• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1601-1607
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• 2010

This paper presents FMEA (Failure Mode Effect Analysis) for maintenance of mail sorting machine which is for automatic sorting of mail. We suggest the update method of regular diagnosis item and period for maintenance of mail sorting machine using the risk priority number which is calculated by severity, occurrence, and detection of failure mode of mail sorting machine, and shows FMEA adoption example of letter sorting machine. This paper also describes the current maintenance system and status of mail sorting machine in the domestic postal logistics environment, and FMEA adoption step. The proposed maintenance using FMEA will be adapted for more easy and efficiency maintenance of mail sorting machine.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.165-168
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• 2008

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 Applied Reliability
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• v.14 no.1
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• pp.71-80
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• 2014

In the mechanical design process various types of errors are bound to occur. In order to prevent such mechanical malfunctions and decrease number of instances of errors, various technique are utilized. The purpose of this research is to demonstrate the effectiveness of the combined service Blueprint and FMEA (Failure Mode and Effect Analysis) by applying such method to machine process. The results are as follows: First, modification can be obtained by discovering the failure mode hidden within the inner side of the blueprint. Second, issues within the company are found when conducting the machine design process that is not visible from the outside. Therefore, potential errors can be effectively resolved by preventing failure mode in advance and eventually high quality of the product could be obtained as well as its reliability.

• Geotechnical Engineering
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• v.13 no.3
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• pp.21-32
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• 1997

In this paper, an enhanced finite element model based on homogenisation technique is proposed to capture the localized failure mode of the intact rock masses. For this, bifurcation analysis at the element level is performed and, once the bifurcation is detected, equivalent material properties of the shear band and neighbouring intact rock are used to trace the post -peak behaviour of the material. It is demonstrated that mesh sensitivity of the strain softening model is overcome and progressive failure mode of rock specimen can be simulated relaistically. Furthermore, the numerical results show that the crack propagation and final failure mode can be captured with relatively coarse meshes and compares well with the experimental data available.

• Steel and Composite Structures
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• v.32 no.3
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• pp.411-422
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• 2019

Six shear-critical square tubed steel reinforced concrete (TSRC) columns using the high-strength concrete ($f_{cu,150}=86.6MPa$) were tested under constant axial and lateral cyclic loads. The height-to-depth ratio of the short column specimens was specified as 2.6, and the axial load ratio and the number of shear studs on the steel shape were considered as two main parameters. The shear failure mode of short square TSRC columns was observed from the test. The steel tube with diagonal stiffener plates provided effective confinement to the concrete core, while welding shear studs on the steel section appeared not significantly enhancing the seismic behavior of short square TRSC columns. Specimens with higher axial load ratio showed higher lateral stiffness and shear strength but worse ductility. A modified ACI design method is proposed to calculate the nominal shear strength, which agrees well with the test database containing ten short square TSRC columns with shear failure mode from this study and other related literature.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.118-131
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• 1995

The shock fracture analysis for the structures of navy vessels subject to underwater explosions or of high speed vessels frequently subject to impact loads has been carried out in two steps such as the global or macro analysis and the fine or micro analysis. In the macro analysis, Doubly Asymptotic Approximation(DAA) has been applied. The three main failure modes of structure members subject to strong shock loading are late time fracture mode such as plastic large deformation mainly due to dynamic plastic buckling, and the early time fracture mode such as tensile tearing failure or transverse shear failure. In this paper, the tensile tearing failure mode is numerically analyzed for the micro analysis by calculating the dynamic stress intensity factor $K_I(t)$, which shows the relation between stress wave and crack propagation on the longitudinal stiffener of the model. Especially, in calculating this factor, the numerical caustic method developed from shadow optical method of caustic well known as experimental method is used. The fully submerged vessel is adopted for the macro analysis at first, of which the longitudinal stiffener, subject to early shock pressure time history calculated in macro analysis, is adopted for the micro analysis.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.19-30
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• 2022

Developing a fragility curve for the levee requires calculating the probability of failure according to the water level for each failure mode. Since probabilistic analysis requires iterative analysis to account for variability in geotechnical parameters, the fragility curve development inevitably requires many iterative calculations. Therefore, approximate probabilistic analysis techniques are usually applied to reduce the amount of calculation in developing the levee fragility curve. However, their accuracy has not been determined clearly. This study calculated the failure probability of slope and piping failure mode for an actual levee through probabilistic methods, such as FOSM, PEM, and MCS. Then, the fragility curve of the levee according to the water level was developed. The results of the approximate methods: FOSM and PEM, were compared with those of MCS to evaluate the applicability to the fragility curve for slope and piping failure mode.

• Structural Engineering and Mechanics
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• v.59 no.2
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• pp.327-341
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• 2016

This study addresses the effect of pre-stressed cables on a pre-stressed mega-braced steel frame through employing static analysis and pushover analysis. The performances of a pre-stressed mega-braced steel frame and a pure steel frame without mega-braces are compared in terms of base shear, ductility, and failure mode. The influence of the cable parameters is also analyzed. Numerical results show that cable braces can effectively improve the lateral stiffness of a pure frame. However, it reduces structural ductility and degenerates structural pre-failure lateral stiffness greatly. Furthermore, it is found that 20% fluctuation in the cable pretension has little effect on structural ultimate bearing capacity and lateral stiffness. As comparison, 20% fluctuation in the cable diameter has much greater impact.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.691-696
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• 1997

In recent years, stengthening of beam by steel plate, carbon fiber sheets, and carbon fiber laminate is spotlighted in order to repair and rehabilitation of R/C structures. In this study, 3 method of rehabilitation technic are analyzed from the tests. Test parameters are the width of cracks, the method of repair and rehabilitation, the magnitude of existing load. Deflection, failure load, strains of reinforcing bar, strains of sheet and plates are measured during tests. The failure mode and ultimate load are analyzed from these measured data. Test result shows that the width of cracks and the magnitude of existing load do not make any difference of ultimate flexural capacity.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.199-204
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• 1998

To analysis the failure character of Low-Heat concrete which is used to prevent the thermal crack caused by hydration heat, static loading test was performed by this test method, "Determination of the Fracture Energy of Motar and Concrete by Means of Three-Point Band Tests on Notched Beam" (suggested by RILEM 50-FMC Committe). This study compared and analysised the fracture energy of Mode I (opening mode), the most general pattern in the view of water-cemente ratio(W/C), compressive strength and age of Ordinary Portland Concrete and Low-Heat Concrete under the same mixture. The test results show that the case of Ordinary Portland Concrete and Low-Heat Concrete, low Water-Cemente ratio(W/C) cause the increase of fracture energy, and high failure-strength decrease failure-deflection, and the fracture energy of Low-Heat Concrete is similar to Ordinary Portland Concrete as the age increase. increase.