• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.5
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• pp.491-498
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• 2011

In this paper, extensive structural behavior and effects of design parameters of steel column-base plate connections under axial and lateral loads were investigated to improve structural details of CFT(Concrete Filled Steel Tube) pier foundation using commercial FE analysis program, ABAQUS. For this study, design criteria of pier foundation was analyzed and numerical study based on the experiment of previous study was conducted to verify analysis methods. The failure behavior and stress distribution of pier foundation were analyzed using the verified analysis method. Various design parameters(base plate, deformed bar, stiffness and sizes of column) were investigated to analyze effects of each design parameters in entire structure.

• Steel and Composite Structures
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• v.8 no.4
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• pp.313-328
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• 2008

This study attempts to suggest bending reinforcement method by applying bending reinforcement to composite profile beam in which the concept of prefabrication is introduced. Profile use can be in place of framework and is effective in improvement of shear and bending strength and advantageous in long-term deflection. As a result of experiment, MPB-CB2 with improved module had higher strength and ductility than the previously published MPB-CB and MPB-LB. In case of bending reinforcement with deformed bar and built-up T-shape section based on MPB-CB2, the MPB-RB series reinforced with deformed bar were found to have higher initial stiffness, bending strength and ductility than the MPB-RT series. The less reinforcement effect of the MPB-RT series might be caused by poor concrete filling at the bottom of the built-up T-shape. In comparison between theoretical values and experimental values using minimum yield strength, the ratio between experimental value and theoretical value was shown to be 0.9 or higher except for MPB-RB16 and MPB-RT16 that have more reinforcement compared to the section, thus it is deemed that the reinforced modular composite profiled beam is highly applicable on the basis of minimum yield strength.

• Land and Housing Review
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• v.2 no.1
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• pp.61-68
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• 2011

In order to clarify the structural performances of Welded Deformed Steel Bar Mats (WDSBM), the research stated includes the tests for standard hook of top bars of slab in concrete slab-wall joints, the tests for embedment length of top bar of slab, and the development strength tests for standard hook. The test results are as follows; (1) For slab-wall joints using WDSBM as reinforcement in slab, if the top bars of WDSBM are spliced by ordinary bars with sufficient development length and size, it is enough for the strength and crack control. (2) When WDSBM of slab is spliced in joint, the strength is increased with the embedment of bars of this WDSBM into wall. Beyond peak strength, however, ductility is diminished to that as no splice due to pull-out failure. (3) For slab-wall system, ultimate strain of concrete for flexural compression zone in lower surface of slab seems much greater than that of normal concrete beam. The reason is that normal concrete beam has the joint with $180^{\circ}$, however slab-wall joint has the $90^{\circ}$ of which concrete can be confined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.813-817
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• 1995

Structural analysis of horizontal cold chamber die casting machine is performed by the FEM. The analyzed model is made up of stationary die platen,movable die platen,link housing platen, C-frame, and tie bar which mainly undertake die locking force and injection force. In modeling, compression gap elements are used for to simulate contacting condition between tie bar and movable die platen, movable die platen and base frame, and link housing and base frame. Unbalanced die locking force imposed on four tie bars are considered. As the results, the deformed shape and the stresses of the die casting machine are given.

• Journal of Chest Surgery
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• v.19 no.3
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• pp.391-398
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• 1986

From Jan. 1983 to Dec. 1985, seven cases of pectus excavatum, six were male and one female, were underwent an operation at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital. The ages of patients ranged from 6 to 27 years. They all had symptoms of feeling inferiority about chest deformity. The concavity on the funnel chest varied in its extent, and the severity, which was measured by water volume filled into it, varied from 59.5cc/m2 to 129.9cc/m2. All but one patients were approached through a bilateral transverse submammary incision and one approached through a vertical midline incision. Successful surgical correction required resection of all deformed costal cartilages with transverse anterior osteotomy and internal fixation using retrosternal metal bar. No serious complication have followed the use of this technique, but minor complications such as serous accumulation, pneumothorax and strut migration have been experienced. All patients were satisfactory about the surgical results.

• Bulletin of the Society of Naval Architects of Korea
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• v.7 no.1
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• pp.13-26
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• 1970

An elastic plate bar jointed to a rigid bar is considered. The bar is subjected to uniform axial tension. A theoretical approximate solution is obtained in an infinite hyperbolic series form and some numerical results for various Poisson's ratios are presented. A rubber plate joined to a strong wooden plate has been tested to obtain an experimental data and the results are compared with theoretical ones. Two values for vertical displacements are in good agreement but it is not satisfactory for horizontal displacements. The conclusion arrived at are as follow : The natures of stress distributions and deformed shapes given by above theoretical solution are compatible in mechanical sense. The magnitudes of stress and displacement components would not be reliable for exact works. A sharp shear stress concentrations are detected at the both ends of the joint.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5A
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• pp.485-493
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• 2010

GFRP rebar with ribs resemble those of deformed steel rebar was developed in 2005. It was reported that ribs of the GFRP rebar were sheared off due to the lower shear strength of polymer. In this study, the basic development length of the GFRP rebar was investigated through pull-out tests, models specified in ACI440.1R-03 and -06, and empirical model derived by Cosenza et al. (2002). As a results of pull-out tests, the critical embeddment length, which is defined as the length when failure mode is changed from pull-out to bar fracture, was 20 times of bar diameter for GFRP rebar and was 15 times for steel rebar. It is believed that the basic development of the GFRP rebar is 21 times of bar diameter, which is determined from the application of average bond strength into the model equation specified in ACI440.1R-03. Compared to the model equation in ACI440.1R-06, that in ACI440.1R-03 is recommendable for design purpose. The Cosenza et al.'s model underestimates the basic development length of the GFRP rebar.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.59-67
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• 2014

In tension lap splices of straight deformed bars, KCI Code (KCI2012) and ACI Code (ACI318-11) requires that the lap lengths for class B splice are 1.3 times as development length. KCI2012 contains development length provisions for the use of headed deformed bars in tension and does not allow their tension lap splices. The purpose of this experimental study is to evaluate that KCI2012 equation for the development length, $l_{dt}$, of headed bars can be used to calculate the lap length, $l_s$, of headed deformed bars in grade SD400 and SD500, having specified yield strength of 400 and 500 MPa. Test results showed that specimens with $l_s$ equal to $1.3l_{dt}$ had maximum flexural strengths as 1.16~1.31 times as the nominal flexural strengths, flexural failure mode, and ductility. These observations indicate that $1.3l_{dt}$ is suitable to the tensile lap length of headed deformed bars in grade SD400 and SD500.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1089-1092
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• 2008

The bond behavior between concrete and reinforcement is a important requirement for reinforced concrete constructions. For practical application, it is very important to study bond behavior of reinforcing bars in recycled fine aggregate concrete. Therefore, pull-out test in order to investigate the bond behavior between recycled fine aggregate concrete and deformed bars was performed. Recycled fine aggregate concrete replacement ratios (i.e., 0% and 100%) and positions of deformed bars (i.e., vertical and horizontal position) were considered as variables in this study. Test results were compared with the bond strength requirement recommended by CEB-FIP code. Based on the test results, It was found that the bond strength between the recycled fine aggregate concrete and deformed bars were influenced by both recycled fine aggregate concrete replacement ratios and positions of deformed bars. The reduction of bonded area at the soffit of horizontal reinforcement caused by concrete bleeding was observed in H type specimen. So, Only V type and HB specimen satisfied the bond strength requirement recommended by CEB-FIP code.

• KCI Concrete Journal
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• v.12 no.1
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• pp.91-99
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• 2000

A new type of retrof=t anchor bolt that uses deformed reinforcing bars and a commercial adhesive was developed and then an experimental study was carried out to determine the behavior of the anchors in direct shear. The steel-to-concl몫ete interface was tested. Plain concrete slabs with about 20-MPa compressive strength were used for 23 direct shear tests performed Test variables were anchor diameters (D16, D22. and D29) and edge effect. Three different shear tests were completed: simple shear, edge shear where anchors were pulled against the concrete core, and edge shear where anchors were pushed against the concrete cover In the simple and the edge shear tests where the anchors were pulled against the core, the theoretical dowel strength determined by (equation omitted) was achieved but with relatively large displacements. The shear resistances increased with the increasing displacements. In the edge shear test where the anchors were pushrd against the cover, the peak shear strengths signif=cantly lower than the theoretical dowel strength were determined due to cracks developed in concrete when the edge distance was 80 mm. The peak strengths were about 50% of the dowel strength for Dl6 bar. and about 25% or less of the dowel strength for D22 and D29 bars. Test results revealed that the edge shear where the anchor was pushed against the cover controled.