandrel beams using the "ANSYS Civil FEM" program. The beams were constructed and tested in the laboratory under eccentric concentrated load at mid-span to obtain a combined loading case: torsion, bending, and shear. The reinforcement case parameters were as follows: without reinforcement, with longitudinal reinforcement only, and reinforced with steel bars and stirrups. All beams were tested under two different combined loading conditions: T/V = 545 mm (high eccentricity) and T/V = 145 mm (low eccentricity). The failure of the plain beams was brittle, and the addition of longitudinal steel bars increased beam strength, particularly under low eccentricity. Transverse reinforcement significantly affected the strength at high eccentricities, that is, at high torque. A program can predict accurately the behavior of these beams under different reinforcement cases, as well as under different ratios of combined loadings. The ANSYS model accurately predicted the loads and deflections for various types of reinforcements in spandrel beams, and captured the critical crack regions of these beams.

• 대한조선학회논문집
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• 제31권4호
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• pp.99-108
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• 1994

본 연구는 "유조선 구조해석을 위한 유한요소 입력자동화 프로그램의 개발"[1]의 연속된 연구결과로서, 유조선, 살물화물선, 콘테이너선등의 일반 상용 선박을 대상으로 유한요소법을 이용하여 선체중앙부(3-D cargo hold)구조해석을 수행할 때, 구조모델링과 해석을 위한 입력자료처리를 효율적으로 자동화하는 과정을 연구하였다. 본 논문에서는 전년도에 발표된 기본 알고리즘을 바탕으로 다양한 형태의 선종별 적용성, MSC/NASTRAN 인터페이스와 관련한 평면 유한요소 자동분할 기법, 파랑하중 직접계산 인터페이스 개발 및 입력자료 처리과정에 도입된 Graphic User Interface기법 등 새로이 개발된 내용에 대하여 자세히 기술하고, 다양한 실적선에 적용함으로써 프로그램의 유용성을 확인하였다.

• 한국가시화정보학회지
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• 제17권1호
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• pp.78-84
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• 2019

A gas turbine is the main equipment of a power plant that generates electricity by high-speed rotation of the rotor in a high-temperature environment. In particular, in the case of medium to large-sized gas turbines, the rotor is composed of a plurality of stages, and each component is exposed to different physical environments. Especially, in the case of the tip clearance of the turbine, it is a very important factor in the performance of the design items and the operation of the stable turbine, and a design considering the physical behavior of all major parts should be done. In this study, we will discuss the process of visualizing the physical behavior of turbine operating conditions and the method of designing tip clearance for stable operation by using commercial finite element analysis program for gas turbine assembly model and single product.