• Computational Structural Engineering
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• v.8 no.4
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• pp.65-74
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• 1995

Direct method developed for the inelastic analysis of planar frames subjected to monotonic loads is extended to cyclic loads. Two frame elements for Direct Method(inelastic truss and inelastic beam) are developed. The accuracy and reliability of the preposed method is verified by comparing the analysis results of example with step-by-step analysis. Direct Method is superior to Step-by-step analysis in view of reliability of solution and analysis cost.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.529-532
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• 2010

본 연구에서는 철근가격 급등과 배근시공도 작성 인력 부족에 대비하여 SDM# 제품군을 사용하여 이음/정착을 고려한 3차원 철근 배근 자동화 기술(RAP)로 철근 배근 자동생성 및 배근시공도 작성 시스템을 개발하였다. 최근 철근가격 급등으로 인한 공사원가상승/인건비 상승/배근시공도 작성 인력 부족 등의 기존현황의 문제점 등을 SDM# 제품군의 철근 배근 자동화 기술(RAP)을 이용하여 자동 철근배근/배근시공도 작성/정밀 골조물량 산출/인력절감/시공 정밀도 향상/골조 공사비 절감 등의 효과와 기존의 현장가공으로 인한 철근 손실률 8%를 공장가공을 적용함으로써 3% 수준으로 낮출 수 있어 5% 내외의 절감효과를 얻을 수 있다. 철근현장가공에서 공장가공 전환으로 골조물량 절감을 기대할 수 있고, 이음/정착/응력분포가 고려된 3차원 철근 배근 자동화 기술(RAP)을 이용하여 자동배근 알고리즘에 의한 배근시공도/가공도 작성 효율을 높이고, 기술 자립을 통해 건설시공 분야의 기술력 향상을 기대할 수 있다.

• Computational Structural Engineering
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• v.26 no.2
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• pp.37-42
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• 2013

준공 후 상당한 시간이 지나 내진설계가 되지 않았거나 내진상세가 이루어지지 않은 건물의 부족한 내진성능을 보완하기 위한 방법의 하나로 좌굴이 제한된 가새형 댐퍼를 적용할 수 있다. 이 방법을 적용할 경우, 기존 내진보강법의 불확실성을 줄일 수 있었음에도 불구하고, 댐퍼의 설계과정이 복잡하여 실무에 적용하기 어려웠다. 그러나 본 원고에서는 강성과 강도개념을 적용한 댐퍼의 설계법을 적용함으로써, 실무에서 쉽게 적용할 수 있도록 하였다. 준공된 지 16년이 지난 비틀림 비정형 건물에 대한 내진성능을 평가한 후, 가새형 댐퍼로 보강한 결과는 다음과 같다. (1) 일방향해석결과 나타난 골조별 하중-지붕변위의 관계를 이용하여, 연약골조의 강성을 강한 골조의 강성과 일치시키고, 이 강성비로부터 댐퍼가 부담하는 최적의 내력비율을 정하여 내진보강을 수행한 결과, 가새를 설치한 방향으로는 가새형댐퍼가 비틀림 방지와 연성증대효과를 구조물에 부여하여 성능이 획기적으로 증가하였다. 또한, 그 가새의 직각방향 하중에 대해서도 가새를 설치함으로써 비틀림 강성이 증가하고, 가새와 코어벽체가 인장과 압축으로 횡력에 저항하여 횡저항 성능이 증가하였다. (2) 내진성능이 부족한 비틀림 비정형 건물의 내진성능을 증진시키기 위해 가새형 댐퍼를 적용함에 있어, 댐퍼의 강성을 이용하여 구조체의 비틀림 거동을 최소화하고, 연성을 증진시키는 방법을 체택할 경우, 실무자들이 보다 쉽게 적용할 수 있으면서 그 효과도 상당히 클 것으로 기대된다.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.629-638
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• 2000

With the positive features of simulated annealing algorithms such as simplicity of the algorithm and the possibility of finding global optimum solution, SA algorithm has been widely applied to structural optimization problems. However, the algorithms are far from practical applications in structural design or optimization of building structures due to requirement of a large number of iterations and dependency on cooling schedule and stopping criteria. In this paper, with the modification of annealing process and stopping criteria, a MSA algorithm is presented in the form of two phase annealing process for optimal seismic design of braced structures. The performance of the proposed algorithm has been illustrated in detail.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.1-12
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• 2007

For the purpose of effective utilization of domestic second-grown larch as structural members, post and beam construction applying traditional construction to Japanese larch glulam members was adopted with processing by machine pre-cut method. In general, horizontal shear test by KS F 2154 is conducted to assess the horizontal shear properties of the wooden structure by post and beam construction. The frame was consisted of post and beam member with appropriate fasteners, and members have their own processed parts (notch, hole, etc.) that can be well-connected each other. The shear wall was consisted of the frame with screw-nail sheathed panel (OSB). The results of horizontal shear loading tests without vertical loads conducted on the frame and the shear wall structures, the maximum strengths were about 1.9 kN/m and about 9.7 kN/m, the shear rigidities were about 167 kN/rad, 8198 kN/rad, respectively. The strength proportion of the frame specimen was about 20% of the wall's and about 2% in initial stiffness. Nail failures are remarkable on the shear wall specimen with punching shears and shear failures. The shear load factor for the shear wall specimen by the method of Architectural Institute of Japan was 1.5, which was obtained by the bi-linear method. Loading method should be considered to obtain smooth load-deformation relationship. For the better shear performance of the structures, column base and post and beam connections and sheathed panel should be further examined as well.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.174-182
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• 2014

To monitor the wind-induced responses of buildings, conventional real-time kinematic (RTK) methods based on two global positioning system (GPS) receivers (e.g., a reference and a rover) are widely applied. However, these methods can encounter problems such as difficulty in securing and maintaining a space for a reference station. With the recently developed virtual reference station (VRS)-RTK approach, the position of a structure can be measured using only a rover receiver. In this study, to evaluate the applicability of VRS-RTK methods in monitoring the lateral structural responses of frame structures, we performed free vibration tests on a one-story frame model (the first natural frequency of 1 Hz) and a three-story frame model (the first natural frequency of 0.85 Hz). To assess the reliability of the displacement and acceleration responses measured by the GPS, we performed a concurrent measurement using laser displacement sensors and an accelerometer. The accelerometer results were consistent with the GPS measurements in terms of the time history and frequency content. Furthermore, to derive an appropriate sampling rate for the continuous monitoring of buildings, the errors in the displacement responses were evaluated at different GPS sampling rates (5, 10, 20 Hz). The results indicate that as the sampling rate increased, the errors in the displacement responses decreased. In addition, in the three-story model, all modal components (first, second, and third modes) could be recorded at a sampling rate of 20 Hz.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.11a
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• pp.289-292
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• 2002

최근들어 파이프 골조의 온실 구조는 해마다 강풍이나 적설 둥으로 인한 파손으로 막대한 경제적 손실을 입고 있으며, 이러한 피해는 환경조절 및 자동화 설비의 설치에 직접적인 영향을 주는 중요한 요인이므로 시설의 구조역학적인 연구가 지속적으로 이루어져야 한다. 그러나 국내에서는 1990년대 초반 온실의 구조안전 및 구조설계 기준 설정, 자재의 규격화 및 표준화에 관한 연구가 일부 수행된 바 있으나, 파이프 골조의 온실은 구조물로서의 공학적 설계나 유지관리에 대한관심이 부족하여 시설의 구조역학적인 연구가 거의 이루어지고 있지 않는 실정이다. (중략)

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.202-208
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• 1999

This study was conducted to investigate the effects of the frame ratio and greenhouse length on the transmissivities of direct and diffuse solar radiation in glasshouse using a computer simulation model developed by Kim and Lee(1997). Transmissivity of diffuse solar radiation slightly decreased as the frame ratio increased. There was no effect of number of spans on the transmissivity of diffuse solar radiation at the same frame ratio. In single or multispan glasshouse, transmissivity of direct solar radiation was 1.5-3.0% higher at the frame ratio of 11.3% than those at the frame ratio of 14.9%. Also the transmissivity of direct solar radiation was 1.5-3.0% lower at the frame ratio of 18.3% than those at the frame ratio of 14.9%. Effect of the increased or decreased frame ratio on the transmissivity of direct solar radiation was similar in I-W or S-N glasshouse. Since the high transmissivity of direct solar radiation exerted a beneficial influence upon the plant growth during winter season, the light and endurable structural members were needed to maximize the transmission of solar radiation in glasshouse. Transmissivity of direct solar radiation in I-W or S-N glasshouse did not vary with the length of 24.5m long or more.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.85-93
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• 2016

In this study, finite element analyses of masonry infilled frames using a general purpose FE program, ABAQUS, were conducted. Analysis models consisted of the bare frame, infilled frames with masonry wall thickness of 0.5B and 1.0B, respectively. The masonry walls were constructed using the concrete bricks which were generally used in Korea as infilled wall. The material properties of frames and masonry for the analysis were obtained from material tests. However, four times increased the tensile strength was used for 1.0B wall, which is seemingly due to the differences in locating the bricks. The force-displacement relation and development of crack from the FE analysis were very similar to those from the experiments. From the FEA results, contact force between the frame and masonry, distribution of shear force and bending moments in frame members were analyzed. Obtained contact stress shows a trianglur distribution, and the contact length for 0.5B speciment and 1.0B specimen were close to the value estimated using ASCE 41-06 equation and ASCE 41-13 equation, respectively. Obtained shear force and bending moment distribution seems to replicate actual behavior which originates from the contact stress and gap between the frame and masonry.

• Computational Structural Engineering
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• v.12 no.2
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• pp.23-33
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• 1999