• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.517-520
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• 2005

The embedded suction anchor(ESA) is and anchor that is driven by a suction pile. The cross-sectional shape of the ESA anchor is circle. Its diameter is the same as that of the suction pile that is used to drive it into the seafloor. For the installation, the anchor is attached to the tip of the suction pile and then driven as a unit with the pile by and applied suction pressure. Once the ESA anchor reaches the desired depth, the pile is retrieved by applying a positive pressure. Finally, only the ESA anchor remains in the soil layer. This paper presents the results of centrifuge model tests to investigate ESA pullout capacity. The main parameters that have effects on the pullout capacity of ESA may include g-level, embedded depth, direction of loading, and loading point. The results of tests show that the pullout loading capacities increase as the loading point shift toward the tip of the anchors for a given loading direction. They also indicate that the loading point associated with the maximum pullout loading capacity is located at approximately 67 percent of the anchor length from the top for the horizontal load.

• Journal of Welding and Joining
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• v.8 no.4
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• pp.69-75
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• 1990

In this paper, ultimate compressive strength of TMCP 50HT steel plates (yield stress .sigma.$_{o}$=36kg/mm$^{2}$) with HAZ softening is studied. Finite element method formulated by the author is applied to analyze the elasto-plastic large deflection behaviour of the plates. The influence of HAZ softening breadth, welding direction and slenderness ratio on the ultimate compressive strength is investigated. The results obtained are summarized as 1) With the increasing of the HAZ softening breadth, early plasticity on the plates is formed and then the ultimate compressive strength is decreased, in which about 8% of the ultimate strength for the plate with h/t=4(h: HAZ softening breadth, t: plate thickness) was reduced comparing with no HAZ softening. 2) The large decrease of the ultimate strength for the case that the welding direction is normal to the loading direction is occurred than the case that the welding direction is parallel to the loading direction. 3) The influence of HAZ softening on the ultimate compressive strength is serious for thick plates, while it may be negligible for thin plates.s.

• Geomechanics and Engineering
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• v.34 no.5
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• pp.481-489
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• 2023

Drained cyclic triaxial tests were conducted on a saturated sand to examine its deformation characteristics under either axial or lateral cyclic loading condition. To apply lateral cyclic loading, the cell pressure was cycled while maintaining a constant vertical stress. The strain accumulations and flow direction in the soil were presented and discussed considering various initial stress ratios (η₀), cyclic stress amplitudes and cyclic stress paths. The results indicate that axial strain accumulation shows an exponential increase with the maximum stress ratio (η^max). The initial deviatoric stress has comparable effects with lateral cyclic stress amplitude on the accumulated axial strain. In contrast, the accumulated volumetric strain is directly proportional to the lateral cyclic stress amplitude but not much affected by η₀ values. Due to the anisotropy of the soil, the accumulated axial and lateral bulging strains are greater in lateral cyclic loading when compared to axial cyclic loading even though η^max is the same. It is also found that η^max affects soil's lateral deformation and increasing the ratio could change the lateral deformation from contraction to bulging. The flow direction depends on η^max in the sand under lateral cyclic loading, regardless of η₀ values and the cyclic stress amplitudes, and a large η^max could lead to great deviatoric strain but a little volumetric strain accumulation.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.582-591
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• 2004

The purpose of this study was to determine the effects of elbow joint angle on mechanical properties, as represented by ultimate load, failure strain and elastic modulus, of bone-tendon specimens of common extensor tendon of the humeral epicondyle. Eight pairs of specimens were equally divided into two groups of 8 each, which selected arbitrarily from left or right side of each pair, positioned at 45$^{\circ}$ and 90$^{\circ}$ of elbow flexion and subjected to tension to failure in the physiological direction of the common extensor tendon. For comparison of the differences in the failure and elastic modulus between tendon and the bone-junction, data for both were evaluated individually. Significant reduction in ultimate load of bone-tendon specimens was shown to occur at 45$^{\circ}$. The values obtained from the bone-tendon junctions with regard to the failure strain were significant higher than those from tendon in both loading directions, but the largest failure strain at the bone-tendon junction was found at 45$^{\circ}$. The elastic modulus was found to decrease significantly at the bone-tendon junction when the loading direction switched from 90$^{\circ}$ to 45$^{\circ}$. Histological observation, after mechanical tensile tests, in both loading directions showed that failure occurred at the interface between tendon and uncalcified fibrocartilage in the thinnest fibrocartilage zone of the bone-tendon junction. We concluded that differences in measured mechanical properties are a consequence of varying the loading direction of the tendon across the bone-tendon specimen.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.806-809
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• 1996

The present development relates to an apparatus for loading or unloading a workpiece, and more particularly, to an apparatus for loading or unloading a workpiece from a press die or supplier An apparatus for loading or unloading a workpiece has been installed in a press in order to load or unload a workpiece from a press die. There has been known such a loading or unloading apparatus as the apparatus can feed a workpiece in not only the horizontal direction but also in the vortical direction. Press working system in automotive factories are now switching over to a transfer press work ing system. The current problem to be sieved immediately is to automate the existing manual press lines for the manpower saving and speedy production. “Automation system for press line”has just been developed to meet the above trend. The loader and unloader are development under the design concept for high performance, easy control and operational safety to meet the more extensive.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.725-728
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• 2004

In this study, the effect of mode II by variation of multilevel loading direction was experimentally investigated in the fatigue crack propagation behavior. To generate mixed-mode I+II loading state, the compact tension shear(CTS) specimen and loading device were used in this tests. The experimental method divided into three steps and three cases that were step I(0$^{\circ}$), step II(30$^{\circ}$, 60$^{\circ}$, 90$^{\circ}$),step III(0$^{\circ}$) and case I(0$^{\circ}$ ⇒ 30$^{\circ}$ ⇒ 0$^{\circ}$), case II(0$^{\circ}$ ⇒ 60$^{\circ}$ ⇒ 0$^{\circ}$), case III(0$^{\circ}$ ⇒ 90$^{\circ}$ ⇒ 0$^{\circ}$). The result of test, the step II affected to the step III in the all case. Specially, The fatigue crack propagation rate was faster and the fatigue life was smaller than of mixed mode I+II(30$^{\circ}$,60$^{\circ}$) due to the effect of mode II in the step III of the case III

• Structural Engineering and Mechanics
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• v.34 no.3
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• pp.377-390
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• 2010

This paper studies fracture initiation direction of two parallel non-coplanar cracks of equal length. Using the dislocation pile-up modelling, singular integral equations for two parallel cracks subjected to mixed-mode loading are derived and the crack-tip field including singular and non-singular terms is obtained. The kinking angle is determined by using the maximum hoop stress criterion, or the ${\sigma}_{\theta}$-criterion. Results are presented for simple uniaxial tension and biaxial loading. The biaxiality ratio has a noticeable influence on crack growth direction. For the case of biaxial tension, when neglecting the T-stress the crack branching angle is overestimated for small crack inclination angles relative to the largest applied principal stress direction, and underestimated for large crack inclination angles.

• Journal of the Korean Ceramic Society
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• v.29 no.10
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• pp.806-814
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• 1992

The aim of this study was to investigate the change in compressive strength, freacture behavior and degradation of piezoelectric properties with compressive cyclic loading in Pb(Zr, Ti)O3 of tetragonal, morphotropic phase boundary and rhombohedral composition. The highest compressive strength was found in rhombohedral composition. After poling treatment the strength increased by 8.4% and 6.5% in tetragonal and morphotropic phase boundary compositions respectively while changed little in rhombohedral. The increase of compressive strength after poling treatment is believed to be due to the internal stress around grain boundary by domain alginment toward electric field direction in the microstructures having tetragonality and the occurrence of domain switching to the direction perpendicular to electrical field during fracture. Fracture mode relatively change from transgranular to intergranular was observed in the large grain sized tetragonal and morphotropic phase boundary compositions before and after poling but the transgranular fracture mode always remained in the rhombohedral composition. From the X-ray diffractometer analysis the domains parallel to the electric field direction is known to undergo rearrangement during the cyclic loading into random direction that is responsible for the degradation of piezoelectric property.

• International Journal of Air-Conditioning and Refrigeration
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• v.12 no.1
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• pp.50-60
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• 2004

An experimental analysis using three-dimensional Laser Doppler Velocimetry(LDV) measurement and computational analysis using the Reynolds stress model in FLUENT are conducted to give a clear understanding of the effect of blade loading on the structure of tip leakage flow in a forward-swept axial-flow fan operating at the maximum efficiency condition ($\Phi$=0.25) and two off-design conditions ($\Phi$=0.21 and 0.30). As the blade loading increases, the onset position of the rolling-up of tip leakage flow moves upstream and the trajectory of tip leakage vortex center is more inclined toward the circumferential direction. Because the casing boundary layer becomes thicker and the mixing between the through-flow and the leakage jet with the different flow direction is enforced, the streamwise vorticity decays more fast with the blade loading increasing. A distinct tip leakage vortex is observed downstream of the blade trailing edge at $\Phi$=0.30, but it is not observed at $\Phi$=0.21 and 0.25.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.4
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• pp.294-304
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• 2003

An experimental analysis using three-dimensional laser Doppler velocimetry(LDV) measurement and computational analysis using the Reynolds stress model in FLUENT are conducted to give a clear understanding of the effect of blade loading on the structure of tip leakage flow in a forward-swept axial-flow fan operating at the maximum efficiency condition ($\Phi$=0.25) and two off-design conditions ($\Phi$=0.21 and 0.30). As the blade loading increases, the onset position of the rolling-up of tip leakage flow moves upstream and the trajectory of tip leakage vortex center is more inclined toward the circumferential direction. Because the casing boundary layer becomes thicker and the mixing between the through-flow and the leakage jet with the different flow direction is enforced, the streamwise vorticity decays more fast with the blade loading increasing. A distinct tip leakage vortex is observed downstream of the blade trailing edge at $\Phi$=0.30, but it is not observed at $\Phi$=0.21 and 0.25.