• Title/Summary/Keyword: 불규칙 피로 하중들

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A Study on Structural Durability due to the Configuration of Ripper at Excavator (굴착기에서의 리퍼의 형상에 따른 구조적 내구성 연구)

  • Kang, Min-Jae;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
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    • v.5 no.2
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    • pp.13-18
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    • 2014
  • In this study, two models due to the configuration of ripper at excavator are investigated by structural and fatigue analyses. The maximum stress and deformation are happened at the axis connected with the body of working device and the direct working part respectively. Model 1 is thought to have more structural durability than model 2. Fatigue life or damage in case of 'SAE bracket history' whose load change is most severest among non-uniform fatigue loads is shown to become most unstable. But life or damage in case of 'Sample history' whose load change is slowest among non-uniform fatigue loads is shown to become most stable. These study results can be effectively utilized with the design of ripper at excavator by anticipating and investigating prevention and durability against its fatigue damage.

Structural Analysis of Engine Mounting Bracket (엔진 마운팅 브라켓의 구조해석)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.4
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    • pp.525-531
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    • 2012
  • This study aims at the structural analysis of vibration and fatigue according to the configuration of engine mount. Maximum equivalent stress or deformation is shown at bracket or case respectively. As harmonic vibration analysis, the maximum displacement amplitude is happened at 4,000Hz. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' or 'Saw tooth' becomes most stable. In case of 'Sample history' or 'Saw tooth' with the average stress of 4,200MPa or 0MPa and the amplitude stress of -3,000MPa or 7MPa, the possibility of maximum damage becomes 70%. This stress state can be shown with 7 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 on engine mount by investigating prevention and durability against its damage.

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.

Structural Safety Analysis on Bicycle Suspension Seat Post (자전거 서스펜션 안장봉에 대한 구조 안정성 해석)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.4
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    • pp.72-81
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    • 2012
  • This study investigates structural, fatigue and modal analyses at bicycle suspension seat post. When weight is applied to the saddle, models 1 and 2 have the weakest strength at the part connected with saddle. And model 2 is greater total deformation and equivalent stress than model 1. 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 $-10^4MPa$ and the amplitude stress of 0 to $10^4MPa$, the possibility of maximum damage becomes 4%. This stress state can be shown with 5 to 7times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. Model 1 has better impulse relaxation and passenger sensitivity than model 2. The structural result of this study can be effectively utilized with the design of bicycle suspension seat post by investigating prevention and durability against its damage.

Structural Analysis on the Wheel of Railway Vehicle (철도차량의 바퀴에 대한 구조 해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.451-458
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    • 2012
  • This study aims at the structural analysis with fatigue according to the configuration of railway vehicle wheel. Maximum equivalent stress or deformation is shown at the lower face in contact with wheel and rail. As model B has the maximum stress or deformation which becomes lower than model A, model B is shown to have more durability than model A. 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 $-10^{11}$ Pa and the amplitude stress of 0 to $10^{10}$ Pa, 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'. The structural result of this study can be effectively utilized with the design of railway vehicle wheel by prevention and durability against its damage.

Structural Safety Analysis of Clutch System (클러치의 구조 안전 해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.5
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    • pp.148-155
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    • 2011
  • This study analyzes stress, fatigue and vibration at clutch on the rotation of wheel. Eigenfrequencies from 1'st to 6'th order about clutch assembly are shown with the vibration at more than 800Hz. Maximum equivalent stress is shown with the frequency of 800Hz in case of the harmonic vibration 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 0MPa to $-10^5$ MPa and the amplitude stress of 0MPa to $10^5$ MPa, the possibility of maximum damage becomes 3.23%. This stress state can be shown with 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 safe design of clutch.

Structure and Fatigue Analyses of the Inspection Equipment Frame of a Semiconductor Test Handler Picker (반도체 테스트 핸들러 픽커 검사장비 프레임에 대한 구조 및 피로해석)

  • Kim, Young-Choon;Kim, Young-Jin;Kook, Jeong-Han;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.5906-5911
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    • 2014
  • Currently, there are many processes of package assembly and inspections of real fields that examine whether a manufactured semiconductor can be operated regularly and can endure low humidity or high temperatures. As the inspection equipment of a semiconductor test handler picker has been used at the inspection process, these inspection equipment frames were modelled in 3D and these models were analyzed using 3 kinds of fatigue loadings. As the analysis result, maximum deformation occurred at the midparts of the frames at cases 1 and 2. Among the cases of nonuniform fatigue loads, the 'SAE bracket history' with the severest change in load became the most unstable but the 'Sample history' became the most stable. Fatigue analysis result can be used effectively with the design of an inspecting equipment frame of a semiconductor test handler picker to examine the prevention and durability against damage.

Structural Durability Analysis of Tie Rod (타이로드의 구조적 내구성 해석)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.5
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    • pp.68-75
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    • 2012
  • This study aims at the structural analysis of vibration and fatigue according to the tie rod configuration. The maximum displacement amplitude is happened at 156Hz by harmonic vibration analysis, this tie rod model can be broken as the weakest state. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sine wave' becomes most stable. In case of 'Sine wave' with the average stress of 0MPa and the amplitude stress of 570MPa, the possibility of maximum damage becomes 70%. This stress state can be shown with 140 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 on tie rod by investigating prevention and durability against its damage.

Study on Fatigue Analysis of DCB Specimen Bonded (접착제로 접합된 DCB 시험편의 피로 해석에 관한 연구)

  • Choi, Hae-Kyu;Hong, Soon-Jik;Kim, Sei-Hwan;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.2865-2871
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    • 2012
  • In this study, the fracture behaviour of DCB(double cantilever beam) specimen with aluminum foam composite materials is analyzed by simulation. By comparing the analysis results with two models of 25 mm and 40 mm, the model with thickness of 25 mm is weaker than 40 mm at fatigue life and damage. Two models are unfavorable at 'SAE Transmission' in case of nonuniform fatigue load and rainflow matrices are weakest at 'SAE Bracket history'. In damage matrices, the model with 25 mm of thickness is weaker than the model with 40 mm of thickness but the model with 40 mm of thickness relative damage possibility is higher than in case of 25 mm. As two models are safest at 'SAE Transmission', the relative damage becomes the lowest value from 1.1 to 1.8 %. The mechanical property can be investigated by applying these analyses results with the real composite structure bonded with adhesive and analyzing fracture behaviour.