단기 동 하중(특히 지진하중)을 받는 비선형 강 프레임 구조물의 안전성을 평가하기 위하여 추계론적 유한요소 개념에 근거한 비선형 시간영역 신뢰성 해석 기법을 제안하였다. 제안된 알고리즘에서는 유한요소 공식화가 응답 표면법, 1차 신뢰성 방법, 그리고 반복 선형보간 기법의 개념들과 결합되어 지는데, 이것이 추계론적 유한요소 개념으로 귀결된다. 실제 지진하중의 시간이력이 구조물의 진동을 위해 사용되므로 사실적인 하중조건의 재현이 가능하다. 가상 응력에 기초한 유한요소 기법이 본 알고리즘의 효율성을 증대하기 위해 사용된다. 본 알고리즘은 지진하중 또는 임의의 단기 동적하중을 받는 유한요소 기법으로 표현되는 어떠한 선형 및 비선형 구조물과 관련된 위험도를 평가할 수 있는 잠재성을 가지고 있다. 수치예제를 통하여 알고리즘을 설명하였으며, 몬테카를로 시뮬레이션 기법을 사용하여 본 알고리즘을 검증하였다.

지역별로 분포하고 있는 특성화된 온실의 장점을 살리고 구조적인 위험요소를 줄임으로서, 지역특성온실로 정착할 수 있도록 하기 위하여 지역별로 특성화된 온실의 구조실태를 조사하고 구조적 안전성을 검토하였으며 그 결과를 요약하면 다음과 같다. 1. 전남지방에 특성화된 온실의 보급이 많았으며, 광폭형하우스와 대형 단동 파이프하우스가 이 지역의 특성화된 온실로서 뚜렷한 경향을 나타내었다. 2. 경남 김해의 목재하우스, 전남 구례의 트러스형하우스, 강원 평창의 돔형 파이프하우스, 충북 옥천의 포도재배하우스 등이 특징적인 온실로 나타나고 있었다. 3. 광폭형하우스, 트러스형하우스, 돔형 파이프하우스 및 포도재배하우스는 15-30년 빈도의 풍하중과 설하중에 대하여 안전한 것으로 나타났으나, 대형 단동 파이프하우스는 약간의 보강이 필요하며, 목재하우스는 매우 불안정하여 사용을 중지하는 것이 좋을 것으로 판단되었다. 4. 대상온실의 기초는 모두 30년 빈도의 강풍에 대하여 충분한 인발저항력을 가지는 것으로 나타나 안전한 것으로 판단되었다.

본 연구는 생물생산시설의 구조설계 과정에서 초기단계의 고정하중을 합리적으로 추정하기 위한 식을 유도하여 구조설계 기준 설정에 기초자료를 제공하고, 생물생산분야 종사자가 간편하게 구조적 안전성을 진단할 수 있는 방법을 개발할 목적으로 수행하였으며 연구 결과를 요약하면 다음과 같다. 1. 국내의 온실설계자료를 수집하여 실제 하중을 산출, 분석해 본 결과 기존의 일본 시설원예기준 적용치와는 차이가 있었으며, 잠정적으로 국내 시설에의 적용을 위한 추정식을 유도하였다. 2. 지역별 설계하중을 적용하여 구조해석을 실시하고, 발생되는 응력의 크기에 따라서 풍하중 및 설하중 지배지역으로 안전설계 지역구분을 실시하였다.

Using GPR(Ground Penetrating Radar) Precise Inspection, the real lining thickness of the tunnel damage was determined and detailed analysis was performed to provide a more accurate structural safety assessment of the tunnel damage. Through this study, It is presented to provide a guide for the application of the tunnel for inspection and diagnosis.

Occurring economic loss of economics by the earthquake, such as Gyeongju and Pohang in Korea, interest in seismic stability of facilities is increasing. Electrical Cabinet Structure in Power Plant should be prepared for malfunctions and its structural safety should be ensured as well an earthquake event. The purpose of this investigation is to increase the seismic stability of the cabinet. Through finite elements analysis, dynamic characteristics of the cabinet were identified herein, and time history analysis was performed by converting the design response spectra. In order to improve safety against earthquakes, a variable analysis was conducted to utilize steel dampers for seismic retrofit of the cabinet, and time history analysis results compared with the response of basic and seismic retrofitted cabinets.

잔교식 안벽의 수중부는 접근이 쉽지 않아서 손상확인이 어려운 곳인데, 최근들어 태풍과 지진이 빈번하게 발생하고 있어 잔교식안벽 수중부 구조물의 손상 누적으로 인한 붕괴가 우려되는 상황이다. 잔교식 안벽의 붕괴를 방지하고 체계적으로 유지관리하기 위한 방안으로 FBG 센서를 이용한 적용 방법과 안전성 평가 방법을 연구하였다. 잔교식 안벽에 파일로 사용되는 원형 강관에 대한 FBG 센서의 적용 방안을 확인하기 위해 실내실험을 실시하고, 센서를 용접하여 부착하는 방법으로 적용해야 하는 것을 확인하였다. 잔교식 안벽에 대한 구조해석을 수행하여 FBG 센서를 부착하기 위한 최적의 부착위치를 확인하였다. 고정하중에 대한 응력을 구조해석을 하여 계산하고, FBG 센서를 통해 얻은 데이터를 이용하여 활하중에 대한 응력을 계산한 다음에 두 응력을 더해서 파일에 작용하고 있는 응력을 계산하였다. 계산한 응력을 허용응력과 비교하여 파일의 안전성 평가를 수행하였다. 본 연구는 잔교식 안벽의 안전성을 실시간으로 평가하는 방안을 찾기 위한 기초 연구로 수행되었다.

Numerical analysis using commercial CFD code was carried out to develop the drag force type vertical axis hydraulic turbine for the improvement of the production efficiency of small hydro energy at low flow velocity condition. Blade pressure changes and internal flows were analyzed according to the presence or absence of the hydraulic turbine blade holes at flow velocity of less than 1.0~3.0 m/s. According to the numerical results, the pressure and flow velocity is severly affected by the flow velocity in turbine blade with no holes, while the influence of flow velocity is comparatively decreased in turbine blade with holes. It is also found that the pressure and flow velocity on the blade surface with holes are evenly distributed with no singular location and it is believed that forming a hole in the blade may be helpful in terms of structural safety.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification

This paper analyzed the effects of rotational stiffness of wedge connection between vertical and horizontal members of system supports. By simulating the connection condition both a hinge connection, which is considered in the design stage, and a spring with the rotational stiffness reflecting the actual behavior, the critical buckling load and the maximum combination stress ratio are compared. The results show that hinge condition somewhat underestimate the actual behavior of vertical members of system supports. However, it is also noted that the horizontal member represents the increased stress due to the rotational stiffness of the connection.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification.

The purpose of this study is to present a suitable maintenance guide or plan for future small scale vulnerable facilities by analyzing the investigation data collected through the safety inspection. For this, we examined about 3,301 buildings. From a number of defects, damages associated with the safety and durability of building were preferentially analyzed.

Recently, buildings tend to be large size, complex shape and functional. As the size of buildings is becoming massive, the need for structural health monitoring(SHM) technique is ever-increasing. Various SHM techniques have been studied for buildings which have different dynamic characteristics and are influenced by various external loads. Generally, the visual inspection and non-destructive test for an accessible point of structures are performed by experts. But nowadays, the system is required which is online measurement and detect risk elements automatically without blind spots on structures. In this study, in order to consider the response of non-linear structures, proposed a signal feature extraction and the adaptive threshold setting algorithm utilized to determine the abnormal behavior by using statistical methods such as control chart, root mean square deviation, generalized extremely distribution. And the performance of that was validated by using the acceleration response of structures during earthquakes measuring system of forced vibration tests and actual operation.

In order to evaluate the seismic safety of weir structure subjected to seismic ground motions, Non-linear elastic 2D plane strain Finite Model (FE) was developed in ABAQUS. Also, the 1994 Northridge earthquake as a ground motion uncertainty was selected. The numerical results show that the tensile stress was increased with increase the friction coefficient

In this study, the structural assessment on the effect of differential deformation of HDRB was performed for double deck warren truss bridge. The results show that the differential deformation of HDRB sharply decreases the safety rate of the superstructure of the bridge.

In order to evaluate the seismic safety of weir structure subjected to seismic ground motions, simple linear elastic 2D plane strain Finite Model (FE) was developed in ABAQUS platform. Also, the 1994 Northridge earthquake as a ground motion uncertainty was selected. The numerical results showed that the compressive stress was significantly increased in comparison to the results from the design spectrum analysis but the horizontal displacement was reduced about 28%.

This study presents the seismic safety evaluation of weir structures subjected to earthquakes. In order to conduct the numerical analysis using KBC 2009 design spectrum, simple linear elastic 2D plane strain Finite Element (FE) model was modeled in ABAQUS. the results obtained from numerical analysis noted that the weir structure was more sensitive to tensile stress than compressive stress.

A RSM-based reliability analysis approach is applied to evaluate the safety of floating structures considering uncertainties associated with various design variables. Uncertainties in both load and resistance related variables are explicitly considered in the analysis. It is expected to be practically applied in the reliability-based design of real structures including floating structures.