• Geomechanics and Engineering
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• v.23 no.6
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• pp.523-533
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• 2020

The current study focuses on the effect of the end shape of steel pipe piles on installation effort and bearing resistance using the pressing method of installation under dense ground conditions. The effect of pile rotation on the installation effort and bearing resistance is also investigated. The model steel piles with a flat end, cone end and cutting-edge end were used in this study. The test results indicated that cone end pile with the pressing method of installation required the least installation effort (load) and showed higher ultimate resistance than flat and cutting-edge end piles. However, pressing and rotation during cutting-edge end pile installation considerably reduces the installation effort (load and torque) if pile penetration in one rotation equal to the cutting-edge depth. Inclusion of rotation during pile installation reduces the ultimate bearing resistance. However, if penetration of the cutting-edge end pile equal to the cutting-edge depth in one rotation, the reduction in ultimate resistance can be minimized. In comparing the cone and cutting-edge end piles installed with pressing and rotation, the least installation effort is observed in the cutting-edge end pile installed with penetration rate equal to the cutting-edge depth per rotation.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.11a
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• pp.23-27
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• 1994

고분자 전해질형 연료전지의 성능을 향상시키기 위하여 막-전극 어셈블리 제조시 hot-pressing 온도와 압력조건을 변화시켜며 단위전지 성능을 관찰하였으며 이에 대한 분석은 열무게분석법(TGA), 기공도, 이온투과계수 등을 사용하였다. 또한 전지의 작동온도 및 압력을 변화시켜가며 전지의 성능을 관찰하였다. 성능 실험은 가습기의 온도와 cell의 온도, 압력을 변화시켜가며 측정하였다.

• Journal of the Korea Furniture Society
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• v.24 no.1
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• pp.79-87
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• 2013

The objective of this study was to increase the utilizability of domestic thinning and small diameter wood as applying in pattern design which can be applied in interior decoration, wood craft and wood furniture, and in developing the designs of furniture and household items. Then we investigated the physical and mechanical characteristics of Acer mono wood by pressurization and heat treatment. Color change is clear, and the wood density is increased with increasing pressing rate. The compressive and bending strengths are decreased as heating time is increased after pressing. However, shrinkage is improved after pressing and heating.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.816-824
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• 1996

The densification behaviors of copper powder under high temperature processing were investigated. Experimental data were obtained for copper powder under hot isostatic pressing, hot pressing and uniaxial compression. Finite element calculations from the constitutive models by McMeeking and co-workers were compared with the experimental data, The agreements between experimental data and theoretical calculations are reasonably good when hydrostatic stress is dominant, but not as good then deviatoric stress increases.

• Composites Research
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• v.14 no.1
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• pp.15-21
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• 2001

The pressing roller was designed and manufactured with high modulus carbon fiber composite material to exploit the high specific stiffness of the composite material. the optimal stacking sequence for the pressing roller was obtained from the FE analysis and the shape of the rubber coating layer was determined based on the calculated deflection for the uniform pressure on the film along the axial length of the pressing roller. Then the static deflection of the manufactured composite pressing roller was experimentally evaluated in comparison with analysis result and dynamic characteristics were measured through vibrational test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.394-402
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• 2000

Densification behavior of titanium alloy powder was investigated under hot isostatic pressing at various pressures and temperatures. Uniaxial creep responses of a dense specimen were also obtained at high temperatures. The densification model of Abouaf and co-workers was implemented into a Finite element program (ABAQUS) to compare with experimental data for titanium alloy powder. The agreements between finite element calculations and experimental data for deformation and densification of titanium alloy powder were good during hot isostatic pressing.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.219-225
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• 2000

Equal channel angular pressing (ECAP) is a convenient forming process to extrude material without substantial changes in the sample geometry and this deformation process gives rise to produce ultrafine grained materials. The properties of the materials are strongly dependent on the plastic deformation behaviour during ECAP. The major process variables during ECAP are 1) die geometries, such as a channel angle and coner angles, and 2) the processes variables, such as lubrication and deformation speed. In this study, the plastic deformation behaviour of materials during the ECAP has been theoretically analysed by the finite element method (FEM). The effect of the die friction on the plastic deformation behaviour during the pressing is discussed by means of FEM calculations.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.740-743
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• 1992

Effects of powder sintering and 2nd, pressing on the superconducting characteristics in the (Bi,Pb)SrCaCuO system have been studied. The sample prepared by the powder sintering process had a porous microstructure with a $T_c$ below 77 K, while the sample prepared by 2nd. pressing process had highly oriented microstructure with a $T_c$ above 100 K. The critical current density($J_c$) was relatively improved in the sample prepared by the 2nd. pressing process. But the value of $J_c$ is cosiderably low in practical use.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.103-108
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• 2005

In this study, to develop a flash-less mold for forming of shoe-outsole, experiments and forming analysis were carried out. In order to reduce the extra-materials, offset method and mass distribution method are used in the preform design. The vertical mold structure pressing the preform was introduced to produce a flash-less shoe-sole. To measure the contact status of parting surface of mold, the pressure film has been used. The guide-gutter system and the continuous pressing mold have been developed for the discharge of extra-materials and re-pressing. By the investigation, flash of shoe-outsole was considerably reduced.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.176-179
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• 2001

A simple cold pressing procedure which allows shear deformations on sheet metals is proposed by designing dies with grooves and applied to aluminum 3003 sheets. shear deformation led to the formation of preferred orientation along <100>//RD, and the effect of initial tortures on the formation of shear textures was also studied Rectangular shaped dislocation cells formed in the deformed microstructure and boundaries of dislocation cells gradually rounded with the increased plastic strain. Upon subsequent annealing textures inherited deformation textures. Recrystallized grains consisted of a large number of fully recovered subgrains with well defined boundaries which persisted even after annealing at a higher temperature.