• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.61-68
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• 2021

Movable weirs with multi-stage control are necessary in many Korean rivers to actively control the water storage level. A mesh dependency test was performed to determine the appropriate number of meshes for structural analysis of movable weirs. The standing angles of movable weirs were set to 60°, 45°, 30°, and 15° for stress analysis. The standing angle of 0° was excluded from the analysis because it was unloaded. Changes in the standing angle led to changes in the water depth, maximum pressure, maximum strain, and maximum stress. The maximum average stress and the structural safety of the multi-stage control movable weir were computed and tested using the Ansys FEA software package.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.16-25
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• 2019

Recently, due to labor shortages in rural areas within South Korea, the demand for upland-field machinery is growing. In addition, there is a lack of development of systematic performance testing of upland-field machinery. Thus, this study examined structural safety and drawbar pull based on soil properties, as a first step for systematic performance testing on the test bed. First, the properties of soil samples from 10 spots within the experimental site were examined. Second, the strain was measured and converted into stress on 8 points of an onion harvester that are likely to fail. More specifically, the chosen parts are linked to the power, along with the drawbar pull, using a 6-component load cell equipped between the tractor and the onion harvester. The water content of the soil ranged between 5.7%-7.5%, and the strength between 250-1171 kPa. The test soil was subsequently classified into loam soil based on the size distribution ratio of the sieved soil. The onion harvester can be considered as structurally safe based on the derived safety factor and the drawbar pull of 115-1194 kgf, according to the working speed based on agricultural fieldwork.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.639-646
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• 2017

This paper describes the sound insulation and structural safety of the shelter which may be used for shooters. The noise level of the shelter should be less than 100 dB on the basis of the Industrial Safety and Act, the World Health Organization and the MIL-STD. The sound insulation design was designed for the shelter structure. The designed shelter performance was verified by the real measurement after completing the construction of the shelter. The system was also designed using the finite element method with data of sound pressure measured in the test. Its response was obtained numerically. It is proved that the shelter structure is sufficiently safe considering the calculated maximum stress level with the allowable stress of structural property.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.701-709
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• 2008

Owing to the decreased work term and the convenience of construction work in Korea, the steel deck plate system has been widely used in the construction field. Most of all, due to its good stiffness and economic consideration, the steel-wire-integrated deck plate system (or truss deck plate system) has become very popular in recent years. But although it has many advantages, the truss deck plate system has a critical defect: it gets rusty in the welding joints between the lattice steel wire and the deck plate, resulting in the cracking of such welding joints and water leakage. To address these problems, a new type of truss deck plate system, which need not be welded and does not rust, was proposed herein: the TOX deck plate system. In this study, tests were conducted on 15 specimens to evaluate the structural safety of the proposed deck plate system during the construction stage. The test parameters were as follows: the depth of the slab the length of the span the diameters of the top, bottom, and lattice steel wire and the material properties of the zinc-coated steel sheets. The test results show that the TOX deck plate system can guarantee structural safety owing to its deflection and strength.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.3-11
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• 1999

The atomic fuel rods between top and bottom end pieces of reactor need to be extended for high combustion rate of future-type fuel to increase the irradiation in the axial direction. For allowing axial extension of the fuel rods, the space between top and bottom end pieces should be expanded. Thus the thickness reduction of the flow plate is necessary. This study was carried out the mechanical strength test by using strain gages as a function of flow plate thickness, the existence of skirt and loading condition for the Korean Fuel Assembly(KOFA). The experimental apparatus was designed for load conditions, uniformly distributed load and displacement. Test method using whiffle tree of uniformly distributed load has been comparatively conservative. The test results were compared with those of finite element analysis and the test method on bottom end piece was established.

• Journal of Auto-vehicle Safety Association
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• v.3 no.2
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• pp.11-16
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• 2011

In recent years, rapid-increasing market share of compact cars and SUVs has brought for both consumer and automaker to pay more attention on crash compatibility between the compact passenger vehicles and the light trucks (i.e., Pickups and SUVs). Vehicle compatibility regarding both self and partner protection in frontal crash of different class vehicles is one of hot issues in vehicle safety. Furthermore, it is expected that the amendment of UNECE-Regulation 94 to implement compatibility issues in couple of coming years. In this study, conceptual design of compatibility compliant frontal vehicle structure which subjects to improve? the distribution of frontal crash loading and structural engagement between vehicles is introduced. The effects of proposed vehicle structure on both possible candidates (i.e. FWRB, FWDB and PDB) for a compatibility evaluation test procedure and car-to-car crash are also investigated.

• Computational Structural Engineering
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• v.9 no.1
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• pp.125-132
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• 1996

This study is to propose a practical and realistic reliability analysis by ETCM (Expected Total Cost Minimization). One of the main objectives is intended to propose the safety assessment and capacity rating of existing reinforced concrete members by evaluation index, that is RF(Rating Factor) from the results of the field test and inspection for reinforced concrete bridge. ETCM method is used for the reliability analysis of the proposed models. The proposed reliability model and method are applied to the safety assessment and system factors of reinforced concrete members.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.38-45
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• 2018

Bridges are structures where safety must be ensured. Generally, the destruction mechanism of bridge deck shows punching shear. Lately, the high-strength concrete is often used to increase the lifespan of bridges. The benefits of using the high-strength concrete are that it increases the durability and strength. On the contrary, it reduces the cross-section of the bridges. This study suggested the optimal thickness of bridge deck with application of high-strength concrete and the study evaluated its structural performance experimentally. The evaluation result shows that 180 mm and 190 mm of thickness are optimal for 100 MPa and 120 MPa high-strength concrete bridge deck respectively.

• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.11-15
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• 1996

For the assessment of fracture behaviors of structural components, various fracture mechanics parameters have been applied to date. New approaches to analyze structural fracture performance under elastic-plastic condition have been proposed by the development of testing methods for characterization of material behavior which is defying to the analysis by conventional fracture parameters. In this study, on the assumption that, initiation of crack propagation of a piping materials occurs when the crack tip strain field reaches "the local fracture strain", following two major issues are discussed ; 1) The relationship between the critical value of J-integral($J_{IC}$) and the local fracture strain (${\varepsilon}_c$) in uniaxial tensile test in the region of maximum reduction area was described. 2) To proved the validity of above relations a series of tests were performed under various temperature and on the different piping materials.materials.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.1
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• pp.70-80
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• 2004

This study proposes a development result for the 1-kW class small wind turbine system, which is applicable to relatively low wind speed regions like Korea and has the variable pitch control mechanism. In the aerodynamic design of the wind turbine blade, parametric studies were carried out to determine an optimum aerodynamic configuration which is not only more efficient at low wind speed but whose diameter is not much larger than similar class other blades. A light composite structure, which can endure effectively various loads, was newly designed. In order to evaluate the structural design of the composite blade, the structural analysis was peformed by the finite element method. Moreover both structural safety and stability were verified through the full- scale structural test.