• Title/Summary/Keyword: Link length

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Effect of link length in retrofitted RC frames with Y eccentrically braced frame

  • INCE, Gulhan
    • Steel and Composite Structures
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    • v.43 no.5
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    • pp.553-564
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    • 2022
  • Many existing reinforced concrete (RC) structures need to be strengthening for reason such as poor construction quality, low ductility or designing without considering seismic effects. One of the strengthening methods is strengthening technique with eccentrically braced frames (EBFs). The characteristic element of these systems is the link element and its length is very important in terms of seismic behavior. The link element of Y shaped EBF systems (YEBFs) is designed as a short shear element. Different limits are suggested in the literature for the link length. This study to aim experimentally investigate the effect of the link length for the suggested limits on the behavior of the RC frame system and efficiency of strengthening technique. For this purpose, a total of 5 single story, single span RC frame specimens were produced. The design of the RC frames was made considering seismic design deficiencies. Four of the produced specimens were strengthened and one of them remained as bare specimen. The steel YEBFs were used in strengthening the RC frame and the link was designed as a shear element that have different length with respect to suggested limits in literature. The length of links was determined as 50mm, 100mm, 150mm and 200mm. All of the specimens were tested under cyclic loads. The obtained results show that the strengthening technique improved the energy consumption and lateral load bearing capacities of the bare RC specimen. Moreover, it is concluded that the specimens YB-2 and YB-3 showed better performance than the other specimens, especially in energy consumption and ductility.

A study on the link composition design of a double link type level luffing jib crane (II) (이중 링크 형식 수평 인입 집 크레인의 링크 구성 설계에 관한 연구(II))

  • Hur, C.W.;Choi, M.S.;Moon, D.H.
    • Journal of Power System Engineering
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    • v.15 no.1
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    • pp.57-63
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    • 2011
  • It is very important to determine link composition of a crane in the basic design of the crane. There are many parameters in the design for the link composition of a double link type level luffing jib crane. We analyze the variation of link composition according to the variation of these parameters which are the angle of fixed link, the angle between the fixed link and backstay when the position of the crane is the maximum working radius, the ratio of fly jib length between two moving hinges to the total length of fly jib, the length of backstay, and the slewing radius. In this paper, we describe the application of the previous analysis program of the link composition design for a double link type level luffing jib crane.

Seismic performance of moment resisting steel frames retrofitted with coupled steel plate shear walls with different link beams

  • Amir Masoumi Verki;Adolfo Preciado;Pegah Amiri Motlagh
    • Steel and Composite Structures
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    • v.46 no.5
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    • pp.591-609
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    • 2023
  • In some buildings, the lateral structural response of steel framed buildings depends on the shear walls and it is very important to study the behavior of these elements under near-field seismic loads. The link beam in the opening of the shear wall between two wall plates is investigated numerically in terms of behavior and effects on frames. Based on the length of the beam and its bending and shear behavior, three types of models are constructed and analyzed, and the behavior of the frames is also compared. The results show that by reducing the length of the link beam, the base shear forces reduce about 20%. The changes in the length of the link beam have different effects on the degree of coupling. Increasing the length of the link beam increases the base shear about 15%. Also, it has both, a positive and a negative effect on the degree of coupling. The increasing strength of the coupling steel shear wall is linearly related to the yield stress of the beam materials, length, and flexural stiffness of the beam. The use of a shorter link beam will increase the additional strength and consequently improving the behavior of the coupling steel shear wall by reducing the stresses in this element. The link beam with large moment of inertia will also increase about 25% the additional strength and as a result the coefficient of behavior of the shear wall.

Cluster and information entropy analysis of acoustic emission during rock failure process

  • Zhang, Zhenghu;Hu, Lihua;Liu, Tiexin;Zheng, Hongchun;Tang, Chun'an
    • Geomechanics and Engineering
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    • v.25 no.2
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    • pp.135-142
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    • 2021
  • This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.

A Study on the Link Composition Design of a Double Link Type Level Luffing Jib Crane (I) (이중 링크 형식 수평 인입 집 크레인의 링크 구성 설계에 관한 연구( I ))

  • Moon, D.H.;Hur, C.W.;Choi, M.S.
    • Journal of Power System Engineering
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    • v.13 no.1
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    • pp.19-25
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    • 2009
  • This paper is a study on the link composition design of a double link type level luffing jib crane using path generation synthesis passing through three precision points according to parameters, the length of backstay, the ratio of fly jib length between two moving hinges to the total length of fly jib, the location of a intermediate passing point etc. when the maximum and minimum working radius of the crane are given. The performance of the crane depends on the deviation of the luffing trajectory at fly jib tip. The luffing trajectories according to the above parameters are analyzed and shown in graphs by the developed computer program. In a real-life design, some trials are needed to arrive at a proper link composition design. Therefore, it is expected that the present computer program can rapidly and exactly deal with a link composition design proper to the design criteria of the crane.

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Queue Management using Optimal Margin method to Improve Bottleneck Link Performance

  • Radwa, Amr
    • Journal of Korea Multimedia Society
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    • v.18 no.12
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    • pp.1475-1482
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    • 2015
  • In network routers, buffers are used to resolve congestion and reduce packet loss rate whenever congestion occurs at bottleneck link. Most of the existing methods to manage such buffers focus only on queue-length-based control as one loop which have some issues of low link utilization and system stability. In this paper, we propose a novel framework which exploits two-loop control method, e.g. queue-length and congestion window size, combined with optimal margin method to facilitate parameter choices. Simulation results in ns-2 demonstrate that bottleneck link performance can be improved with higher link utilization (85%) and shorter queue length (22%) than the current deployed scheme in commercial routers (RED and DropTail).

Walking robot Optimum Design by Jansen's mechanism (Jansen's Mechanism 기반의 보행로봇 최적설계)

  • Kim, Taehyun;Seo, Hankook;Lee, Seohyun
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.443-454
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    • 2016
  • This study focus to make 8 legs robot based on Jansen's mechanism. In the process of making, we found GL(Ground length),GAC(Ground Angle Coefficient) and the height difference of tract and compare Several models with M.Sketch to find link's Length ratio Optimised simple walking and crossing of obstacles. In the process, our team Analyzed the difference ideal tract (Jansen holy number model's track) contrived by Jansen and our final model tract. As a result, we found optimal link's length ratio to over the obstacles and some features that our model differ from Jansen holy number model. It means that optimal link's length ratio depends on certain circumstances, perfect length ratio is nonexistent.

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Optimal Link Length Design for Departure Time-based Link Travel Time Information (출발시각기준 링크통행시간 정보의 공간적 설계 (연속류를 중심으로))

  • Kim, Jae-Jin;No, Jeong-Hyeon;NamGung, Seong;Park, Dong-Ju
    • Journal of Korean Society of Transportation
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    • v.25 no.2 s.95
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    • pp.145-155
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    • 2007
  • The objectives of this study aye to develop an on-line departure time-based travel time estimation method and to determine an optimal link length for the estimation. This study developed a link-based rolling horizon logic as the travel time estimation method. In order to determine an optimal link length, the information error of the travel time provision from the user's perspective was defined and employed as a selection criterion. It was found that, when the travel time aggregation size was set as five minutes, a link length of four kilometers gave the most accurate result.

Compensation for the Distorted WDM Channels in the Long-Haul Transmission Link with the Randomly Distributed SMF Lengths and RDPS (SMF 길이와 RDPS가 랜덤하게 분포하는 장거리 전송 링크에서의 왜곡된 WDM 채널의 보상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.19 no.4
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    • pp.323-329
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    • 2015
  • The compensation characteristics of the distorted WDM channels compensated for by dispersion management (DM) and optical phase conjugation in the long-haul ($50\;fiber\;spans{\times}80km$) transmission link with the randomly distributed single mode fiber (SMF) length and residual dispersion per spans (RDPS) for implementing of the flexible link configuration are investigated. It is confirmed that the compensation effect in the link with the randomly distributed SMF length and RDPS is similar with that in the link with the uniform distribution, when the launch power of WDM channels are restricted within 0 dBm. This result means that the proposed link configuration is useful for designing and deploying the long-haul WDM transmission link.

Investigation of the link beam length of a coupled steel plate shear wall

  • Gholhaki, M.;Ghadaksaz, M.B.
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.107-125
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    • 2016
  • Steel shear wall system has been used in recent years in tall buildings due to its appropriate behavior advantages such as stiffness, high strength, economic feasibility and high energy absorption capability. Coupled steel plate shear walls consist of two steel shear walls that are connected to each other by steel link beam at each floor level. In this article the frames of 3, 10, and 15 of (C-SPSW) floor with rigid connection were considered in three different lengths of 1.25, 2.5 and 3.75 meters and link beams with plastic section modulus of 100% to the panel beam at each floor level and analyzed using three pairs of accelerograms based on nonlinear dynamic analysis through ABAQUS software and then the performance of walls and link beams at base shear, drift, the period of structure, degree of coupling (DC) and dissipated energy evaluated. The results show that the (C-SPSW) system base shear increases with a decrease in the link beam length, and the drift, main period and dissipated energy of structure decreases. Also the link beam length has different effects on parameters of coupling degrees.