• Title/Summary/Keyword: damage history

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Study on Structural Analysis of Flywheel under Rotary Power (회전력을 받는 플라이휠의 구조해석에 관한 연구)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.2
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    • pp.137-143
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    • 2012
  • This study analyzes flywheel through the analyses of stress, fatigue and vibration. Maximum equivalent stress is 15.271MPa at the mid round shape and maximum deformation is 0.02264mm at the outer teeth. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -$10^4$MPa and the amplitude stress of 1000 to 2900MPa, the possibility of maximum damage becomes 30%. This stress state can be 20 times greater than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The range of natural frequencies becomes 200 to 820Hz and the values of these deformations are not more than 10mm. The structural result of this study can be effectively utilized with the design of flywheel by investigating prevention and durability against its damage.

Study on Fatigue Durability Analysis of Poclain Bucket (포크레인 버켓의 피로 내구성 해석에 대한 연구)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.2
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    • pp.8-13
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    • 2013
  • This study analyzes about poclain bucket through fatigue durability analysis. Maximum equivalent stress and total deformation are shown at the lower of bucket and edge part respectively. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -10000Pa to 5000MPa and the amplitude stress of 0 to 6000MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 or 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of poclain bucket by investigating prevention and durability against fatigue damage.

Structural and Fatigue Analysis on Bicycle Pedal (자전거 페달에 대한 구조 및 피로 해석)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.1
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    • pp.51-57
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    • 2012
  • This study investigates structural and fatigue analyses at bicycle pedal. Maximum deformation at model 1 is 2 times as much as model 2 at static analysis. Models 1 and 2 have the possibility of the weakest strength at the part of contact with chain gear. Among the cases of nonuniform fatigue loads at Models 1 and 2, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-10^4$ MPa and the amplitude stress of 0 to $10^4$ MPa, the possibility of maximum damage becomes 4%. This stress state can be shown with 5 to 7 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The analysis result of this study can be effectively utilized with the safe design of pedal.

Study on Durability by Structural Analysis of Bulldozer (불도저의 구조해석에 의한 내구성 연구)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.3
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    • pp.239-244
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    • 2011
  • This study analyzes the behaviors on stress, fatigue and vibration about bulldozer in operation. Maximum equivalent stress is shown with the frequency of 100 Hz in case of the harmonic vibration analysis applied with force. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to -105MPa and the amplitude stress of 0 to $1.617{\times}105MPa$, the possibility of maximum damage becomes 3.23%. This stress state can be shown with 5 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of bulldozer by investigating prevention and durability against its damage.

Structural Analysis on Control Arm of Automobile under Nonuniform Fatigue Load (불규칙 피로 하중을 받는 자동차의 컨트롤 암의 구조 해석)

  • Cho, Jae-Ung
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.3
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    • pp.87-92
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    • 2011
  • This study analyzes structural stress and fatigue on control arm of automobile under nonuniform load. Maximum equivalent stress at bolt part is shown with 419.1MPa and the corner is deformed with maximum displacement of 1.1628mm. Among 3 cases of nonuniform fatigue loads applying on control arm, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of $-10^5MPa$ to $10^5MPa$ and the amplitude stress of 0 MPa to $10^5MPa$, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. Safety and durability on automobile can be effectively improved by applying the fatigue analysis result on control arm.

Study on Structural Safety Analysis of Upper Arm (어퍼암의 구조적 안전성 해석에 대한 연구)

  • Cho, Jaeung;Han, Moonsik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.113-125
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    • 2013
  • This study analyzes upper arm as the part of suspension through the structural analyses of fatigue. Maximum displacement is shown at the knuckle joint connected with the bracket of automotive body. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. Maximum life at 'Sample history' or 'SAE transmission' can be shown with 60 or 3.5 times more than 'SAE bracket history' respectively. In case of 'Sample history' with the average stress of $-4{\times}10^4$ to $4{\times}10^4$ MPa and the amplitude stress 0 to $8{\times}10^4$ MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 or 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. This study result is applied with the design of upper arm and it can be useful at predicting prevention and durability against its damage.

Study on Fatigue Fracture at Disk Brake (원판브레이크에서의 피로파괴연구)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.2
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    • pp.201-206
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    • 2009
  • This study investigates fatigue life and possibility damaged at disk brake of automobile by the simulation of fatigue analysis. Among nonconstant fatigue loads, the case of 'SAE Bracket History' which is the severest at the variation of load tends to be most unstable. The case of 'Sample History' which becomes slower at the variation of load tends to be most stable. The value of maximum relative damage in case of 'SAE Bracket History' is occurred near the average stress '0' and this case can be shown to have the possibility to affect more damage than another case. As the result of this study is applied to automobile parts with non constant loads, durability can be improved during drive by preventing any damage.

A Study of the Concept of Cold Damage and The Shanghanlun (Treatise on Cold Damage) as They Appear in The Diary of Muk-Jae (『묵재일기(默齋日記)』 속 상한(傷寒) 및 『상한론(傷寒論)』에 대한 인식 연구)

  • Cho, Seong-Hwan;Kim, Dong-Ryul
    • The Journal of Korean Medical History
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    • v.32 no.1
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    • pp.77-86
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    • 2019
  • The Diary of Muk-Jae is a historical record that describes many social aspects of the Joseon period in the 16th century. It records many scenes of its author, Lee Mun-Geon, treating patients. This paper uses The Diary of Muk-Jae to examine changes in the perception of the concept of cold damage and the text of the Shanghanlun (Treatise on Cold Damage) in the Joseon period in the 16th century. In The Diary of Muk-Jae, cold damage is understood in connection with two categories: 'dangerous disease' and 'disease caused by cold'. The Diary of Muk-Jae also presents the Shanghanlun not as a work limited to the concept of cold damage, but as a medical text that could be widely used for many different diseases. Thus, The Diary of Muk-Jae may represent a point of transition between in the perception of cold damage as seen in the Uibang Yuchui (The Collection of Medical Procedures) of the 15th century and the Donguibogam of the 17th century.

Developing a Standardized Patient Program using Internal Damage Fever Cases in Korean Medical Education (한의학 교육에서 내상발열(內傷發熱) 증례를 이용한 표준화환자 프로그램 개발 연구)

  • Jo, Hak-jun;Jo, Na-young
    • Journal of Korean Medical classics
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    • v.33 no.4
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    • pp.33-56
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    • 2020
  • Objectives : The objective of this paper is to develop a standardized patient program with a focus on diagnosis and treatment of internal damage fever in Korean Medical education. Methods : First, cases of diagnosis and treatment of internal damage fever were collected from various classical texts, then a module was developed according to pre-existing standardized patient program's protocols based on selected cases. Careful consideration was given to developing evaluation criteria on history taking and physical examination that are necessary to accurately differentiating the 9 types. Results : Nine types of differentiation models on internal damage fever were selected, which are qi deficiency from overexertion/fatigue and famish; blood deficiency from overexertion/fatigue, famish and fullness; fire stagnation from excessive eating and cold foods; food damage; yang deficiency; yin deficiency; phlegm; stagnated blood; liver qi stagnation. For each type, evaluation criteria in regards to history taking, physical examination, communication with patient, and patient education were developed. Conclusions : When developing a standardized patient program using internal damage fever cases, it would better reflect the characteristics of Korean Medicine in clinical education of Korean Medicine if the program is based on classical texts. It would also be useful in evaluating students' graduation competence in exams such as CPX.

Structural Analysis on Durability of Forklift due to Opening and Closing Between Forks (개폐에 따른 지게차 포크의 내구성에 대한 구조해석)

  • Cho, Jaeung;Han, Moonsik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.199-205
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    • 2013
  • Stress and deformation on forklift happened at loading, unloading or moving freight are studied by structural and fatigue analysis in this study. As model 1 as closing type between forks has lower stress and stain than model 2 at opening type, model 1 has more durability than model 2. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'SAE bracket history' with the severest change of load at model 1 and 2, maximum life is shown with Cycle. Minimum damage with 854 at model 2 becomes much higher than model 1. As the gap between forks becomes open, the damage probability becomes higher. The structural result of this study can be effectively utilized with the safe and stable design of forklift by investigating prevention and durability against its damage.