• 전산구조공학
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• 제7권1호
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• pp.125-134
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• 1994

Response variability of reinforced concrete frame subjected to material property randomness has been evaluated with the aid of the finite element method. The spatial variation of Young's modulus is assumed to be a two-dimensional homogeneous stochastic process. Young's Modulus of concrete material has been investigated based on the uiaxial strength of concrete cylinder. Direct Monte Carlo simulation method is used to investigate the response of reinforced concrete frame due to the variation of Young's modulus with the Neumann expansion method and the pertubation method. The results by three analytic methods are compared with those by deterministic finite element analysis. These stochastic technique may be an efficient tool for evaluating the structural safety and reliability of reinforced concrete structures.

• 한국공간구조학회논문집
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• 제17권4호
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• pp.159-165
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• 2017

In this paper, uniaxial tensile tests of ETFE films with three kinds of thicknesses(100, 200, $250{\mu}m$) and two kinds of directions(machine direction & transverse direction) are performed and the tensile strength, the tensile strain at break and the Young's modulus of ETFE films are compared for two kinds of specimen types(2 & 5). It could be figured out that there are no significant difference between tensile strengths of two specimen types but the tensile strain at break and the Young's modulus of ETFE films are affected by the specimen types. And it is concluded that the uniaxial tensile test of specimen type 2 are more reliable than that of specimen type 5.

• 한국전기전자재료학회논문지
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• 제16권6호
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• pp.454-459
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• 2003

We investigate the structure and properties of SiC (Silicon Carbide) nanotubes using molecular dynamics simulation based on the Tersoff bond-order potential. For small diameter tubes, the Si-C bond distance of SiC nanotubes decreases as the nanotube diameter is decreased, due to curvature of the nanotube surface. We find that Young's modulus of SiC nanotubes is somewhat smaller than that of the other nanotubes considered so far. However, Young's modulus for SiC nanotubes is larger than that of ${\beta}$-SiC and almost equal to the experimental value for SiC nanorod and SiC whisker. The strain energy of the SiC nanotubes is also lower than that of the other nanotubes. The lower strain energy of SiC nanotubes raises the possibility of synthesis of SiC nanotubes.

• 한국생산제조학회지
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• 제7권5호
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• pp.72-84
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• 1998

In order ot study the influence of a circular inclusion on a stress field near a crack tip, mutual interference of a slant crack and the circular inclusion is analyzed of a bimaterial inclusion. As the crack emanates at the equivalent slant crack angle the correction factors FⅠ and FⅡ for the inclusion wit small Young's modulus were found to decrease as the inclusion radius increased. The correction factors for inclusion with large Young's modulus increase as the inclusion radius increases at the equivalent radius of the inclusion, the correction factors decrease as the slant crack angle increases for the aspect ratio $\frac{c}{W}$ = 0.1 irrespective of the Young's modulus. For $\frac{c}{W}$ greater than 0.2, they increase as the slant crack angle increases. There is no influence of stress mutual interfce after crack emanates beyond the inclusion radius.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.150-152
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• 2007

It has been known that the underfilling technique is effective in reducing thermal and environmental stress concentration at solder joint in FC asscemblies. In this paper, the effect of thermomechanical properties of underfill such as coefficient of thermal expansion(CTE) and Young's modulus on reliability of FC assembly under thermal cycling was investigated. For parametric study for optimal design of underfill, finite element analyses(FEA) were performed for seven different CTEs and five different Young's modulus. The results show that the concentrated maximum stress decreases as Young's modulus of underfill increases and the CTE of underfill decreases.

• 한국소음진동공학회논문집
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• 제11권9호
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• pp.391-397
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• 2001

The characteristic values of damping materials are variant on frequency and temperature. We measure the characteristic values(loss factor, young\\\\`s modulus) of damping materials in vibration test. We can not measure characteristic values of damping materials by themselves. So, we proposed a method, sticking damping material to thin steel beam and measuring of characteristic values of damping material on frequency and temperature. We didn\\\\`t use constraining layer but we measured characteristic values on conditioning temperature.

• Macromolecular Research
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• 제11권4호
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• pp.256-259
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• 2003

Measurements of Young's modulus, dielectric loss and a.c. conductivity have been carried out on EPDM rubber samples loaded with different concentrations of $CrCl_3$ (0,2,4 and 6 phr). The values of Young's modulus was found to be linearly dependent on the $CrCl_3$ content. Variation of the dielectric loss with temperature showed that $CrCl_3$ may act as plasticizer. However, at higher frequencies the dielectric loss was found to be independent of frequency and the rubber samples may behave as non-polar dielectric. Investigations of the a.c conductivity suggested that the conduction in these rubber samples can be described by small polaron tunneling. In addition, conductivity was found to increase with $CrCl_3$ content.

• 한국소음진동공학회논문집
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• 제14권9호
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• pp.852-860
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• 2004

There are many standard methods for measuring vibration damping properties of the beam type material. Among them, three standards ASTM E 756, ISO 6721 and JIS G 0602, are compared. Loss factor and Young's modulus of the steel beam are evaluated by using five different methods and their results are compared. Logarithmic decay method and half-power bandwidth method are used to calculate the loss factor. It was observed that Young’s modulus is agree well, but loss factors are different from test to test. So the same test method must be applied to measure damping properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2524-2526
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• 1998

In this paper, the residual stress and young's modulus of the p+ thin film have been estimated by using the electrostatic resonators. The electrostatic plate resonator with four corrugated bridges and another with four flat ones have been fabricated. The deflection of the plate has been calculated under the induced tension and the residual stress and compared with the dynamic test results. When the young's modulus of the p+ silicon is 125 GPa. The estimated residual stresses of the flat and the corrugated bridges are about 15 MPa and less than 5 MPa, respectively. It has been confirmed that the corrugated structure releases the residual tensile stress resulted from the heavy boron diffusion process.

• Advances in Computational Design
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• 제8권1호
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• pp.77-96
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• 2023

Calculating size-dependent mechanical properties of the nano-scale materials usually involves cumbersome numerical and theoretical works. In this paper, we aim to present a closed-form relation to calculate the length-dependent Young's modulus of carbon nanotubes (CNTs) based on nonlocal elasticity theory. In this regard, a single wall carbon nanotube (SWCNT) is considered as a rod structure and the governing nonlocal equations are developed under uniaxial tensile load. The equations are solved using analytical methods and strain distribution, total displacement and the size-dependent equivalent Young's modulus are obtained. Further, the results are compared with the molecular dynamics results from the literature. The outcome indicates that the calculated relations are coincident with the molecular dynamics results.