• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.146-149
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• 2003

Two-way shape memory effect(TWSME) under residual stresses are considered in the present study. The structure using two-way shape memory alloy(SMA) concept returns to its initial shape by increasing or decreasing temperature under the initially given residual stress. In the present study, we use a thermo-mechanical constitutive equation of SMA and laminated composite plates are considered as simple morphing structural components which are based on first order shear deformable laminated composite plate with large deflection. Numerical results of fully coupled SMA-composite structures are presented

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.141-148
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• 1998

An analytical model which can simulate the post-cracking behavior of reinforced concrete structures subjected to in-plane shear and normal stresses is presented. Based on the force equilibriums, compatibility conditions, and bond stress-slip relationship between steel and concrete, a criterion to simulate consider the tension-stiffening effect is proposed. The material behavior of concrete is described by an orthotropic constitutive model, and focused on the tension-compression region with tension-stiffening and compression softening effects defining equivalent uniaxial relations in the axes of orthotropy. Correlation studies between analytical results and available experimental data are conducted with the objective to establish the validity of the proposed model.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.646-655
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• 2002

장대 교량이 위치한 지반에서 지진에 의한 지반 운동은 교량의 길이 방향으로 공간적인 변화를 일으킨다. 지형 변화나 지반 매질의 물성 변화가 있는 비균질한 지반에서 지반 운동의 진폭과 주파수 성분은 변화하고 이 부지 효과(site effect)는 교량의 지진 응답에 지배적인 영향을 미치며 그 영향은 파전파 효과(wave passage effect)에 의한 지반 각 지점의 지진파 도달시간 차이나 비균질성이 큰 지반에서 파의 다중 반사, 굴절에 의한 영향보다 크다[1]. (중략)

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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• pp.127-132
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• 1992

The effect of 5 typical rise ratio(h/a=2/9, 5/18, l/3, l/2, 2/3) on the buckling characteristics of single-layer latticed domes with rectangular network under the external pressure are the theoretically studied on the basis of geometically nonlinear FEM and shell analogy method. The loading conditions are 4 types, that is, 1) the uniform pressure loading 2)the uniform snow loading 3) the half - sided asymmetric pressure loading 4) the half - sided asymmetric snow loading.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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• pp.29-38
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• 1992

Approximate Constant Shear Angle Theory is usually used to take a transversal shear deformation of thick plate into consideration, which cannot be effectively considered the influence of transversal warping of cross-section with an increase of thickness. It right be the best way to represent the exact warping of cross-section. In this study, the derivation of warping function is attempted, and the effect of shear deformation and transversal warping is to be considered through the nolinear analysis of plate.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.230-237
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• 2000

Tubular joints of jacket structures are usually reinforced using thicker can section, internally ring stiffeners, diaphragm, or externally gusset plates to increase load carry capacity. In this paper, the effect of reinforcement type and geometric parameters of stiffener on the ultimate strength of tubular X-joints subjected to brace compression have been studied numerically Three reinforcement methods were considered; (1)can reinforcement (2)internally ring stiffener (3)internally longitudinal diaphragm. The ANSYS software was used nonlinear strength analysis. It was found that there is significant strength enhancement for reinforced joints.

• Earthquakes and Structures
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• 제6권1호
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• pp.89-110
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• 2014

Nonlinear dynamic analyses are carried out to investigate the influence of the pinching hysteretic response of the exterior RC beam-column joints on the seismic behavior of multistory RC frame structures. The effect of the pinching on the local and global mechanisms of an 8-storey bare frame and an 8-storey pilotis type frame structure is evaluated. Further, an experimental data bank extracted from literature is used to acquire experimental experience of the range of the real levels that have to be considered for the pinching effect on the hysteretic response of the joints. Thus, three different cases for the hysteretic response of the joints are considered: (a) joints with strength and stiffness degradation characteristics but without pinching effect, (b) joints with strength degradation, stiffness degradation and low pinching effect and (c) joints with strength degradation, stiffness degradation and high pinching effect. For the simulation of the beam-column joints a special-purpose rotational spring element that incorporates the examined hysteretic options developed by the authors and implemented in a well-known nonlinear dynamic analysis program is employed for the analysis of the structural systems. The results of this study indicate that the effect of pinching on the local and global responses of the examined cases is not really significant at early stages of the seismic loading and especially in the cases when strength degradation in the core of exterior joint has occurred. Nevertheless in the cases when strength degradation does not occur in the joints the pinching may increase the demands for ductility and become critical for the columns at the base floor of the frame structures. Finally, as it was expected the ability for energy absorption was reduced due to pinching effect.

• 국제초고층학회논문집
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• 제5권4호
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• pp.271-291
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• 2016

There is much architectural and engineering literature which discusses the virtues of exterior bracing and diagrid systems in regards to sustainability - two systems which generally reduce building materials, enhance structural performance, and decrease overall construction cost. By surveying past, present as well as possible future towers, this paper examines another attribute of these structural systems - the blend of structural functionality and aesthetics. Given the external nature of these structural systems, diagrids and exterior bracings can visually communicate the inherent structural logic of a building while also serving as a medium for artistic effect. Viewed in this light, the visual appeal of these systems can be enhanced to give a tower a more distinct urban identity. This entails the creation of structural elements that are aesthetically pleasing, geometrically coherent and that demonstrate dexterity of application in regards to a building's composition, while also respecting the laws of physics and mechanics. In this fashion, an artistic approach can exhibit structural systems as not just purely rational features that enable the construction of tall buildings, but as important visual components that afford opportunities for creative expression. This paper, therefore, synthesizes the concepts of structural performance and creative artistry to facilitate a better understanding of the aesthetic developments in skyscrapers worldwide.

• Structural Engineering and Mechanics
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• 제30권4호
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• pp.445-466
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• 2008

This paper presents a novel structural damage detection method with a new damage index based on the statistical moments of dynamic responses of a structure under a random excitation. After a brief introduction to statistical moment theory, the principle of the new method is put forward in terms of a single-degree-of-freedom (SDOF) system. The sensitivity of statistical moment to structural damage is discussed for various types of structural responses and different orders of statistical moment. The formulae for statistical moment-based damage detection are derived. The effect of measurement noise on damage detection is ascertained. The new damage index and the proposed statistical moment-based damage detection method are then extended to multi-degree-of-freedom (MDOF) systems with resort to the leastsquares method. As numerical studies, the proposed method is applied to both single and multi-story shear buildings. Numerical results show that the fourth-order statistical moment of story drifts is a more sensitive indicator to structural stiffness reduction than the natural frequencies, the second order moment of story drift, and the fourth-order moments of velocity and acceleration responses of the shear building. The fourth-order statistical moment of story drifts can be used to accurately identify both location and severity of structural stiffness reduction of the shear building. Furthermore, a significant advantage of the proposed damage detection method lies in that it is insensitive to measurement noise.

• 기독교교육논총
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• 제64권
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• pp.173-202
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• 2020

본 연구는 교회 가정사역 프로그램 참여자의 학습참여동기가 서번트 리더십에 미치는 영향과 공동체 의식의 구조적 관계를 탐색하기 위해서 수행되었다. 먼저 선행연구 분석을 통해 구조모형을 구성하였다. 구조모형 검증을 위해 전국의 교회 및 단체에서 실시하는 교회 가정사역에 프로그램에 참여하고 있는 부부를 대상으로 배포한 설문지 700부 중 607부를 대상 자료로 수집하였다. 자료수집은 교회 가정사역 이후 학습참여동기, 서번트 리더십, 공동체 의식을 설문지를 사용하여 수집하였다. 수집된 자료는 구조방정식 모형 분석 방법을 사용하여 학습참여동기에 대한 서번트 리더십의 영향과 공동체 의식의의 구조적 관계에 대해 분석하였다. 그 결과 본 연구에서 제안한 구조적 모형이 타당한 것으로 검증되었다. 이에 학습참여 동기 가운데 내재적 동기와 외재적 동기의 영향을 공동체 의식이 매개하여 서번트 리더십에 영향을 주는 것으로 검증되었으며, 서번트 리더십의 영향을 공동체 의식이 매개하는 경로가 영향력을 가지고 있는 것으로 검증되었다. 이에 교회 가정사역을 운영할 때, 참여자들의 내재적 참여동기와 외재적 참여동기를 고려하여 공동체 의식을 조절한다면 학습참여동기의 수준을 조절할 수 있다는 시사점을 제시할 수 있다.