• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.190-196
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• 1999

In this study, a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool has been established. The edge of a single point tool including circular nose is modified to the equivalent straight edge, then 3-D cutting with a single point tool is reduced to equivalent oblique cutting. Transforming the conventional coordinate systems and using the measured three component of cutting forces, force components on the rake face and the shear plane of the equivalent oblique cutting system can be obtained. And it can be possible to assess the chip-tool friction and shear characteristics in 3-D cutting with a single point tool.

• Advances in nano research
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• v.7 no.5
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• pp.351-364
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• 2019

In this work, dynamic behavior of functionally graded (FG) porous nano-beams is studied based on nonlocal nth-order shear deformation theory which takes into the effect of shear deformation without considering shear correction factors. It has been observed that during the manufacture of "functionally graded materials" (FGMs), micro-voids and porosities can occur inside the material. Thus, in this work, the investigation of the dynamic analysis of FG beams taking into account the influence of these imperfections is established. Material characteristics of the FG beam are supposed to be vary continuously within thickness direction according to a "power-law scheme" which is modified to approximate material characteristics for considering the influence of porosities. A comparative study with the known results in the literature confirms the accuracy and efficiency of the current nonlocal nth-order shear deformation theory.

• Advances in nano research
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• v.14 no.6
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• pp.495-506
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• 2023

We study the bending wave, shear wave and longitudinal wave characteristics in the double nanobeams in this paper for the first time, in the process of research, based on the Reddy's higher-order shear deformation theory and considering shear layer stiffness, linear stiffness, inter-laminar stiffness, the pore volume fraction, temperature variation, functionally graded index influence on wave propagation, based on the nonlocal strain gradient theory and Hamilton variational principle, the wave equation of the double-nanometer beams are derived. Since there are three different motion states for the double nanobeams, which includes the cases of "in phase", "out of phase" and "one nanobeam fixed", the propagation characteristics of shear-, bending-, and longitudinal- waves in these three cases are discussed respectively, and some valuable conclusions are obtained.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.415-422
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• 1999

A series of crosshole tests was conducted to evaluate the mechanical characteristics of railway subgrade materials which has been experiencing mud-pumping. The shear wave velocity profiles of mud-pumped sites were compared with those of adjacent intact sites. The shear wave velocities of mud-pumped layers are less than 150 m/sec.

• Archives of Pharmacal Research
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• v.2 no.2
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• pp.89-97
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• 1979

To find out the rheological characteristics of several pharamaceutical semisolid products, experiments were carriedout over the temperature range of 20 to 30 .deg.C . From continuous shear rheograms obtained with a Ferranti-Shirley cone and plate viscometer, loop area, shear rates, ryild values, limiting viscosities and activation energies were calculated. The systems were metastable and their viscosity decreased with time. As the temperature was raised, products studied showed a decrease in viscosity and yield value.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1133-1138
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• 2000

The interface necessarily exists in joints using cement mortar, UP(Unsaturated Polyester : UP) mortar and SBR(SBR-latex) mortar. Characteristics of shear transfer in joint interface consisting of different materials are studied with experimental and analytical methods. The uniaxial compressive shear experiments are accomplished with various angle of inclination (35, 45, 55, 65, 75°), materials of old and new-cast mortar. In this study, The results are as follows ① Mohr-coulomb's slip theory be applied to the interface consisting different materials ② The cohesion of UP mortar is superior to that f cement mortar, SBR mortar.

• Earthquakes and Structures
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• v.25 no.3
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• pp.161-175
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• 2023

High-damping rubber bearings (HDRB) are commonly used as seismic isolation devices to protect civil engineering structures from earthquakes. However, the nonlinear hysteresis characteristics of the HDRB, such as their dependence on material properties and hardening phenomena, make predicting their behavior during earthquakes difficult. This study proposes a hysteretic model that can accurately predicts the behavior of shear deformation considering the nonlinearity when designing the seismic isolation structures using HDR bearings. To model the hysteretic characteristics of the HDR, dynamic loading tests were performed by applying sinusoidal and random waves on scaled-down specimens. The test results show that the nonlinear characteristics of the HDR strongly correlate with the shear strain experienced in the past. Furthermore, when shear deformation occurred above a certain level, the hardening phenomenon, wherein the stiffness increased rapidly, was confirmed. Based on the experimental results, the dynamic characteristics of the HDR, equivalent stiffness, equivalent damping ratio, and strain energy were quantitatively evaluated and analyzed. In this study, an improved bilinear HDR model that can reproduce the dependence on shear deformation and hardening phenomena was developed. Additionally, by proposing an objective parameter-setting procedure based on the experimental results, the model was devised such that similar parameters could be set by anyone. Further, an actual dynamic analysis could be performed by modeling with minimal parameters. The proposed model corresponded with the experimental results and successfully reproduced the mechanical characteristics evaluated from experimental results within an error margin of 10%.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.314-323
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• 2010

Recently, granular soils having a large particle size are frequently used as a filling material in the construction of foundation, harbor, dam, and so on. The shear behavior of this granular soil plays a key role in the stability of structures. For example, soil particle crushing occurring at the interface between structure and soil and/or within soil mass can cause the disturbance of ground characteristics and consequently induce an issues in respect of stability of structures. In order to investigate the shear behavior according to an existence and nonexistence of particle crushing, numerical analyses were conducted by using the DEM(Discrete Element Method)-based software program PFC(Particle Flow Code). Using the crushing model and non-crushing model which were created in this study, numerical analyses of ring shear test were conducted and their results were analyzed and compared. In general, landslide and slope stability are accompanied by a large displacement and consequently not only a peak strength but also a residual strength are very important in the analysis of landslide and slope stability. However the direct shear test which has been commonly used in the determination of shear strength parameters has a limitation on displacement therefore the residual strength parameters can not be obtained. The characteristics of residual shear behavior were investigated through the numerical analyses in this study.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.7-14
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• 2003

In this study, undrained shear test was performed$K_o$ consolidation in order to study the shear strength characteristics of oysters-marine clay mixtures for three mixed ratios(0%, 25% and 50%). And, in order to study shear strength characteristics of oysters-marine clay mixtures, three different effective vertical stresses(200, 300 and 400kPa) were applied for the $K_o$ consolidation tests. In addition three different axial strain rates(0.005%/min, 0.05%/min, 0.5%/min) were applied for the case of effective vertical stress, 300kPa. According to experimental results, the more mixed ratios were increased, the more deviator stress was increased by crushing effect of oysters particles. especially, when effective vertical stress is 300kPa and mixed ratio increase from 25% to 50%, Test shows the increase of shear strength. But axial strain rate was not effect on the undrained shear strength. In the comparison and analysis that are based on the values of tests on the oysters-marine clay mixtures and the Mayne & Bishop's empiric formula, the undrained shear strength ratio shows a similar pattern of the tests. But for the prediction of the coefficient of the pore water pressure, the value of empiric formula shows more overestimated than the values of the tests at 0%, mixture ratio.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.11-20
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• 2014

This paper aims at comparing and analyzing shear buckling characteristics between sinusoidal corrugation shape and trapezoidal one. For this, I adopted the equal-length trapezoidal corrugation and sinusoidal one for the analytical models, and analyzed their shear buckling characteristics through linear buckling analysis and on its theory. Generally, the shear buckling shapes of corrugated steel plates are classified into local buckling, global buckling, and interactive buckling from the two buckling modes. Sinusoidal corrugation shape, unlike trapezoidal corrugation, does not have flat sides, which causes another tendency in shear buckling mode. Especially, the changes and different aspects of shear buckling on the boundary between local buckling and global buckling appear in different corrugation shapes. According to the analysis results, interactive buckling mode appeared on the boundary of local buckling and global bucking in trapezoidal corrugation. However, in the case of corrugated steel plates with sinusoidal configuration, interactive buckling mode appeared in the part where global bucking takes place. Besides, trapezoidal shapes are of advantages on shear buckling resistance in the local buckling section, and so are sinusoidal shapes in the global buckling section.