• Title/Summary/Keyword: whipping

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The measured contribution of whipping and springing on the fatigue and extreme loading of container vessels

  • Storhaug, Gaute
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.1096-1110
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    • 2014
  • Whipping/springing research started in the 50'ies. In the 60'ies inland water vessels design rules became stricter due to whipping/springing. The research during the 70-90'ies may be regarded as academic. In 2000 a large ore carrier was strengthened due to severe cracking from North Atlantic operation, and whipping/springing contributed to half of the fatigue damage. Measurement campaigns on blunt and slender vessels were initiated. A few blunt ships were designed to account for whipping/springing. Based on the measurements, the focus shifted from fatigue to extreme loading. In 2005 model tests of a 4,400 TEU container vessel included extreme whipping scenarios. In 2007 the 4400 TEU vessel MSC Napoli broke in two under similar conditions. In 2009 model tests of an 8,600 TEU container vessel container vessel included extreme whipping scenarios. In 2013 the 8,100 TEU vessel MOL COMFORT broke in two under similar conditions. Several classification societies have published voluntary guidelines, which have been used to include whipping/springing in the design of several container vessels. This paper covers results from model tests and full scale measurements used as background for the DNV Legacy guideline. Uncertainties are discussed and recommendations are given in order to obtain useful data. Whipping/springing is no longer academic.

Experimental investigations of higher-order springing and whipping-WILS project

  • Hong, Sa Young;Kim, Byoung Wan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.1160-1181
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    • 2014
  • Springing and whipping are becoming increasingly important considerations in ship design as container ships increase in size. In this study, the springing and whipping characteristics of a large container ship were investigated through a series of systematic model tests in waves. A multi-segmented hull model with a backbone was adopted for measurement of springing and whipping signals. A conversion method for extracting torsion springing and whipping is described in this paper for the case of an open-section backbone. Higher-order springing, higher-mode torsion responses, and the effects of linear and nonlinear springing in irregular waves are highlighted in the discussion.

A study on prediction of whipping effect of very large container ship considering multiple sea states

  • Kim, Beomil;Choung, Joonmo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.387-398
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    • 2020
  • In the design stage of the very large container ships, some methodologies for the whipping effects have been developed, but most of them are based on single sea state. We developed a methodology that considers multiple sea states. Fluid-structure Interaction (FSI) analyses with one dimensional structural model were carried out to capture slamming-induced transient whipping behaviors. Because of the nature of random phases of the applied wave spectra, the required period for entire FSI analyses was determined from the convergence study where the whipping effect became stable. Low pass filtering was applied to the transient whipping responses to obtain the hull girder bending moment processes. Peak counting method for the filtered whipping responses was used to obtain collection of the vertical bending moment peaks. The whipping effect from this new method is compared with that from based on single sea state approach. The efficiency and advantage of the new methodology are presented.

A Study on the Whipping Phenomena Effect on the Structural Response of Large Container Ships (대형 컨테이너 선박의 구조 응답에 미치는 휘핑 영향도 분석)

  • Kim, Beom-Il;Kim, Min-Su;Seo, Sun-Kee;Park, Jae-Hong
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.4
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    • pp.341-349
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    • 2018
  • Recently, it has been reported that the whipping response, which is the elastic phenomenon of the ship, may be one of the causes of the ship accident. Unfortunately, the commonly used methodology for evaluating the whipping effect effectively has not been developed yet. In this study, we developed a procedure to estimate the whipping effect of hull in actual design stage. Fluid-structure interaction analysis was performed for a dominant short term sea state to obtain the time series data of vertical wave bending moment including the whipping response by slamming. In order to estimate the whipping effect by using the time series, some signal processing and statistical techniques such as low pass filtering, Weibull fitting and so on, were applied. the hydro-elasticity analysis was performed on container ships of various sizes to evaluate the whipping effect. The parameters that can affect the response of the hull vibration was selected and the effect of these parameters on whipping was analyzed.

Whipping factor - a Measure of Damage Potential of an UNDEX Bubble Pulse (휘핑계수-수중폭발 가스구체 압력파 크기의 척도)

  • Kwon, Jeong-Il;Chung, Jung-Hoon;Lee, Sang-Gab
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.6 s.144
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    • pp.637-643
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    • 2005
  • A new novel Whipping Factor is proposed as a measure of the ship damage potential due to an underwater explosion bubble pulse. The factor was derived from the relationships among the charge weight, its depth and the fluid acceleration due to pulsating gas bubble. From the whipping response analyses for three uniform Timoshenko beams with similar characteristics of real naval surface ships, we have confirmed the maximum bending moment responses of beams due to whipping are almost same if the applied whipping factor is constant regardless of the charge weights and depths, which could validate the proposed whipping factor.

Effect of Milk Protein Isolate/κ-Carrageenan Conjugates on Rheological and Physical Properties of Whipping Cream: A Comparative Study of Maillard Conjugates and Electrostatic Complexes

  • Seo, Chan Won;Yoo, Byoungseung
    • Food Science of Animal Resources
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    • v.42 no.5
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    • pp.889-902
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    • 2022
  • With increasing consumer demand for "clean label" products, the use of natural ingredients is required in the food industry. Protein/polysaccharide complexes are considered good alternatives to synthetic emulsifiers and stabilizers for formulating stable emulsion-based foods. Milk protein and carrageenan are widely used to improve the physical properties and stability of dairy food products. In a previous study, milk protein isolate (MPI) was conjugated with 𝛋-carrageenan (𝛋-Car) in a wet-heating system through the Maillard reaction, and the Maillard conjugates (MC) derived from MPI and 𝛋-Car effectively improved the stability of oil-in-water emulsions. Therefore, MPI/𝛋-Car conjugates were used in whipping cream as natural emulsifiers in this study, and the physical and rheological properties of whipping creams stabilized using MPI/𝛋-Car MC and MPI/𝛋-Car electrostatic complexes (EC) were investigated. The whipping creams stabilized with MPI/𝛋-Car MC have lower rheological parameters (ηa,50, K, G', and G'') than those of whipping creams stabilized with MPI/𝛋-Car EC. Although the overrun value was slightly reduced owing to the addition of MPI/𝛋-Car MC, the stability of the whipped creams with MC was effectively improved due to enhanced water-holding ability by conjugation.

Functional Properties of Cholesterol-removed Compound Whipping Cream by Palm Oil

  • Shim, S.Y.;Ahn, J.;Kwak, H.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.6
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    • pp.857-862
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    • 2004
  • The present study was carried out to examine the changes in functional properties of cholesterol-removed compound whipping cream made by $\beta$-CD treated cream and palm oil. Six different ratios of cream to palm oil (10:0 as control, 9:1, 8:2, 7:3, 6:4, and 5:5, v/v) were tested. The overrun percentage increased with an increased amount of palm oil. When the ratio of cream to palm oil was 10:0 (control), the overrun was 130%, which was significantly lower than other ratios reached to 150%. Foam instability was measured as 3.1 ml defoamed cream in control, however, the value of foam instability decreased with an increase of palm oil addition. The TBA value of cholesterol-removed compound whipping cream increased from 0.08 to 0.13 with no addition of palm oil during 4 wk storage. When the ratio of cream to palm oil was 5:5, TBA value increased dramatically at 3 wk and thereafter. Among sensory characteristics, texture value increased with higher amount of palm oil, however, flavor and overall preferences were opposite. Above results indicated that partial substitution of palm oil in manufacture of cholesterol-removed compound whipping cream resulted in a stable foam development with little adverse effect on flavor and lipid oxidation during storage. The present study showed a possible application in manufacture of cholesterol-removed compound whipping cream, which may be effective in other foods.

Parametric Study of Numerical Prediction of Slamming and Whipping and an Experimental Validation for a 10,000-TEU Containership

  • Kim, Jung-Hyun;Kim, Yonghwan
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.2
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    • pp.115-133
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    • 2015
  • This paper describes an approach for the numerical analysis of container ship slamming and whipping and various parameters that influence slamming and whipping. For validation purposes, the numerical analysis results were compared with experimental results obtained as part of the Wave-Induced Loads on Ships Joint Industry Project. Water entry problems for two-dimensional (2D) sections were first solved using a 2D generalized Wagner model (GWM) for various drop conditions and geometries. As the next step, the hydroelastic numerical analysis of a 10,000-TEU container ship subjected to slamming and whipping loads in waves was performed. The analysis method used is based on a fully coupled model consisting of a three-dimensional (3D) Rankine panel model, a 3D finite element model (FEM), and a 2D GWM, which are strongly coupled in the time domain. Parametric studies were carried out in both numerical and experimental tests with various forward speeds, wave heights, and wave periods. The trends observed and the validity of the numerical analysis results are discussed.

Structural Assessment of Container ships Considering Hydroelastic Responses (컨테이너선의 유탄성 응답을 고려한 구조강도 평가 기술)

  • Park, Jun Seok;Choi, Byung Ki;Choi, Ju Hyuck;Jung, Byoung Hoon
    • Special Issue of the Society of Naval Architects of Korea
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    • 2017.10a
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    • pp.80-87
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    • 2017
  • This paper is related to structural assessment considering the hydroelastic response of ultra large container ships, especially from whipping (bow or stern impacts) and from springing (resonance). In general, whipping contributes both to increased fatigue and extreme loading, while springing does mainly contribute to increased fatigue loading. To evaluate the hydroelastic response quantitatively with high accuracy, numerical code considering hydro-structure coupling was applied and fatigue strength of a 13,100 TEU class containership was verified. The segmented model test and full scale measurement were also needed to assess the effect of whipping and springing on the fatigue and extreme capacity in more realistic way and for verification of the numerical tools. With reference to class rule, fatigue assessment considering springing effect and extreme assessment considering whipping effect were introduced.

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Whipping-based criterion for the identification of slamming events

  • Dessi, Daniele
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.1082-1095
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    • 2014
  • In this paper, a new criterion for the identification of slamming events is formulated. This criterion is based on the analysis of the high-frequency response, expressed in terms of the amidships VBM, which occurs after the slams. For this reason, it is named 'whipping' criterion underlining that is based on the analysis of global effects than on the kinematic description of the impact dynamics that was provided by Ochi criterion. Both the new 'whipping' criterion and the Ochi criterion are presented and compared also with respect to their practical application to the experimental data collected in the seakeeping tests with an elastic segmented model.