• Steel and Composite Structures
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• 제18권3호
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• pp.711-737
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• 2015

Steel Plate Shear Walls (SPSWs) have been accepted widely as an effective lateral load resisting system. For seismic performance evaluation of a multi-story building with SPSWs, detailed finite element models or a strip model can be used to represent the SPSW components. However, such models often require significant effort for tall or medium height buildings. In order to simplify the analysis process, discrete elements for the framing members can be used. This paper presents development of a simplified equivalent braced model to study the behavior of the SPSWs. The proposed model is expected to facilitate a simplification to the structural modeling of large buildings with SPSWs in order to evaluate the seismic performance using regular structural analysis tools. It is observed that the proposed model can capture the global behavior of the structures quite accurately and potentially aid in the performance-based seismic design of SPSW buildings.

• 한국해양공학회지
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• 제15권3호
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• pp.120-127
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• 2001

The potential pollution problems resulting from tanker collision necessitate the requirement for an effective structural design and the development of relevant safety regulations. During a few decades, the great effort has been made by the international Maritime Organization and the Administration, etc, to reduce oil spillage from collision accidents. However there is still a need for investigation in the light of structural evaluation method for the experiments and rational analysis, and design development for an operational purpose of ships. This study aims for investigating a complicated structural response of bow structures of simplified models and oil carriers for assessing the energy dissipation and crushing mechanics of the striking vessels through a methodology of the numerical analysis for the various models and its design changes. Through these study an optimal bow construction absorbing great portion of kinetic energy at the least penetration depth prior to reach to the cargo area and an effective location of collision bulkhead are investigated. In order to obtain a rational results in this study, three stages of collision simulation procedures have been performed step by step as follows; 1) 16 simplified ship models are used to investigate the structural response against bow collision with variation of primary and secondary members. Mass and speed are also varied in four conditions. 2) 21 models consisted of 5 sizes of the full scaled oil carriers are used to perform the collision simulation with the various sizes and deadweight delivered in a recent which are complied with SOLAS and MARPOL. 3) 36 models of 100l oil carrier are used to investigate the structural response and its influence to the collision bulkhead against bow collision in variation with location of collision bulkhead, primary members, framing system and colliding conditions, etc. By the first study using simplified models the response of the bow collision is synthetically evaluated for the parameters influencing to the absorbed energy, penetration depth and impact force, etc.

• 전산구조공학
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• 제26권3호
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• pp.42-46
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• 2013

• 한국융합학회논문지
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• 제4권3호
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• pp.1-5
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• 2013

본 연구에서는 소형풍력발전용 블레이드의 축소모델을 대상으로 단순 하중 계산 및 구조 시험을 수행하였다. 먼저, 연구 대상인 블레이드의 초기 모델의 0.2 비율만큼 축소하여 설계 및 제작하였다. 그리고 소형 풍력발전 국제 규격인 IEC 61400-2에 의거한 단순 하중 계산식을 이용하여 모멘트를 획득하였다. 또한, 추를 이용한 구조시험을 수행하여 최대 모멘트를 획득하였다. 이를 통하여 계산 및 시험에 따른 최대 모멘트를 비교하였다.

• Computers and Concrete
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• 제22권6호
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• pp.515-525
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• 2018

This paper presents a numerical study on the performance of reinforced concrete (RC) bridge structures subjected to heavy goods vehicle (HGV) collision. The objectives of this study are to investigate the dynamic response and failure modes of different types of bridges under impact loading as well as to give an insight into the simplified methods for modeling bridge structures. For this purpose, detailed finite-element models of HGV and bridges are established and verified against the full-scale collision experiment and a recent traffic accident. An intensive parametric study with the consideration of vehicle weight, vehicle velocity, structural type, simplified methods for modeling bridges is conducted; then the failure mode, impact force, deformation and internal force distribution of the validated bridge models are discussed. It is observed that the structural type has a significant effect on the force-transferring mechanism, failure mode and dynamic response of bridge structures, thus it should be considered in the anti-impact design of bridge structures. The impact force of HGV is mainly determined by the impact weight, impact velocity and contact interface, rather than the simplification of the superstructure. Furthermore, to reduce the modeling and computing cost, it is suggested to utilize the simplified bridge model considering the inertial effect of the superstructure to evaluate the structural impact behavior within a reasonable precision range.

• 전산구조공학
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• 제10권4호
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• pp.267-280
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• 1997

본 논문은 철근콘크리트 보의 시간의존적 거동인 크리이프 변형의 산정에 관한 것으로 크리이프 Compliance 함수의 1차 순환적 단계 알고리즘에 토대를 둔 적층단면법에 대하여 논의하였으며, 단면의 평형조건과 적합조건으로부터 구조물의 크리이프 변형을 쉽게 예측할 수 있는 간략 해석법을 제안하였다. 여러 실험치와 기존 해석방법 및 설계 규준과의 비교를 통해 제안된 해석모델의 효율성을 검증하였고, 적층단면법을 사용한 다양한 해석을 통해 단면의 형상, 철근비의 변화 및 균열의 유무에 따른 구조물의 시간의존적 거동에 비교 및 분석되었다.

• 한국전산구조공학회논문집
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• 제29권1호
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• pp.67-75
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• 2016

본 논문에서는 폭발해석에서 주로 사용되는 폭발하중의 압력-시간 이력곡선과 폭발하중 산정식인 Conwep 모델을 소개하고, 이를 더욱 간편하게 계산할 수 있는 간략 폭발하중 산정식을 제안한다. 폭발해석에서 폭발하중은 일반적으로 압력-시간 이력곡선의 형태로 적용되며, 그에 대한 주요 값들은 폭발하중 산정식에 의해 계산된다. 대부분의 폭발해석에서 사용되는 폭발하중 산정식인 Conwep 모델은 환산거리(scaled distance)를 핵심변수로 하여 계산되는데, 그 계산 과정이 매우 복잡한 단점이 있다. 따라서 본 논문에서는 환산거리를 변수로 갖는 간략한 유리식을 사용하여 주요 값들을 계산하고, 단순화된 압력-시간 이력곡선으로 폭발하중을 산정할 수 있도록 제안하였다. 간략식을 찾는 과정에서 Conwep 모델의 계산 결과를 바탕으로 곡선 적합(curve fitting) 방식이 사용되었으며, 제안된 간략식에 의한 주요 값의 계산 결과는 Conwep 모델과 비교하여 1% 미만의 오차를 갖는다. 또한, 유한요소를 이용한 폭발해석에 적용하였으며 Conwep 모델을 적용한 결과와 비교를 통해 검증하였다.

• Structural Engineering and Mechanics
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• 제3권6호
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• pp.529-539
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• 1995

The rigid-plastic yield-line analysis of isotropically reinforced concrete slabs acting in conjunction with torsionally weak supporting beams is developed as the lower-bound form of a linear programming formulation. The analysis is extended to consider geometric variation of chosen yield-line patterns by the technique of sequential linear programming. A strategy is followed of using a fine potential yield-line mesh to identify possible collapse modes, followed by analysis using a coarser, simplified mesh to refine the investigation and for use in conjunction with geometric optimization of the yield-line system. The method is shown to be effective for the analysis of three slabs of varying complexity. The modes detected by the fine and simplified analyses are not always similar but close agreement in load factors has been consistently obtained.

• Earthquakes and Structures
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• 제8권5호
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• pp.1091-1111
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• 2015

Base isolation is an effective method for protecting structures against earthquake hazard. It elongates the period of vibration and introduces supplemental damping to the structural system. The stiffness, damping and displacement are coupled forcing the code seismic design procedure to be unnecessarily complicated. In addition, the force reduction factor -a key parameter in the design procedurehas not been well addressed by seismic design codes at the high levels of damping due to the pronounced difference between pseudo and actual accelerations. In this study, a comparison has been conducted to evaluate eight different methods, in the literature, for calculating the force reduction factor due to damping. Accordingly, a simplified seismic analysis procedure has been proposed based on the well documented N2 method. Comprehensive analysis has been performed for base-isolated structure models for direct application and verification of the proposed procedure. The results have been compared with those of the European code EC8, the nonlinear time history analysis and investigations in the literature, where good agreement has been reported. In addition, a discussion has been elaborated for the resulted response of the base-isolated structure models with respect to the dynamic characteristics of the base isolation system.

• 한국전산구조공학회논문집
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• 제32권1호
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• pp.7-16
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• 2019

본 논문에서는 해양플랜트용 매니폴드 구조물의 내진해석을 위해, 단순화 모델에 대해 응답스펙트럽해석(RSA) 및 시간이력해석(THA)을 여러 조건으로 진행하여 비교 검토하였다. 응답스펙트럼해석은 ISO19901-2에 따른 내진설계 절차를 이용하였다. 시간이력해석의 경우, 응답스펙트럼으로 가속도와 변위에 대한 지진이력을 인공적으로 만든뒤 Explicit와 Implicit 솔버를 사용하여 해석하였다. 단자유도 모델을 사용하여 해석방법을 검증하였으며, 매니폴드 구조물을 단순화한 모델에서 시간이력해석과 응답스펙트럼해석법의 차이를 분석하였다. 복잡한 실제 구조물에 대해서 직접적인 시간이력해석은 불가능하므로 응답스펙트럼해석법을 적용하였고, 단순화 모델에서 분석한 결과 차이를 활용하여 실제 구조물의 안전성을 판단하였다.