• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.378-385
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• 2000

Fracture resistance (J-R) curves, which are used for elastic-plastic fracture mechanics analyses, decreased under tension-compression loading condition. This phenomenon was proved by several former researches, but the causes have not been clear yet. The objective of this paper is to investigate the cause of this phenomenon. On the basis of fracture resistance curve test results, strain hardening hypothesis, stress redistribution hypothesis and crack opening hypothesis were built. In this study, hardness tests, Automated Ball Indentation(ABI) tests, theoretical stress field analyses, and crack opening analyses were performed to prove the hypotheses. From this study, strain-hardening of material, generation of tensile residual stress at crack tip, and crack opening effects are proved as the causes of the decrease hypothesis.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.37-42
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• 2004

This paper presents a simple method to estimate fully plastic crack tip stresses of unequally notched specimen based on the equilibrium condition of the least upper bounds for plane strain deformation fields. The method is applied to unequally notched specimens under bending and tension. For various notch angle the limit loads and crack tip stresses are estimated from the present method and compared with results from finite element limit analyses.

• Journal of Chest Surgery
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• v.6 no.2
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• pp.165-170
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• 1973

The selection and treatment with resection and drainage for patients with emphysematous bullae is discussed with reference to two patients recently. One case with bilateral multiple bullous emphysema resulting tension pneumothorax due to rupture of the bullae on right, 47 year old man with pulmonary tuberculosis history for 16 years, was treated with resection of the bullae on right including upper lobectomy and c!osed rhoracostomy drainage on left for another spontaneous pneumothorax, and result was excellent for 6 month after discharge. Another 53 year old man with giant tension air cysts occupying right whole lung field and shifting mediastinum to the left was treated with right under water sealed closed thoracostomy drainage for 7 days in vain, and resection was not performed for his poor respiratory function and general condition. The most useful preoperarive information was obtained from a study of the plain chest radiogram and the surgical procedure of choice was obliteration of the bullae at thoracotomy.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.423-426
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• 2001

In this paper a large scale direct tension test of plain concrete is represented. Two independently controlled actuators were used to ensure a homogeneous tensile field and to avoid secondary flexural stresses. Fracture energies evaluated by a classical prediction equation and this test are compared. The result indicated that the classical prediction equation is not adequate to predict the fracture energy of large sized specimens. From this test, it was determined that the fracture energy obtained from large scale direct tension tests is significantly higher than the one obtained in wedge splitting tests on laboratory sized specimens. But the tensile strength was about half the value determined from splitting tensile strength test with cylindrical specimens.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.91-96
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• 2011

The flat slab is well-known as a structural system to reduce the story height, so it is broadly used for recent building. However, the normal RC flat slab is not appropriate for the long span, and the quantity of reinforcement bar and concrete is raised. Recently, the post-tensioning system has been introduced and used widely as an alternative method. Nevertheless, in Korea, it is not used broadly due to lack of the understanding and field experience. Especially, the post-tensioning system is hesitated to use due to uncertainty of construction ability and economics. This paper will introduce applicability to site and economics of unbonded post-tensioning system through construction examples.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.786-793
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• 2006

For the purpose of developing a vibration-based tension force evaluation procedure for hangers in suspension bridges, a 3D finite element model of hangers is constructed in this paper. With the developed finite element formulation, a frequency-based sensitivity-updating algorithm is applied to identify the target cable system the proposed method is also able to identify the flexural rigidity. the axial rigidity, and the torsion rigidity of a cable. For a field application, a vibration test on hangers of the Yong Jong Grand Suspension Bridge is carried out and the collected data is used to verify the proposed method.

• Journal of Yeungnam Medical Science
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• v.29 no.1
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• pp.31-34
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• 2012

Tension pneumothorax during one-lung ventilation (OLV) is a rare but life-threatening complication. A 79-year-old male patient who was diagnosed with lung cancer underwent $Univent^{(R)}$ Tube (Fuji Systems Corporation, Tokyo) intubation for left upper lobectomy. Two hours after the initiation of OLV, the patient could not tolerate it. Thus, one-and two-lung ventilation were alternatively applied to continue the operation. After the operation, an emergent chest radiograph was taken, and pneumothorax was found at the right (dependent) lung field.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1345-1347
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• 1994

High frequency Magnetic Properties of amorphous $Fe_{78}B_{13}Si_9$ ribbon were studied. Squareness ( Br/Bs ) and coercive force ( Hc ) of the specimen field annealed at $380^{\circ}C$ for 2 hrs are changed with the tension and the measuring frequency. So, we could optimise the tension having good magnetic properties at a certain frequency.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.149-160
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• 2001

In this paper, the stability analyses were performed for masonry retaining wallls in Seoul subway System. This masonry retaining wallls were reinforced with earth anchor system for the construction, but it was removed after construction. Therefore, the stability of masonry retaining wallls should be checked after the earth anchors removed. For stability analysis of masonry retaining wallls. FDM analysis(FLAC Ver.3.3) and slope stability analysis (SLOPE/W) were performed applying the test results from laboratory and field tests(Schmidt hammer test, cack examination). As conclusion, the tension force of earth anchors should be kept, therefore, substitutional method was required in order to keep the tension force of earth anchor system.