• 한국생산제조학회지
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• 제25권6호
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• pp.445-451
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• 2016

The Inconel 718 alloy is a well-known super-heat-resistant alloy and a difficult-to-cut material. Inconel 718 with excellent corrosion and heat resistance is used in harsh environments. However, the heat generated is not released owing to excellent physical properties, making processes (e.g., adhesion and thermal fatigue) difficult. Tool condition monitoring in machining is significant in reducing manufacturing costs. The cutting tool is easily broken and worn because of the material properties of Inconel 718. Therefore, tool management is required to improve tool life and machinability. This study proposes a method of predicting the tool wear with non-contacting sensors (e.g., IR thermometer for measuring the cutting temperature and a microphone for measuring the sound pressure level in machining). The cutting temperature and sound pressure fluctuation according to the tool condition and cutting force are analyzed using experimental data. This experiment verifies the effectiveness of the non-contact measurement signals in tool condition monitoring.

• Journal of Welding and Joining
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• 제34권6호
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• pp.28-34
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• 2016

Galvannealed(GA) steels are now generally used in car body manufacturing for corrosion resistance. In this study, the weldability and joint mechanical behavior of a newly developed 1.2GPa grade GA ultra high strength TRIP(transformation induced plasticity) steel was investigated for three joining processes, such as adhesive bonding, resistance spot welding and weldbonding. Under both shear and peel stress conditions, the failure mode of the adhesive joints were the mixture of the adhesive cohesive failure, adhesive interface failure and coating layer failure. It means that the adhesion strength of GA coating onto the base metal was similar to that of adhesive bonding onto the GA coating. Under the shear stress condition, the weldbonding exerted to expand the optimal spot welding condition of 1.2GPa GA TRIP steel because the strength of adhesive bond overwhelmed that of the resistance spot weld. Under the peel stress condition, the weldbonding also exerted to expand the optimal spot welding condition of 1.2GPa GA TRIP steel by inducing the tear fracture mode rather than the partial plug fracture mode.

• 한국공작기계학회논문집
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• 제14권2호
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• pp.62-68
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• 2005

The objective of this study is structural analysis and modal analysis of treadmill roller. A 3D finite element model is implemented to calculate the stress, strain and natural frequency for treadmill roller In order to analyses treadmill roller, many variables such as load condition, boundary condition, weight condition and resonance are considered. Natural frequency of treadmill is compare to motor revolution.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.996-999
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• 2001

This study is the election of optimum forming condition for RP system using ADS. Program using ADS reduces the required time for feedback between design and manufacturing of workpiece. When we produce rapid prototype using RP system, we investigate the relationship between Facetres in system variable number of AutoCAD and circularity of rapid prototype, and we will find optimum forming condition in RP system.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 제2회 단조심포지엄 단조기술의 진보
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• pp.74-80
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• 1995

Forged aluminum lower arm has been developed to provide weight reduction of suspension parts. It was utilized FEM analysis in design of parts. Prototype parts were producted to two shape & different forging condition. Difference of forging condition was manufacturing process of stock, forging press, forging die, heat treatment condition. As a result, weight reduction of 44%, 38% was achived. Strength and fatigue endurance of forged aluminum lower arm was excellent.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.573-578
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• 2000

Recently, Tailor Welded Blanks(TWB) is widely used in automotive industry since the transformation characteristics of its material can be changed. However, clearance between welding surface becomes the important factor which affect the quality of the laser weld, causing difficulties in preparing the sheet. The objective of this paper is to systematically evaluate the effects of previously presented fracture criterion and shearing condition on precise mechanical shearing simulation result. Also predict the optimum shearing condition, effect of shearing condition such as clearance and punch radius on the shear plane shape was evaluated.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.73-77
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• 2004

This study is object to design and structural analysis of Long Pull weight machine. Structural analysis of Long Pull weight machine using result from ANSYS code. This structural analysis results, many variables such as boundary condition, constraints and load condition were considered.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.69-74
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• 2002

This study is object to structural analysis of high pressure injection nozzle. The finite element model was developed to compute the stress, strain for high pressure injection nozzle. For structural analysis using result from FEM code. This structural analysis results, many variables such as internal pressure, boundary condition, constraint condition and load condition are considered.

• 한국기계가공학회지
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• 제13권1호
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• pp.1-7
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• 2014

An impeller is difficult to machine due to the complex, overlapping and twisted shapes that form the blades of an impeller. Therefore, most CAM software companies have developed a CAM module for manufacturing an impeller in addition to their CAM software. However, it is not easy for inexperienced users to machine impellers. The purpose of this paper is to outline the development of an automatic CAM module for the manufacturing of an impeller (E-ICAM) which is based on visual basic language and which uses a CATIA graphical environment in order to simplify the machining of impellers. The automatic CAM module generates a tool path and proposes the recommended cutting condition according to the stock and tool material. In addition, it includes a post-processor for five-axis control machining. Therefore, a user can easily machine impellers using this automation module. There are two types of impellers: the closed and open types. The closed-type impeller consists of the body and cover parts. To combine these two parts, it is necessary to create tap holes on the shroud of the body. Therefore, in the study, a drilling CAM program for a closed-type impeller is developed and manufactured by creating NC data from the developed drilling program. After manufacturing the test specimen, its compatibility was verified.

• 한국환경보건학회지
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• 제30권3호
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• pp.272-282
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• 2004

Stress is a primary health promotion issue in worksite research because psychological distress is closely related not only to workers　 health status but also to their job performance. This study identified the work environment and work condition factors affecting workers　 stress symptoms among the Korean manufacturing factory workers. A total of 7,818 factory workers employed in 1,562 manufacturing companies participated in the Korean nation-wide occupational health survey conducted by the Korean Occupational Safety and Health Agency in 2003. Participants were selected by the stratified proportional sampling process by standardized industry classification, company size, and locations. Trained interviewers visited the target companies and interviewed the factory workers randomly selected in each company. Work environments included physical work environments (temperature, noise, hazardous organic compounds, and so on) and psychological work environments (job demands, job control, and social support at work), and work conditions included daily working hour, rest time, and so on. Men were 71.5% and the mean age was 34.0 years old. The average working period in the present company was 6.9 years. The average stress score was 26.2 under the perfect score, 50, which means the moderate level of stress. Perceived stress had significant correlations with young age, poor physical work environment, high fatigue, bad perceived health status, and high job demands in Pearson's simple correlation analysis. Perceived health status and perceived fatigue explained 21% variance of stress symptoms and the work environment factor explained 4.8% of that; however, work condition did not have the sufficient effect. In particular, psychosocial work environment variables (job demand, job control, and social support at work) had a clear effect on stress symptoms rather than the physical work environments. Poor perceived health status, severe perceived fatigue, poor physical work environment, high job demands, low social support, heavy alcohol consumption and little exercise were significantly related to high stress symptoms in the Korean manufacturing workers.