• Title/Summary/Keyword: idealized triangular impulse

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Study on Structural Strength of Mark III type LNG Cargo Containment System by Idealized Triangular Impulse Load (MarkIII LNG 방열 시스템의 강도평가를 위한 삼각형 충격 하중에 대한 구조응답에 대한 연구)

  • Hwang, Se Yun;Kim, Sung Chan;Lee, Jang Hyun;Nho, In Sik
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.615-624
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    • 2014
  • It has been well known the sloshing pressure has complex shape and various patterns. The pattern of sloshing pressure is variously characterized by the pressure amplitude, duration time and skewness. The structural response induced by the sloshing pressure is also affected by the pattern of sloshing pressure and the type of structural members. In order to understand the structural response by the perspective view of categorized pattern, it is more efficient to make simple sloshing pressure pattern than to reflect the complex pressure history. In this study, the sloshing pressures obtained by the small scale model test are simplified with respect to their duration and skewness. Dynamic analyses of Mark-III LNG CCS are then parametrically performed with the consideration of various types of sloshing impact. Meanwhile, the failure pressures given the duration and skewness are investigated after parametric calculations are conducted to investigate the effect of pressure parameters on the structural response.

A Fundamental Study for Time History Modeling of Fluid Impact Pressure (유체 충격압력 시계열의 모델링에 관한 기초 연구)

  • Nho, In-Sik;Lee, Jae-Man;Yeom, Cheol-Woong
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.2
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    • pp.242-247
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    • 2010
  • To consider effects of essential parameters of water impact pressure on dynamic structural responses of bow bottom structures, a parametric study for a ship bottom panel is carried out. The idealized pressure time history models were assumed by triangular and rectangular shapes in time domain. The main loading parameters are duration time and peak pressure value maintaining the same impulse value. The structural models for local bottom stiffened panels of a container ship are analysed. The natural frequency analysis and transient dynamic response analysis are performed using MSC/NASTRAN. Added mass effects of contacting water are considered and the pressure distributions are assumed to be uniform in the whole water contacting surface. The effects of loading parameters on the structural responses, especially maximum displacements, are considered. Besides the peak pressure value, effects of duration time correlated with natural frequencies are thought to be the important parameters.