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Bae, Woo Seok;Oh, Se Wook;Shin, Bang Woong
- KSCE Journal of Civil and Environmental Engineering Research
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- v.26 no.1C
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- pp.19-24
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- 2006
In this study, centrifugal model tests were performed to evaluate the stress sharing between SCP and surrounding clayey soil at composite ground improved by sand compaction pile with the low area replacement ratio. The SCPs were formed by the "frozen pile" method and pressure cells were installed on pile and surrounding clayey soil to observe stress sharing characteristics. As a result of centrifugal tests, it is shown that the value of stress concentration ratio is mainly affected by area replacement ratio, loading condition and elapsed time.
https://doi.org/10.12652/Ksce.2006.26.1C.019 인용 PDF

Seungwoon Park;Yeong Hwan Han;Ho Young Jeon;Chul-Hee Lee
- Journal of Drive and Control
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- v.20 no.4
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- pp.9-16
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- 2023
This paper analyzed a drainage tower used to drain water in flooded areas. Multi-body dynamics simulation was used to analyze the dynamic behavior of the drainage tower. Structural analysis, flexible-body dynamic analysis, and rigid body dynamic analysis were done to study the maximum Von-Mises stress of the drainage tower. The results showed that the maximum Von-Mises stress occurs at the turn table, and it decreases when the angle of the boom is increased. Also, the rate of the change of angle affects the maximum stress so that the maximum stress changes more when the angular velocity of the boom increases. Based on the rigid body dynamic analysis and the theoretical analysis results, the centrifugal force from the angular velocity makes the difference in the maximum stress at the turn table because of the difference in their direction. Consequently, it was concluded that the centrifugal force should be considered when designing construction machinerythat can rotate.
https://doi.org/10.7839/ksfc.2023.20.4.009 인용 PDF

Pak, Sung Joon;Ju, Heongkyu
- Journal of Korea Foundry Society
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- v.41 no.2
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- pp.127-131
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- 2021
Based on its good compatibility with high-temperature environments, the Ti-48Al-2Cr-2Nb alloy is used for high-temperature materials of industrial equipment. In this study, a Ti-48Al-2Cr-2Nb alloy turbocharger turbine wheel was fabricated by a vacuum centrifugal casting method. The conditions that prevent misrun defects of the turbocharger turbine wheel blade from centrifugal casting using alumina molds were investigated. The microstructure of the alloy prepared by vacuum centrifugal casting was studied by means of optical microscopy (OM), with a micro-Vickers hardness analyzer (HV), by X-ray diffraction (XRD) and by SEM-EDS. The HV and SEM-EDS examinations of the as-cast Ti-48Al-2Cr-2Nb alloy showed that the thickness of the oxide layer (α-case) was typically less than 50 ㎛. At a high preheating temperature of 1,100℃, a moderate RPM of 260, and with an alumina mold with a large gate size, there were almost no misrun defects. Therefore, it was confirmed that a Ti-48Al-2Cr-2Nb alloy turbocharger turbine wheel with fewer misrun defects could be achieved through a high preheating temperature, a moderate RPM, a large gate size and an alumina mold to suppress the formation of alpha-case components.
https://doi.org/10.7777/jkfs.2020.41.2.127 인용 PDF KSCI