• Wind and Structures
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• 제31권6호
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• pp.533-548
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• 2020

Despite the current technologic developments, failures in existent tensile fabric structures (TFS) subjected to wind do happen. However, design pressure coefficients are only obtained for large projects. Moreover, studies on TFSs with realistic supporting frames, comparing static and dynamic analyses and discussing the design implications, are lacking. In this study, fluid-Structure analyses of a TFS supported by masts and inclined cables, by subjecting it to different wind speeds, are carried out, to gain more understanding in the above-referred aspects. Wind-induced stresses in the fabric and axial forces in masts and cables are assessed for a hypar by using computational fluid dynamics. Comparisons are carried out versus an equivalent static analysis and also versus loadings deemed representative for design. The procedure includes the so-called form-finding, a finite element formulation for the TFS and the fluid formulation. The selected structure is deemed realistic, since the supporting frame is included and the shape and geometry of the TFS are not uncommon. It is found that by carrying out an equivalent static analysis with the determined pressure coefficients, differences of up to 24% for stresses in the fabric, 5.4% for the compressive force in the masts and 21% for the tensile force in the cables are found with respect to results of the dynamic analysis. If wind loads commonly considered for design are used, significant differences are also found, specially for the reactions at the supporting frame. The results in this study can be used as an aid by designers and researchers.

• 한국해양공학회지
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• 제29권5호
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• pp.342-350
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• 2015

A seismic reliability analysis of the jacket-type support structure for an offshore wind turbine was performed. When defining the limit state function using the dynamic response of the support structure, numerous dynamic calculations should be performedin an approach like the FORM (first-order reliability method). This causes a substantial increase in the analysis cost. Therefore, in this paper, a new reliability analysis approach using the static response is used. The dynamic effect of the response is considered by introducing a new parameter called the peak response factor (PRF). The probability distribution of the PRF could be estimated using the peak value of the dynamic response. The probability distribution of the PRF was obtained for a set of ground motions. A numerical example is considered to compare the proposed approach with the conventional static-response-based approach.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.164-169
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• 2005

The TTX(Tilting Train eXpress) is designed to achieve high driving speed up to 200 km/h and to run on conventional curved rails without speed reduction. In order to maintain power collection between catenary and pantograph collector while train body is tilted, the TTX pantograph must have tilting structure (or Sledge). The power quality is determined by the tilting structure. Static and dynamic characteristics of tilting structure, therefore, are important to evaluate the pantograph performance. The current prototype of the tilting structure is overweight model and its structural characteristics have not been investigated. In this study, the finite element model of TTX tilting structure is established and static analysis is performed. Finally, using this result, a light weight model is proposed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.196-201
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• 1992

The purpose of this study is to develop the computer software for the nonlinear analysis of R/C frame structure under static loads. For this purpose, strain-rate dependant material model and physical element model considering both flexural and shear deformation are adopted and they are connected with 'TWO-D'which is commerical software for elastic structural analysis. The analytical results using the developed software are compared to the experiment results and they are generally satisfactory.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.618-621
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• 2002

This paper proposes a static vu compensator using hybrid cascade 5-level PWM inverter, Circuit DQ transformation is used for modeling and analysis of the system, and it reveals the important characteristics and related equations of the system. Also, a multilevel PWM technique suitable to hybrid structure Is proposed for less harmonics in the input currents of the system. Finally, the validity of tile characteristics analysis is shown through PSIM simulations.

• Steel and Composite Structures
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• 제2권2호
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• pp.113-128
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• 2002

The performance of steel MRF with rigid connections, proportioned by adopting different capacity design criteria, is evaluated in order to highlight the effectiveness of static non-linear procedure in predicting the structural seismic behavior. In the framework of the performance-based design, some considerations are made on the basis of the results obtained by both dynamic time histories and push-over analyses, particularly with reference to the damage level and the structure ability to withstand a strong earthquake.

• Earthquakes and Structures
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• 제12권3호
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• pp.271-284
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• 2017

This paper presents a multimodal adaptive nonlinear static method of analysis that, differently from the nonlinear static methods suggested in seismic codes, does not require the definition of the equivalent Single-Degree-Of-Freedom (SDOF) system to evaluate the seismic response of structures. First, the proposed method is formulated for the assessment of r.c. plane frames and then it is extended to 3D framed structures. Furthermore, the proposed nonlinear static approach is re-elaborated as a displacement-based design method that does not require the use of the behaviour factor and takes into account explicitly the plastic deformation capacity of the structure. Numerical applications to r.c. plane frames and to a 3D framed structure with inplan irregularity are carried out to illustrate the attractive features as well as the limitations of the proposed method. Furthermore, the numerical applications evidence the uncertainty about the suitability of the displacement demand prediction obtained by the nonlinear static methods commonly adopted.

• Structural Engineering and Mechanics
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• 제46권1호
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• pp.75-90
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• 2013

In order to identify damage of highway bridges rapidly, a method for damage identification using dynamic response of bridge induced by moving vehicle and static test data is proposed. To locate damage of the structure, displacement energy damage index defined from the energy of the displacement response time history is adopted as the indicator. The displacement response time histories of bridge structure are obtained from simulation of vehicle-bridge coupled vibration analysis. The vehicle model is considered as a four-degree-of-freedom system, and the vibration equations of the vehicle model are deduced based on the D'Alembert principle. Finite element method is used to discretize bridge and finite element model is set up. According to the condition of displacement and force compatibility between vehicle and bridge, the vibration equations of the vehicle and bridge models are coupled. A Newmark-${\beta}$ algorithm based professional procedure VBAP is developed in MATLAB, and used to analyze the vehicle-bridge system coupled vibration. After damage is located by employing the displacement energy damage index, the damage extent is estimated through the least-square-method based model updating using static test data. At last, taking one simply supported bridge as an illustrative example, some damage scenarios are identified using the proposed damage identification methodology. The results indicate that the proposed method is efficient for damage localization and damage extent estimation.

• 한국구조물진단유지관리공학회 논문집
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• 제9권1호
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• pp.119-126
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• 2005

본 연구는 H형 및 Channel형 복공판의 정적 하중에 대한 성능을 규명하는데 그 목적이 있다. 보다 향상된 복공판의 성능이 요구되어짐에 따라 보강의 가능성 및 효율성을 파악하였고, 정적재하시험 및 구조해석을 통해 시험체의 개선효과를 비교 검토하였다. 정적재하시험을 통하여 응력과 처짐을 측정하였고, 이를 FEM 해석결과와 비교하였을 때 극한 하중 및 변위, 지간 중앙부와 상 하 플랜지의 휨응력 등에서 H형 복공판은 Channel형 복공판에 비해 약 3배 이상의 높은 강성을 보유하고 있는 것으로 나타났다.

• 한국화재소방학회논문지
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• 제31권4호
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• pp.86-94
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• 2017

본 연구에서는 소방시설의 내진설계기준에 의한 Cook Book 방식과 Static System Analysis 방식을 비교 해석하였다. Cook Book 방식은 배관을 동일 구간마다 나누어 해석한다. 이 방식은 배관, 물 그리고 관부속의 무게에 따라 버팀대를 설계하는 방식으로 해석하는 구간 외에는 응력해석이 불가능하다. 그러나 Static System Analysis는 배관 전체를 하나의 구조체로 보기 때문에 전체 배관에 대한 응력해석이 가능하다. 국소적으로 발생되는 치명적 응력 값에 대해서는 국부적으로 배관의 응력을 해소할 수 있는 장치의 설치를 통해 적극적으로 배관해석을 할 필요가 있다. 국내의 경우 소방시설의 내진설계기준이 Cook Book 방식만을 제시하고 있어 내진설계의 다양화에 많은 문제점을 가지고 있다. 그러므로 공학적으로 검증된 여러 종류의 Static System Analysis 방법을 통해 배관의 내진 설계를 방법을 적용할 필요가 있다.