L-year maximum values of local ice loads on ship hulls

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

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Comparison principles for free-surface flows with gravity

Journal of Fluid Mechanics ◽

10.1017/s0022112091000770 ◽

1991 ◽

Vol 230 ◽

pp. 231-243 ◽

Cited By ~ 3

Author(s):

Walter Craig ◽

Peter Sternberg

Keyword(s):

Solitary Waves ◽

Finite Depth ◽

Free Surface Flows ◽

Immiscible Fluids ◽

Steady Flows ◽

Two Dimensional ◽

Surface Flows ◽

Ship Hulls ◽

Geometrical Information ◽

Supercritical Flows

This article considers certain two-dimensional, irrotational, steady flows in fluid regions of finite depth and infinite horizontal extent. Geometrical information about these flows and their singularities is obtained, using a variant of a classical comparison principle. The results are applied to three types of problems: (i) supercritical solitary waves carrying planing surfaces or surfboards, (ii) supercritical flows past ship hulls and (iii) supercritical interfacial solitary waves in systems consisting of two immiscible fluids.

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Draft Genome Sequences of Four Alteromonas macleodii Strains Isolated from Copper Coupons and Grown Long-Term at Elevated Copper Levels: TABLE 1

Genome Announcements ◽

10.1128/genomea.01311-16 ◽

2016 ◽

Vol 4 (6) ◽

Author(s):

Kathleen D. Cusick ◽

Jason R. Dale ◽

Brenda J. Little ◽

Justin C. Biffinger

Keyword(s):

Marine Bacterium ◽

Draft Genome ◽

Genome Sequences ◽

Ship Hulls ◽

Early Stages ◽

Antifouling Agent ◽

Alteromonas Macleodii

Alteromonas macleodii is a marine bacterium involved in the early stages of biofouling on ship hulls treated with copper as an antifouling agent. We report here the draft genome sequences of an A. macleodii strain isolated from copper coupons and three laboratory mutants grown long-term at elevated copper levels.

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Corrigendum to “The measurement accuracy of instrumented ship structures under local ice loads using strain gauges” [Mar. Struct. 76 (2021) 102919]

Marine Structures ◽

10.1016/j.marstruc.2021.103037 ◽

2021 ◽

pp. 103037

Author(s):

Angelo Mario Böhm ◽

Rüdiger Ulrich Franz von Bock und Polach ◽

Hauke Herrnring ◽

Sören Ehlers

Keyword(s):

Measurement Accuracy ◽

Strain Gauges ◽

Ship Structures ◽

Ice Loads

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The Nonlinear Roll Damping of a FPSO Hull

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.4025870 ◽

2013 ◽

Vol 136 (1) ◽

Cited By ~ 9

Author(s):

Allan C. de Oliveira ◽

Antonio Carlos Fernandes

Keyword(s):

Nonlinear Damping ◽

Challenging Problem ◽

Roll Damping ◽

Ship Hulls ◽

Damping Behavior ◽

Industry Standards ◽

Long Time ◽

Technological Developments ◽

Traditional Approaches ◽

The 19Th Century

The ship-rolling problem is a subject that has been studied for a long time. Since Froude's time (in the 19th century) to nowadays, this subject was revisited several times in order to adjust the theory to changes in ship hulls, dimensions, materials, appendages, etc. On the other hand, ship analysis technological resources, including both experimental techniques and computational capacity (that did not exist in Froude's time), have also amazingly improved. But despite all those technological developments, the assessment of the nonlinear roll damping of some types of hulls still is a challenging problem. The floating production storage and offloading (FPSO) hull fitted with larger bilge keels, for instance, has behaved in such a way that it is impossible to obtain results from nowadays industry standards via decaying tests. This paper discusses an alternative way to assess the nonlinear damping behavior of FPSO hulls with large bilge keels. Since it is fairly easy to perform decaying tests, the paper also proposes an alternative way to analyze the FPSO properties through this kind of testing by grouping multiple results instead of using only a single test. This artifice brought improvements, such as an increased agreement between the alternative model and the experimental data. The paper also compares the more traditional approaches with the alternative method and finally shows the latter's applicability.

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Wave Pressure Distributions Along the Midship Transverse Section of a VLCC

Volume 4: Ocean Engineering; Offshore Renewable Energy ◽

10.1115/omae2008-57649 ◽

2008 ◽

Cited By ~ 2

Author(s):

Zhi Shu ◽

Torgeir Moan

Keyword(s):

Transverse Section ◽

Roll Damping ◽

Wave Pressure ◽

Ship Hulls ◽

Pressure Distributions ◽

The Difference ◽

Hydrodynamic Code ◽

Long Term Prediction ◽

External Wave

The external wave pressure distributions along the transverse section in the midship region of a VLCC are evaluated in this paper. The commercial hydrodynamic code WASIM issued by DnV has been adopted to perform the hydrodynamic computation. The ship hulls have been discretized with coarser and finer mesh to investigate the effect of panel size on the hydrodynamic pressures. It is found that the difference between these two mesh finenesses is small. It is also found that the roll damping has a significant influence on the wave pressure of vessel especially in beam sea. A sensitivity analysis is carried out in the sense of assessing the influence of the roll damping on the wave pressure. Finally, the long term prediction of the wave pressure has been compared for different roll damping values.

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