• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.418-423
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• 1998

This paper is intended to investigate the behavior of flexural-shear cracking in reinforced concrete beams without web reinforcement with FEM incorporated into a linear elastic fracture mechanics approach(LEFM). Each crack was propagated progressively by a finite length, then the quantitative reponses were examined. The results show that the horizontal crack was initiated by the bond-jnduced shear stress due to horizontal shearing action of the T-C force couple after the formation of the critical flexural crack. Also, the horizontal crack is considered to be a major factor of shear failure in slender reinforced concrete beams without web reinforcement.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.163-172
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• 2010

In order to investigate the changes in mechanical properties of sanitary nonwoven fabrics actually used as a top sheet, the fabric was treated with a mixture of chitosan and nanosilver colloidal solution in accordance with the prescribed ratio. The former is a natural polymer with excellent biocompatibility and the latter can give an additional performance while compensating the weaknesses of chitosan of deteriorating adherence efficiency. It was shown that the bending and shearing characteristics of the chitosan/nanosilver treated fabrics decreased, which helped to make it softer, smoother and more flexible. The shape stability and drapability of the treated fabrics improved. As KES-FB system evaluation showed that Koshi was deduced, and both Numeri and Fukurami were increased. Thereby, the chitosan/nanosilver treated fabrics were smoother to provide elasticity. In the change of hand value compared to chitosan only treatment, a better THV was shown in the fabrics treated with chitosan/nanosilver mixed solution than the fabric treated with chitosan alone.

• Korea-Australia Rheology Journal
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• v.19 no.4
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• pp.227-232
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• 2007

The use of various shearing apparatuses to study the phase behavior of poly(styrene-b-isoprene) diblock copolymer micelles is described. A DMTA rheometer was modified so that one can apply oscillatory shear and obtain the scattering pattern along the shear gradient direction. A cone and plate shear cell was designed to access scattering along the shear vorticity direction, and both oscillatory and steady shear can be applied. The most popular way to employ steady shear on relatively low viscosity fluids is to use a Couette cell, because a high shear rate can be readily achieved without disturbing the sample by overflow. In this work, oscillatory shear was used to obtain a single crystal-like scattering pattern, and thereby to examine the mechanism of the thermotropic transition between face-centered cubic (fcc) and body-centered cubic (bcc) lattices. By applying the steady shear, the response of the fcc lattices to various shear rates is discussed.

• Geomechanics and Engineering
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• v.8 no.1
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• pp.33-52
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• 2015

Based on the Mohr-Coulomb failure criterion, a gradient-dependent plastic model that considers the strain-softening behavior is presented in this study. Both triaxial shear tests on conventional specimen and precut-specimen, which were obtained from an ancient landslide, are performed to plot the post-peak stress-strain entire-process curves. According to the test results of the soil strength, which reduces from peak to residual strength, the Mohr-Coulomb criterion that considers strain-softening under gradient plastic theory is deduced, where strength reduction depends on the hardening parameter and the Laplacian thereof. The validity of the model is evaluated by the simulation of the results of triaxial shear test, and the computed and measured curves are consistent and independent of the adopted mesh. Finally, a progressive failure of the ancient landslide, which was triggered by slide of the toe, is simulated using this model, and the effects of the strain-softening process on the landslide stability are discussed.

• Geomechanics and Engineering
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• v.13 no.2
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• pp.353-370
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• 2017

This paper presents a case study and numerical investigation to study the hydro-mechanical response of a shallow landslide in unsaturated slopes subjected to rainfall infiltration using a coupled model. The coupled model was interpreted in details by expressing the balance equations for soil mixture and the coupled constitutive equations. The coupled model was verified against experimental data from the shearing-infiltration triaxial tests. A real case of shallow landslide occurred on Mt. Umyeonsan, Seoul, Korea was employed to explore the influence of rainfall infiltration on the slope stability during heavy rainfall. Numerical results showed that the coupled model accurately predicted the poromechanical behavior of a rainfall-induced landslide by simultaneously linking seepage and stress-strain problems. It was also found that the coupled model properly described progress failure of a slope in a highly transient condition. Through the comparisons between the coupled and uncoupled models, the coupled model provided more realistic analysis results under rainfall. Consequently, the coupled model was found to be feasible for the stability and seepage analysis of practical engineering problems.

• Journal of Pharmaceutical Investigation
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• v.5 no.3
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• pp.43-49
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• 1975

The rheological properties of seven mixed sugar solutions of glucose, fructose, maltose, sucrose, and two kinds of honey, the chestnut and the acacia, were discussed. The fluidity of the above samples were studied by using the applied pressure horizontal viscometer with which glycerine was confirmed to be a Newtonian flow at $25^{\circ}C$. Time required to pass the constant volume of the sample fluids through the capillary was measured at various pressure differences, ${\Delta}p$, and the ${\Delta}p$ vs ${\Delta}p{\cdot}t$ in the Poiseuille equation was plotted. Shear rate against shearing stress, on the other hand, was plotted for the sample fluids and it was found that all the sample fluids have shown a Newtonian behavior. It was interesting to note that the shear viscosity increased as the concentration of sugar solutions increased, and as the concentration of sucrose became higher than that of maltose, although the total concentration of sugar solution is constant.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.217-220
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• 2005

The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The reinforced concrete pier coping consists of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, reinforced concrete pier coping is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. The results show that strut-tie model can be a rational and an economical design than current conventional design methods.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.260-263
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• 2005

Fatigue fracture behavior of a hybrid joint between side-panel and under-frame by riveting and adhesive bonding has been evaluated. Two kinds of joint specimens based on real geometry were fabricated for shearing test as well as bending test. Static and cyclic loadings were used for fatigue assessment. Fatigue fracture results obtained by such experiments were reflected in modifications of design parameters of the hybrid joint.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.4
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• pp.28-37
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• 1993

Flow characteristics within the three-dimensional square cavity are studied experimentally by adopting PIV(Particle Image Velocimetry). A new method for tracking the same particle pairs in the consecutive flow image is suggested resulting in more effective acquisition of the velocity vectors. Two methods for supplying the shearing stress within the cavity are developed by continuous moving belt and 2-dimensional plane Poiseuille flow. The effect of TGL vortex in the case of belt-moving flow is remarkable owing to the distribution of the kinetic energy in the spanwise direction. But, for the plane Poiseuille flow, velocity profiles similar to a forced vortex are obtained and its tendency increases with the Reynolds number.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1516-1523
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• 1996

The present study is concerned with the development of anisotropy and deformation texture in polycrystals. The individual grain in an aggregate is assumed to experience the viscoplastic dedformation with crystallographic slip that unsure uniquenessof the active slip systems and shearing rate onthese systems. Two different methods for updating the grain orientation are examined. Texture development for some deformation modes such as plane strain compression, uniaxial tension and simple shear are found. Changes in anisotropic flow potential due to texture development during large deformation are also given. Anisotropic behavior of polycrystals with defferent textures are examined.