• 한국안전학회지
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• 제32권3호
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• pp.66-73
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• 2017

This study examined the structural behavior of bracket scaffolds reflecting the influence of bracket's deflection. Even though the supporting condition of bracket scaffolds is different to that of general earth-supported scaffolds, there is no clear standards about the installation of bracket scaffolds. To compare the structural behaviors of the earth-supported scaffolds without settlements in columns and those of bracket scaffolds installed on the bracket structure, the finite element analysis was performed. The results show that the differential settlement between the scaffold columns installed on the bracket was occurred due to the deflection of the bracket. The differential settlement gave birth to remarkable secondary stress to the scaffold columns. It is resonable to locate all scaffold columns on the brackets, and if unavoidable situation is faced at a site, the horizontal members should not placed alone without columns on the brackets. Moreover, the structural analysis should be performed to ensure structural safety of bracket scaffolds before installation. In addition, the location of wall connection to the structures is recommended to the scaffolds columns installed on the brackets.

• 국제초고층학회논문집
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• 제6권3호
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• pp.279-284
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• 2017

The purpose of structural health monitoring is to evaluate structural behavior due to various external loads through installation of appropriate measurement. Accordingly, a guideline for monitoring standards is necessary to evaluate the safety and performance of a structure. This paper introduces preliminary design of SHM for high-rise buildings, which is the stage creating a guideline. As for preliminary design of SHM, first step is to calculate the displacement and member force through structural analysis. After that, limitations or qualifications are proposed for management. Secondly, based on the results from first step, issues related monitoring such as monitoring method, measurement type, or installation location are determined. This method leads building managers to reasonably define the structural safety over the whole life cycle. Furthermore, this experience contributes to development of SHM forward and it is expected to be useful for other types of structures as well such as spatial structures or irregular buildings.

• Coupled systems mechanics
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• 제9권5호
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• pp.433-454
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• 2020

In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures. The structural integrity of platform components under the maximum and minimum operating loads of environmental conditions is required for risk assessment and inspection plan development. In-place analyses have been executed to check that the structural member with all appurtenances robustness and capability to support the applied loads in either storm condition or operating condition. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the pile-soil interaction to estimate the in-place behavior of a typical fixed offshore platform. The analysis includes interpretation of dynamic design parameters based on the available site-specific data, together with foundation design recommendations for in-place loading conditions. The SACS software is utilized to calculate the natural frequencies of the model and to obtain the response of platform joints according to in-place analysis then the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have important effects on the results of the in-place analysis behavior. The result shows that the in-place analysis is quite crucial for safe design and operation of offshore platform and assessment for existing offshore structures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.365-368
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• 2006

RBSN Method, Rigid-Body-Spring Network Method, is a structural analysis method that overcomes the problems faced in FEM analysis of concrete or crack forming structures. In RBSN, irregular lattices are used to model structural components consisting of bulk material, curvilinear reinforcements, and their interfaces. Because reinforcements and their interfaces in the bulk material are freely positioned, meshing is irrespective of the geometry of the representing bulk material. In this paper, RBSN method of 3D is applied in simulating the pull-out test of FRP (Fiber Reinforced Polymer) embedded in concrete. The comparison of analysis results to experimental results shows that RBSN method simulates the shear-slip behavior very precisely. From the analysis results, 3D RBSN method is proven to be an effective and accurate analysis method for concrete structural analysis. Also, the results show that RBSN method can be a potential analysis method for concrete structures that can replace the current FEM analysis.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.248-255
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• 2006

Among a variety of influencing components, time-variant seepage and long-term underground motion are important to understand the abnormal behavior of tunnels. Excessiveness of these two components could be the direct cause of severe damage on tunnels. however, it is not easy to quantify the effect of these on the behavior of tunnels. These parameters can be estimated by using inverse methods once the appropriate relationship between inputs and results are clarified. Various inverse methods or parameter estimation techniques such as artificial neural network and least square method can be used depending on the characteristics of given problems. Numerical analyses, experiments, or monitoring results are frequently used to prepare a set of inputs and results to establish the back analysis models. In this study, a back analysis method has been developed to estimate geotechnically hard-to-known parameters such as permeability of tunnel filter, underground water table, long-term rock mass load, size of damaged zone associated with seepage and long-term underground motion. The artificial neural network technique is adopted and the numerical models developed in the firstpart are used to prepare a set of data for learning process. Tunnel behavior especially the displacements of the lining has been exclusively investigated for the back analysis.

• 한국전산구조공학회논문집
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• 제25권1호
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• pp.1-8
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• 2012

본 연구는 다양한 건설 구조물 중 휨 응력을 받는 부재인 슬래브, 거더 등에 FRP(Fiber Reinforced Polymer) 박스부재를 적용하기 위한 기초 실험적 연구이다. 조립이 가능한 FRP 부재를 제작하여 FRP 박스부재의 대형단면으로서의 연결 후 압축파괴 거동 특성을 분석하기 위하여 다양한 조건으로 실험을 수행하였다. FRP 박스부재의 상부에 충진재와 하중재하 방법 및 연결형태에 따른 압축파괴 거동 실험을 실시하였으며, 이를 이용하여 유한요소해석을 수행하였다. 해석결과를 실험결과와 비교한 결과 강성이 약간 낮게 조사되었으나 시험체의 파괴지점에 응력이 집중되는 것을 확인할 수 있었다.

• 한국전산구조공학회논문집
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• 제34권6호
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• pp.371-383
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• 2021

강-콘크리트 편개형 방폭문은 외피 구조로서의 강박스 내에 콘크리트 슬래브가 채워진 구조로서 힌지 및 렛치와 같은 지지부재에 의해 벽체에 고정되어 설치된다. 폭압이 작용하는 방향과 같은 정방향으로의 처짐 거동에 대해서는 많은 연구가 되어 왔으나, 부방향 처짐 거동에 대한 연구는 상대적으로 미흡한 수준이다. 본 연구에서는 폭압을 받는 편개형 방폭문의 부방향 처짐 단계에서 발생하는 반발 거동(rebound behavior)에 대해 유한요소해석으로 변수 분석을 하였다. 분석결과에 따르면 방폭문의 소성변형 내지는 파괴 정도, 반발작용 전후의 운동량 및 운동에너지 변화가 반발거동에 영향을 미치는 주요 요소로 분석되었다. 또한, 방폭문의 거동 특성이 준정적 영역에 속하는 경우에 비해 충격영역에 속하는 경우에서 더 큰 반발력이 발생하는 것으로 나타났는데, 이와 같은 결과는 변형에너지 보다 운동에너지가 상대적으로 더 크게 증가하는 충격영역에서의 거동 특성이 원인인 것으로 사료된다. 반발작용의 결과로 인해 지지부재에 과도한 변형이 발생할 수 있으므로 성능분석 및 설계 과정에서 이에 대한 고려가 필요하다. 또한, 부압이 미치는 영향을 검토한 결과에 따르면 강-콘크리트 방폭문의 경우에서도 반발에 의한 영향 및 부압 모두가 방폭문의 부방향 처짐에 기여할 때 반발력이 상대적으로 더 크게 증가하는 것으로 나타났다. 이와 같은 중첩 효과의 발생조건은 구조체 특성 및 폭발조건 등에 따라 다를 수 있으므로 이에 대해서는 더 많은 연구가 필요할 것으로 판단된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.3-11
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• 2005

The structural analysis considering the soil-structure interaction is very important in the design process of underground structures located on the site with various soil conditions. In practice, simplified modelling techniques to obtain the approximate solution are used in accordance with the specifications. However, their details are insufficient for practical engineers to obtain the stable solutions and the analysis results of each engineer occasionally my be different in spite of the same problem. In this study, the sensitivity of structural behaviour on the underground structures is analyzed according to the structural modelling techniques of existing specifications. It is performed to obtain the fundamental informations to establish the guide to obtain the stable solutions in practical analysis of the underground structures such as subway structures.

• International Journal of Aeronautical and Space Sciences
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• 제16권1호
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• pp.110-122
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• 2015

In this paper, the unsteady aerodynamics and blade structural dynamics of an experimental bearingless rotor were analyzed. Due to the multiple load path and nonlinear behavior of a bearingless rotor, sophisticated structural modeling and structural-aerodynamic coupled analysis is required. To predict the internal load and deformation of an experimental bearingless rotor, trim analysis was implemented. The results showed good agreement when compared with those predicted by CAMRAD II the rotorcraft comprehensive analysis. It is possible to extend the present structural-aerodynamic combined analysis to further advanced configurations of the bearingless rotor in the future.

• 한국ITS학회 논문지
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• 제14권5호
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• pp.13-22
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• 2015

최근 교통사고 주요 원인인 인간행동(인적요인)에 대해 관심이 높아졌으며 운전행동분석 도구인 DBQ(Driver Behavior Questionnaire)를 활용한 운전행동(Driving Behavior)에 관한 연구가 활발히 진행되고 있다. 국내에서 진행된 선행연구는 분석대상이 연구원이나 군 공무원으로 한정되며 분석방법은 요인분석 및 회귀분석을 통해 이루어졌다. 이에 본 연구에서는 일반운전자의 운전행동이 위험운전에 미치는 영향요인을 파악하고 이들의 영향관계를 규명하고자 한다. 연구의 범위는 운전경력이 있는 일반운전자를 대상으로 DBQ설문을 실시하여 300부의 유효 표본수를 분석하였으며, 선행연구 고찰을 통해 교통사고의 주요 요인을 DBQ에서 측정가능한 'Lapse, Mistake, Violation' 세 가지속성으로 도출하고 구조방정식 모형을 통한 위험운전행동 모형을 구축하였다. 또한, 위험운전군별 차이를 확인하기 위하여 다중집단분석을 활용하였다. 분석결과 첫째, 'Lapse, Mistake, Violation 요인은 위험운전행동에 영향을 미칠 것이다'라는 가설검증 결과 모든 요인의 통계적 유의성이 확인되었다. 위험운전행동에 미치는 영향정도는 Violation 0.464, Lapse 0.383, Mistake 0.158 순으로 나타났으며 영향을 가장 많이 미치는 요인이 Violation으로 분석되었다. 둘째, 'Lapse, Mistake, Violation 요인이 위험운전행동에 미치는 영향은 위험군에 따라 다를 것이다'라는 가설검증 결과 Lapse 요인이 위험운전행동에 미치는 영향력이 차이가 있는 것으로 분석되었다. 본 연구결과는 위반행동 Violation과 부주의한 실수 Lapse를 고려한 교통사고 예방 프로그램 및 교육도입에 기초자료로 활용 가능할 것이다.