• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.315-319
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• 2004

Static and dynamic responses of micro cantilever beam structures undertaking electrostatic forces are obtained employing Galerkin's method based on Euler beam theory. Variations of static and dynamic responses as well as resonant frequencies are estimated for several sets of beam properties and applied voltages. It is shown that the applied voltage influences the deflection and the modal characteristics significantly. Such information can be usefully employed for the design of MEMS structures.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.388-395
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• 2002

Recently, adapt cases of concrete structure are increasing according to structural largeness and variety. We energetically continue to study empirical research about Steel Fiber but analytic research of Two-spans Beam With Steel Fiber to model real structure is just beginning stage. This study will suggest analytic algorithm of Two-spans Beam With Steel Fiber by comparing and analyzing deflection and strain of Two-spans Beam With Steel Fiber after we develop Nonlinear Analysis Program considering edge stress analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.77-82
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• 2002

Recently, adapt cases of concrete structure are increasing according to structural largeness and variety. We energetically continue to study empirical research about Steel Fiber but analytic research of Two-spans Beam With Steel Fiber to model real structure is just beginning stage. This study will suggest analytic algorithm of Two-spans Beam With Steel Fiber by comparing and analyzing deflection and strain of Two-spans Beam With Steel Fiber after we develop Nonlinear Analysis Program considering edge stress analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.385-387
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• 2002

The electron beam simulation technology is indispensable for the recent electron gun design. The technology is becoming more and more important for deflection yoke (DY) design and investigation of the interference effects between gun and DY. Further, it may become vital even for shadow mask, glass funnel, exposure lens and magnetic shield.

• Bulletin of the Korean Chemical Society
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• v.18 no.5
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• pp.547-549
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• 1997

• Computers and Concrete
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• v.12 no.6
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• pp.739-754
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• 2013

Creep and shrinkage have pronounced effects on the long-term deflection of prestressed concrete members. Under repeated loading, the rate of creep in prestressed concrete members is often accelerated. In this paper, an iterative computational procedure based on the well known Model B3 for creep and shrinkage was developed to predict the time-dependent deflection of partially prestressed concrete members. The developed model was validated using the experimental observed deflection behavior of a simply supported partially prestressed concrete beam under repeated loading. The validated model was then employed to make predictions of the long-term deflection of the prestressed beams under a variety of conditions (e.g., water cement ratio, relatively humidity and time at drying). The simulation results demonstrate that ignoring creep and shrinkage could lead to significant underestimation of the long-term deflection of a prestressed concrete member. The model will prove useful in reducing the long-term deflection of the prestressed concrete members via the optimal selection of a concrete mix and prestressing forces.

• Structural Engineering and Mechanics
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• v.10 no.3
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• pp.197-209
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• 2000

The effects of weight and axial inertia of a beam are taken into account for studying the nonlinear vibration of the Timoshenko beam due to external loads. The combination of Galerkins method and Runge-Kutta method are employed to obtain the dynamic responses of the beam. A concentrated force and a two-axle vehicle traversing on the beam are taken as two examples to investigate the response characteristics of the beam. Results show that the effect of axial inertia of the beam increases the fundamental period of the beam. Further, both the dynamic deflection and the dynamic moment of the beam obtained with including the effect of axial inertia of the beam are greater than those of the beam without including that effect of the beam.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.139-146
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• 2014

Recently, in field of bridge construction, modular technology has been studied to reduce construction period, traffic impact and environmental impact. This study is a part of research related to the modular bridges. The aim of the study is to analyze the structural behavior and evaluate a serviceability for transverse connection of modular slab bridge. A total of four specimens were fabricated. including a control beam for finding the maximum load by static test. And one control beam and two segmental beams were fabricated for cyclic loading test. As the test result, the beams that were introduced 100% of the design prestressing force showed a smaller maximum deflection, residual deflection and crack width than the control beam. The beam for serviceability evaluation was satisfied with structural serviceability limits of the deflection and crack.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.3
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• pp.236-243
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• 2004

In this paper a dynamic behavior of a simply supported cracked pipe conveying fluid with the moving mass is presented. Based on the Timoshenko beam theory, the equation of motion can be constructed by using the Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory. And the crack is assumed to be in th first mode of fracture. As the depth of the crack and velocity of fluid are increased the mid-span deflection of the pipe conveying fluid with the moving mass is increased. As depth of the crack is increased, the effect of the velocity of the fluid on the mid-span deflection appears more greatly.

• Smart Structures and Systems
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• v.22 no.3
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• pp.291-302
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• 2018

This paper presents a flexibility based method for damage identification from static measurements in beam-type structures. The response of the beam at the Damaged State is decomposed into the response at the Reference State plus the response at an Incremental State, which represents the effect of damage. The damage is localized by detecting slope discontinuities in the deflection of the structure at the Incremental State. A denoising filtering technique is applied to reduce the effect of experimental noise. The extent of the damage is estimated through comparing the experimental flexural stiffness of the damaged cross-sections with the corresponding values provided by analytical models of cracked beams. The paper illustrates the method by showing a numerical example with two cracks and an experimental case study of a simply supported steel beam with one artificially introduced notch type crack at three damage levels. A Digital Image Correlation system was used to accurately measure the deflections of the beam at a dense measurement grid under a set of point loads. The results indicate that the method can successfully detect and quantify a small damage from the experimental data.