• Steel and Composite Structures
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• v.43 no.4
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• pp.419-429
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• 2022

In response to the sustainability requirements set in the EU Commission's "Green Deal" towards reduction of the greenhouse gas emissions, it is estimated that the structural design for deconstruction is going to contribute considerably to the sustainable development of the built environment. The demountability of multi-material structural systems basically depends on the shear connectors used in the structural system. This paper focuses on a type of demountable injected shear connector with an injected steel-reinforced resin (iSRR) which consists of spherical steel particles embedded in a resin. Its application to steel-to-concrete and steel-to-Fiber Reinforced Polymer (FRP) decks is presented along with its benefits. In parallel, an overview of the experimental and numerical research on the evaluation of the mechanical properties of the demountable bolted connectors with iSRR is discussed. Last, detailed finite element (FE) models and a parametric study are performed to quantify the confinement level of the SRR material influenced by the oversized hole diameter.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.118-123
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• 2004

Cast austenitic stainless steel have been widely used for primary coolant piping in light water reactors. This material is subject to thermal embrittlement at reactor operating temperature. CF-8M and CF-8A cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing, and valve bodies in light water reactors. Thermal embrittlement results in spinodal decomposition of delta-ferrite leading to decreased fracture toughness. In this study, the specimens were prepared using an accelerated aging method. The measurement of ferrite content, Charpy impact test and J-R test were performed to verify the predicting equation for aged material properties. In case of above 25% ferrite content, predicted result of J-R curve might be non-conservative.

• Tribology and Lubricants
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• v.16 no.1
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• pp.15-21
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• 2000

Radiation of Nd-YAG laser changes and refines the surface microstructure of steels, which gives rise to enhancement of hardness and resulting wear resistance. In the present work, the effect of processing parameters during the surface modification with laser on the wear behavior of the SM45C steel was studied by means of wear testing. The counter material was alumina ceramics. The microstructure observation revealed the dependence of molten depth and width on the defocusing distance. The laser modification of steel surface give rise to improved wear resistance in the testing speed range of either <0.2 m/s or >0.9 m/s Material transfer from steel was wear observated the surface of counter material when testing speed was lower than 0.7 m/s.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.3
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• pp.1-11
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• 1997

This study aims to estimate the relative importance of quality management items through the defect analysis in the landscape construction process. The RIQMI are decided by the defect coefficient and it's cause weight. The defect items in the landscape construction process were classified by 56 items based on the classification form of '96 landscape architectural construction standard and the cause pattern were categorized 4 types as design, material, construction, and environment factors. To analyze the defect coefficient and the aucse weight by defect, the researcher surveyed the questionnaires on the 103 engineers and the 31 experts on the landscape architectural construction. The result of this study are as follows. The relative importance by facilities pattern turn out to be much higher construction, material fator than design. environment factor in wood facilities, paving facilities, and steel facilities, the RIQMI is very high in timber crack, timber vending, faulty of timber against decay, welding faulty of steel facilities in material factor, and timber crack, faulty of timber against decay, finish faulty of steel facilities, welding faulty of steel facilities in construction factor.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.234-238
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• 2006

In this research, an analysis of damaged instance and forming fault for disc part in automotive steel wheel was performed. Rolled steel material, which had been used in the manufacturing of the damaged disc part, was prepared for tensile test, quantitative analysis of chemical component and acquirement of scanning electron microscope images. Although the results of mechanical properties and chemical component ratio for the material satisfied the suggested specification, some material inherent problem was found in the scanning electron microscope images. Finally, in an analysis of chemical component for the damaged disc part used in road condition, mismatching of chemical component ratio between the suggested specification and test result was found.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.524-525
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• 2009

Heavy-weight impact noise(HN) is the most irritating noise in Korean apartment houses. It has been proclaimed standard floor system of 210mm thick slab with isolation material in the wall type structure. But this regulation is applied only new construction field and is not considered remodeling field. In general, the LN can be reduced by using isolation material but HN is known as relating with stiffness, strength & boundary condition of slab. Therefore it is difficulty in improving the HN on remodeling field. In this study, We conducted the reinforcement of concrete slab using C.F.S.(carbon fiber sheet), steel plate and steel beam after on-dol with isolation material on the remodeling field. As the test results, It appeared using C.F.S was no improved but using steel plate & steel beam were a little improved on HN.

• Journal of the Korean Society for Heat Treatment
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• v.15 no.6
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• pp.269-271
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• 2002

For the investigation of the hardness profiles and distortion characteristics of SCM415 steel, test pieces of SCM415 steel were gas and vacuum carburizing treated. The hardness profiles and distortion characteristics of vacuum and gas carburized SCM415 steel show different results. Vacuum carburizing can offer more improved hardness profiles than alternate methods of carburizing. Compared to alternate methods of carburizing, vacuum carburizing can offer improved mechanical properties and reduced cycle times of the process.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.121-126
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• 2003

Steel frame construction is divided into subsidiary materials with column, beam, girder and bracing. After these are processed in factory for using installing in construction field. These prefabricated furniture is very important in accordance with design drawing about processing and prefabricating. In the case of design process using information transmission in blueprint, omission of material number, processing measure and finishing material, or discordance of each structure drawing and selecting incongruent structural material generated an error in the process of design. These error caused delaying tine and increasing cost and increasing safety accident in the steel-structure work operating process. therefore, design process should consider problem of operating process.

• Journal of the Korea Institute of Building Construction
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• v.3 no.2
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• pp.111-118
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• 2003

Steel frame construction is divided into subsidiary materials with column, beam, girder and bracing. After these are processed in factory for using installing in construction field. These prefabricated furniture is very important in accordance with design drawing about processing and prefabricating. In the case of design process using information transmission in blueprint, omission of material number, processing measure and finishing material, or discordance of each structure drawing and selecting incongruent structural material generated an error in the process of design. These error caused delaying time and increasing cost and increasing safety accident in the steel-structure work operating process. therefore, design process should consider problem of operating process.

• Transactions of Materials Processing
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• v.23 no.5
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• pp.311-316
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• 2014

In the current study, the R-value behavior of a two-layer clad steel was investigated using finite element analysis. Hill's 1948 anisotropic yield equation was employed to characterize the anisotropic behavior of the steel with different assumed properties: isotropic (R=1) and anisotropic (R=2). Experimental R-values were determined by measuring the width and thickness ratios of tensile specimens. Finite element analysis results demonstrate a difference in strain behavior in the width and the thickness directions of the clad steel. The R-value behavior depends on the fraction of the clad materials and total elongation.