• 제목/요약/키워드: I Connection

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Increasing plastic hinge length using two pipes in a proposed web reduced beam section, an experimental and numerical study

  • Zahrai, Seyed M.;Mirghaderi, Seyed R.;Saleh, Aboozar
    • Steel and Composite Structures
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    • v.23 no.4
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    • pp.421-433
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    • 2017
  • Experimental and numerical studies of a newly developed Reduced Beam Section (RBS) connection, called Tubular Web RBS connection (TW-RBS) have been recently conducted. This paper presents experimental and numerical results of extending the plastic hinge length on the beam flange to increase energy dissipation of a proposed version of the TW-RBS connection with two pipes, (TW-RBS(II)), made by replacing a part of flat web with two steel tubular web at the desirable location of the beam plastic hinge. Two deep-beam specimens with two pipes are prepared and tested under cyclic loads. Obtained results reveal that the TW-RBS(II) like its type I, increases story drift capacity up to 6% in deep beam much more than that stipulated by the current seismic codes. Based on test results, the proposed TW-RBS(II) helps to dissipate imposed energy up to 30% more than that of the TW-RBS(I) specimens at the same story drift and also reduces demands at the beam-to-column connection up to 30% by increasing plastic hinge length on the beam flange. The TW-RBS(II) specimens are finally simulated using finite element method showing good agreement with experimental results.

Mobility Analysis Metric for Ad Hoc Network Using Pairwise Clustering (이진 Clustering을 이용한 Ad Hoc 망의 이동성 해석 측도)

  • Ahn, Hong-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.193-199
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    • 2010
  • In this paper, we propose a new metric to measure the dynamic connection states of Ad Hoc network. The new metric measures the total path break up time $\sum_{i}T_i$, where $T_i$ is the time period during which maximum cluster distance exceeds the radio range. $T_i$ can be calculated from the maximum cluster distance function of time, which can be computed from the node position samples of mobility model. The proposed metric can be used as a total system metric as well as an individual connection metric.

Experiments on Slip Coefficients of High-Strength Bolt Connection with Weathering Steel (I) (내후성강재 고장력볼트 이음부 미끄럼계수 평가 실험 (I))

  • Park, Yong Myung;Seong, Taek Ryong
    • Journal of Korean Society of Steel Construction
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    • v.12 no.2 s.45
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    • pp.167-175
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    • 2000
  • An experimental research to evaluate the slip coefficient of high-strength slip-critical-type bolt connection of weathering steel plate has been performed in this paper. Experiments were performed with several surface conditions such as clean mill scale with hand or power brush cleaning, shot blast cleaned, inorganic zinc primer coated, and weather coated surfaces. Also, the relaxation of bolt clamping force was estimated during 500 hours. It was ascertained from the experiments that slip coefficients are greater than 0.40 in all faying surface conditions except mill scale surface with power brushing. The quantify of relaxation depended on the surface conditions and was $3{\sim}8%$, i.e., less than 10%.

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Numerical analysis of the mechanical behavior of welded I beam-to-RHS column connections

  • Rosa, Rosicley J.R.;Neto, Juliano G.R.
    • Coupled systems mechanics
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    • v.8 no.2
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    • pp.185-197
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    • 2019
  • Considering the increasing use of tubular profiles in civil construction, this paper highlights the study on the behavior of welded connections between square hollow section column and I-beam, with emphasis on the assessment of the joint stiffness. Firstly, a theoretical analysis of the welded joints has been done focusing on prescriptions of the technical literature for the types of geometries mentioned. Then, a numerical analysis of the proposed joints were performed by the finite element method (FEM) with the software ANSYS 16.0. In this study, two models were evaluated for different parameters, such as the thickness of the cross section of the column and the sizes of cross section of the beams. The first model describes a connection in which one beam is connected to the column in a unique bending plane, while the second model describes a connection of two beams to the column in two bending planes. From the numerical results, the bending moment-rotation ($M-{\varphi}$) curve was plotted in order to determine the resistant bending moment and classify each connection according to its rotational capacity. Furthermore, an equation was established with the aim of estimating the rotational stiffness of welded I beam-to-RHS column connections, which can be used during the structure design. The results show that most of the connections are semi-rigid, highlighting the importance of considering the stiffness of the connections in the structure design.

On Generalized 𝜙-recurrent Kenmotsu Manifolds with respect to Quarter-symmetric Metric Connection

  • Hui, Shyamal Kumar;Lemence, Richard Santiago
    • Kyungpook Mathematical Journal
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    • v.58 no.2
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    • pp.347-359
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    • 2018
  • A Kenmotsu manifold $M^n({\phi},\;{\xi},\;{\eta},\;g)$, (n = 2m + 1 > 3) is called a generalized ${\phi}-recurrent$ if its curvature tensor R satisfies $${\phi}^2(({\nabla}_wR)(X,Y)Z)=A(W)R(X,Y)Z+B(W)G(X,Y)Z$$ for all $X,\;Y,\;Z,\;W{\in}{\chi}(M)$, where ${\nabla}$ denotes the operator of covariant differentiation with respect to the metric g, i.e. ${\nabla}$ is the Riemannian connection, A, B are non-vanishing 1-forms and G is given by G(X, Y)Z = g(Y, Z)X - g(X, Z)Y. In particular, if A = 0 = B then the manifold is called a ${\phi}-symmetric$. Now, a Kenmotsu manifold $M^n({\phi},\;{\xi},\;{\eta},\;g)$, (n = 2m + 1 > 3) is said to be generalized ${\phi}-Ricci$ recurrent if it satisfies $${\phi}^2(({\nabla}_wQ)(Y))=A(X)QY+B(X)Y$$ for any vector field $X,\;Y{\in}{\chi}(M)$, where Q is the Ricci operator, i.e., g(QX, Y) = S(X, Y) for all X, Y. In this paper, we study generalized ${\phi}-recurrent$ and generalized ${\phi}-Ricci$ recurrent Kenmotsu manifolds with respect to quarter-symmetric metric connection and obtain a necessary and sufficient condition of a generalized ${\phi}-recurrent$ Kenmotsu manifold with respect to quarter symmetric metric connection to be generalized Ricci recurrent Kenmotsu manifold with respect to quarter symmetric metric connection.

Development of I-HTTP for supporting Interactive Learning Object (상호작용적 학습 객체 지원을 위한 I-HTTP 개발)

  • 정영식
    • Journal of the Korea Computer Industry Society
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    • v.4 no.10
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    • pp.713-722
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    • 2003
  • The purpose of this study was to define an interactive learning object of ILO through implementation of learning object content standardization technology for the reuse of interactive tools between learners, and to develop I(Interactive)-HTTP for the ILO to properly communicate with LMS. 1-HTTP developed here was enabled to keep connection status during the entire session by improving the existing HTTP with its stateless connection property. This ceaseless connection made it possible to provide users with the real-time interactivity between learners that happened frequently in the ILO. Also, because the I-HTTP was an expanded version of HTTP, it was possible to conduct general HTML documentation as well as ILO. In particular, the standardized launch process between LMS and ILO was embodied in adding the INIT, GETVAL, SETVAL, COMMBT, FINISH methods in the protocol, and the results from the interactivity between ILO learners were channeled to the database storage to save them through separately defined data models.

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STRESS ANALYSIS OF SUPPORTING TISSUES AND IMPLANTS ACCORDING TO IMPLANT FIXTURE SHAPES AND IMPLANT-ABUTMENT CONNECTIONS (임플랜트 고정체의 형태와 연결방식에 따른 임플랜트 및 지지조직의 응력분포)

  • Han Sang-Un;Park Ha-Ok;Yang Hong-So
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.2
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    • pp.226-237
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    • 2004
  • Purpose: Four finite element models were constructed in the mandible having a single implant fixture connected to the first premolar-shaped superstructure, in order to evaluate how the shape of the fixture and the implant-abutment connection would influence the stress level of the supporting tissues fixtures, and prosthethic components. Material and methods : The superstructures were constructed using UCLA type abutment, ADA type III gold alloy was used to fabricate a crown and then connected to the fixture with an abutment screw. The models BRA, END , FRI, ITI were constructed from the mandible implanted with Branemark, Endopore, Frialit-2, I.T.I. systems respectively. In each model, 150 N of vertical load was placed on the central pit of an occlusal plane and 150 N of $40^{\circ}$ oblique load was placed on the buccal cusp. The displacement and stress distribution in the supporting tissues and the other components were analysed using a 2-dimensional finite element analysis . The maximum stress in each reference area was compared. Results : 1. Under $40^{\circ}$ oblique loading, the maximum stress was larger in the implant, superstructure and supporting tissue, compared to the stress pattern under vertical loading. 2. In the implant, prosthesis and supporting tissue, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA & END). 3. In the superstructure and implant/abutment interface, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA & END). 4. In the implant fixture, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA & END). 5 The stress was more evenly distributed in the bone/implant interface through the FRI of trapezoidal step design. Especially Under $40^{\circ}$ oblique loading, The maximum stress was smallest in the bone/implant interface. 6. In the implant and superstructure and supporting tissue, the maximum stress occured at the crown loading point through the ITI. Conclusion: The stress distribution of the supporting tissue was affected by shape of a fixture and implant-abutment connection. The magnitude of maximum stress was reduced with the internal connection type (FRI) and the morse taper type (ITI) in the implant, prosthesis and supporting tissue. Trapezoidal step design of FRI showed evenly distributed the stress at the bone/implant interface.

A mathematical steel panel zone model for flanged cruciform columns

  • Saffari, Hamed;Sarfarazi, Sina;Fakhraddini, Ali
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.851-867
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    • 2016
  • Cruciform sections are an appropriate option for columns of orthogonal moment resisting frames for equal bending strength and stiffness about two main axes and the implementation is easier for continuity plates. These columns consist of two I-shaped sections, so that one of them is cut out in middle and two generated T-shaped sections be welded into I-shaped profile. Furthermore, in steel moment frames, unbalance moment at the beam-column connection leads to shear deformation in panel zone. Most of the obtained relations for panel zone strength derived from experimental and analytical results are on I-shaped columns with almost thin flanges. In this paper, a parametric study has been carried out using Finite Element Method (FEM) with effective parameters at the panel zone behavior. These parameters consist of column flange thickness, column web thickness, and thickness of continuity plates. Additionally, a mathematical model has been suggested to determine strength of cruciform column panel zone and has been shown its accuracy and efficiency.

Development of a 50kW Photovoltaic Power Generation System for Gird Connection(I) (50 kW급 계통연계형 태양광 발전시스템 개발(I))

  • Ahn, K.S.;Lim, H.C.;Hwang, I.H.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.31-33
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    • 1999
  • In this paper, a operating characteristics of the 50 kW grid-connected Photovoltaic(PV) Power system which is by means of initial PV datum analyzing is reported. The development of a 50 kW class photovoltaic power generation system including a DC/AC inverter is suggested to investigate the system performance for grid connection. The results of the demonstration test of a 50 kW class grid-connected PV system show that the system utilization rate is 15.6% and the inverter efficiency is 94% at 80% load.

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A parametric investigation on the hysteretic behaviour of CFT column to steel beam connections

  • Esfandyary, R.;Razzaghi, M.S.;Eslami, A.
    • Structural Engineering and Mechanics
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    • v.55 no.1
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    • pp.205-228
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    • 2015
  • The results of a numerical investigation pertaining to the hysteretic behaviour of concrete filled steel tubular (CFT) column to I-beam connections are discussed in detail. Following the verification of the numerical results against the available experimental tests, the nonlinear finite element (FE) analysis was implemented to evaluate the effects of different parameters including the column axial load, beam lateral support, shape and arrangement of stiffeners, stiffness of T-stiffeners, and the number of shear stiffeners. Pursuing this objective, an external CFT column to beam connection, tested previously, was selected as the case-study. The lateral forces on the structure were simulated, albeit approximately, using an incremental cyclic loading reversal applied at the beam tip. The results were compared in terms of hysteretic load-displacement curves, stress distributions in connection, strength, rotation, and energy dissipation capacity. It was shown that external T-stiffeners combined with internal shear stiffeners play an important role in the hysteretic performance of CFT columns to I-beam connections.