Random Combination Factors for Still Water and Wave Bending Moments

Volume 3: Structures, Safety, and Reliability ◽

10.1115/omae2019-96665 ◽

2019 ◽

Author(s):

Wenbo Huang

Keyword(s):

Statistical Analysis ◽

Weibull Distribution ◽

Ship Hull ◽

Combined Processes ◽

Bending Moments ◽

Hull Girder ◽

Random Combination ◽

Load Combination ◽

Characteristic Values ◽

Wave Models

Abstract Based on the extreme value of the primary loads of ship hull girder instead of characteristic values, the more reasonable load combination factors are defined. In order to evaluate the random variation of newly defined load combination factors, based on Ferry-Berges & Castanheta (FBC) and Poisson square wave models, the still water bending moments (SWBM), vertical wave bending moments (VWBM) and their combined processes are simulated to get the random realizations of load combination factors. The statistical analysis results show that the load combination factors take the value of 1 with the highest probability and can be well fitted by the Weibull distribution. Such information should be incorporated appropriately in the reliability analysis of ship hull girder.

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Effect of the nonlinear vertical wave-induced bending moments on the ship hull girder reliability

Ocean Engineering ◽

10.1016/j.oceaneng.2015.12.005 ◽

2016 ◽

Vol 119 ◽

pp. 193-207 ◽

Cited By ~ 14

Author(s):

B. Gaspar ◽

A.P. Teixeira ◽

C. Guedes Soares

Keyword(s):

Ship Hull ◽

Bending Moments ◽

Hull Girder ◽

Wave Induced

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Evaluation of Cumulative Collapse of a LNG Carrier Hull Girder Under Dynamic Cyclic Bending Moments

10.1115/omae2021-61655 ◽

2021 ◽

Author(s):

Jian Ji ◽

Bin Liu ◽

Lin Chen ◽

Xianting Liao ◽

C. Guedes Soares

Keyword(s):

Finite Element ◽

Ultimate Strength ◽

Failure Modes ◽

Ship Hull ◽

Bending Moments ◽

Nonlinear Finite Element Method ◽

Cyclic Bending ◽

Hull Girder ◽

Hull Structure ◽

The Difference

Abstract The present paper continues the recent work reported by Liu and Guedes Soares [1] where finite element simulations were conducted to investigate the ultimate strength of a container ship hull girder under cyclic bending moments. Here a membrane LNG carrier is investigated to evaluate the “cyclic ultimate strength” of this specialized ship hull structure including double bottoms, sides and decks. The paper aims to analyze the ultimate strength and to compare the collapse modes of a LNG carrier hull girder under monotonic and dynamic cyclic bending moments, revealing the difference in their failure modes. Nonlinear finite element method is employed, using the explicit LS-DYNA solver, to analyze the ultimate strength of hull structures. The numerical results show that the cyclic ultimate strength of hull structures is about 20% lower than the monotonic ultimate strength in the present study.

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Assessment of the Total Ship’s Hull Girder Bending Stresses for Unified Model of Sagging and Hogging Bending Moments

Ship Technology Research ◽

10.1179/str.2009.56.4.004 ◽

2009 ◽

Vol 56 (4) ◽

pp. 177-197

Author(s):

Lyuben D. Ivanov ◽

Keyword(s):

Unified Model ◽

Bending Moments ◽

Hull Girder ◽

Bending Stresses

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The Effect of Sloshing in Tanks on the Hull Girder Bending Moments and Structural Reliability of Damaged Vessels

Journal of Ship Research ◽

10.5957/josr.56.1.110015 ◽

2012 ◽

Vol 56 (1) ◽

pp. 48-62 ◽

Cited By ~ 3

Author(s):

Huirong Jia ◽

Torgeir Moan

Keyword(s):

Structural Reliability ◽

Bending Moments ◽

Hull Girder

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Statistical Analysis and Prediction on Tensile Strength of 316L-SS Joints at High Temperature Based on Weibull Distribution

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/281/1/012062 ◽

2017 ◽

Vol 281 ◽

pp. 012062 ◽

Cited By ~ 1

Author(s):

Z L An ◽

T Chen ◽

D L Cheng ◽

T H Chen ◽

Z Y Wang

Keyword(s):

Tensile Strength ◽

High Temperature ◽

Statistical Analysis ◽

Weibull Distribution

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Code Development for Ship Structures—A Demonstration

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2829052 ◽

1997 ◽

Vol 119 (2) ◽

pp. 114-119 ◽

Cited By ~ 2

Author(s):

A. E. Mansour ◽

P. H. Wirsching ◽

B. Ayyub ◽

G. White

Keyword(s):

Failure Modes ◽

Safety Margin ◽

Limit States ◽

Hull Girder ◽

Load Combination ◽

Plate Buckling ◽

Design Variables ◽

Critical Detail ◽

Safe Side ◽

Future Publication

A demonstration summary of a reliability-based structural design code for ships is presented for two ship types: a cruiser and a tanker. One reason for the development of such a code is to provide specifications which produce ship structure having a weight savings and/or improvement in reliability relative to structure designed by traditional methods. Another reason is to provide uniform safety margin for ships within each type. For both ship types, code requirements cover four failure modes: hull girder bulkling, unstiffened plate yielding and buckling, stiffened plate buckling, and fatigue of critical detail. Both serviceability and ultimate limit states are considered. Because of limitation on the length, only hull girder modes are presented in this paper. Code requirements for other modes will be presented in future publication. A specific provision of the code will be safety check expression, which, for example, for three bending moments (still water Ms, wave Mw, and dynamic Md), and strength Mu, might have the form, following the partial safety factor format: γsMs+γwMw+γdMd≤φMu γs, γw, γd, and φ are the partial safety factors. The design variables (M’s) are to be taken at their nominal values, typically values in the safe side of the respective distributions. Other safety check expressions for hull girder failure that include load combination factors, as well as consequence of failure factors, are considered. This paper provides a summary of safety check expressions for the hull girder modes.

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