Prediction of Nonlinear Acceleration Response of a Large Container Ship and the Validation of Excessive Acceleration Failure Mode

Abstract The excessive acceleration is one of five stability failure modes for intact stability being discussed at IMO. The excessive acceleration usually occurs in shallow draft state, under which the ship is prone to large nonlinear rolling motion. Therefore, the accurate prediction and evaluation of the acceleration response are required in ship intact stability analysis. This paper proposes a 5-DOF model in time domain to calculate the nonlinear acceleration response of a large container ship. The nonlinear restoring force and wave exciting forces (F-K force) are calculated through pressure integration on instantaneous wetted surfaces. A model test has been carried out to verify the prediction method of ship nonlinear acceleration response in the regular and irregular waves. It turns out the ship nonlinear acceleration response in regular and irregular waves obtained by the nonlinear time domain simulation agrees well with the experimental results. The vulnerability criteria for excessive acceleration are also validated by numerical and experimental results. In addition, the influence factor of ship lateral acceleration is studied. The results show that the prediction accuracy of 5-DOF model is acceptable. However, the accuracy needs to be improved for the condition of short wavelength. The influence of angular velocity can be ignored.

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Numerical investigation on a container ship navigating in irregular waves by a fully nonlinear time domain method

Ocean Engineering ◽

10.1016/j.oceaneng.2021.108705 ◽

2021 ◽

Vol 223 ◽

pp. 108705

Author(s):

Ying Tang ◽

Shi-Li Sun ◽

Hui-Long Ren

Keyword(s):

Numerical Investigation ◽

Time Domain ◽

Time Domain Method ◽

Irregular Waves ◽

Container Ship ◽

Fully Nonlinear ◽

Domain Method ◽

Nonlinear Time Domain

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Parametric Rolling in Regular Head Waves of the KRISO Container Ship: Numerical and Experimental Investigation in Shallow Water

Volume 7A: Ocean Engineering ◽

10.1115/omae2019-96341 ◽

2019 ◽

Author(s):

Manases Tello Ruiz ◽

Jose Villagomez ◽

Guillaume Delefortrie ◽

Evert Lataire ◽

Marc Vantorre

Keyword(s):

Shallow Water ◽

Water Depth ◽

Water Waves ◽

Failure Modes ◽

Container Ship ◽

Parametric Roll ◽

Parametric Rolling ◽

Wave Characteristics ◽

Intact Stability ◽

Head Waves

Abstract The IMO Intact Stability Code considers the parametric rolling phenomenon as one of the stability failure modes because of the larger roll angles attained. This hazardous condition of roll resonance can lead to loss of cargo, passenger discomfort, and even (in the extreme cases) the ship’s capsize. Studies as such are mostly conducted considering wave characteristics corresponding to wave lengths around one ship length (λ ≈ LPP) and wave amplitudes varying from moderate to rough values. These wave characteristics, recognised as main contributors to parametric rolling, are frequently encountered in deep water. Waves with lengths of such magnitudes are also met by modern container ships in areas in close proximity to ports, but with less significant wave amplitudes. In such areas, due to the limited water depth and the relatively large draft of the ships, shallow water effects influence the overall ship behaviour as well. Studies dedicated to parametric rolling occurrence in shallow water are scarce in literature. In spite of no accidents being yet reported in such scenarios, its occurrence and methods for its prediction require further attention; this in order to prevent any hazardous conditions. The present work investigates the parametric roll phenomenon numerically and experimentally in shallow water. The study is carried out with the KRISO container ship (KCS) hull. The numerical investigation uses methods available in literature to study the susceptibility and severity of parametric rolling. Their applicability to investigate this phenomenon in shallow water is also discussed. The experimental analysis was carried out at the Towing Tank for Manoeuvres in Confined Water at Flanders Hydraulics Research (in co-operation with Ghent University). Model tests comprised a variation of different forward speeds, wave amplitudes and wave lengths (around one LPP). The water depth was fixed to a condition equivalent to a gross under keel clearance (UKC) of 100% of the ship’s draft.

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Time Domain Analysis of Springing and Whipping Responses Acting on a Large Container Ship

Volume 6: Ocean Engineering ◽

10.1115/omae2011-49218 ◽

2011 ◽

Cited By ~ 1

Author(s):

Yongwon Lee ◽

Zhenhong Wang ◽

Nigel White ◽

Spyros E. Hirdaris

Keyword(s):

Time Domain ◽

Nonlinear Effects ◽

Time Domain Analysis ◽

Container Ship ◽

Wave Loads ◽

Ocean Engineering ◽

Hull Girder ◽

Engineering Research ◽

Large Container ◽

Element Method

As part of WILS II (Wave Induced Loads on Ships) Joint Industry Project organised by MOERI (Maritime and Ocean Engineering Research Institute, Korea), Lloyd’s Register has undertaken time domain springing and whipping analyses for a 10,000 TEU class container ship using computational tools developed in the Co-operative Research Ships (CRS) JIP [1]. For idealising the ship and handling the flexible modes of the structure, a boundary element method and a finite element method are employed for coupling fluid and structure domain problems respectively. The hydrodynamic module takes into account nonlinear effects of Froude-Krylov and restoring forces. This Fluid Structure Interaction (FSI) model is also coupled with slamming loads to predict wave loads due to whipping effects. Vibration modes and natural frequencies of the ship hull girder are calculated by idealising the ship structure as a Timoshenko beam. The results from springing and whipping analyses are compared with the results from linear and nonlinear time domain calculations for the rigid body. The results from the computational analyses in regular waves have been correlated with those from model tests undertaken by MOERI. Further the global effects of springing and whipping acting on large container ships are summarised and discussed.

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Large Containerships’ Fatigue Analysis due to Springing and Whipping

Volume 7: Ocean Engineering ◽

10.1115/omae2016-54525 ◽

2016 ◽

Author(s):

Huilong Ren ◽

Kaihong Zhang ◽

Hui Li ◽

Di Wang

Keyword(s):

Statistical Analysis ◽

Fatigue Damage ◽

Time Domain ◽

High Frequency ◽

Influence Factor ◽

Irregular Waves ◽

Wave Loads ◽

Analysis Method ◽

Load Case ◽

Factor Modification

As the sea transport demand increases constantly, marine corporations around the world are pursuing solutions with large scale and low cost, which makes ultra large containerships’ construction consequentially. Ultra large containerships are more flexible relatively, and the 2-node natural frequency can easily fall into the encountered spectrum frequency range of normal sea state. Meanwhile, as the speed of containerships is high and its large bow flare, when sailing with high speed, the bow structures may suffer severe slamming forces which can increase the design wave loads’ level and the fatigue damage. The importance of hydroelastic analysis of large and flexible containerships of today has been pointed out for structure design. Rules of Many Classification Society have made changes on design wave loads’ value and fatigue influence factor modification. The paper firstly introduced 3-D linear hydroelasticity theory to calculate the Response Amplitude Operator (RAO) in frequency domain, and then described 3-D nonlinear hydroelasticity theory to obtain the nonlinear wave loads time history in irregular waves in time domain, considering large amplitude motion and slamming force due to severe relative motion between ship hull and wave. Based on the theories, computer programs are made to conduct the calculations under specified load case, and some calculation and statistical results are compared with experimental results to verify the accuracy and stability of the programs secondly. The paper focused on the influence of springing and whipping on fatigue damages of 8500TEU and 10000TEU containerships in different loading cases, using spectrum analysis method and time domain statistical analysis method. The spectrum analysis method can calculate fatigue damage due to low-frequency wave loads and high-frequency springing separately, while the time domain statistical analysis can calculate fatigue damage due to the high-frequency damping whipping additionally, based on 3-D time domain nonlinear hydroelasticity wave loads’ time series simulation in irregular waves and rain flow counting method. Finally, discussions on influence factor of springing and whipping with different loading cases are made. Based on these two containerships in example, the fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. According to the wave loads influence factor, the fatigue assessment of different position on midship section is done on the basis of nominal stress. Besides, some suggestions on calculating load case selection are made to minimize the quantity of work in frequency and time domain. Thus the tools for fatigue influence factor modification are provided to meet the demand of IACS’ UR[1].

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A Study on Forced Vibration of Double Bottom Structure due to Whipping on an Ultra Large Container Ship

Volume 3A: Structures, Safety and Reliability ◽

10.1115/omae2017-61149 ◽

2017 ◽

Cited By ~ 3

Author(s):

Yohei Kawasaki ◽

Tetsuo Okada ◽

Hiroaki Kobayakawa ◽

Ichiro Amaya ◽

Tetsuji Miyashita ◽

...

Keyword(s):

Ultimate Strength ◽

Time Domain ◽

Forced Vibration ◽

Wave Frequency ◽

Container Ship ◽

Hull Girder ◽

Vibratory Response ◽

Bottom Structures ◽

Large Container ◽

Wave Induced

Worldwide expansion of economy has brought about prominent and rapid enlargement of container ships. Their greater beam has caused more flexible double bottom structure, giving rise to concerns about its adverse effect to the ultimate strength of hull girder. To accurately assess the ultimate strength of hull girder, it is essential to precisely grasp how the double bottom structures behave in the actual sea state, in terms of whipping and vibratory response as well as wave frequency response. In this paper, the authors investigated structural behavior of the double bottom of a 14,000 TEU ultra large container ship in long-crested irregular head seas. Firstly, time domain ship motion and wave pressure on the hull surface was obtained through numerical analysis using Rankine source method. Subsequently, the obtained loads were applied to 3-dimensional whole ship finite element model, and time domain elastic responses of all over the hull structures were analyzed using Newmark-β method in terms of both whipping and wave frequency responses. As a result, regarding the wave frequency response, it was found that maximum wave induced upward bending of the midship double bottom structures is exerted almost simultaneously with the maximum wave induced hogging hull girder bending moment. The correlation factors between the double bottom bending and the hull girder bending were about 0.94 around the midship region, and they decreased in the fore and aft region. Regarding the whipping and vibratory response, it was found that large whipping response induces forced vibration of the double bottom structures, especially in the midship region. Because of the higher natural frequencies of the double bottom structures compared with that of whipping, the double bottom structures are excited in the same phase as the hull girder whipping, resulting in superimposed longitudinal stresses in way of the bottom shell plating. From these observations, it can be concluded that the local bending behavior of the double bottom structures adversely affects the hull girder ultimate strength, both in terms of wave loads and whipping loads, and it is necessary to take sufficient care to the double bottom rigidity.

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Time-domain numerical and segmented ship model experimental analyses of hydroelastic responses of a large container ship in oblique regular waves

Applied Ocean Research ◽

10.1016/j.apor.2017.07.005 ◽

2017 ◽

Vol 67 ◽

pp. 78-93 ◽

Cited By ~ 9

Author(s):

Zhanyang Chen ◽

Jialong Jiao ◽

Hui Li

Keyword(s):

Time Domain ◽

Container Ship ◽

Regular Waves ◽

Ship Model ◽

Experimental Analyses ◽

Large Container

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Advanced Fault Isolation Technique Using Electro-Optical Terahertz Pulse Reflectometry (EOTPR) for 2D and 2.5D Flip-Chip Package

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0021 ◽

2012 ◽

Author(s):

Lihong Cao ◽

Manasa Venkata ◽

Meng Yeow Tay ◽

Wen Qiu ◽

J. Alton ◽

...

Keyword(s):

Time Domain ◽

Flip Chip ◽

Time Domain Reflectometry ◽

Fault Isolation ◽

Experimental Results ◽

Terahertz Pulse ◽

Isolation And Identification ◽

Isolation Technique ◽

Non Destructive

Abstract Electro-optical terahertz pulse reflectometry (EOTPR) was introduced last year to isolate faults in advanced IC packages. The EOTPR system provides 10μm accuracy that can be used to non-destructively localize a package-level failure. In this paper, an EOTPR system is used for non-destructive fault isolation and identification for both 2D and 2.5D with TSV structure of flip-chip packages. The experimental results demonstrate higher accuracy of the EOTPR system in determining the distance to defect compared to the traditional time-domain reflectometry (TDR) systems.

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