• Title, Summary, Keyword: L-Shaped

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Nonlinear FEM Analysis for Strength Characteristics of L-shaped Walls with Different Load-directions (가력방향이 다른 L형 벽체의 내력특성 평가를 위한 비선형 FEM 해석)

  • 조남선;하상수;최창식;오영훈;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.443-448
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    • 2002
  • The cross sections of structural walls have various shapes such as T, L, and H-shaped. The L-shaped walls frequently appear in the comer of the structural plans. There are a little researches on the structural performance of L-shaped walls subjected to hi-directional loads. L-shaped wall subjected to hi-directional loads might be failed due to high compressive stress in the corner of the wall. L-shaped wall subjected to bi-directional(45$^{\circ}$ direction) loads was failed by the compressive failure more possible than that of one-directional(0$^{\circ}$ direction) loads. Therefore, in this paper, Two L-shaped wall specimens are chosen and presented. One is LCU specimen subjected to the bi-directional loads, the other is LCX specimen subjected to the one-directional loads. Also, the experimental results compared with the analytical results from nonlinear FEM analysis.

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Monotonic behavior of C and L shaped angle shear connectors within steel-concrete composite beams: an experimental investigation

  • Shariati, Mahdi;Tahmasbi, Farzad;Mehrabi, Peyman;Bahadori, Alireza;Toghroli, Ali
    • Steel and Composite Structures
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    • v.35 no.2
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    • pp.237-247
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    • 2020
  • Shear connectors are essential elements in the design of steel-concrete composite systems. These connectors are utilized to prevent the occurrence of potential slips at the interface of steel and concrete. The two types of shear connectors which have been recently employed in construction projects are C- and L-shaped connectors. In the current study, the behavior of C and L-shaped angle shear connectors is investigated experimentally. For this purpose, eight push-out tests were composed and subjected to monotonic loading. The load-slip curves and failure modes have been determined. Also, the shear strength of the connectors has been compared with previously developed relationships. Two failure modes of shear connectors were observed: 1) concrete crushing-splitting and 2) shear connector fracture. It was found that the L-shaped connectors have less shear strength compared to C-shaped connectors, and decreasing the angle leg size increases the shear strength of the C-shaped connectors, but decreases the relative ductility and strength of L-shaped connectors.

Investigation on the Doping Effects on L-shaped Tunneling Field Effect transistors(L-shaped TFETs) (도핑효과에 의한 L-shaped 터널링 전계효과 트랜지스터의 영향에 대한 연구)

  • Shim, Un-Seong;Ahn, Tae-Jun;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.450-452
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    • 2016
  • The effect of channel doping on L-shaped Tunneling Field-Effect Transistors (TFETs) have been investigated by 2D TCAD simulation. When the source doping is over $10^{20}cm^{-3}$, the subthreshold swing (SS) is abruptly decreased, and when drain doping concentration is below $10^{18}cm^{-3}$, the leakage current in the negative voltage is reduced.

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Evaluation of behavior of updated three-dimensional panel under lateral load in both independent and dependent modes

  • Rezaifar, Omid;Nik, Hamun Adeli;Ghohaki, Majid
    • Earthquakes and Structures
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    • v.14 no.1
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    • pp.11-20
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    • 2018
  • Three-dimensional panels are one of the modern construction systems which can be placed in the category of industrial buildings. There have always been a lot of studies and efforts to identify the behavior of these panels and improve their capacity due to their earthquake resistance and high speed of performance. This study will provide a comparative evaluation of behavior of updated three-dimensional panel's structural components under lateral load in both independent and dependent modes. In fact, this study tries to simultaneously evaluate strengthening effect of three-dimensional panels and the effects of system state (independent, L-shaped and BOX shaped Walls) with reinforcement armatures with different angles on the three-dimensional panels. Overall, six independent wall model, L-shaped, roofed L-shaped, BOX-shaped walls with symmetric loading, BOX -shaped wall with asymmetrical loading and roofed BOX-shaped wall were built. Then the models are strengthened without strengthened reinforcement and with strengthened reinforcements with an angle of 30, 45 and 60 degrees. The applied lateral loading, is exerted by changing the location on the end wall. In BOX-shaped wall, in symmetric and asymmetric loading, the load bearing capacity will be increased about 200 and 50% respectively. Now, if strengthened, the load bearing capacity in symmetric and asymmetric loading will be increased 3.5 and 2 times respectively. The effective angle of placement of strengthened reinforcement in the independent wall is 45 and 60 degrees. But in BOX-shaped and L-shaped walls, the use of strengthened reinforcement 45 degrees is recommended.

Across-wind dynamic loads on L-shaped tall buildings

  • Li, Yi;Li, Qiu-Sheng
    • Wind and Structures
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    • v.23 no.5
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    • pp.385-403
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    • 2016
  • The across-wind dynamic loads on L-shaped tall buildings with various geometric dimensions were investigated through a series of wind tunnel testing. The lift coefficients, power spectral densities and vertical correlation coefficients of the across-wind loads were analyzed and discussed in details. Taking the side ratio and terrain category as key variables, empirical formulas for estimating the across-wind dynamic loads on L-shaped tall buildings were proposed on the basis of the wind tunnel testing results. Comparisons between the predictions by the empirical formulas and the wind tunnel test results were made to verify the accuracy and applicability of the proposed formulas. Moreover, a simplified procedure to evaluate the across-wind dynamic loads on L-shaped tall buildings was derived from the proposed formulas. This study aims to provide a simple and reliable way for the estimation of across-wind dynamic loads on L-shaped tall buildings.

Fatigue Test and Simulation on the Steel Welded L-Shaped Frame (L 형상 용접 프레임의 피로 실험 및 시뮬레이션)

  • Lee, Jung-Hee;Kim, Jae-Hoon;Kong, Jeong-Pyo;Han, Kyu-Hyun;Lee, Young-Shin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.1
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    • pp.63-69
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    • 2008
  • A fatigue test on the steel welded L-shaped frame was conducted. The frame was consisted with carbon steel tube and reinforced bracket. The four type reinforced brackets were fabricated. They were two rectangular plate reinforced bracket, two sided pentagon plate reinforced bracket, triangular plate reinforced bracket and fully reinforced bracket. The fatigue test of frame was conducted with axial tension loading. The fatigue simulation of the steel welded L-shaped frame was also performed by the finite element method with code FEMFAT. The frame of fully reinforced bracket had the highest fatigue life and reinforced quality factor.

L-Shaped Columellar Strut in East Asian Nasal Tip Plasty

  • Dhong, Eun-Sang;Kim, Yeon-Jun;Suh, Man Koon
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.616-620
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    • 2013
  • Background Nasal tip support is an essential consideration for rhinoplasty in East Asians. There are many techniques to improve tip projection, and among them, the columellar strut is the most popular technique. However, the conventional design is less supportive for rotating the tip. The amount of harvestable septal cartilage is relatively small in East Asians. For an optimal outcome, we propose an L-shaped design for applying the columellar strut. Methods To evaluate the anthropometric outcomes, the change in nasal tip projection and the columella-labial angle were analyzed by comparing preoperative and postoperative photographs. The anthropometric study group consisted of 25 patients who underwent the same operative technique of an L-shaped strut graft using septal cartilage and were followed up for more than 9 months. Results There were statistically significant differences between the preoperative and postoperative values in the nasal tip projection ratio and columella-labial angle. We did not observe any complications directly related to the L-shaped columellar strut in the anthropometric study group. Conclusions The L-shaped columellar strut has advantages not only in the controlling of tip projection and rotation, but in that it needs a smaller amount of cartilage compared to the conventional septal extension graft. It can therefore be an alternative technique for nasal tip plasty when there is an insufficient amount of harvestable septal cartilage.

Broadband Characterization of Circularly Polarized Waveguide Antennas Using L-Shaped Probe

  • Fukusako, Takeshi
    • Journal of electromagnetic engineering and science
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    • v.17 no.1
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    • pp.1-8
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    • 2017
  • This paper introduces a technique to obtain the broadband characteristics of circularly polarized antennas using an L-shaped probe. A waveguide antenna is suitable for obtaining high gain and handling convenience in some applications; however, the asymmetrical structure of the L-shaped probe results in cross-polarization and frequency dependence on the field distribution of higher-order modes (HOM). In addition to the basic characteristics of a waveguide antenna with an L-shaped probe, the author discusses some techniques to reduce the HOM and cross-polarization. As a result, the 3-dB axial ratio (AR) is obtained with the fundamental mode even when the frequency is expanded to the region for HOM of TM. This reduction is mainly due to the cutoff structure to the TM mode around the short wall of the waveguide. Furthermore, some aperture modification techniques can reduce the cross-polarization in a wide range of angles in the radiation pattern. Such techniques and their mechanisms are discussed in this paper. The obtained performance shows that the proposed antennas have a wide range of angles of 3-dB AR in the radiation pattern, broadband characteristics in impedance and AR, and low variation in group velocity.

A Study on the Multiple Resonance Characteristics of Crossed Planar Monopole Antenna by L-Shaped Slit (십자형 평판 모노폴 안테나의 L자형 슬릿에 의한 다중 공진 특성 연구)

  • Shim, Jae-Ruen
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.1-5
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    • 2009
  • In this paper, a novel wideband crossed planar monopole antenna with the multiple resonance characteristics is proposed. The proposed monopole antenna can be designed by a wideband crossed planar monopole antenna with L-shaped slits. In order to generate multiple resonance characteristics on the proposed monopole antenna, the length of L-shaped slit and the number of L-shaped slits are determined at an interesting frequency. The proposed antenna having an omnidirectional radiation pattern and a high gain over the multiple resonance frequency bands, respectively, is suitable for a mobile antenna.

Coupled Bending and Torsional Vibrations Analysis of Cracked L-shaped Beam (크랙을 가진 L형 단면 보의 횡-비틀림 연성진동 해석)

  • Son, In-Soo;Kim, Chang-Ho;Cho, Jeong-Rae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.4
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    • pp.8-15
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    • 2011
  • In this paper, the influence of a crack on the natural frequency of cracked cantilever L-shaped beam with coupled bending and torsional vibrations by analytically and experimentally is analyzed. The L-shaped beam with a crack is modeled by Hamilton's principle with consideration of bending and torsional energy. The two coupled governing differential equations are reduced to one sixth-order ordinary differential equation in terms of the flexural displacement. The crack is assumed to be in the first, second and third mode of fracture and to be always opened during the vibrations. The theoretical results are validated by a comparison with experimental measurements. The maximal difference between the theoretical results and experimental measurements of the natural frequency is less than 7.5% in the second vibration mode.