• 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'.

• 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.

• 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.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.1-8
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• 2013

This study investigates life and damage due to structural and fatigue load at speaker placer with wall hanger type. As the small stress and deformation are shown at the models of A, B and C shapes on structural analysis, there is no problem at installing speaker placer. As the largest stress is happened at the middle part of joint on the models of A, B and C shapes, this part must be considered at the design. A shape is thought to have most fatigue damage among 3 shape models. C shape model has most excellent, but A model has least at fatigue durability. This study result is applied with the design of speaker placer and it can be useful at predicting prevention and durability against its damage.

• Journal of Biosystems Engineering
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• v.23 no.6
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• pp.539-548
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• 1998

This study was intended to develop a load spectrum acting on a transmission of agricultural tractors. Transmission loads were measured at the input shaft of the transmission and final drive shaft of the tractors. The measurement were conducted in five field conditions at two speed levels under plowing operations in Korea. Two torque transducers were developed for the respective load measurements and other necessary instrumentations were made to collect the data and store them in a data logger. The time-histories of the torque loads were analyzed and transformed into the load spectra using the rainflow counting and Smith-Watson-Topper methods. Comparisons of the load spectra developed under different conditions were made to investigate their characteristics. The effects on the load levels of soil and plowing speeds were also investigated. Finally, a load spectrum combining the results of the spectrum analysis was developed and proposed as a load source for the reliability test of transmissions.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.88-95
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• 1998

The purpose of this study is to predict the life of a Lug under the real service load history. The techniques of predicting a fatigue life under load spectrum are discussed and some are developed. The stress is calculated by multiplying the stress under unit force with the Finite Element Analysis. The cycles are counted by the Rainflow counting method and then the mean stress effect is considered by the suggested conversion function. The Manson's Double Linear Damage Rule is used as the cummulative damage method.

• 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.

• 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.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.185-190
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• 2005

In order to evaluate that factors such as span length, member type and train loading affected on fatigue of steel railway bridges, in this paper, a series of field tests were carried out for some plate girder bridges. From the result estimated by rainflow counting method to analyze real strain-time curve obtained from the field test, it was known that the fatigue effect is more significant in the bridges having short span length and the secondary members regardless of train load types.