• Title/Summary/Keyword: embedded surface

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ELEMENTARY DISKS IN TRUNCATED TRIANGULATIONS

  • Kang, Ensil
    • The Pure and Applied Mathematics
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    • v.22 no.1
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    • pp.91-99
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    • 2015
  • A normal surface is determined by how the surface under consideration meets each tetrahedron in a given triangulation. We call such a nice embedded disk, which is a component of the intersection of the surface with a tetrahedron, an elementary disk. We classify all elementary disk types in a truncated ideal triangulation.

Experimental Study for Shear Behavior of RC Beam Strengthened with Channel-type FRP Beam (채널형 FRP빔으로 보강된 RC보의 전단거동에 관한 실험적 연구)

  • Hong, Ki-Nam
    • Journal of the Korean Society of Safety
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    • v.24 no.3
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    • pp.39-46
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    • 2009
  • A recent and promising method for shear strengthening of reinforced concrete(RC) members is the use of near surface mounted(NSM) fiber reinforced polymer(FRP) reinforcement. In the NSM method, the reinforcement is embedded in grooves cut onto the surface of the member to be strengthened and filled with an appropriate binding agent such as epoxy paste or cement grout. This paper illustrates a research program on shear strengthening of RC beams with NSM channel-type FRP beams which is developed in this study. The objective of this study is to clarify the role of channel-type FRP beam embedded to the beam web for shear strengthening of reinforced concrete beams. Included in the study are effectiveness in terms of spacing and angle of channel-type FRP beams, strengthening method, and shear span ratio. the study also aims to understand the additional shear capacity due to glass fiber reinforced polymer beams and carbon reinforced polymer beams. And anther objective is to study the failure modes, shear strengthening effect on ultimate force and load deflection behavior of RC beams embedded with channel-type FRP beams on the shear region of the beams.

Numerical analysis of offshore monopile during repetitive lateral loading

  • Chong, Song-Hun;Shin, Ho-Sung;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.19 no.1
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    • pp.79-91
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    • 2019
  • Renewed interest in the long-term pile foundations has been driven by the increase in offshore wind turbine installation to generate renewable energy. A monopile subjected to repetitive loads experiences an evolution of displacements, pile rotation, and stress redistribution along the embedded portion of the pile. However, it is not fully understood how the embedded pile interacts with the surrounding soil elements based on different pile geometries. This study investigates the long-term soil response around offshore monopiles using finite element method. The semi-empirical numerical approach is adopted to account for the fundamental features of volumetric strain (terminal void ratio) and shear strain (shakedown and ratcheting), the strain accumulation rate, and stress obliquity. The model is tested with different strain boundary conditions and stress obliquity by relaxing four model parameters. The parametric study includes pile diameter, embedded length, and moment arm distance from the surface. Numerical results indicate that different pile geometries produce a distinct evolution of lateral displacement and stress. In particular, the repetitive lateral load increases the global lateral load resistance. Further analysis provides insight into the propagation of the shear localization from the pile tip to the ground surface.

Lateral Displacement Analysis of Concrete Electric Pole Foundation Grounds (배전용 콘크리트전주 기초지반의 횡방향변위 분석)

  • Ahn, Tae-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.5
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    • pp.42-49
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    • 2009
  • The effects of various forces acting on concrete pole are analyzed using finite element method how the forces affect on ground displacement. The soil types, wind load location of anchor block embedded depth of pole, and distance between poles are varied to find out effects on lateral displacement. Anchor block is effective when it is located at 1/4 of embedded depth The displacement is decreases as elastic modulus increases. Concrete reinforcement for loosened ground is necessary for double poles because double poles cause large excavation. When embedded depth ratio decrease, lateral displacement increase as closer to ground surface. Large embedded depth is effective to reduce lateral displacement, and the distance between poles is not much large factor.

Application of Electro-deposition Method for Crack Closing and Surface Improvement of Reinforced Concrete (철근콘크리트의 균열폐색 및 표면개선을 위한 전착의 응용)

  • 문한영;류재석
    • Journal of the Korea Concrete Institute
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    • v.11 no.6
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    • pp.79-88
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    • 1999
  • In this paper, the electro-deposition method for the rehabilitation of cracked concrete, based on the electro-chemical technique, is presented. The main purpose of this paper is to apply this technique to reinforced concrete members on land. After cracking with a specified load(crack width 0.5mm), 10$\times$10$\times$20cm concrete specimens with embedded steel bars were immersed in several solutions, then a constant current density between the embedded steel in concrete and an electrode in the solution was applied for 4~20 weeks. The results indicate that electro-deposits formed in this process are able to close concrete cracks and to coat the concrete surface and that formation of these electro-deposits is confirmed to have an effect of protection against detrimental materials. Therefore, it is demonstrated that the electro-deposition method can be usefully applied for the rehabilitation technique of concrete.

New Protocol at Fast Scan Mode for Sea-surface Small Target Detection

  • Cha, Sangbin;Park, Sanghong;Jung, Jooho;Choi, Inoh
    • IEMEK Journal of Embedded Systems and Applications
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    • v.17 no.2
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    • pp.101-107
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    • 2022
  • In this article, we propose a new protocol at fast scan mode for a sea-surface small target detection. The conventional fast scan mode is composed of coherent intrascan integration to suppress sea clutter and non-coherent interscan integration to exclude sea spikes. The proposed method realizes the coherent interscan integration by the new Fourier relationship between carrier-frequency and initial-radial-range, which can be analytically derived by using multiple carrier frequencies at fast scan mode, leading to improved detection performance, compared to the conventional non-coherent methods. In simulations, our proposed method is verified.

Study on Thermal Residual stresses and Transmission Characteristics in Loop Type Frequency Selective Surface Embedded Composite Structures (루프 종류의 FSS가 결합된 복합재료 구조의 잔류응력과 전파 투과 특성)

  • Park, Kyoung-Mi;Hwang, In-Han;Chun, Heoung-Jae;Hong, Ic-Pyo;Park, Yong-Bae;Kim, Yoon-Jae
    • Composites Research
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    • v.26 no.5
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    • pp.279-288
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    • 2013
  • In this paper, the delamination and deformed FSS caused by residual stresses in the Loop type FSS embedded composites and the transmission characteristic changes due to deformation of FSS by residual stresses were studied. FSS may have different electromagnetic characteristics depending on the type of element, design variables, and array. Therefore, design variables of square loop FSS embedded composites structures were determined to obtain the transmission characteristic for X-band (8~12 GHz). Then the design variables of other types of loops (triangular loop and circular loop) were determined based on the dimensions of square loop. Thereafter, the residual stresses and transmission characteristics of FSS embedded composite structures with various single and double loop FSS's, and stacking sequence of composite laminates were compared.

Evaluation of Rocking Mechanism for Embedded Shallow Foundation via Horizontal Slow Cyclic Tests (수평반복하중 실험을 이용한 근입된 얕은 기초의 회전거동 메커니즘 평가)

  • Ko, Kil-Wan;Ha, Jeong-Gon;Park, Heon-Joon;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.32 no.8
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    • pp.47-59
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    • 2016
  • Rocking behavior of shallow foundation reduces the superstructure load during earthquake. However, because of deficiency of understanding of rocking mechanism and soil permanent deformation, it has not been applied to real construction. In this study, slow cyclic tests were conducted for embedded shallow foundations with various slenderness ratio via centrifuge tests. From the variation of earth pressure 'soil rounding surface' phenomenon which makes maximum overturning moment equal to ultimate moment capacity was observed. Rocking and sliding behavior mechanism was evaluated. Also, nonlinear behavior and energy dissipation increase as rotation angle increases. And ultimate moment capacity of embedded foundation is larger than that of surface foundation. Finally, adequate ultimate moment capacity can be suggested for seismic design through this study.