• Title, Summary, Keyword: Rainflow matrix

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The Analysis of Fatigue Damage in Structure under Variable Load (변동 하중을 받는 구조물에서의 피로 파손 해석)

  • 한문식;조재웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.4
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    • pp.85-93
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    • 2004
  • The variable fatigue load is simulated in this study, The stability and the life of the material are analyzed theoretically by the program of Ansys workbench. These results are successfully applied to the practical structures to predict the prevention of fracture and the endurance, The life and the damage on the every part of the fatigue specimen can be predicted. As the available lives are compared for every loading variation, the rainflow and damage matrix results can be helpful in determining the effects of small stress cycles in any loading history. The rainflow and damage matrices illustrate the possible effects of infinite life. The safety and stability of fatigue specimen according to the variable load can be estimated by using the results of this study.

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.

Analysis of Fatigue Damage at Wheel under Variable Load (불규칙 하중을 받는 휠에서의 피로 파손 해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.19 no.6
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    • pp.753-759
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    • 2010
  • The variable fatigue load is simulated in this study. The stability and the life of the material are analyzed theoretically by Ansys program. These results are successfully applied to the practical wheel to predict the prevention of fracture and the endurance. The life and the damage on the every part of the fatigue specimen can be predicted. As the available lives are compared for every loading variation, the rain flow and damage matrix results can be helpful in determining the effects of small stress cycles in any loading history. The rainbow and damage matrices illustrate the possible effects of infinite life. The safety and stability of wheel and the other practical structures according to the variable load can be estimated by using the results of this study.

Development of Programs to Analyze Mechanical Load Data of Wind Turbine Generator Systems and Case Studies on Simulation Data (풍력발전시스템의 기계적 하중 데이터 분석 프로그램 개발과 시뮬레이션 데이터 적용 사례)

  • Bang, Je-Sung;Han, Jeong-Woo;Gil, Kyehwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.8
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    • pp.789-798
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    • 2013
  • The procedures and relevant programs developed for analyzing mechanical load data of wind turbine generator systems, which are obtained through type certification tests, are verified. The following issues according to IEC 61400-13 are covered in the developed programs: data validation, time series analysis, summary load statistics, generation of fatigue load spectra, and estimation of equivalent loads. A capture matrix for normal power production is generated to determine whether the collected data sets are sufficient to carry out fatigue analysis. Fatigue load spectra are obtained through the rainflow counting method using 50 load ranges; finally, equivalent loads are calculated using different S-N curve slopes, m, according to the relevant materials. Case studies are performed using aero-elastic simulation data of the NREL 5 MW baseline wind turbine with a monopile foundation.

Analysis on Fatigue Fracture at Cam Shaft (캠축에서의 피로파괴해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.4
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    • pp.102-108
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    • 2008
  • This study investigates the fatigue life and the damage possibility of cam shaft by the fatigue tool of Ansys. Among nonconstant fatigue loads, the case of 'SAE Bracket History' which is severest at the variation of load tends to be most unstable. The 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 take more damage than other cases. The case of 'Sample History' which becomes a little slow at the variation of load tends to be most stable. But there is most damaged possibility of 5% as 7 times at the range of mean stress from 0Pa to -104MPa and amplitude stress from 0MPa to 104MPa than the case of 'SAE Bracket History' or 'SAE Transmission'.

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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.

The Analysis of Fatigue Damage of Connecting Rod under Various Load (다양한 하중을 받는 커넥팅 로드의 피로 파손 해석)

  • Cho, Jae-Ung;Choi, Doo-Seuk;Kim, Key-Sun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.154-162
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    • 2005
  • This study investigates the fatigue life and the damage possibility of connecting rod by the fatigue tool of Ansys workbench. The case of constant fatigue loading variation 'Sine' becomes more stable than that of nonconstant loading but the magnitude of constant load becomes larger than that of nonconstant load. Among nonconstant fatigue loads, the case of 'SAE Bracket History' which is severest at the variation of load tends to be most unstable. The case of 'Sample History2' which becomes a little slow at the variation of load tends to be most stable. The 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 take more damage than another case.

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.