Journal of Marine Science and Technology

, Volume 11, Issue 4, pp 260–269 | Cite as

Wave responses of a coastal cargo ship consisting of unit modules

  • Budi S. Prasodjo
  • Kimio Saito
  • Yasushi Higo
  • Hisashi Nobukawa
  • Katsuya Maeda
Original article

Abstract

This article discusses the dynamic responses of a coastal cargo ship that consists of unit modules with advance forward speed in waves. We introduce a simple way of connecting the modules that has enough capability to link the modular parts of the ship as a unified whole. The flexible connection consists of male and female rubber fenders with additional pretensioned ropes. This kind of connection system is proposed for use in coastal regions with relatively calm waters wherein the modular ship can move at a moderate speed. The modules are assumed to be rigid compared to the connections. Computations were performed to investigate the vertical elastic responses of four modules connected end-to-end with the assumption that in the simple hinge, no gaps occur in the flexible rubber connections between adjacent modules. A simple method, which is an extension of the computational analysis we reported previously, is presented to study the hydroelasticity and rope tension forces of the modular ship with forward speed in waves. Experiments with a three-dimensional model at Froude numbers of 0 and 0.16 in head waves were performed to evaluate the effectiveness of the calculation method. In the experiments, deflections for each part were measured using calibrated potentiometers. Force transducers were used to measure the rope tension force between the modules of the articulated cargo ship. Some slight differences were observed, but generally the calculated results showed the same trends as the experimental values.

Key words

Elastic responses Deflection Rope tension force Coastal cargo ship Flexible joints 

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Copyright information

© JASNAOE 2006

Authors and Affiliations

  • Budi S. Prasodjo
    • 1
  • Kimio Saito
    • 1
  • Yasushi Higo
    • 1
  • Hisashi Nobukawa
    • 2
  • Katsuya Maeda
    • 3
  1. 1.Graduate School for IDECHiroshima UniversityHigashi-HiroshimaJapan
  2. 2.Hiroshima UniversityHiroshimaJapan
  3. 3.National Maritime Research Institute (NMRI)TokyoJapan

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