• 한국강구조학회 논문집
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• 제13권5호
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• pp.557-566
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• 2001

데크플레이트를 사용한 합성슬래브가 합성거동을 발휘하기 위해서는 데크플레이트와 콘크리트의 부착강도가 확보되어야한다. 합성슬래브에서 전단부착강도는 콘크리트와 데크플레이트의 화학적 부착력, 마찰저항 기계적 상호작용에 의해 발생한다. 또 기계적 상호작용은 길이 방향 전단력 전달 장치인 엠보싱 및 쉬어코넥터, 데크플레이트 형상 등에 의해서 확보되어 진다. 그리고 기계적 상호작용의 효과는 상호 접착부의 수직박리를 구속할 수 있는 데크의 형상과 쉬어코넥터 설치에 따른 단부정착 여부에 따라 크게 달라진다. 그러므로, 본 연구에서는 폐쇄형 데크플레이트에 대하여 기계적 전달장치인 엠보싱과 쉬어 코넥터로 사용되는 스터드 볼트에 대한 전단 보강장치의 부착효과를 Push-off 실험을 통하여 규명하였으며 이들 인자들에 대하여 제안식을 제시하였다. 이는 합성슬래브 설계방법의 기초자료로 이용될 수 있을 것으로 사료된다.

• 한국지반환경공학회 논문집
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• 제10권5호
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• pp.59-67
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• 2009

본 연구에서는 단독말뚝의 주변에서 실시되는 터널의 굴착이 지반 및 말뚝에 미치는 영향을 3차원 수치해석을 통하여 분석하였다. 수치해석에서는 말뚝과 주변지반 사이에 경계면요소를 이용하여 소성항복 발생조건을 모델링하였다. 수치해석을 통하여 풍화토 및 풍화암에 시공된 터널과 말뚝의 상호거동에 대한 분석을 실시하였다. 수치해석을 통해 말뚝의 침하, 말뚝과 지반 경계면에서의 상대변위, 전단응력 및 말뚝의 축력변화를 분석하였다. 특히 터널의 굴착과 관련된 전단응력의 전이과정에 대한 심도있는 분석을 실시하였다. 터널굴착에 의한 말뚝-지반 경계면에서 상대변위의 변화로 인하여 말뚝에 작용하는 전단응력 및 축력의 분포가 변하게 된다. 말뚝 본체 대부분에서는 상향의 전단응력이 발생하는 반면(Z/L=0.0-0.8), 말뚝선단부근에서는(Z/L=0.8-1.0) 하향의 전단응력이 발생하여 말뚝에 인장력이 발생된다. 수치해석을 통해서 터널굴착이 말뚝 거동에 미치는 영향을 상세하게 분석하였다.

• Interaction and multiscale mechanics
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• 제6권3호
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• pp.287-300
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• 2013

In this paper, the effect of impulsive line on the propagation of shear waves in non-homogeneous elastic layer is investigated. The rigidity and density in the intermediate layer is assumed to vary quadratic as functions of depth. The dispersion equation is obtained by using the Fourier transform and Green's function technique. The study ends with the mathematical calculations for transmitted wave in the layer. These equations are in complete agreement with the classical results when the non-homogeneity parameters are neglected. Various curves are plotted to show the effects of non-homogeneities on shear waves in the intermediate layer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.102-107
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• 1990

The research program is directed at studying the behavior and the strength of reinforced concrete slabs subjected to certain combination of punching shear and in-plane tension. Major variables to be investigated are the shear span to depth ratio of reinforced concrete slabs and the degree of the in-plane tensile force which is acting tangent to the slabs. The experimental results are used for understanding of the degree of the interaction between the two loadings, and for developing a new practical design equation.

• Geomechanics and Engineering
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• 제12권6호
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• pp.1021-1046
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• 2017

The assessment of slope stability is an essential task in geotechnical engineering. In this paper, a three-dimensional (3D) finite element analysis (FEA) was employed to investigate the performance of different shear pin arrangements to increase the stability of a soil block resting on an inclined plane with a low-interface friction plane. In the numerical models, the soil block was modeled by volume elements with linear elastic perfectly plastic material in a drained condition, while the shear pins were modeled by volume elements with linear elastic material. Interface elements were used along the bedding plane (bedding interface element) and around the shear pins (shear pin interface element) to simulate the soil-structure interaction. Bedding interface elements were used to capture the shear sliding of the soil on the low-interface friction plane while shear pin interface elements were used to model the shear bonding of the soil around the pins. A failure analysis was performed by means of the gravity loading method. The results of the 3D FEA with the numerical models were compared to those with the physical models for all cases. The effects of the number of shear pins, the shear pin locations, the different shear pin arrangements, the thickness and the width of the soil block and the associated failure mechanisms were discussed.

• Structural Engineering and Mechanics
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• 제5권1호
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• pp.1-19
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• 1997

A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

• 대한기계학회논문집
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• 제19권3호
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• pp.834-845
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• 1995

An experimental study is made in a nearly two-dimensional 90.deg. curved duct to investigate the effects of interaction between streamline curvature and mean strain on turbulence. The initial shear at the entrance to the curved duct is varied by an upstream shear generator to produce five different shear conditions ; a uniform flow (UF), a positive weak shear (PW), a positive strong shear(PS), a negative weak shear (NW) and a negative strong shear(NS). With the mean field data of the case UF, variations of the momentum thickness, the shape factor and the skin friction over the convex(inner) surface and the concave (outer) surface are scrutinized quantitatively in-depth. It is found that, while the pressure loss due to curvature is insensitive to the inlet shear rates, the distributions of wall static pressure along both convex and concave surfaces are much influenced by the inlet shear rates.

• Earthquakes and Structures
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• 제16권1호
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• pp.41-54
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• 2019

Reinforced Concrete (RC) shear walls are widely used in Nuclear power plants as effective lateral force resisting elements of the structure and these may experience nonlinear behavior for higher earthquake demand. Short shear walls of aspect ratio less than 1.5 generally experience combined shear flexure interaction. This paper presents the results of the displacement-controlled experiments performed on six RC short shear walls with varying aspect ratios (1, 1.25 and 1.5) for monotonic and reversed quasi-static cyclic loading. Simulation of the shear walls is then carried out by Finite element modeling and also by macro modeling considering the coupled shear and flexure behaviour. The shear response is estimated by softened truss theory using the concrete model given by Vecchio and Collins (1994) with a modification in softening part of the model and flexure response is estimated using moment curvature relationship. The accuracy of modeling is validated by comparing the simulated response with experimental one. Moreover, based on the experimental work a multi-linear hysteretic model is proposed for short shear walls. Finally ultimate load, drift, ductility, stiffness reduction and failure pattern of the shear walls are studied in details and hysteretic energy dissipation along with damage index are evaluated.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.504-512
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• 2002

Bileaflet mechanical valves have the complications such as hemolytic and thromboembolic events, leaflet damage, and leaflet break. These complications are related with the fluid velocity and shear stress characteristics of mechanical heart valves. This fact makes clear the importance of determining the fluid velocity and shear stress characteristics of mechanical heart valves, and requires a detailed understanding of these system properties and further substantial research. The first aim of current study is to introduce fluid-structure interaction method for calculation of unsteady and three-dimensional blood flow through bileaflet valve and leaflet behavior interacted with its flow, and to overcome the shortness of previous studies, where the leaflet motion has been ignored or simplified, by using FSI method. To accomplish this goal, a finite volume computational fluid dynamics code and a finite element structure dynamics code have been used concurrently to solve the flow and structure equations, respectively, to investigate the interaction between the blood flow and leaflet. Physiologic ventricular and aortic pressure waveforms were prescribed as flow boundary conditions. The interaction of aortic flow and valve motion were computed.

• Korea-Australia Rheology Journal
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• 제13권3호
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• pp.141-148
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• 2001

In this research, experimental studies leave been performed on the hydrodynamic interaction between a spherical particle and a plane wall by measuring the force between the particle and wall. To approach the system as a resistance problem, a servo-driving system was set-up by assembling a microstepping motor, a ball screw and a linear motion guide for the particle motion. Glycerin and dilute solution of polyacrylamide in glycerin were used as Newtonian and non-Newtonian fluids, respectively. The polymer solution behaves like a Boger fluid when the concentration is 1,000 ppm or less. The experimental results were compared with the asymptotic solution of Stokes equation. The result shows that fluid inertia plays all important role in the particle-wall interaction in Newtonian fluid. This implies that the motion of two particles in suspension is not reversible even in Newtonian fluid. In non-Newtonian fluid, normal stress difference and viscoelasticity play important roles as expected. In the dilute solution weak shear thinning and the migration of polymer molecules in the inhomogeneous flow field also affect the physic of the problem.