• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.695-700
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• 2001

The objective of this study is to evaluate the flexure strength of steel fiber reinforced concrete beams and the effect of the adding steel fiber to flexural strength, and is to compare the proposed equation with the previous equation for predicting the flexural strength of fiber reinforced concrete beams. Based on earlier published studies and tests, predictive equation is proposed for evaluating the flexural strength of steel fiber reinforced concrete beams. The proposed equation gave good prediction for the flexural strength of the tested beams.

• Earthquakes and Structures
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• v.8 no.1
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• pp.101-132
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• 2015

This research formulates a closed-form equation to predict a glass panel cracking failure drift for several curtain wall and storefront systems. An evaluation of the ASCE 7-10 equation for Dclear, which is the drift corresponding to glass-to-frame contact, shows that the kinematic modeling assumed for formulation of the equation is sound. The equation proposed in this paper builds on the ASCE equation and offers a revision of that equation to predict drift corresponding to cracking failure by considering glazing characteristics such as glass type, glass panel configuration, and system type. The formulation of the proposed equation and corresponding analyses with the ASCE equation is based on compiled experimental data of twenty-two different glass systems configurations tested over the past decade. A final comparative analysis between the ASCE equation and the proposed equation shows that the latter can predict the drift corresponding to glass cracking failure more accurately.

• International Journal of Concrete Structures and Materials
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• v.5 no.1
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• pp.35-42
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• 2011

In this paper, a design equation for the punching shear capacity of steel fiber reinforced concrete (SFRC) slabs is proposed based on the Japan Society of Civil Engineers (JSCE) standard specifications. Addition of steel fibers into concrete improves mechanical behavior, ductility, and fatigue strength of concrete. Previous studies have demonstrated the effectiveness of fiber reinforcement in improving the shear behavior of reinforced concrete slabs. In this study, twelve SFRC slabs using hooked-ends type steel fibers are tested with varying fiber dosage, slab thickness, steel reinforcement ratio, and compressive strength. Furthermore, test data conducted by earlier researchers are involved to verify the proposed design equation. The proposed design equation addresses the fiber pull-out strength and the critical shear perimeter changed by the fiber factor. Consequently, it is confirmed that the proposed design equation can predict the punching shear capacity of SFRC slabs with an applicable accuracy.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.280-285
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• 2000

A viscoelastic constitutive equation of rubber that is under small oscillatory load superimposed on large static deformation is proposed. The proposed model is derived through linearization of Simo's viscoelastic constitutive model and reference configuration transformation. The proposed constitutive equation is extended to a generalized viscoelastic constitutive equation that includes widely used Mormin's model as a special case using objective stress increment. Static deformation correction factor is introduced to consider the influence of Pre-strain on the relaxation function. The proposed constitutive model is tested fer dynamic behavior of rubber specimens with different carbon black contents. It is concluded from the test that the viscoelastic constitutive equation for filled rubber must include the influence of the static deformation on the time effects. The suggested constitutive equation with static deformation correction factor shows good agreement with test values.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.1
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• pp.52-61
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• 2000

Permeability is important factor in the geotechnical problems, such as seepage discharge and dissipation of excess pore water pressure. The Kozeny-Carman equation works well for graded soils but serious discrepancies are found in clays. Major factor for these discrepancies is the tortuous flow path and unequal pore size. To estimate the permeability of fine grained soils, a permeability equation in which swelling potential is coupled with Kozeny-Carman equation is proposed in this study. To verify proposed equation, a series of variable head permeability test was carried out for steel making slag and sludge mixed with bentonite. The coefficients of permeability which is measured in the laboratory is compared with the values by the proposed equation. From the comparison, it is shown that the proposed equation can predict the coefficient of permeability of clays with satisfaction. As steel making slag and sludge is industry waste, it is reused as material of road foundation and cement but the rate of use is low. It mixed sodium-bentonite with high swelling property and permeability decrease effect. Then, Admixture investigates reuse possibility as liner of waste fill.

• Journal of Korean Society of Steel Construction
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• v.13 no.2
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• pp.177-189
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• 2001

It is a common practice to cut openings in the beam webs for the passage of service ducts or pipes in steel building structures. The objective of this paper is to propose a strength interaction equation of H beams with web holes based on the plastic collapse mechanism. In the development of the equation, the basic assumptions used in the previous strength equations and their limitations were investigated. Based on the investigation, a new equation which is simple and easy to understand was proposed. The reliability of the proposed method was evaluated using the test results of previous research made so far. Comparison of the ultimate strength by the proposed equation with previous test results showed that the proposed equation gives more reasonable prediction than the previous strength equations which are commonly used in practice.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.285-295
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• 1994

Double Injection(DI) switching devices consist of PS0+T and nS0+T contact separated by a nearly intrinsic semiconductor region containing deep trap. The equation set for DI switching device simulation by FEM is proposed. The existance of deep trap requires the modification of conventional equation set. So recombination rate equation is modified and a new equation is included in the equation set which conventionally consists op Poisson equation and current continuity equation. Consequently, the modeling equation set, which is proposed in this paper, can be applied to other semiconductor devices with trap.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.389-392
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• 2004

An accurate and rational analytical proposal for determining the shear strengths of interior beam-column joints is presented in this paper. The proposed equation is derived using a compatiblity aided truss model theory. The accuracy of the proposed equation was checked by comparing calculated shear strength of joints with experimental results reported papers in literature. The comparison showed that the proposed equation predicted the experimental shear strength of joints with reasonable agreement.

• Structural Engineering and Mechanics
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• v.12 no.1
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• pp.85-100
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• 2001

In this paper, an analytical procedure for solving several static and dynamic problems of non-uniform beams is proposed. It is shown that the governing differential equations for several stability, free vibration and static problems of non-uniform beams can be written in the from of a unified self-conjugate differential equation of the second-order. There are two functions in the unified equation, unlike most previous researches dealing with this problem, one of the functions is selected as an arbitrary expression in this paper, while the other one is expressed as a functional relation with the arbitrary function. Using appropriate functional transformation, the self-conjugate equation is reduced to Bessel's equation or to other solvable ordinary differential equations for several cases that are important in engineering practice. Thus, classes of exact solutions of the self-conjugate equation for several static and dynamic problems are derived. Numerical examples demonstrate that the results calculated by the proposed method and solutions are in good agreement with the corresponding experimental data, and the proposed procedure is a simple, efficient and exact method.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.2
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• pp.37-44
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• 2008

A theoretical equation was proposed to consider the effect of ponding for the excess pore water pressure in agricultural reservoir on soft clay ground. The value of excess pore water pressure predicted using the proposed equation was compared to those predicted with the Terzaghi's method and the finite difference method(FDM), respectively, for the purpose of verification. The degree of consolidation according to ponding predicted by applying the proposed equation was close to the observed degree of consolidation on the double drainage condition(at DP-3) but it was less than the observed degree of consolidation on the single drainage condition(at DP-5). The equation was very applicable to practice because the analysis result by the equation was close to the observed data.