• 한국지반환경공학회 논문집
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• 제2권4호
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• pp.15-27
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• 2001

본 연구에서는 유한요소해석을 통해 파형강판 암거의 단면력(압축력, 휨모멘트) 계산식을 제안하였다. 3단계의 시공과정(정점부까지의 뒷채움, 토피고까지의 뒷채움, 활하중 재하)에 대해 지반-구조물 상호작용을 고려한 거동분석으로부터 최대 압축력 및 최대 휨모멘트 발생조건을 도출하였고, 이러한 거동분석 결과와 반원 아치구조에 대한 Castigliano 제2정리의 적용으로부터 단면력식의 형태를 제안하였다. 또한, 최대 압축력 및 최대 휨모멘트를 유발하는 조건하에서 다양한 기하형태와 지반-구조물의 상대강성을 고려한 유한요소해석 결과로부터 제안된 단면력식을 구성하는 계수를 결정하였다.

• 한국산학기술학회논문지
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• 제7권1호
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• pp.63-69
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• 2006

본 연구에서는 비지지 길이 한쪽 단에 계단식 단면 변화를 가지는 보에 대해 횡-비틀림 좌굴 강도를 합리적으로 산정하기 위한 새로운 모멘트구배 수정계수를 개발, 제안하였다. 새로운 모멘트구배 수정계수식을 개발하기 위하여 유한요소해석 프로그램이 활용되었으며, 제안식은 기존에 발표된 식들과 비교·분석되었다. 구조물에 발생가능한 대부분의 하중조건이 본 연구에 고려되었으며, 본 논문을 통해 제안된 새로운 모멘트구배 수정계수식은 건물과 교량의 설계 및 유지관리 기술자들이 간편하고 경제적인 설계를 유도하는 데 크게 기여할 것이다.

• 대한기계학회논문집A
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• 제28권9호
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• pp.1262-1269
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• 2004

This study predicts muscle forces acting on the lower extremity when the knee joint is in deep flexion. The whole body was approximated as a link model, and then the moment equilibrium equations at the lower extremity joints were derived far given reaction farces against the ground. Measurement of deep flexion was carried out by placing ten markers on the body. This study calculated the moment acting at each Joint from the equations of force and moment, classified the complicated muscles around the knee joint, and then predicted the muscle forces to balance the joint moment. Two models were proposed in this study: the simpler one that consists of three groups of muscle and the more detailed one of nine groups of muscle.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1288-1293
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• 2003

This study predicts muscle forces acting on the lower extremity when the knee joint is in deep flexion. The whole bodies were approximated as a link model, and then the moment equilibrium equations at the lower extremity joints were derived for given reaction forces against the ground. Measurement of deep flexion was carried out by placing ten markers on the body. This study calculated the moment acting at each joint from the equations of force and moment, classified the complicated muscles around the knee joint. and then predicted the muscle forces to balance the joint moment. Two models were proposed in this study: the simpler one that consists of three groups of muscle and the more detailed one of nine groups of muscle.

• 한국정밀공학회지
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• 제12권4호
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• pp.127-134
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• 1995

The dynamic characteristics of a system can be critically influenced by system uncertainty, so the dynamic system must be analyzed stochastically in consideration of system uncertainty. This study presents a generalized stochastic model of dynamic system subjected to bot external and parametric nonstationary stochastic input. And this stochastic system is analyzed by a new stochastic process closure method and moment equation method. The first moment equation is numerically evaluated by Runge-Kutta method. But the second moment equation is founded to constitute an infinite coupled set of differential equations, so this equations are numerically evaluated by cumulant neglect closure method and Runge-Kutta method. Finally the accuracy of the present method is verified by Monte Carlo simulation.

• 한국강구조학회 논문집
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• 제18권2호
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• pp.191-201
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• 2006

본 연구에서는 비지지길이 양단에 계단식 단면 변화를 가지는 보에 대해 횡-비틀림 좌굴강도를 합리적으로 산정하기 위 한 새로운 모멘트 구배 수정계수를 개발, 제안하였다. 제안된 식은 건물과 교량에 사용된 보의 양단에 개별 지지만 존재하는 경우와, 슬래브 등이 타설되어 상부플랜지에 연속적인 횡방향 지지가 존재하는 경우로 구분되어 연구되었다. 새로운 모멘트 구배 수정계수식을 개발하기 위하여 유한요소해석 프로그램이 활용되었으며, 제안식은 기존에 발표된 식들과 비교 분석되었다. 구조물에 발생가능한 대부분의 하중조건이 본 연구에 고려되었으나, 본 논문에서는 하나의 집중하중과 등분포하중이 작용하는 경우를 중점으로 기술되었다. 본 연구에서는 비지지길이와 보작용시 적용 가능하도록 식이 개발 제안되었다. 본 논문을 통해 제안된 새로운 모멘트 구배 수정계수식들은 건물과 교량의 설계 및 유지관리 기술자들이 간편하고 경제적인 설계를 유도하는 데 크게 기여할 것이다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제21권4호
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• pp.215-224
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• 2017

The moment closure method is an approximation method to compute the moments for stochastic models of chemical reaction systems. In this paper, we develop an analytic estimation of errors generated from the approximation of an infinite system of differential equations into a finite system truncated by the moment closure method. As an example, we apply the result to an essential bimolecular reaction system, the dimerization model.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.167-172
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• 2002

Nonlinear analysis of the reinforced concrete beam subjected to torsion is presented. Seventeen equations involving seventeen variables are derived from the equilibrium equation, compatibility equation, and the material constitutive laws to solve the torsion problem. Newton method was used to solve the nonlinear simultaneous equations and efficient algorithms are proposed. Present model covers the behavior of reinforced concrete beam under pure torsion from service load range to ultimate stage. Tensile resistance of concrete after cracking is appropriately considered. The softened concrete truss model and the average stress-strain relations of concrete and steel are used. To verify the validity of Present model, the nominal torsional moment strengths according to ACI-99 code and the ultimate torsional moment by present model are compared to experimental torsional strengths of 55 test specimens found in literature. The ultimate torsional moment strengths by the present model show good results.

• International Journal of Precision Engineering and Manufacturing
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• 제1권1호
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• pp.22-32
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• 2000

This paper describes the development of a precision 3-component load cell with plate beams which may be used for measuring forces Fx, Fy and moment Mz simultaneously in industry. The equations to predict the bending strains on the surface of the beams under forces or moment are derived, the attachment location of strain gages of each sensor is determined, and 3-component load cell is carried out. It reveals that the rated strain calculated from the derived equations are good agreement with the results from Finite Element Method analysis.

• Structural Engineering and Mechanics
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• 제38권4호
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• pp.459-477
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• 2011

Due to the low elastic modulus of FRP, concrete members reinforced with FRP rebars show greater deflections than members reinforced with steel rebars. Deflection is one of the important factors to consider the serviceability of horizontal members. In this study flexural test of AFRP reinforced concrete beams was performed considering reinforcement ratio and compressive strength as parameters. The test results indicated that flexural capacity and stiffness increase in proportion to the reinforcement ratio. The test results were compared with existing proposed equations for the effective moment of inertia including ACI 440. The most of the proposed equations were found to over-estimate the effective moment of inertia while the equation proposed by Bischoff and Scanlon (2007) most accurately predicted the values obtained through actual testing.