• Tribology and Lubricants
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• v.36 no.5
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• pp.262-266
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• 2020

Herein, we present a numerical investigation of wear analysis of sliding systems with a constant speed subjected to Archard's wear law. For this investigation, we compared two methods: eigen-wear analysis and adaptive meshing technique. The eigen-wear analysis is advantageous to predict the evolution of contact pressure due to wear using the initial contact pressure and contact stiffness. The adaptive meshing technique in finite element analysis is employed to obtain transient wear behavior, which needs significant computational resources. From the eigen-wear analysis, we can determine the appropriate element size required for finite element analysis and the time increment required for wear evolution by a dimensionless variable above a certain value. Since the prediction of wear depends on the maximum contact pressure, the finite element model should have a reasonable representation of the maximum contact pressure. The maximum contact pressure and wear amount according to this dimensionless variable shows that the number of fine meshes in the contact area contributes more to the accuracy of the wear analysis, and the time increment is less sensitive when the number of contact nodes is significantly larger. The results derived from a two-dimensional wear model can be applied to a three-dimensional wear model.

• The Research Journal of the Costume Culture
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• v.11 no.1
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• pp.47-65
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• 2003

The purpose of this study was to examine the characteristics of consumer evaluative criteria based on clothing quality perception of adult males and females. A demonstrative study was conducted using a questionnaire on adults over 20 years old who were considered to afford to purchase clothes. A total of 650 questionnaires were distributed, and among them, 380 were used for the demonstrative analysis. The study used SPSSWIN V.8.0 for the analysis. Factor analysis and reliability analysis were introduced as analysis methods using the varimax rotation to classify consumer evaluative criteria for clothing purchasing. In addition, frequency analysis, correlation analysis, 1-test, multiple regression analysis, and duncan test are executed. The study result is as follows. First. expectation, importance and performance are examined by customer quality perception. Four factors- practicability, care, aesthetics, and symbolism- are classified through the factor analysis of 19 evaluative attributes based on importance. Second, differences of quality perception f3r expectation, importance and performance were found partly in customers' demographic characteristics. Third, the influential relation of satisfaction and quality perception is examined. Aesthetics and practicability have significant influence on the general satisfaction of evaluative attributes by performance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.266-269
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• 2003

This paper is concerned with a forming analysis of front side members and the application of the forming effect in crash analysis of auto-body. Drawbead restraining forces are calculated with ABAQUS/Strandard in order to identify the boundary condition in forming process. Forming analysis with equivalent drawbead is carried out with LS-DYNA3D. In order to demonstrate the validity of the forming analysis, quantitative comparison of the thickness variation between the real product and the numerical simulation result is carried out. Forming histories obtained from the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.94-98
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• 2002

This study aimed to search for the fundamental accident causes using a categorical analysis, a kind of statistical methods. As the analysis methods, correlation analysis, independence test and logistic regression analysis were used. And the SPSS package, a general-purpose mathematical library, was used to obtain statistical characteristics. As the result of this study, the accident causes associated with factor of 'lost working days' were factors such as 'employed periods', 'sex', 'type of accident', 'month'. In case of applying independence test method, the most important cause was the factor of 'month'. In case that logistic regression analysis method was applied, the cause contributed to the increase structure'. 'less than 6 month'. On the basis of these results, the plan for accident prevention and the proper investment for accident prevention expenditure could be carried out in each workshop.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.613-616
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• 1997

MDO(Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided engineering(CAE) system. And this paper treats the structural design problem of RIROB(Reactor Inspection Robot) through the application of MDO methodology. In a MDO methodology application to the structural design of RIBOS, kinetodynamic analysis is done using a simple fluiddynamic analysis model for the warter flow over the sensor support surface instead of difficult fluid dynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. The minimum thickness (0.8cm) of the RIROB housing is obtained for the safe design of RIROB. The kinetodynamic analysis of RIROB. The kinetodynamic analysis of RIROB is done using ADAMS and the static structural analysis of RIROB is done using NISA.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.497-511
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• 1996

The equivalent static force procedure and the response spectrum analysis method are widely used for seismic analyses of multi-story buildings. The equivalent static force procedure is one of the most simple but less accurate method in predicting possible seismic response of a structure. The response spectrum analysis method provides more accurate results while it takes much longer computational time. In the response spectrum method, dynamic response of a multi-story building is obtained by combining modal responses through a proper procedure such as SRSS or CQC method. Since all of the analysis results are expressed in absolute values, structural engineers have difficulties to combine them with the results obtained from the static analysis. Design automation is interrupted at this stage because of the difficulty in the decision of the most critical design load. Pseudo-dynamic analysis method proposed in this study provides more accurate seismic analysis results than those of the equivalent static force procedure since the dynamic characteristics of a structure is considered. And the proposed method has an advantage in combination of the analysis results due to gravity loads and seismic loads since the direction of the forces can be considered.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.164-170
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• 2003

The finite element analysis of tires has been conventionally performed by either neglecting tread pattern or modeling only circumferential grooves. Besides, the tire analysis has been mainly limited to static or steady state rolling analysis. In this paper, a transient dynamic analysis of a patterned tire rolling over a cleat with an explicit finite element program is presented. The patterned tire with detailed tread blocks is modeled by a systematic mesh generation procedure, in which tire body and tread pattern meshes are separately generated in the beginning and then both meshes are combined by the tie constraint method. The cleat impact analysis is conducted by using both the patterned tire and the smooth tire models to predict the cleat enveloping characteristics. It is seen that the analysis results of the patterned tire model are in a good agreement with the experimental results.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.59-66
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• 2014

PURPOSES : This study is to suggest heavy snow risk analysis in Seoul. METHODS : Recently, the increase of extreme weather caused by global warming raises the occurrences of unpredictable natural disasters and the loss potential of human disasters by land use facilities accumulation. It is necessary to develop the risk analysis for the natural and human disasters. RESULTS : In this study, heavy snow risk analysis among natural disasters in Seoul was suggested. The spatial unit of risk analysis level was established for the lines and administrative districts. CONCLUSIONS : The risk analysis was performed using risk matrix of disaster occurrence score and disaster damage score. The components affecting the risk disaster analysis by types were analyzed and the application of heavy snow risk analysis was suggested.

• Journal of Welding and Joining
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• v.19 no.1
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• pp.104-111
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• 2001

This study presents an analysis method for heat flow and deformation of sheet metal laser welding. A heat source model for 2-dimensional heat flow analysis of laser welding process was suggested in this paper. To investigate the availability of the heat source model, the analysis results were compared and estimated with the results of previous researches. We could get a good agreement between the results of numerical analysis and experiments in the temperature distribution of weldment. Due to the characteristics of welding process, some kinds of deformations are usually generated in a welded structure. Generally, the degree of deformation is dependent on the welding sequence constraints as well as input power Therefore, in this paper we evaluate the deformation of gas pressure vessel according to the welding sequence and input power. In the analysis of weld deformation, 2-dimensional thermo-elasto-plastic analysis was performed for the gas pressure vessel by using a commercial FE program package.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.292-293
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• 2014

Transfer Path Analysis is technique predicting transmitted energy through each path. Using the Transfer Path Analysis, structure-borne noise and air-borne noise can be predicted from the system. In this study, however, the Transfer Path Analysis to target only the structure-borne noise due to the noise radiated from the vibrating panel was performed. Predicted noise by the Transfer Path Analysis and measured noise by the experiment were a high correlation. We confirmed the validity of the Transfer Path Analysis through the analysis of these results, showed how to apply the Transfer Path Analysis.