• Title/Summary/Keyword: structural evaluation

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Integrated Analysis of Hydrodynamic Motions and Structural Behavior of Large-Scaled Floating Structures using AQWA-ANSYS Coupling (AQWA-ANSYS 연계에 의한 대형 부유구조체의 파랑운동-구조거동 통합해석)

  • Lee, Du-Ho;Jeong, Youn-Ju
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.6
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    • pp.601-608
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    • 2011
  • In order to design floating structures, it should be required to evaluate hydrodynamic motions and structural behavior under the wave loadings. Then, structural behavior of floating structures should be evaluated including the effects of wave-induced hydraulic pressure subjected to floating structures. However, there has been a problem to exactly evaluate structural behavior of floating structures since it was difficult to directly connect wave-induced hydraulic pressure resulting from hydrodynamic analysis with structural analysis model. In this study, in order to exactly evaluate structural behavior of floating structures under the wave loading, integrated analysis of hydrodynamic motion and structural behavior was carried out to the large-scaled floating structure. The wave-induced hydraulic pressure resulting from hydrodynamic analysis AQWA were directly mapped to structural analysis model ANSYS bia Workbench interface of ANSYS Inc.. As the results of this study, it was found that the integrated analysis of this study evaluate exactly structural behavior of floating structures under the wave loadings since this method can directly reflect wave-induced hydraulic pressure resulting from hydrodynamic analysis to structural analysis model. Also, as the results of structural behavior evaluation, it was found that the tensile stress on the top slab was maximized at the wave direction of $0^{\circ}$, and tensile stress on the bottom slab was maximized at the wave direction of $45^{\circ}$, respectively.

Effect of Investment Evaluation Criteria of Public ICT Projects on Business Success (공공 정보통신기술(ICT)사업의 투자 평가기준이 사업성공에 미치는 영향)

  • Kim, Yong-Kul;Lee, Sang-Yun;Chae, Myeong-Sin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.4
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    • pp.157-169
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    • 2021
  • Establishing an investment evaluation system for public ICT projects is ultimately to increase the success rate of public ICT projects in which government finances are invested and to revitalize the projects, thereby establishing a foundation for national economic growth and enhancing the competitiveness of the global ICT industry. This study tried to empirically verify the effect of public ICT project investment evaluation factors established according to the existing evaluation system on actual project success, and to suggest directions for future investment evaluation factors. Five evaluation factors such as public interest, economic feasibility, technology, policy and budget efficiency were derived through prior research, and the effect of these evaluation criteria on actual project success was verified through questionnaires from experts who directly participated in the actual project. In addition, it was confirmed whether the government's support system had a moderating effect between the investment evaluation factors and the project success of the ICT project. The reliability and validity of measurement tools, structural model analysis, and path analysis were empirically analyzed, and the significance of existing ICT investment evaluation factors was verified.

Revaluation of Inelastic Structural Response Factor for Seismic Fragility Evaluation of Equipment (기기의 지진취약도 평가를 위한 구조물 비탄성구조응답계수의 재평가)

  • Park, Junhee;Choi, In-Kil
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.3
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    • pp.241-248
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    • 2015
  • There are a lot of equipment related to safety and electric power production in nuclear power plants. The structure and equipment in NPPs were generally designed considering a high safety factor to remain in the elastic zone under earthquake load. However it is needed to revaluate the seismic capacity of the structure and equipment as the magnitude of earthquake was recently increased. In this study the floor response due to the nonlinear behaviors of structure was analyzed and the inelastic structural response factor was calculated by the nonlinear time history analysis. The inelastic structural response factor was calculated by the EPRI method and the nonlinear analysis method to realistically evaluate the seismic fragility for the equipment. According to the analysis result, it was represented that the inelastic structural response factor was affected by the natural frequency of equipment, the location of equipment and the dynamic property of structure.

A Comparative Study for the Fatigue Assessment of fillet Weldments Using Structural Stress and Hot Spot Stress (필릿 용접구조물의 피로해석을 위한 기준응력에 대한 비교 연구 -구조응력 및 핫스팟응력-)

  • Ha Chung-In;Kang Sung-Won;Kim Man-Soo;Sohn Sang-Yong;Heo Joo-Ho;Kim Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.4 s.148
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    • pp.476-483
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    • 2006
  • Fatigue strength assessments with two types of load carrying fillet weldment under out-of-plane bending load have been carried out by using both hot spot stress and structural stress methods. In this study, a derivation for the structural stress method using shell element models is discussed in detail. Finite element analysis using shell element models have been performed for the assessment of fatigue strength. As a result of the fatigue strength evaluation for load carrying transverse fillet weldment, hot spot stress method is found to be consistent with structural stress method and measurement. Hot spot stress, however, estimated for the load carrying longitudinal fillet weldment exhibit large variation with respect to mesh size and element type while the calculated structural stress for the longitudinal fillet weldment is relatively independent of mesh size. On the other hand, drawbacks and doubts associated with applying the structural stress method such as the guidance of virtual node method have been discussed.

A Study of Structural Behavior Analysis of Inegral and Semi-Integral Hybrid Slab Bridge (일체식 및 반일체식 복합슬래브 교량의 구조거동 분석에 관한 연구)

  • Choi, Young-Guk;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.123-128
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    • 2018
  • Girder bridges and slab bridges are equipped with a system consisting of a flexible joint unit, support, inverted T shaped abutment, and a separate connecting slab structure. These systems have problems such as an increase in cost due to frequent breakage of the expansion joints and a decrease in durability due to a structure with low moment redistribution. To improve these problems, propose Inegral and Semi-Integral Hybrid Slab Bridge and examine the safety through structural analysis. As a result of the review, Inegral and Semi-Integral Hybrid Slab Bridge was the section stiffness is small. but it is confirmed that the structural safety, ductility and flexibility are higher than existing bridges because the moment redistribution and the force transmission are surely performed.

A Study on the Comparison of Structural Performance Test and Analysis for Design Verification of Bimodal Tram Vehicle Made of Sandwich Composites (샌드위치 복합재 적용 바이모달 트램 차체의 설계검증을 위한 구조 성능 시험 및 해석적 비교 연구)

  • Ko, Hee-Young;Shin, Kwang-Bok;Jeong, Jong-Cheol
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.518-525
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    • 2009
  • This paper describes the evaluation of structural performance test and finite element analysis to verify the design of Bimodal Tram made of sandwich composites. The sandwich composite applied to vehicle structure was composed of a aluminum honeycomb core and WR580/NF4000 glass fabric/epoxy laminate composite facesheet. The load tests of vehicle structure were conducted for vertical load, compressive load, torsion and modal analysis according to JlS E 7105. The structural Integrity of vehicle was evaluated by the measurement of displacement, stress and natural frequency obtained from dial gauge, strain gauge and gravity sensor, respectively. And finite element analysis using ANSYS v11.0 was done to compare with structural test. The results showed that the displacement, stress and natural frequency were in an good agreement with those of structural analysis using the proposed finite element models.

Evaluation of the Applicability of Structural Steels to Cold Regions by the Charpy Impact Test (샤르피 충격시험을 통한 구조용강재의 극한지 적용성 검토)

  • Lee, Chin-Hyung;Shin, Hyun-Seop;Park, Ki-Tae;Yang, Seunng-Hyun
    • Journal of Korean Society of Steel Construction
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    • v.23 no.4
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    • pp.483-491
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    • 2011
  • The fabrication of steel structural members always involves welding process such as flux cored arc welding. Therefore, for the application of structural steels to cold regions, it is a prerequisite to clarify the service temperature of the welded joints in order to ensure the structural integrity of the welded parts. In this study, the Charpy impact test was conducted to evaluate the service temperature of structural steel weld. The Charpy impact test is a commercial quality control test for steels and other alloys used in the construction of metallic structures. The test allows the material properties for service conditions to be determined experimentally in a simple manner with a very low cost. Standard V-notch Charpy specimens were prepared and tested under dynamic loading condition. The service temperatures of the weld metal, HAZ (heat affected zone) and base metal were derived by the absorbed energy and the impact test requirements; thus the applicability of the structural steels to cold regions was discussed in detail.