• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.1
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• pp.57-61
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• 2007

Special quality of automobile clutch master cylinder(CMC) and analyzed aluminum, plastic material comparison. Efficiency of plastic master cylinder can modularize higher, light weight anger of parts, several piece parts by single parts, prove NVH(Noise, Vibration, Harshness) than aluminum master cylinder as analysis result. Also, structure is easy simplicity, exchange, maintenance costs can be reduced and decrease environmental pollution because recycling is superior. According as content of glass fiber increases, mechanical properties of matter of material increase equally and glass fiber changed variously by condition on manufacturing process. Through comparison analysis with Plastic body development connection site, did verification.

• Journal of Welding and Joining
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• v.19 no.6
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• pp.652-657
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• 2001

To analyze and predict crack initiation position and propagation directions on the spot welded area are very important for strength design of the automobile body structure. It is necessary to test by method considering random loads with variable amplitude for strength design of vehicle body structure, because driving cars are actually subjected to random loads with variable amplitude in the road. Although this condition, nearly all tests haute been performed under constant load conditions in the laboratory because it is impossible to replay like an actual conditions. In this study, using in-plane bending type specimens, the overload factor affecting on the fatigue strength, crack initiation and propagation directions of spot-welded specimens have been studied.

• Proceedings of the KWS Conference
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• 2006.05a
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• pp.71-73
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• 2006

Magnesium alloys are becoming important material for light weight car body, due to their low specific density but high specific strength. However they have a poor weldability, caused high oxidization tendency and low vapor temperature. In this study, the laser welding performance of magnesium alloys was investigated for automobile application. The materials were rolled magnesium alloy sheet contains 3%Al and 1%Zn. To evaluate the weldability, we examined the appearance of welding bead. The mechanical property was measured for welded specimen by tensile test. And formability was checked with the Erichsen tester. For the results, the performance of weld in laser welding was enough for press forming such as car body. But it was recommended to use filler wire for reduce the under fill.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.140-150
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• 1990

Further developments on a dynamic biomechanical model are presented to assess musculoskeletal stresses and human responses. The model being developed is an extension of the Articulated Total Body (ATB) Model, originally developed by Calsapan Corp. for the study of human dynamics during automobile crashes, later adopted to the U.S.Air Force to simulate the reactions of aircrew personnel to such forces typically encountered in various phases of flight operations. Further refinements were introduced by Freivalds and Kaleps(1984) to account for a human neuromusculature. In this study, modelling of active neuromusculature was described and simulations of whole-body human motion were performed using the ATB Model. It indicated the potential of using a muscularized biomechanical model coupled with CAD capabilities to simulate human responses in a variety of industrial settings as well. This will serve as a basis of incorporating computer aided design methods into a muscularized biomechanical models.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.109-114
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• 2005

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.35-41
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• 2000

The crashworthiness of vehicles with finite element methods depends on the geometry modeling and the material properties. The vehicle body structures are generally composed of various members such as frames, stamped panels and deep-drawn parts from sheet metals. In order to ensure the impact characteristics of auto-body structures, the dynamic behavior of sheet metals must be examined to provide the appropriate constitutive relation. In this paper, high strain-rate tensile tests have been carried out with a tension type split Hopkinson bar apparatus specially designed for sheet metals. Experimental results from both static and dynamic tests with the tension split Hopkinson bar apparatus are interpolated to construct the Johnson-Cook and a modified Johnson-Cook equation as the constitutive relation, that should be applied to simulation of the dynamic behavior of auto-body structures. Simulation of auto-body structures has been carried out with an elasto-plastic finite element method with explicit time integration. The stress integration scheme with the plastic predictor-elastic corrector method is adopted in order to accurately keep track of the stress-strain relation for the rate-dependent model accurately. The crashworthiness of the structure with quasi-static constitutive relation is compared to the one with the rate-dependent constitutive model. Numerical simulation has been carried out for frontal frames and a hood of an automobile. Deformed shapes and the Impact energy absorption of the structure are investigated with the variation of the strain rate.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.85-91
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• 2001

Background : It goes without saying that cumulative trauma disorders is spreading to various types of occupation in many advanced countries including America, and it forms considerable rate of total occupational disorders already. and as the result of it, the seriousness of worker health problem and economic loss owing to production loss, recuperation expense, etc. are on the increasing trend through whole society. In case of Korea, the related measures as well as accurate fact-finding survey data on cumulative trauma disorders aren't prepared in detail, so it implies forward problem would be serious. Purpose : The purpose of this study is to draw the risk factor of cumulative trauma disorders in production factory, to forecast the rate of occurrence of cumulative trauma disorders on the basis of subjective symptoms, and to present forward realistic and effective prevention measures by showing the risk of cumulative trauma disorders, objecting the production factory of a domestic riding automobile assembly shop, by estimating in the aspect of human-engineering through the analysis of risk factor being a cause of cumulative trauma disorders. Methods : For this study, I investigated work type and on-duty hours, breathing time, and subjective symptoms of cumulative trauma disorders through questionnaire, objecting the workers in press. car body, coating, and outfit factory. Results : As a result of research, 81.2% of workers were in the physical burden due to present working, and the highest prevalence by part of body is an waist. The higher a rule score, The higher the number of workers complaind for working intensity, and the higher age work duration, tool used time, the higher prevalence of subjective symptoms by part of body. The number of workers complaind subjective symptom for treatment is the highest in drugstore.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.31.1-31.14
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• 2022

Background: This study aimed to investigate the characteristics of work-related musculoskeletal disorders (WRMSDs) in occupational disease claims and identify patterns of WRMSDs for each body part by industry and occupation. Methods: This study analyzed the raw data of occupational disease claims for musculoskeletal disorders deliberated by the Occupational Disease Decision Committee of the Korea Workers' Compensation & Welfare Service in 2020. The data was classified into 6 body parts with the highest numbers of occupational disease cases by using the complete enumeration data on principal diagnoses and 4 types of subdiagnoses in the raw data. The characteristics and approval rates of WRMSDs by body part, industry and occupation were examined and summarized. Results: A total of 13,015 occupational disease cases for WRMSDs were classified, and lumbar spinal (back) diseases accounted for the largest proportion of claimed diseases, followed by shoulder, elbow, wrist, knee, and neck diseases in a descending order. The occupations with the highest and second highest numbers of occupational disease cases by body part were found to be automobile assemblers and production-related elementary workers for the neck, school meal service workers and cooks for the back, construction frame mold carpenters and school meal service workers for the shoulder, elementary workers in mining and food service workers for the elbow, food service workers and automobile parts assemblers for the wrist, and ship welders and school meal service workers for the knee. Conclusions: This study examined the characteristics and approval status of WRMSDs by body part and occupation. Based on the study results, management strategies for the prevention of WRMSDs should be established regarding occupations with a high risk of WRMSDs for each body part.

• Proceedings of the KWS Conference
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• 2001.10a
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• pp.184-186
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• 2001

Quality estimation of the weld has been one of the important issues in RSW which is a main process of the sheet metal fabrication in auto-body industry. It was well known that among the various welding process variables, dynamic resistance has a close relation with nugget formation. In this study, a new quality estimation algorithm is developed with the primary dynamic resistance measured at welding machine timer. For this, Back propagation algorithm of neural network is used.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5113-5119
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• 2010

Anthropometry has been broadly explored in various fields including automobile industry, home electronic appliances, medical appliances and sports goods with aiming at reaching satisfaction to consumer's need and efficiency. However, current technologies to measure a human body still have barriers in which the methods mostly seem to be contingent on expensive devices such as scanner and digital measuring instruments and to be directly touchable to the body when obtaining body size.. Therefore, in this paper, we present a general method to automatically extract size of body from a real body image acquired from a camera and to utilize it into recommend systems including clothing and bicycle fitting. At first, Haar-like features and AdaBoost algorithm are employed to detect body position. Then features of body can be recognized using AAM. Finally clothing and bicycle recommending modules have been implemented and experimented to validate the proposed method.