• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.795-798
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• 2010

본 논문에서는 상사진동에서의 응답을 통해 구성된 모드유연도에 의해 추정되는 손상유발 변위를 이용하여 전당빌딩의 손상을 탐지하는 진동기반의 손상탐지 방법을 제시하였다. 이 방법은 전단빌딩의 층간변위를 활용하여 오직 손상이 존재할 때에만 발생하는 Damage-induced inter-story deflection (DI-ID)을 통해 손상탐지를 수행하는 방법이다. 구조물의 전체 자유도에 양의 전단력을 발생시킴으로써 층간변위를 분명히 파악할 수 있도록 하는 양전단력 탐색하중(Positive Shear Inspection Load)을 통해 DI-ID를 산정한다. 제안된 방법의 검증을 위해 5층의 전단빌딩 축소모형을 대상구조물로 선정하여 수치모의실험을 수행했다. 단일손상과 다중손상의 모사를 위해 1층과 3층의 휨강성을 각각 10% 씩 저감시켰고, 수치모의실험 결과, 단일손상과 다중손상 모두 정확히 손상발생 구역을 확인했다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.44-47
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• 2011

본 논문에서는 상사진동에서의 응답을 통해 구성된 모드유연도 행렬에 의해 추정되는 변위/변형을 이용해 전당빌딩의 손상을 정량적으로 평가하는 방법을 제시하였다. 제안된 방법은 전단빌딩의 손살발생 후의 층간변위와 손상발생 전 후의 층간변위 차이인 Damage-induced inter-story deflection(DI-ID)의 관계를 이용해 손상을 정량적으로 평가하는 방법이다. 구조물이 양전단력만을 발생시킴으로써 층간변위를 분명히 파악할 수 있도록 하는 양전단력 탐색하중(Positive Shear Inspection Load)을 통해 DI-ID를 산정한다. 제안된 방법의 검증을 위해 5층의 전단빌딩 축소모형을 대상구조물로 선정했으며, 단일손상과 다중손상의 모사를 위해 1층과 3층의 휨강성을 각각 10% 씩 저감시켰다. Static test와 modal test를 통해 각각의 결과를 비교하는 방법으로 제안된 방법의 성능검증을 수행했으며, 축소모형실험 결과, 두 실험간 평균오차 1% 이내로 정확도를 검증했다.

• Tunnel and Underground Space
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• v.25 no.4
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• pp.383-396
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• 2015

It is analyzed the risk of building damage due to ground surface subsidence occurred during constructing a tunnel below buildings in sand-gravel layer. The overburden and the thickness of sand-gravel layer is about 20m and the width and the height of the tunnel are 12m and 8.6m, respectively. The tunnel is pre-reinforced by umbrella method with three rows of long steel pipes and grouting. Surface subsidence is measured at 36 points surrounding buildings and measured data are used to calculate optimized three dimensional subsidence surface. Depending on the building location, deflection ratio and horizontal strain are calculated to evaluate the risk of building damage. No damage occurs at the buildings because of both the small deflection ratios involved 1~4mm subsidence and compressive horizontal strains.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.1-11
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• 2008

Stiffness estimation of a shear building due to local damages is usually achieved though structural analysis based on the assumed material properties and idealized numerical modeling of structure. Conventional numerical modeling, however, frequently causes an inevitable error in the structural response and this makes it difficult to exactly predict the damage state in structure. To solve this problem, this paper introduces a damage detection technique for shear building using genetic algorithm. The introduced algorithm evaluates the damage in structure using a flexibility matrix since the flexibility matrix can exactly be obtained from the field test in spite of using a few lower dynamic modes of structure. The introduced algorithm is expected to be more effectively used in damage detection of structures rather than conventional method using the stiffness matrix. Moreover, even in cases when an accurate measurement of structural stiffness cannot be expected, the proposed technique makes it possible to estimate the absolute change in stiffness of the structure on the basis of genetic algorithm. The validity of the proposed technique is demonstrated though numerical analysis using OPENSEES.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.15-24
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• 2004

This paper describes a GIS-based assessment of residential building damage caused by the 1994 Northridge earthquake in which the fractions of existing buildings damaged at various percentages of replacement cost are related to a range of seismic parameters. The assessment uses data from safety inspection reports and tax assessor records, both of which were geocoded and linked to seismic parameters derived from strong motion records at 164 different sites. The paper also describes a GIS-based pattern recognition algorithm for identifying locations of most intense building damage. The algorithm provides a framework for rapidly screening remote sensing data and dispatching emerging services.

• Explosives and Blasting
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• v.29 no.2
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• pp.1-12
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• 2011

Progressive collapse analyses of high-rise buildings subjected to abnormal loading such as fires, impacts, earthquakes, typhoon, bomb blasts etc. are intended. However it is difficult to perform collapse experiments of the real scale building to determine the capacity of the structure under an extreme loading events. In this study, collapse behavior of a 15 story RC structure building loaded by external explosion pressures were simulated using Extreme Loading Structures (ELS) software. The standoff distance between the RC building and explosives of 1500 kg was 1, 2, 5, 10, and 15 meters. The explosive demolition analysis techniques based on removal of partial support structures following blast scenario was adapted to investigate the transition process of progressive collapse-local damage.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.377-384
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• 2022

In the design of composite aircraft structures, it is very important to set material allowables and design values, which take into account certification. And when determining the material allowable and design value of composite structures, the static strength, damage tolerance requirements, and environmental effects should be considered. The building block approach has been applied to the civil and military aviation industry for a long time and provides the principal certification methodology. This current certification methodology is based on extensive testing including coupon, element, sub-component, and full scale test. In this paper, some examples of composite allowable tests have been presented and the fundamental background and application methods of the building block approach have been presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.121-122
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• 2012

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.331-340
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• 2021

The blast damage behavior of reinforced concrete (RC) structures exposed to unexpected extreme loading was investigated. To enhance the accuracy of numerical simulation for blast loading on RC structures with seven blast points, the calculation of blast loads using the Euler-flux-corrected-transport method, the proposed Euler-Lagrange coupling method for fluid-structure interaction, and the concrete dynamic damage constitutive model including the strain rate-dependent strength and failure models was implemented in the ANSYS-AUTODYN solver. In the analysis results, in the case of 20 kg TNT, only the slab member at three blast points showed moderate and light damage. In the case of 100 kg TNT, the slab and girder members at three blast points showed moderate damage, while the slab member at two blast points showed severe damage.

• Computational Structural Engineering
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• v.4 no.3
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• pp.89-97
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• 1991

Conventional aseismic design methods of R/C frame all but disregard the state of damage over the entire building frame. This paper presents an automated damage-controlled design method for R/C frames which aims at an uniform energy dissipation rate throughout the building frame, so that the resulting damage is uniformly distributed as much as possible over all element. The accuracy of the basic hystertic model and the damage model for R/C members is verified by reproducing the experimental load-deformation curves of one-bay one-story frames. Application of this design method to various frame structures indicate that 1) regardless of the structural properties or input earthquake characteristics, damage-controlled frames generally survive more severe earthquake excitations and suffer less damage than conventionally designed frames, and 2) member yielding strength in the lower stories of damage-controlled frames is larger than that for conventionally designed frames, while the trend is opposite in the upper stories.