• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.3 s.168
• /
• pp.93-100
• /
• 2005

The top and bottom nozzles of PWR fuel assembly are connected by guide thimbles and an instrumentation tube that are connected with spacer grids. The fuel rods are inserted into the each cell of spacer grids. The loads acting on the fuel assembly are transmitted to the guide thimbles through the flow plate of top nozzle The axial loads applied to the fuel assembly are not equally distributed among the guide thimble due to the geometry of the top nozzle flow plate and spacer grid. In this study, the load concentration factors for the $17\times17$ fuel assembly were calculated. The analytical model fur the calculation of the load concentration factor of top nozzle flow plate was developed using ANSYS 5.6. The finite element analyses were performed using the model composed of top nozzle, guide thimble, and spacer grid. And, the analysis results were compared with the test results.

• Structural Engineering and Mechanics
• /
• v.4 no.4
• /
• pp.397-413
• /
• 1996

In this paper the elastic post-buckling behaviour of plates under non-uniform compressive edge stress is investigated. The compatibility differential equations is first solved analytically and then an approximate solution of the equilibrium equation is obtained using the Galerkin method. Explicit expressions are derived for the load-deflection, ultimate strength and membrane stress distributions. Analytical effective width formulations, based on the characteristics of the stress field of the buckled plate, are proposed for this general loading condition. The predicted load-deflection expression is compared with independent test results. Results are also presented detailing the load-deflection behaviour and stress distribution for various aspect ratios.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.3 s.258
• /
• pp.304-312
• /
• 2007

The objective of this study is to develop a local failure criterion for a wall thinning defect of piping components. For this purpose, a series of tensile tests was performed using several types of simulated specimens with different stress states, including smooth round bar, notched round bar (five different notch radii), and grooved plate (three different groove radii). In addition, finite element (FE) simulations were performed on the simulated specimen tests and the results were compared with the test results. From the comparisons, the equivalent stress and strain corresponding to maximum load and final failure of notched specimens were proposed as failure criteria under tensile load. The criteria were verified by employing them to the estimation of failure of grooved plate specimens that simulate the wall thinning defect. It showed that the proposed criteria accurately estimate the maximum load and final failure of grooved plate specimen tests.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.4 no.1
• /
• pp.40-46
• /
• 2013

This paper presents the design, fabrication and performance of a reinforced concrete beam strengthened by GFRP box plate and its possibility for structural rehabilitations. The load capacity, ductility and failure mode of reinforced concrete structures strengthened by FRP box plate were investigated and compared with traditional FRP plate strengthening method. This is intended to assess the feasibility of using FRP box plate for repair and strengthening of damaged RC beams. A series of four-point bending tests were conducted on RC beams with or without strengthening FRP systems the influence of concrete cover thickness on the performance of overall stiffness of the structure. The parameters obtained by the experimental studies were the stiffness, strength, crack width and pattern, failure mode, respectively. The test yielded complete load-deflection curves from which the increase in load capacity and the failure mode was evaluated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.9
• /
• pp.2402-2408
• /
• 2009

This study conducted a static tensile test in order to prevent the lowering of load carrying capacity caused by critical sections made by over bolt holes in the base plate and the cover plate of steel member joints using high-tension bolts. The change of the load carrying capacity of joints was examined by comparison of the maximum load on joint fracture obtained from the tensile test with critical section rate and design strength. According to the results, the rate of decrease in strength was higher when the critical section rate was high, and in particular, decrease in strength was affected much more by critical sections in the base plate than by those in the cover plate. In high-tension bolt joints using over bolt holes for the base plate and the cover plate, load carrying performance was somewhat lower than that in joints using standard bolt holes, but the maximum tensile strength on facture was over 15% higher than design fracture strength. According to the results of this study, the use of over bolt holes in high-tension bolt joints had an insignificant effect on the lowering of load carrying capacity, so the allowance of over bolt holes in the joints of steel members is expected to enhance to the economy and efficiency of the works.

• KCI Concrete Journal
• /
• v.12 no.1
• /
• pp.69-77
• /
• 2000

The reinforced concrete(RC) flexural members strengthened with steel plate/CFS at soffit have initial stresses and strains in reinforcements and concrete caused by the service loads at the time of retrofitting works. These initial residual stresses and strains of strengthened beams may affect the flexural performance of the rehabilitated beams. The objective of this study is to evaluate and verify the effectiveness of rehabilitation by external bonded steel plates and CFS to the tension face of the beams under three conditions of pre-loading. Thirteen beam specimens are tested and analyzed. Main test parameters are pre-loading conditions, strengthening materials and reinforcement ratio of specimens. The effect of test parameters on the strengthened beams is analyzed from the maximum load capacity, load-deflection relationship, state of stress of the materials. crack propagation phase, and failure modes. Both test results and design formulas of ACI Code provisions are compared and evaluated.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.6
• /
• pp.135-141
• /
• 1997

Low velocity impact test and compressive residual strength test after impact were performed by using Hercules AS4/3501-6[45/0/-45/90]$_{2s}$ laminated plate to investigate the low velocity impact damage behavior and the post-impact strength degradation on orthotropic composite laminate plate. Due to the lateral impact losd, the load path showed "" shape according to the laminate central deflection. Damage in a laminate occurs by inclined matrix crack at the damage initiation load stage and vertical matrix crack, occurs on the outer surface. Evaluating the compressive residual strength after the low velocty impact test, it could be found that there is a transient range where the compressive residual strength drop suddenly in the initial damage which is in the matrix crack range and the initial delamination area. is in the matrix crack range and the initial delamination area.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.5 no.1 s.16
• /
• pp.33-43
• /
• 2005

The girder wheel load distribution factors stated in the Korean Bridge Specification and AASHTO Standard Specifications do not account for the effect of skewness of plate girders, and very little research has been conducted on girder wheel load distribution factors. The purpose of the study is to propose load distribution factor formulas for skew plate girder bridges which comprise various parameters through structural analysis. To confirm the validity of finite element models used in this study analytic values are compared with the field test results. From the results it should be noted that span length is not such a dominant parameter compared with others. In view of better load distribution of interior girders, skew arranged cross beams or bracing are preferable, furthemore bracing system is more effective than cross beam system. By means of regression analysis on the basis of analytic results wheel load distribution factor formulas are proposed and compared with current codes.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.1
• /
• pp.293-303
• /
• 2005

The girder wheel load distribution factors stated in the Korean Bridge Specification and AASHTO Standard Specifications do not account for the effect of skewness of plate girders, and very little research has been conducted on girder wheel load distribution factors. The purpose of the study is to propose load distribution factor formulas for skew plate girder bridges which comprise various parameters through structural analysis. To comprise the validity of finite element models used in this study analytic values are compared with the field test results. From the results it should be noted that span length is not such a dominant parameter compared with others. In view of better load distribution of interior girders, skew arranged cross beams or bracing are preferable, furthemore bracing system is more effective than cross beam system. By means of regression analysis on the basis of analytic results wheel load distribution factor formulas are proposed and compared with current codes.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.59 no.5
• /
• pp.73-81
• /
• 2017

The improved movable weir supplements the advantages and disadvantages of the rubber weir and the conduction gate. It consists of a stainless steel gate, air bags, and a steel clamping plate. The stainless steel gate is the main body of the weir, and the inflatable rubber sheet serves to support the steel gate. The steel clamping plate is typically in direct continuous contact with water, but this leads to corrosion issues that can reduce the life of the entire movable weir. In this study, a panel-type glass-fiber-reinforced polymer (GFRP) clamping plate was designed and fabricated. The test results showed that the flexural load of the panel-type GFRP composite clamping plate was over twice that of the wings type GFRP clamping plate. The lowest moisture absorption value was obtained upon exposure to tap water, and exposure to other solutions showed similar values. Additionally, flexural load testing after exposure to an accelerated environment found the lowest residual loads of 80.51 % and 78.50 % at 50 and 100 days, respectively, for exposure to a $CaCl_2$ solution, while exposure to other environments showed residual failure loads of over 80 % at both 50 and 100 days.