• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.178-185
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• 2005

Crack tip displacement is originated by tensile stress component, s and shear stress component, t on pure Mode I and pure Mode II. The crack tip displacement(CTD) depends on combined types of different two stress components under mixed-mode loading conditions (MMLC). Thus, the analysis of crack tip displacement must be CTD vector, dv which is composition of ds and dt under MMLC. In this paper, various effects of MMLC on the crack closure are studied experimentally. The crack closure magnitude is calculated from the information of crack tip displacement under MMLC. This information has been obtained from the high resolution optical microscope in direct observations of crack displacement behavior at the crack tip. Observed crack tip displacement is analyzed by using CTD vector to determine crack opening load. The various effects of MMLC on the crack closure are explained using crack opening ratio with crack length and mode mixture. The effective stress intensity factor considering crack closure is also discussed.

• Smart Structures and Systems
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• v.16 no.3
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• pp.521-535
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• 2015

Vibration-based monitoring is one approach used to perform structural condition assessment. By measuring structural response, such as displacement, dynamic characteristics of a structure may be estimated. Often, the primary dynamic responses in civil structures are below 5 Hz, making accurate low frequency measurement critical for successful dynamic characterization. In addition, static deflection measurements are useful for structural capacity and load rating assessments. This paper presents a DC coupled continuous wave radar to accurately detect both dynamic and static displacement. This low-cost radar sensor provides displacement measurements within a compact, wireless unit appropriate for a range of structural monitoring applications. The hardware components and operating mechanism of the radar are introduced and a series of laboratory experiments are presented to assess the performance characteristics of the radar. The laboratory and field experiments investigate the effect of factors such as target distance, motion amplitude, and motion frequency on the radar's measurement accuracy. The results demonstrate that the radar is capable of both static and dynamic displacement measurements with sub-millimeter accuracy, making it a promising technology for structural health monitoring.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.55-65
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• 1976

The influences of the mandibular displacement and valium administration on the muscular activity were observed by spectrophotometric analysis of glycogen, glucose, G-6-P, lactate, pyruvate, ATP, phosphocreatine ana protein. Experimental animals were divided into three groups; the first was the mandibular displacement group, the second was valium administered group and the third was the mandibular displacement and valium admministered group. In mandibular displacement group, the high inclined plane with a gap of 2.5mm to 3.0mm between the upper and lower incisors was created by setting the silver crowns on the lower incisors. By creating such a high inclined plane, the bite was opened and the mandible was dispalced posteriorly. In valium administered group, 5mg/kg body weight of valium was administered intraperitoneally every day until the animal was sacrificed. Results were as follows: I) The body weight of all experimental rats was decreased in the beginning of experimental periods. The body weight of the mandibular displacement group showed the similar increasing rate as the control group from 15 days of experimental period. 2) The superficial masseter muscles of the mandibular displacement group appeared to be decreased it's functional activity at 36hrs, 60hrs and 96hrs of experimental periods as revealed by the decrease of various metabolites studied in this experiment. From 96hrs of experimental periods, the contents of those metabolites tended to increase up to the control level. 3) The superficial masseter muscle of 2nd group showed the decreased value of all metabolites at until 60hrs and the values were recovered to almost the same as the control at 168hrs. 4) Glycogen and G-6-P contents induced by mandibular displacement plus valium administration, showed longer duration of the decreased value than 1st group. And the decrease of glucose and pyruvate contents induced by mandibular displacement at 36hrs and 60hrs of experimental periods was enhanced by valium administration. However, the contents of lactate in 3rd group were decreased continuously until the end of experiment.

• Geomechanics and Engineering
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• v.10 no.3
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• pp.357-386
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• 2016

In this research work, an exact analytical solution for thermal stability of solar functionally graded rectangular plates subjected to uniform, linear and non-linear temperature rises across the thickness direction is developed. It is assumed that the plate rests on two-parameter elastic foundation and its material properties vary through the thickness of the plate as a power function. The neutral surface position for such plate is determined, and the efficient hyperbolic plate theory based on exact neutral surface position is employed to derive the governing stability equations. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the quadratic distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Just four unknown displacement functions are used in the present theory against five unknown displacement functions used in the corresponding ones. The non-linear strain-displacement relations are also taken into consideration. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the present theory, demonstrating its importance and accuracy in comparison to other theories.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.649-665
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• 2015

The present paper attempts to investigate the propagation of plane waves in generalized piezo-thermoelastic medium under the effect of rotation. The normal mode analysis is used to obtain the expressions for the displacement components, the temperature, the stress and the strain components. Comparisons are made with the results predicted by different theories (Coupled theory, Lord-Schulman, Green-Lindsay) in the absence and presence of rotation.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.81-94
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• 2010

The steady state response of a rotating generalized thermoelastic solid to a moving point load has been investigated. The transformed components of displacement, force stress and temperature distribution are obtained by using Fourier transformation. These components are then inverted and the results are obtained in the physical domain by applying a numerical inversion method. The numerical results are presented graphically for a particular model. A particular result is also deduced from the present investigation.

• Steel and Composite Structures
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• v.32 no.6
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• pp.779-793
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• 2019

The purpose of this research paper is to depict the thermomechanical interactions in transversely isotropic magneto thermoelastic solid with two temperatures and without energy dissipation in generalized LS theories of thermoelasticity. The Laplace and Fourier transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain numerically. The effect of two temperature and relaxation time are depicted graphically on the resulting quantities.

• Geomechanics and Engineering
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• v.19 no.1
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• pp.29-36
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• 2019

The present research deals with the deformation in transversely isotropic thin circular thermoelastic rotating plate due to time-harmonic sources. Frequency effect in the presence of rotation and two temperature is studied under thermally insulated as well as isothermal boundaries. The Hankel transform technique is used to find a solution to the problem. The displacement components, stress components, and conductive temperature distribution with the radial distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. Some specific cases are also figured out from the current research.

• Coupled systems mechanics
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• v.8 no.1
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• pp.55-70
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• 2019

This investigation is focused on the variations in transversely isotropic thick circular plate due to time harmonic thermomechanical sources. The homogeneous thick circular plate in presence and absence of energy dissipation and two temperatures has been considered. Hankel transform is used for solving field equations. The analytical expressions of conductive temperature, displacement components, and stress components are computed in the transformed domain. The effects of frequency at different values are represented graphically. Some specific cases are also figured out from the current research.

• Coupled systems mechanics
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• v.8 no.3
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• pp.219-245
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• 2019

The present research deals in two dimensional (2D) transversely isotropic magneto generalized thermoelastic solid without energy dissipation and with two temperatures due to time harmonic sources in Lord-Shulman (LS) theory of thermoelasticity. The Fourier transform has been used to find the solution of the problem. The displacement components, stress components and conductive temperature distribution with the horizontal distance are calculated in transformed domain and further calculated in the physical domain numerically. The effect of two temperature are depicted graphically on the resulting quantities.