• Title/Summary/Keyword: Thread Joint Stiffness

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The Effect of the Bolted Joint Stiffness on the Thrust Measurement Stand (볼트의 체결 강성이 추력 시험대에 미치는 영향)

  • Lee, Kyujoon;Jung, Chihoon;Ahn, Dongchan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.5
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    • pp.31-39
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    • 2016
  • This paper is studied on the effect of the bolt joint stiffness on the Thrust Measurement Stand(TMS). TMS is a test stand for thrust performance of the propulsion system, which depends on two factors: The $1^{st}$ is the parallel degree between directions of the thrust vector and action lines of the corresponding measuring load cells for the vector, and the $2^{nd}$ is the orthogonality between action lines of the measuring load cells. Therefore, it is essential to maintain the original shape of the TMS under operating conditions. In this paper, it is examined how the geometric tolerance of the bolt joints and threads of the load cell trains affect the performance of the TMS. Also, some techniques to overcome related problems are proposed.

Performance control analysis of concrete-filled steel tube sepa-rated spherical joint wind power tower

  • Yang Wen;Guangmao Xu;Xiazhi Wu;Zhaojian Li
    • Structural Engineering and Mechanics
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    • v.87 no.2
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    • pp.137-149
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    • 2023
  • In this study, to explore the working performance of the CFST split spherical node wind power tower, two groups of CFST split spherical joint plane towers with different web wall thicknesses and a set of space systems were analyzed. The tower was subjected to a low-cycle repeated load test, and the hysteresis and skeleton curves were analyzed. ABAQUS finite element simulation was used for verification and comparison, and on this basis parameter expansion analysis was carried out. The results show that the failure mode of the wind power tower was divided into weld tear damage between belly bar, high strength bolt thread damage and belly rod flexion damage. In addition, increasing the wall thickness of the web member could render the hysteresis curve fuller. Finally, the bearing capacity of the separated spherical node wind power tower was high, but its plastic deformation ability was poor. The ultimate bearing capacity and ductility coefficient of the simulated specimens are positively correlated with web diameter ratio and web column stiffness ratio. When the diameter ratio of the web member was greater than 0.13, or the stiffness ratio γ of the web member to the column was greater than 0.022, the increase of the ultimate bearing capacity and ductility coefficient decreased significantly. In order to maximize the overall mechanical performance of the tower and improve its economy, it was suggested that the diameter ratio of the ventral rod be 0.11-0.13, while the stiffness ratio γ should be 0.02-0.022.