Ultimate strength assessment of corroded box girders

2013 ◽  
Vol 58 ◽  
pp. 35-47 ◽  
Author(s):  
S. Saad-Eldeen ◽  
Y. Garbatov ◽  
C. Guedes Soares
Keyword(s):  
Ultimate Strength ◽  
Box Girders ◽  
Strength Assessment

Corrosion-Dependent Ultimate Strength Assessment of Aged Box Girders Based on Experimental Results

2011 ◽  
Vol 55 (04) ◽  
pp. 289-300 ◽  
Author(s):  
S. Saad-Eldeen ◽  
Y. Garbatov ◽  
C. Guedes Soares
Keyword(s):  
Service Life ◽  
Residual Stresses ◽  
Ultimate Strength ◽  
Bending Moment ◽  
Experimental Results ◽  
Time Dependent ◽  
Strength Analysis ◽  
Box Girders ◽  
Strength Assessment ◽  
Equivalent Time

This paper presents a corrosion-dependent analysis of the ultimate strength analysis of aged box girders based on experimental results. Three multispan corroded stiffened box girders subjected to four-point vertical load are analyzed, idealizing the behavior of midship sections of full ships. The specimens have three levels of corrosion. Two corrosion-dependent formulas for assessing the ultimate strength as well as the ultimate bending moment of corroded structures are proposed. Using a time-dependent corrosion growth model, equivalent time-dependent formulations are developed. The effect of corrosion degradation on the residual stresses during the service life is also analyzed, and a regression equation for predicting the remaining residual stresses along the service life is proposed. Finally, a corrosion-dependent moment-curvature relationship has been developed accounting for the changes in geometrical characteristics and material properties of the tested box girders.

scholarly journals Collapse Strength of Intact Ship Structures

2021 ◽  
Vol 9 (10) ◽  
pp. 1079
Author(s):  
Mesut Tekgoz ◽  
Yordan Garbatov
Keyword(s):  
Ultimate Strength ◽  
Structural Design ◽  
Structural Failure ◽  
Box Girders ◽  
Ship Structures ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Structural Capacity ◽  
Longitudinal Strength ◽  
Future Work

Ship structures are subjected to complex sea loading conditions, leading to a sophisticated structural design to withstand and avoid structural failure. Structural capacity assessment, particularly of the longitudinal strength, is crucial to ensure the safety of ships, crews, the marine environment, and the cargoes carried. This work aims to overview the ultimate strength assessment of intact ship structures in recent decades. Particular attention is paid to the ultimate strength of plates, stiffened panels, box girders, and entire ship hull structures. A discussion about numerical and experimental analyses is also provided. Finally, some conclusions and suggestions about potential future work are noted.

Buckling and Ultimate Strength Assessment of FPSO Structures

2005 ◽  
Author(s):  
Haihong Sun ◽  
Xiaozhi Wang
Keyword(s):  
Ultimate Strength ◽  
Oil And Gas ◽  
Element Analysis ◽  
Strength Criteria ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Oil And Gas Fields ◽  
Extensive Test ◽  
Offshore Oil And Gas ◽  
Classification Society

Floating production, storage and offloading systems (FPSOs) have been widely used for the development of offshore oil and gas fields because of their attractive features. They are mostly ship- shaped, either converted from existing tankers or purposely built, and the hull structural scantling design for tankers may be applicable to FPSOs. However, FPSOs have their unique characteristics. FPSOs are sited at specific locations with a dynamic loading that is quite different from those arising from unrestricted service conditions. The structures are to be assessed to satisfy the requirements of all in-service and pre-service loading conditions. The fundamental aspects in the structural assessment of FPSOs are the buckling and ultimate strength behaviors of the plate panels, stiffened panels and hull girders. The focus of this paper is to address the buckling and ultimate strength criteria for FPSO structures. Various aspects of the criteria have been widely investigated, and the results of the design formulae proposed in this paper have been compared to a very extensive test database and numerical results from nonlinear finite element analysis and other available methods. The procedures presented in this paper are based on the outcomes of a series of classification society projects in the development of buckling and ultimate strength criteria and referred to the corresponding classification society publications.

PHOTOGRAMMETRY MEASUREMENTS OF INITIAL IMPERFECTIONS FOR THE ULTIMATE STRENGTH ASSESSMENT OF PLATES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
A Cubells ◽  
Y Garbatov ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Compressive Load ◽  
Initial Imperfection ◽  
Maximum Load ◽  
Surface Shape ◽  
Element Analysis ◽  
Strength Assessment ◽  
Load Carrying ◽  
Geometrical Imperfections

The objective of the present study is to develop a new approach to model the initial geometrical imperfections of ship plates by using Photogrammetry. Based on images, Photogrammetry is able to take measurements of the distortions of plates and to catch the dominant surface shape, including the deformations of the edges. Having this data, it is possible to generate faithful models of plate surface based on third order polynomial functions. Finally, the maximum load- carrying capacity of the plates is analysed by performing a nonlinear finite element analysis using a commercial finite element code. Three un-stiffened and four stiffened plates have been modelled and analysed. For each plate, two initial imperfection models have been generated one, based on photogrammetric measurements and the other, based on the trigonometric Fourier functions. Both models are subjected to the same uniaxial compressive load and boundary conditions in order to study the ultimate strength.

Numerical and Experimental Research on the Ultimate Strength for a Stiffened Titanium Cylinder

2018 ◽  
Author(s):  
Siming Yuan ◽  
Qiang Chen
Keyword(s):  
Ultimate Strength ◽  
Research Work ◽  
High Strength ◽  
Simulation Method ◽  
Influential Factors ◽  
Material Nonlinearity ◽  
Cylinder Pressure ◽  
Scaled Model ◽  
Strength Evaluation ◽  
Strength Assessment

Titanium alloys are widely used in naval ships due to its high strength, low density, no magnetism, corrosion resistance and so on. However, the material nonlinearity brings new challenges to the ultimate strength evaluation on the Titanium structure. This work is to evaluate the ultimate strength for a stiffened titanium cylinder with consideration of material nonlinearity by numerical analysis and scaled model experiment. Firstly, a series of titanium alloy stiffened cylinder pressure hulls are analyzed for their ultimate strength by non-linear Finite Element Method (FEM). Secondly, model tests are carried out for the above titanium cylinders to obtain their ultimate carrying capacity. Thirdly, the good agreement between experiment and numerical results verify that the numerical simulation method is suitable for ultimate strength evaluation. Finally, some influential factors on the ultimate capacity of the stiffened titanium cylinder are investigated, including stiffeners arrangement, thickness of cylinder hulls, inside diameter. The research work can map the limitations of the current rules and to support the development of ultimate strength assessment guidelines for titanium cylinder pressure hulls.

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