• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.160-167
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• 2002

Stretch fabrics are wide-spread for high performance clothing use with requirements of fitness and adaptability to human's movement. A newly developed 100% PET high stretch fabric has excellent properties with respect to stretch, softness, bulkiness, and apparent volume compared to PET filament fabrics. The 100% PET high stretch fabric shows advantages of a dimensional stability, dye and agent adaptability in dying and finishing process, a property of stretch recovery after washing and lower production cost than that of spandex fabric. KES-FB was used to measure mechanical properties to various directions of the fabric. This study centered on whether the 100% PET high stretch fabric is suitable to quality and shape retention of fabric by testing several properties including tensile, compression, shear, bending and surface characteristic to various measuring directions. Tensile linearity showed maximum value at $0^{\circ}$ in plain and $90^{\circ}$ in twill. Shear Stiffness of plain and twill showed maximum value equally at $45^{\circ}\;and\;135^{\circ}$. Bending rigidity showed maximum value at $0^{\circ}$ in plain and $45^{\circ}$ twill. Mean deviation of MIU showed maximum value at $0^{\circ}\;and\;90^{\circ}$ in plain and $135^{\circ}$ in twill.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.391-398
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• 2000

The index properties of cohesive soils play an important role to examine entire tendency of soil properties. Especially, the Atterberg limits have a good correlation with compression and shear strength of cohesive soils. However, these values strongly depend on their testing methods. In this study, for Pusan clays the Atterberg limits were peformed under different conditions; for example, four kinds of specimen preparation, two kinds of testing equipment, and four kinds of estimating method. And a laboratory vane test was peformed to compare the undrained shear strength with that of the fall cone test. As experimental results, the value of liquid limit performed for oven-dried sample, followed in ASTM D4318, underestimated by about 10% compared to those of another three methods, irrespective to the used equipments. But the value of plastic limit was not influenced by sample preparation methods and equipments. The liquid limits by one-point methods(Leroueil et al., 1996; Nagaraj et al., 1981) were agreed well with those of different methods. Finally, the undrained shear strength by laboratory vane test was relatively larger than that of fall cone test, and the relationship between both showed a bad trend.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.4
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• pp.135-142
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• 2020

The new method for evaluating the displacement tolerance of sky-bridges with pin-roller type supports was proposed considering both return period of phase difference between connected buildings and geometrical characteristics of skybridge. Because displacement tolerance is relative value, which is most affected by the phase difference of the connected buildings, the dynamic response of these building with time history analysis should be evaluated. However, the initial phase could not be specified, so the result of displacement tolerance would be varied with respect to initial value. Thus, the tolerance can be reasonably evaluated SRSS calculation with design displacements based on statistical approach and of each building. In addition, the geometrical characteristics of sky-bridge should be considered because the transverse displacement of sky-bridge span causes the shear deformation of the bridge and longitudinal displacement tolerance cannot release the shear deformation. Therefore, the some pin-end support in sky-bridge should have longitudinal displacement tolerance to accommodate the shear deformation. By resolving this shear deformation, it is possible not only to accommodate transverse displacement, but also to avoid the complicated joint details such as both pot bearing and guided supports with shear key.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.73-84
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• 2013

When a slope failure or a debris flow occurs, a shear strength on failure plane becomes nearly zero and soil begins to flow like a non-cohesive liquid. A consistency of cohesive soils changes as a water content increases. Even a cohesive soil existing at liquid limit state has a small amount of shear strength. In this study, a water content, at which a shear strength of cohesive soils is zero and then cohesive soils will start to flow, was proposed. Three types of clays (kaolinite, bentonite and kaolinite (50%)+bentonite (50%)) were mixed with three different solutions (distilled water, sea water and microbial solution) at liquid limit state and then their water contents were increased step by step. Then, their undrained shear strength was measured using a portable vane shear device called Torvane. The ranges of undrained shear strength at liquid and plastic limits are 3.6-9.2 kPa and 24-45 kPa, respectively. On the other hand, the water content that corresponds to the value of the undrained shear strength changing most rapidly is called flow water content. The flow limit refers to the water content when undrained shear strength of cohesive soils is zero. In order to investigate the relationship between liquid limit and flow limit, the cohesive index was defined as a value of the difference between flow limit and liquid limit. The new plasticity index was defined as the value of difference between flow limit and plastic limit. The new liquidity index was also defined using flow limit. The values of flow limit are 1.5-2 times higher than those of liquid limit. At the same time, the values of new plasticity index are 2-5.5 times higher than those of original plasticity index.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.168-170
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• 2007

Sn-Bi eutectic solder alloy have is good wetting and physical properties. The results of solder paste properties test, melting point is about $139^{\circ}C$ and spread test is represent spread properties of $7{\sim}16%$. The results of shear strength after as reflowed, thermal shock test, high temperature storage test of 500hr and 1000hr at $100^{\circ}C$. The shear strength value range is from 6000 to 11000gf, pull strength value range is from 2200 to 3300gf.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.101-110
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• 2000

A practical approach of calculating the ultimate strength of composite beams with unreinforced web opning is proposed through shear behavioral tests. In this method, the slab shear contribution at the opening is calculated as the smaller value of the pullout capacity of shear connector at the high moment end and the one way shear capacity of slab. A simple interaction equation is used to predict the ultimate strength under simultaneous bending moment and shear force. Strength prediction by the proposed method is compared with previous test results and the predictions by other analytical methods. The comparison shows that the proposed method predicts the ultimate capacity with resonable accuracy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.784-787
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• 2003

Electrorheological(ER) and magnetorheological(MR) fluid-based dampers are typically analyzed using Bingham-plastic shear model under quasi-steady fully developed flow conditions. A Herschel-Bulkley constitutive shear flow relationship is that the linear shear stress vs. strain rate behavior of Bingham model is replaced by a shear stress that is assumed to be proportional to a power law of shear rate. This power is called the flow behavior index. Depending on the value of the flow behavior index number, varying degrees of post-yield shear thickening or thinning behavior can be analyzed. But it is not practical to analyze the damping force in a flow mode damper using Herschel-Bulkley model because it is needed to solve a polynomial equation. A useful guide is suggested to analyze the damping force in a damper using the Herschel-Bulkley model.

• Steel and Composite Structures
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• v.18 no.3
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• pp.757-773
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• 2015

This work attempts to implement multiple regression analysis (MRA) for modeling and predicting the shear buckling strength of a steel beam with corrugated web. It was recognized from theoretical and experimental results that the shear buckling strength of a steel beam with corrugated web is complicated and affected by several parameters. A model that predicts the shear strength of a steel beam with corrugated web with reasonable accuracy was sought. To that end, a total of 93 experimental data points were collected from different sources. Then mathematical models for the key response parameter (shear buckling strength of a steel beam with corrugated web) were established via MRA in terms of different input geometric, loading and materials parameters. Results indicate that, with a minimal processing of data, MRA could accurately predict the shear buckling strength of a steel beam with corrugated web within a 95% confidence interval, having an $R^2$ value of 0.93 and passing the F- and t-tests.

• Korea-Australia Rheology Journal
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• v.15 no.2
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• pp.63-73
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• 2003

An experimental technique was developed to determine the strain-rate in a tensile specimen. Then one can calculate the transient isothermal elongational viscosity. Both shear and elongational viscosities were measured to study the effect of shear and elongational fields on the flow properties. The comparison between these viscosities shows that the onset of rapid viscosity growth as crystallization solidification proceeds occurs at about the same value of time at very small deformation rates (0.0028 and 0.0047 $s^{-1}$). The comparison of these measured viscosities as functions of shear and elongational Hencky strains also reveals that the onset of rapid viscosity growths starts at critical Hencky strain values. The behaviour of steady shear viscosity as function of temperature sweep was also explored at three different low shear rates. Finally, the influence of changing oscillatory frequencies and strain rates was also investigated.

• Journal of Technologic Dentistry
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• v.37 no.4
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• pp.243-250
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• 2015

Purpose: The aim of this study was to investigate the shear bond strength between various commercial zirconia coping and veneering ceramic, and to observe the failure mode. Methods: For each zirconia block (iJAM Emerald, LUXEN Smile block, ICE Zirkon transluzent), 10 rectangular specimens were layered with Cercon ceram kiss, IPS e.max ceram, ICE Zirkon ceramic according to recommended by the manufacturer. The shear bond strength tests of the veneering porcelain to zirconia were carried out until fracture by a universal testing machine. After the shear bond tests, failure modes were characterized visually, under a stereomicroscope, such as adhesive, cohesive, or mixed. Data were analyzed with One-way ANOVA followed by Scheffe's tests. Results: The shear bond strength ($mean{\pm}SD$) of zirconia-veneer ceramic were JC group $13.9{\pm}3.6MPa$; JE group $17.7{\pm}2.4MPa$; JI group $15.1{\pm}2.5MPa$; LC group $9.5{\pm}1.5MPa$; LE group $16.2{\pm}2.3MPa$; LI group $12.6{\pm}0.8MPa$; ZC group $16.0{\pm}2.3MPa$; ZE group $18.5{\pm}3.4MPa$; and ZI group $15.3{\pm}3.2MPa$. The One-way ANOVA showed a significant difference between groups (p<0.05). The failure mode in most experimental groups was mixed failure, except for the LC group, which showed adhesive failure, and JE group, LE group and ZE group showed cohesive failure. Conclusion: For IPS e.max ceram, the shear bond strength value was highest for all kinds of zirconia blocks. For ICE Zirkon transluzent, the shear bond strength value was highest for all kinds of veneering ceramics. Most of experimental group interfaces revealed mixed failure mode.