• Title/Summary/Keyword: Embedded length

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A review on uplift response of symmetrical anchor plates embedded in reinforced sand

  • Niroumand, Hamed;Kassim, Khairul Anuar
    • Geomechanics and Engineering
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    • v.5 no.3
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    • pp.187-194
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    • 2013
  • The most soil anchor works have been concerned with the uplift problem on embedded in non-reinforced soils under pullout test. Symmetrical anchor plates are a foundation system that can be resisting tensile load with the support of around soil in which symmetrical anchor plate is embedded. Engineers and authors proved that the uplift response can be improved by grouping the symmetrical anchor plates, increasing the unit weight, embedment ratio and the size of symmetrical anchor plates. Innovation of geosynthetics in the field of geotechnical engineering as reinforcement materials found to be possible solution in symmetrical anchor plate responses. Unfortunately the importance of reinforcement in submergence has received very little attention by researchers. In this paper, provision of tensile reinforcement under embedded conditions has been studied through uplift experiments on symmetrical anchor plates by few researchers. From the test results it has been showed that the provision of geogrid reinforcement system enhances the uplift response substantially under uplift test although other results are such as increase the ultimate uplift response of symmetrical anchor plate embedded using geosynthetic and Grid Fixed Reinforced (GFR) and symmetrical anchor plate improvement is very dependent on geosynthetic layer length and increases significantly until the amount of beyond that further increase in the layer length does not show a significant contribution in the anchor response.

Bond-slip behaviour of H-shaped steel embedded in UHPFRC

  • Huang, Zhenyu;Huang, Xinxiong;Li, Weiwen;Chen, Chufa;Li, Yongjie;Lin, Zhiwei;Liao, Wen-I
    • Steel and Composite Structures
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    • v.38 no.5
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    • pp.563-582
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    • 2021
  • The present study experimentally and analytically investigated the push-out behaviour of H-shaped steel section embedded in ultrahigh-performance fibre-reinforced concrete (UHPFRC). The effect of significant parameters such as the concrete types, fibre content, embedded steel length, transverse reinforcement ratio and concrete cover on the bond stress, development of bond stress along the embedded length and failure mechanism has been reported. The test results show that the bond slip behaviour of steel-UHPFRC is different from the bond slip behaviour of steel-normal concrete and steel-high strength concrete. The bond-slip curves of steel-normal concrete and steel-high strength concrete exhibit brittle behaviour, and the bond strength decreases rapidly after reaching the peak load, with a residual bond strength of approximately one-half of the peak bond strength. The bond-slip curves of steel-UHPFRC show an obvious ductility, which exhibits a unique displacement pseudoplastic effect. The residual bond strength can still reach from 80% to 90% of the peak bond strength. Compared to steel-normal concrete, the transverse confinement of stirrups has a limited effect on the bond strength in the steel-UHPFRC substrate, but a higher stirrup ratio can improve cracking resistance. The experimental campaign quantifies the local bond stress development and finds that the strain distribution in steel follows an exponential rule along the steel embedded length. Based on the theory of mean bond and local bond stress, the present study proposes empirical approaches to predict the ultimate and residual bond resistance with satisfactory precision. The research findings serve to explain the interface bond mechanism between UHPFRC and steel, which is significant for the design of steel-UHPFRC composite structures and verify the feasibility of eliminating longitudinal rebars and stirrups by using UHPFRC in composite columns.

Exact solution for transverse bending analysis of embedded laminated Mindlin plate

  • Heydari, Mohammad Mehdi;Kolahchi, Reza;Heydari, Morteza;Abbasi, Ali
    • Structural Engineering and Mechanics
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    • v.49 no.5
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    • pp.661-672
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    • 2014
  • Laminated Rectangular plates embedded in elastic foundations are used in many mechanical structures. This study presents an analytical approach for transverse bending analysis of an embedded symmetric laminated rectangular plate using Mindlin plate theory. The surrounding elastic medium is simulated using Pasternak foundation. Adopting the Mindlin plate theory, the governing equations are derived based on strain-displacement relation, energy method and Hamilton's principle. The exact analysis is performed for this case when all four ends are simply supported. The effects of the plate length, elastic medium and applied force on the plate transverse bending are shown. Results indicate that the maximum deflection of the laminated plate decreases when considering an elastic medium. In addition, the deflection of the laminated plate increases with increasing the plate width and length.

Mechanical Properties on the Pull-Out Response of Steel Fibers Embedded in Cementitious Matrices (시멘트 매트릭스 내 강섬유의 매입 일반에 관한 성능)

  • Jeon Esther;Kim Sun Woo;Park Wan Shin;Han Byung Chan;Hwang Sun Kyung;Yun Hyun Do
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.762-765
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    • 2004
  • The main objective of this study is to provide a parametric evaluation of the pull-out response of steel fibers embedded in cementitious matrices. The various parameters controlling the behavior of the bond stress versus end slip relationship are analyzed; their effects on the entire pull-out load versus end slip response and the corresponding pull-out energy up to total pull-out are investigated. Also discussed are the effects of the fiber length, the water/binder ratio of the mixtures and embedded length.

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Behavior of Mechanical Anchorage of Bars Embedded in Concrete Blocks

  • You, Young-Chan;Park, Keun-Do;Kim, Keung-Hwan;Lee, Li-Hyung
    • KCI Concrete Journal
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    • v.14 no.2
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    • pp.86-91
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    • 2002
  • This paper presents an experimental study to investigate the behavior of mechanical anchorage of reinforcing bars in concrete members. Three kinds of mechanical anchorage which are a kind of headed reinforcements are considered in this study. Total seven specimens were prepared to consider the effects of anchoring methods (Type A, Type B and Type C) and anchorage lengths of the reinforcing bars (14 $d_{b}$, 12 $d_{b}$, 9 $d_{b}$). Pullout tests conforming to ASTM were carried out to assess the effects of several variables on anchoring strength of bars. Based on the test results, it was concluded that the behavior of the specimen anchored by the mechanical anchorage with the anchor-age length of 12 $d_{b}$, is as good as, or better than that of the specimen anchored by 90-degree standard hook.rd hook.

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The Analysis of 3MW Embedded Type PMSG for Wind Turbine (풍력 발전기용 3MW 매립형 영구자석동기발전기 해석)

  • Won, Jeonghyun;Lee, Sangwoo;Kim, D.E.;Chung, Chinwha;Park, H.C.
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.180.1-180.1
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    • 2010
  • This paper introduces a 3MW embedded Permanent Magnet Synchronous Generator(PMSG) for wind turbine. The generator features 313mm stator inner radius and 974mm stator length. The blade rotor angular velocity is 15.7 rpm and the gear ratio is set to be 92.93. The nominal generator rpm at rated load is about 1459. The number of poles is six and embedded in the generator rotor. Embedded permanent magnet excitation shows higher reliability, and better efficiency. Using the finite element method, electromagnetic and thermal results are simulated by ANSYS and the results are summarized in this report.

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Buckling analysis of double walled carbon nanotubes embedded in Kerr elastic medium under axial compression using the nonlocal Donnell shell theory

  • Timesli, Abdelaziz
    • Advances in nano research
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    • v.9 no.2
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    • pp.69-82
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    • 2020
  • In this paper, a new explicit analytical formula is derived for the critical buckling load of Double Walled Carbon Nanotubes (DWCNTs) embedded in Winkler elastic medium without taking into account the effects of the nonlocal parameter, which indicates the effects of the surrounding elastic matrix combined with the intertube Van der Waals (VdW) forces. Furthermore, we present a model which predicts that the critical axial buckling load embedded in Winkler, Pasternak or Kerr elastic medium under axial compression using the nonlocal Donnell shell theory, this model takes into account the effects of internal small length scale and the VdW interactions between the inner and outer nanotubes. The present model predicts that the critical axial buckling load of embedded DWCNTs is greater than that without medium under identical conditions and parameters. We can conclude that the embedded DWCNTs are less susceptible to axial buckling than those without medium.

Reliability analysis of an embedded system with multiple vacations and standby

  • Sharma, Richa;Kaushik, Manju;Kumar, Gireesh
    • International Journal of Reliability and Applications
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    • v.16 no.1
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    • pp.35-53
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    • 2015
  • This investigation deals with reliability and sensitivity analysis of a repairable embedded system with standby wherein repairman takes multiple vacations. The hardware system consists of 'M' operating and 'S' standby components. The repairman can leave for multiple vacations of random length during its idle time. Whenever any operating unit fails, it is immediately replaced by a standby unit if available. Moreover, governing equations of an embedded system are constructed using appropriate birth-death rates. The vacation and repair time of repairman are exponentially distributed. The matrix method is used to find the steady-state probabilities of the number of failed components in the embedded system as well as other performance measures. Reliability indexes are presented. Further, numerical experiments are carried out for various system characteristics to examine the effects of different parameter. Using a special class of neuro-fuzzy systems i.e. Adaptive Network-based Fuzzy Interference Systems (ANFIS), we also approximate various performance measures. Finally, the conclusions and future research directions are provided.

Performance Analysis of a Packet Voice Multiplexer Using the Overload Control Strategy by Bit Dropping (Bit-dropping에 의한 Overload Control 방식을 채용한 Packet Voice Multiplexer의 성능 분석에 관한 연구)

  • 우준석;은종관
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.1
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    • pp.110-122
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    • 1993
  • When voice is transmitted through packet switching network, there needs a overload control, that is, a control for the congestion which lasts short periods and occurrs in local extents. In this thesis, we analyzed the performance of the statistical packet voice multiplexer using the overload control strategy by bit dropping. We assume that the voice is coded accordng to (4,2) embedded ADPCM and that the voice packet is generated and transmitted according to the procedures in the CCITT recomendation G. 764. For the performance analysis, we must model the superposed packet arrival process to the multiplexer as exactly as possible. It is well known that interarrival times of the packets are highly correlated and for this reason MMPP is more suited for the modelling in the viewpoint of accuracy. Hence the packet arrival process in modeled as MMPP and the matrix geometric method is used for the performance analysis. Performance analysis is similar to the MMPP IG II queueing system. But the overload control makes the service time distribution G dependent on system status or queue length in the multiplexer. Through the performance analysis we derived the probability generating function for the queue length and using this we derived the mean and standard deviation of the queue length and waiting time. The numerical results are verified through the simulation and the results show that the values embedded in the departure times and that in the arbitrary times are almost the same. Results also show bit dropping reduces the mean and the variation of the queue length and those of the waiting time.

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Analysis and design of demountable embedded steel column base connections

  • Li, Dongxu;Uy, Brian;Patel, Vipul;Aslani, Farhad
    • Steel and Composite Structures
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    • v.23 no.3
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    • pp.303-315
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    • 2017
  • This paper describes the finite element model for predicting the fundamental performance of embedded steel column base connections under monotonic and cyclic loading. Geometric and material nonlinearities were included in the proposed finite element model. Bauschinger and pinching effects were considered in the simulation of embedded column base connections under cyclic loading. The degradation of steel yield strength and accumulation of plastic damage can be well simulated. The accuracy of the finite element model is examined by comparing the predicted results with independent experimental dataset. It is demonstrated that the finite element model accurately predicts the behaviour and failure models of the embedded steel column base connections. The finite element model is extended to carry out evaluations and parametric studies. The investigated parameters include column embedded length, concrete strength, axial load and base plate thickness. Moreover, analytical models for predicting the initial stiffness and bending moment strength of the embedded column base connection were developed. The comparison between results from analytical models and those from experiments and finite element analysis proved the developed analytical model was accurate and conservative for design purposes.