• Title/Summary/Keyword: 모멘텀 굽힘모멘트

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Effect of Flexibility Variations on Ship Responses (강성변화의 선체응답에의 영향)

  • 권영섭
    • Journal of Ocean Engineering and Technology
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    • v.6 no.2
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    • pp.151-171
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    • 1992
  • 선체응답의 변화를 고찰, 계산 결과를 요약하였다. 이에 대한 계산은 유체 동력학적 해석을 이용하였으며 본 이론의 합리성을 아울러 지적하였다. 선체의 유연성을 증가시킴으로서 추격선두 굽힘 모멘트는 줄지만, 모멘컴 굽힘 모멘트는 일반적으로 증가함이 나타났다.

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Numerical Analysis of Ship Motions and Wave Loads Including Momentum Slamming (모멘텀 슬래밍을 고려한 선체 운동 및 파랑하중 해석)

  • Hwang, Ji-Hee;Park, In-Kyu;Koo, Weon-Cheol
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.2
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    • pp.109-115
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    • 2012
  • Slamming phenomenon may occur when a ship navigates a high sea region, where the response of ship can be expected as elastic behaviour and the resultant wave loads may increase. In this paper, numerical analysis of ship motions and wave loads including momentum slamming was performed using the strip theory with regular waves. In order to analyze the effect of slamming force on the global ship motions, time histories of each mode of displacement and forces were simulated by using Newmark-beta time integration scheme. The added mass and damping coefficients calculated by Lewis form method were compared with the results of given references. For verification of numerical results, the motion RAOs of a S175 containership were calculated as an example of application and time histories of respective displacement and vertical bending moment were compared with the results of ITTC workshop benchmark test.

A Comparison Study on the Simplified Formulae for Ship Motion and Global Loads in Waves (선박의 거동 및 파랑하중 계산을 위한 약산식 비교 검토)

  • Choi, Mun-Gwan;Park, In-Kyu;Koo, Weoncheol
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.6
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    • pp.534-540
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    • 2012
  • The global performance of various ships estimated by simplified formulae of classification societies is compared with the numerical results by a strip-theory-based whipping analysis program including slamming impact(USLAM). Heave acceleration, pitch angle and the vertical acceleration are compared and the effectiveness of simplified formulae is evaluated. Four different ship models are used for comparison study, which include S175, Flokstra, 6000TEU and 8100TEU container ships. In order to verify the numerical results, the vertical bending moment of S175 is compared with the results of ITTC workshop data.

Numerical Prediction of Slamming Impact Loads and Response on a Ship in Waves Considering Relative Vertical Velocity (상대수직속도를 고려한 파랑중 선박의 슬래밍 충격하중 및 응답 계산)

  • Choi, Mun-Gwan;Park, In-Kyu;Koo, WeonCheol
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.6
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    • pp.503-509
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    • 2014
  • This paper describes the time-domain numerical method for prediction of slamming loads on a ship in waves using the strip theory. The slamming loads was calculated considering the relative vertical velocity between the instantaneous ship motion and wave elevation. For applying the slamming force on a ship section, the momentum slamming theory and the empirical formula-based bottom slamming force were used corresponding to the vertical location of wetted body surface. Using the developed method, the vertical bending moments, relative vertical velocities, and impact forces of S175 containership were compared in the time series for various section locations and wave conditions.

Whipping analysis of hull girders considering slamming impact loads (슬래밍 충격하중을 고려한 선체 휘핑 해석)

  • Seong-Whan Park;Keun-Bae Lee;Chae-Whan Rim
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.3
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    • pp.99-109
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    • 2000
  • Elastic dynamic responses analysis program for ship hulls considering slamming impact loads due to the voyage in large amplitude waves is developed. Ship hull structures are modeled by a thin-walled beam model in order to consider effects of shear deformation. The momentum slamming theory is used to derive nonlinear hydrodynamic forces considering intersection between wave particles and ship section. For the validation of the developed computer program, motions of a V-shaped simple section model and S-175 standard container model are calculated and analyzed. In each numerical example, time histories of relative displacement, velocity and vertical bending moment of a ship section are derived, considering the effect of slamming impacts in various wave conditions.ures near the free surface as well as the wake of the hydrofoil.

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