• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.577-585
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• 2006

In this research, nonlinear Timoshenko beam element that is able to capture nonlinear shear deformation is developed. The proposed model shows more reasonable prediction than Bernoulli beam theory in short columns or strong shear column due to the consideration of shear deformation. The cross-section is modeled as fiber approach. Since the model is based on the fiber approach for section discretization, the plastic progress of the section can be traced and the coupling effect of the axial and flexural response. The developed element is implemented into the finite element program to analysis general reinforced concrete structures. As parametric study, reinforced concrete columns are analyzed and compared with experimental results, analyzed the property of behavior for reinforced concrete columns.

• Transactions of Materials Processing
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• v.13 no.7
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• pp.570-579
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• 2004

정상상태 압연공정의 오일러리안 공정해석 모델에 관한 연구들을 종합 정리하였다 본 연구의 유한요소해석 모델은 집합조직의 발전에 따른 이방성과 미세기공의 성장에 따른 기계적 성질의 열성화를 평형방정식에 직접 결합하였다 따라서 집합조직의 발전 및 기공률의 변화를 예측하고 동시에 이방성과 기계적성질의 열성화를 해석에 반영할 수 있다. 더불어 오일러리안 해석에서 형상예측을 위하여 자유곡면 수정법과 유선추적법을 유한요소해석 모델에 결합하였다 본 연구의 공정해석 모델을 평판 압연, 클래드압연, 삼차원 사각단면봉의 압연 및 형상압연에 적용하여 집합 조기의 발전, R-값, 항복곡면, 결함성장 등의 기계적성질의 변화 예측과 클래드 압연시에 이중재 접촉면 형상, 배불림, 형상압연 시의 단면변화 등의 형상변화 예측을 보여주었다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.2
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• pp.117-125
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• 2001

본 논문에서는 케이블 지지구조물의 비선형 정적해석과 동적해석에 사용할 수 있는 개선된 유한요소가 제시되었다. 케이블의 모델화를 위해 등가탄성계수를 사용하고 처짐곡선을 현수선함수로 가정한 케이블요소가 제안되었다. 프레임 부재에 사용되는 안정함수는 수치적으로 안정한 해를 얻기 위하여 수정되었다. 본 논문에서 제안한 요소의 유용성과 효율성을 검토하기 위하여 다양한 검증문제에 대한 수치해석이 수행되었다. 해석결과 본 논문에서 제시한 유한요소는 케이블 지지구조물의 모델화에 매우 유용하고 효율적으로 사용될 수 있을 것으로 판단된다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.283-286
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• 2009

척추경 나사못을 이용한 요추 유합술은 가장 보편적으로 사용되어지는 수술적 치료 방법이다. 과거 여러 연구들에서 이러한 척추 유합술의 임상적 우수성은 이미 입증 되었으며, 척추경 나사못은 시술 부위의 운동을 완전히 제한함으로써 높은 유합율을 얻을 수 있으나, 상대적으로 인접 분절의 조기 퇴행성 변화의 요인 중 하나로 보고되고 있다. 따라서 본 연구에서는 유한요소해석 방법을 이용하여 척추경 나사못 시술에 따른 척추체의 운동범위 및 인접 분절 추간판의 스트레스 증가량을 계산하였고, 척추경 나사못 모델과 유합 후 나사못 제거에 따른 모델 또 시술하기 전 정상모델과 비교하여 생체 역학적 측면에서 분석하여 척추경 나사못을 이용한 요추 유합술 후, 척추경 나사못의 제거의 임상적 효과와 그 이론적 근거를 제시하고자 한다.

• Computational Structural Engineering
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• v.4 no.1
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• pp.109-120
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• 1991

This paper introduces a geometric modelling system adopted in a newly developed preprocessor for finite element analysis of three dimensional structures. The formulation is characterized by hierachical construction of structural model which consists of control points, curves, surfaces and solids. Various surface and solid modelling schemes based on blending functions and boundary representation are systematized for finite element mesh generation. The modelling system is integrated with model synthesis and operations which facilitate modelling of complex structures.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.306-311
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• 1996

CANFLEX 연료봉 다발을 구성하는 우라늄 펠릿이 장전된 핵연료봉의 공기중 진동특성을 진동 실험과 유한요소 해석을 통하여 구하였다. 유한요소 해석 시에는 우라늄 펠릿의 강성은 무시하고 질량은 지르칼로이 튜브에 부가하며, 연료봉 양단의 용접부위를 단순 지지보로 처리하는 모델을 제시하였다. 이 모델로부터 얻은 해석결과를 진동실험에서 구한 측정값과 비교하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.449-455
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• 2011

Recently, international collaborative research which was organized at Bhabha Atomic Research Centre in India, was conducted to develop for pressure capacity and nonlinear behavior of PHWR 1/4 scale nuclear containment building between experimental test and numerical code. In this paper, a nonlinear finite element analysis was carried out in order to predict ultimate pressure capacity and nonlinear behavior of the 1/4 scale containment building. The 1/4 scale containment building is consisted of basemat, cylinder wall, dome and 4-buttress. For the finite element analysis, commercial program ABAQUS was used. Finite element models including concrete, rebar and tendon have been developed for assessment of ultimate pressure capacity and failure mode for nuclear containment building. From the analysis results, first crack of the concrete, the yielding of the rebar and ultimate capacity pressure occurred at $1.6P_d$(design pressure), $3.36P_d$ and $4.0P_d$, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.361-374
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• 2016

The material property of the rubber has been studied in order to improve the reliability of the finite element model of a lead rubber bearing (LRB) which is a typical base isolator. Rubber exhibits elastic behaviour even within the large strain range, unlike the general structural material, and has a hyper-elastic characteristics that shows non-linear relationship between load and deformation. This study represents the mechanical characteristics of the rubber by strain energy function in order to develop a finite element (FE) model of LRB. For the study, several strain energy functions were selected and mechanical properties of the rubber were estimated with the energy functions. A finite element model of LRB has been developed by using material properties of rubber and lead which were identified by stress tests. This study estimated the horizontal and vertical force-displacement relationship with the FE model. The adequacy of the FE model was validated by comparing the analytical results with the experimental data.

• Journal of Korean Society of Steel Construction
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• v.30 no.2
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• pp.97-104
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• 2018

The safety evaluation of horizontal and vertical bolted connection between PHC piles is presented. The numerical analysis model is constructed using the commercial finite element program, ABAQUS, in which 3D solid element is used to model all the connection devices. The actual bolted connection is idealized by the contact and tie condition given in ABAQUS. Through the finite element analysis, the compression, tensile, bending and shear behaviors of PHC pile connection were analyzed. The safety factor based on Von-Mises and yield stress was calculated for the safety evaluation of each connection devices.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.709-715
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• 2010

The coupled model with hydrogen transport and elasto-plasticity behavior was introduced. In this paper, the effective factor of the hydrogen diffusion equation has been described. To assess the effective factor, finite element (FE) analyses including hydrogen transport and mechanical loading for boundary layer specimens with low-strength steel properties are carried out. The results of the FE analyses are compared with those from previous studies conducted by Taha and Sofronis (2001).