• KCI Concrete Journal
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• v.12 no.1
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• pp.23-34
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• 2000

Experiments were carried out to investigate the seismic behaviors, such as lateral strength, ductility and energy-dissipation capacity. of high-strength concrete (HSC) square short column confined in thin steel shell. The primary objective of the study was to investigate the suitability of using HSC square columns confined in thin steel shell in region of moderate-to-high seismic risk. A total of six columns, consisting of two ordinarily reinforced concrete square short columns and four reinforced concrete square short columns confined in thin steel shell was tested. Column specimens, short columns in a moment resisting frame with girder. were tested under a constant axial and reversed cyclic lateral loads. To design the specimens. transverse reinforcing methods, level of axial load applied, and the steel tube width-thickness ratio (D/t) were chosen as main parameters. Test results were also discussed and compared in the light of improvements in general behaviors, ductility, and energy-absorption capacities. Compared to conventionally reinforced concrete columns, the HSC columns confined in thin steel shell had similar load-displacement hysteretic behavior but exhibited greater energy-dissipation characteristics . It is concluded that, in strong earthquake areas, the transverse reinforcing method by using a thin steel shell (D/t=125) is quite effective to make HSC short columns with very strong and ductile.

• Journal of Welding and Joining
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• v.7 no.1
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• pp.42-50
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• 1989

The application of fracture mechanics is being increased gradually to assess the safety of welded structures containing crack. Fatigue crack propagation behavior and elastic-plastic fracture toughness J$_{IC}$ of home made flux cored wire(1.22mm) CO$_{2}$ weldments was discussed. Especially fatigue crack propagation test was carried out by .DELTA.K control instead of load control and elastic-plastic fracture toughness J$_{IC}$ was obtained by ASTM-R curve method on C.T.specimen in transverse direction of weldments. The results obtained are as follows; (1) Weld metal presented an almost complete similarity to base metal on fatigue crack propagation rate in transverse direction. (2) Weld metal was more than base metal on J$_{IC}$ value in transverse direction. (3) F.C.W. CO$_{2}$ weldments had an excellent characteristic of fatigue crack propagation rate and J$_{IC}$ in less than 50kg/mm$^{2}$ steel grade, this would result from that weld metal had good static strength.trength.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.311-318
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• 2009

An experimental investigation was conducted to examine the hysteretic behaviors of ultra-high strength concrete tied columns. The purpose of this study is to propose the volumetric ratio of transverse reinforcement for ultra-high strength concrete tied columns with 100 MPa compressive strength. Nineteen 1/3 scaled columns were fabricated to simulate an 1/2 story of actual structural members with the main variables of axial load ratio, configurations and volumetric ratios of transverse reinforcement. The results show that the deformability of columns are affected by the configurations and volumetric ratios of transverse reinforcement. Especially, it has been found that the behavior of columns are affected by axial load ratio rather than the amounts and the configurations of transverse reinforcement. To improve the ductility behavior of RC column using ultra high strength concrete in a seismic region, We suggested the amount of transverse reinforcement for all data that satisfy the required displacement ductility ratio over 4. It is means that the lateral confining reduction factor (${\lambda}^c$) considering the effective legs, configuration and spacing of transverse reinforcement and axial load ratio was reflected for the volumetric ratio of transverse reinforcement.

• Earthquakes and Structures
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• v.1 no.1
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• pp.1-19
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• 2010

It has been known that one-dimensional rod theory is very effective as a simplified analytical approach to large scale or complicated structures such as high-rise buildings, in preliminary design stages. It replaces an original structure by a one-dimensional rod which has an equivalent stiffness in terms of global properties. If the structure is composed of distinct constituents of different stiffness such as coupled walls with opening, structural behavior is significantly governed by the local variation of stiffness. This paper proposes an extended version of the rod theory which accounts for the two-dimensional local variation of structural stiffness; viz, variation in the transverse direction as well as longitudinal stiffness distribution. The governing equation for the two-dimensional rod theory is formulated from Hamilton's principle by making use of a displacement function which satisfies continuity conditions across the boundary between the distinct structural components in the transverse direction. Validity of the proposed theory is confirmed by comparison with numerical results of computational tools in the cases of static, free vibration and forced vibration problems for various structures.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.4
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• pp.336-343
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• 2004

This paper reports the first known free vibration data for thin rectangular plates with V-notches. The classical Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. These sets include (1) mathematically complete algebraic-trigonometric polynomials which guarantee convergence to exact frequencies as sufficient terms are retained, and (2) corner functions which account for the bending moment singularities at the sharp reentrant corner of the Y-notch. Extensive convergence studies summarized herein confirm that the corner functions substantially enhance the convergence and accuracy of nondirectional frequencies for rectangular plates having the V-notch. In this paper, accurate frequencies and normalized contours of vibratory transverse displacement are presented for various notched plates, so that the effect of corner stress singularities may be understood.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.601-613
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• 1998

This paper reports the first-of-its-kind free vibration solutions for sectorial plates having re-entrant corners causing stress singularities when the circular edge is either clamped or simply supported. The Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. Accurate frequencies and normalized contours of the transverse vibratory displacement are presented for the spectra of sector angles.

• Journal of Chest Surgery
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• v.6 no.2
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• pp.237-242
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• 1973

Two cases of traumatic diaphragmatic hernia are reported, who were operated on in this department during the last 12 months` period. The first case, a 34 year old male, fell from 6 meters` height while he was working on electric pole. He sustained rib fractures, left 8th, 9th and 10th rib, left diaphragmatic rupture and ileal perforation. In the pleural cavity, there were stomach, omentum, left lobe of liver, transverse colon and ileum, which were reduced into the peritoneal cavity, and the diaphragmatic aperture was closed through anterolateral thoracotomy. After closure of the thoracic incision, median abdominal incision was made and closed the ileal perforation by primary suture. The second case was a 19 year old tyre repairman, who felt abrupt severe abdominal pain during lifting a heavy lyre. A barium study revealed a marked displacement of the stomach into the left pleural cavity. Immediately, thoracotomy was performed and closed the ruptured diaphragm after reduction of the herniated stomach, omentum, transverse colon, spleen and small intestine. The size of the diaphragmatic aperture were measured 17cm. in first case and 12cm. in the other respectively. Both cases discharged after uneventful recovery.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.214-225
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• 1999

An accurate method is presented for flexural vibrations of sectorial plates having simply supported-free and free-free radial edges, when the circular edge is either clamped or simply supported. The classical Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. These sets consist of : (1) mathematically complete algebraic-trigonometric polynomials which gurantee convergence to exact frequencies as sufficient terms are retained, and (2) comer functions which account for the bending moment singularities at re-entrant comer of the radial edges having arbitrary edge conditions. Accurate (at least four significant figures) frequencies and normalized contours of the transverse vibratory displacement are presented for the spectra of corner angles [90$^{\circ}$, 180$^{\circ}$(semi-circular), 270$^{\circ}$, 300$^{\circ}$, 330$^{\circ}$, 350$^{\circ}$, 355$^{\circ}$, 360$^{\circ}$ (complete circular)] causing a re-entrant comer of the radial edges. Future solutions drawn from alternative numerical procedures and finite element techniques may be compared with these accurate results.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.777-784
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• 2000

During past earthquakes several bridges have failed due to a loss of support at their bearings, seats, and/or expansion joints. Most efforts to prevent this have been directed toward tying bridges together at their bearings and expansion joints. Longitudinal restrainers are installed to limit the relative displacement at joints and thus decrease the chance of a loss of support as these locations. Transverse restrainers are necessary in many cases to keep the superstructure from sliding off in the transverse direction. Vertical restrainers are used at bearings to prevent uplifting deck, but usually not economically justified unless additional bearing retrofit is being performed. To obtain this three function of restrainer, a universal restrainer is developed. The load capacities were evaluated in static and dynamic experimental test. The test results show that the measured capacity or strength of the bridge deck restrainer is similar to that of design value.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.275-278
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• 2005

This paper presents a model for evaluating the contribution by arch action and frame action to shear resistance in shear-critical reinforced concrete beams without stirrup. The rotating angle softened truss model is employed to calculate the shear deformation of the web and the relative axial displacement of the compression and tension chord by the shear flow are also calculated. From this shear compatibility condition in a beam, the shear contribution by the arch action is numerically decoupled. The transverse strain obtained from the proposed model is selected for shear failure criterion. Using the failure criterion, shear strength of RC slender beams without stirrup is predicted.