• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.208-213
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• 2015

In this study, two models due to the configuration of caliper cylinder among the parts of automotive brake system are studied by structural and fatigue analysis. As the maximum equivalent stress at model 2 becomes 1.5 times lower than model 1, model 2 can endure load higher than model 1. In case of fatigue damage analysis on model 1 and 2, model 1 has the damage area more than model 2. Fatigue damage at model 1 happen more than model 2. These study results can be effectively utilized with the design on caliper cylinder by anticipating prevention against its damage and investigating durability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.534-538
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• 2008

The vehicle system is exposed to random source in service. Therefore, it is important to consider dynamic effect of the system. But, fatigue analysis is traditionally performed by using time signal of loading. To obtain dynamic effect of resonance, we carried out resonance durability analysis with frequency response and the dynamic load on frequency domain. The study shows that the damage considering resonant frequency of fuel tank system can be effectively estimated.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.137-144
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• 2013

This study analyzes structural analysis with fatigue and natural frequency on ATV knuckle. The maximum equivalent stresses are happened at the end of knuckle in case of model 1, 2 and 3. As these stresses are below the allowable stress, these models can be stable structurally. The fatigue damage possibility at model 1 becomes more than model 2 and 3. Model 2 or 3 has more durability than model 1 at fatigue. As the resonances are happened at the frequency more than 2000 Hz in case of model 1, 2 and 3, there is no resonance possibilities at real driving. Prevention against damage and durability prediction on automotive chassis parts can be effectively improved by applying this study result on knuckle and improving structural strength.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.68-74
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• 2014

This study analyzes structural stress and fatigue about three types of automotive wheels. As maximum equivalent stresses at 1, 2 and 3 types become lower than the yield stress of material and deformations become minute, theses types are thought be safe on durability. Type 2 model has the most fatigue life among three kinds of types and the rest of models with fatigue lives are shown in the order of type 1 and 3. As the most fatigue frequency of type 2 model happens at the state of average stress and amplitude stress on the stress range narrower than type 1 or 3, type 2 model becomes most stable. In case of type 2 with the state near the average stress of 0 MPa and the amplitude stress of 300MPa, the possibility of maximum damage becomes 30%. This stress state can be shown as the most damage possibility. These study results can be effectively utilized with the design on automotive wheel by anticipating and investigating prevention and durability against its damage.

• Corrosion Science and Technology
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• v.20 no.6
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• pp.384-390
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• 2021

In this paper, durability evaluation and surface damage mechanism were investigated through solid particle erosion (SPE) test after applying hot-dip aluminizing (HDA) technology for the purpose of maintenance of marine economizer tube. Damaged surface shape was analyzed using SEM and 3D microscope. Compositional changes and microstructure of the HDA layer were analyzed through EDS and XRD. Durability was evaluated by analyzing weight loss and surface damage depth after SPE. HDA was confirmed to have a two-layer structure of Al and Al₅Fe₂. HDA+HT was made into a single alloy layer of Al₅Fe₂ by diffusion treatment. In the microstructure of HDA+HT, void and crack defect were induced during the crystal phase transformation process. The SPE damage mechanism depends on material properties. Plastic deformation occurred in the substrate and HDA due to ductility, whereas weight loss due to brittleness occurred significantly in HDA+HT. As a result, the substrate and HDA showed better SPE resistance than HDA+HT.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.28-38
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• 2019

Purpose: The purpose of this study is to contribute to improvement of measurement management level of construction structure and technology development of monitoring sensor by presenting the detailed causes and improvement plans of construction monitoring sensor's decline in durability. Method: The causes and improvement plans of the durability degradation of the construction monitoring sensor were divided into the construction field and the electric, electronic field. The detailed status was reviewed. Results: In the field of construction, approval and inspection, inspection and testing, verification and calibration, and minimization of loss and damage ratio were reviewed. In the field of electric and electronics, sensor package and sealing, disconnection of stress concentration area, damage caused by lightning and corrosion were reviewed. Conclusion: It is expected that the durability of monitoring sensors applied to the construction site will become longer than the present status based on the study that analyzed causes and improvement plans of construction monitoring sensor's decline in durability in the field of construction and electric, electronic devices.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.143-149
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• 2017

Purpose: In recent years, weight reduction for improving fuel efficiency of the vehicle and cost reduction have been developed. The structure of suspension link is widely used as a single plate press structure which can reduce process and weight compared to existing pipe welding method. However, it was found that the lifetime of a single plate press structure is determined by initial defects that occurred during initial manufacturing rather than fatigue damage caused by driving. Methods: I research the mechanism of failure phenomenon of the single plate press assist arm of rear wheel. In addition, I investigate durability effect parameters to determine the link lifetime in inserting bush into single plate press process through durability test. Conclusion: I discover significant durability effect parameter in inserting bush into single plate press process. It is expected that the durability can be improved by suggesting a bush inserting process inspection guide for similar suspension link like single plate press structure.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.427-433
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• 2011

Chassis part in automotive body is affected by fatigue load at driving on the ground. Universal joint on this part is influenced extremely by the fatigue load. Fatigue life, damage and natural frequency are analyzed at universal joint under nonuniform fatigue load. The york part at universal joint is shown with the maximum equivalent stress and displacement of 60.755 MPa and 0.21086 mm as strength analysis. The possible life in use in case of 'SAE bracket' is the shortest among the fatigue loading lives of 'SAE bracket', 'SAE transmission' and 'Sine Wave'. The damage at loading life of 'SAE transmission' is the least among 3 types. The frequency of damage in case of 'Sine Wave' is 0.7 with the least among 3 fatigue loading life types but this case brings the most possible damage as 80% at the average stress of 0. Natural vibration at this model is analyzed with the orders of 1'st to 5'th and maximum frequency is shown as 701.73 Hz at 5'th order. As the result of this study is applied by the universal joint on chassis part, the prevention on fatigue damage in automotive body and its durability are predicted.

• 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.