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This paper presents an experimental study on the effect of corrosion degradation on the ultimate strength of corroded steel box girders. Two specimens, built as box girders, were immersed in natural sea water in a harbour. After corrosion, the box girder sections were tested under four-point loading, producing a constant bending moment until collap...
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... Most marine products use composite steel, making them highly susceptible to corrosion. Material strength can decrease by more than 50% in severe corrosion cases [55]. Therefore, corrosion is crucial to model and incorporate into structural strength analysis. ...
... In this study, the material used was carbon steel. Carbon steel is commonly used in ship construction [55]. Carbon steel has material properties as outlined in Table 3. Carbon steel has a Young's modulus of 207 GPa, a Poisson's ratio of 0.3, a yield strength of 250 MPa, and a coefficient of thermal expansion of 1.25 × 10 −5°C . ...
This study presents a comprehensive analysis using the finite element method (FEM) to examine and evaluate the behavior of fuel carrier ship structure. Sandwich panels are effective structures for use in ship structures due to their lightweight yet robust nature. Sandwich panels used in ship structures have various core shapes, such as hexagonal, circular, and square, as needed. The sandwich panel structure can be widely implemented in ship construction, for example, on the deck, hull, and bulkhead of the ship’s cabin. Hydrogen is an alternative fuel that can replace fossil fuels. In this modern era, hydrogen is high valuable energy commodity, so accidents involving carrier ships could have significant consequences. Hydrogen is produced from liquefied natural gas (LNG), so if a leak occurs, for instance, in a storage tank or fuel tank, it has the potential to lead to accidents such as fires. Corrosion is a significant concern for the maritime industry, as it can jeopardize the structural integrity of these vessels and pose substantial safety and environmental risks. In this research, FEM was utilized to model and simulate the effects of corrosion on hydrogen carrier ships when exposed to fire, considering various environmental and operational factors. Through a systematic investigation, it is aimed to gain insights into the impact of corrosion on ship structural components during fires, such as hulls and storage tanks. The result of this study will contribute to improving corrosion and fire mitigation strategies, ensuring the safety and longevity of hydrogen and LNG carrier ships, and supporting the sustainable transportation of hydrogen to meet global energy demands. No research has been conducted on the structural behavior resulting from hydrogen fires and corrosion simultaneously. To achieve this, it is assumed to use the corrosion properties of steel in heavily traveled ship routes such as the Panama Canal Zone, Barent Sea, North Sea, and Suez Canal Zone. This study utilized an approach by modeling corrosion using shell thickness in Abaqus Quasi-Static and applying boundary conditions in the form of temperature increase up to 800°C and subsequent cooling back to the initial temperature. At the maximum temperature, the most significant mid-span displacement occurred in the circular core sandwich panel, with a value of 4 mm. The axial force in the structure was inversely proportional to the mid-span displacement. In the case of the circular core sandwich panel, the axial force was 96 kN. The most resilient core type was hexagonal because it experiences the least deformation when compared to circular and square cores.
... Thus, corrosion is a surface geometric damage that usually reduces the thickness of the plate, changes the sectional characteristics of the component, and produces complex corrosion surface morphology, which change the buckling behavior of the plate and then reduce the flexural capacity of components [20][21][22]. At the same time, pitting position, pitting shape, and pitting degree can affect the shear capacity of plates [23], and the yield and ultimate tensile strengths of the hull steel plate can also be significantly reduced [24,25]. The degradation of mechanical properties of steel structures after corrosion is not only related to corrosion depth but also to the uneven distribution of corrosion forms and positions in 3D space [26]. ...
... Pit density and pit depth both impacted the mechanical properties of materials (Tang et al., 2014;Sheng and Xia, 2017;Javed et al., 2020a;Javed et al., 2020b;Zhang et al., 2020). In abiotic corrosion studies, it was found that corrosion activity degraded the ultimate strength of steel (Saad-Eldeen et al., 2012). It is suggested that when SRB are present, some engineering materials are likely to fail in a relatively shorter time than in an abiotic environment (Javaherdashti, 2011). ...
Apart from pinhole leaks, MIC (microbiologically influenced corrosion) can also cause catastrophic failures such as pipe ruptures and support beam collapses due to mechanical property degradation or stress corrosion cracking. In this work, X80 pipeline steel dogbone coupons and square coupons were immersed in 150 ml broths containing Desulfovibrio vulgaris, a common corrosive sulfate reducing bacterium (SRB), for up to 14 days. The headspace volumes in the anaerobic bottles were increased from 150 ml to 200 ml and 300 ml to increase MIC severity. After 14 days of SRB incubation in ATCC 1249 culture medium with X80 coupons at 37°C, the sessile cell counts were 6.5 × 10⁷ cells cm⁻² for 150 ml, 2.3 × 10⁸ cells cm⁻² for 200 ml and 1.4 × 10⁹ cells cm⁻² for 300 ml headspace volumes, respectively owing to reduced H2S cytotoxicity in the broth with a larger headspace because it allowed more biogenic H2S to escape from the broth. Weight losses were 1.7 mg cm⁻², 1.9 mg cm⁻² and 2.3 mg cm⁻² for 150 ml, 200 ml and 300 ml headspace volumes, respectively. The corresponding pit depths were 2.6 μm, 4.2 μm and 6.2 μm for 150 ml, 200 ml and 300 ml headspace volumes, respectively. Electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and potentiodynamic polarization results corroborated the increasing weight loss and pitting data trends as a result of increased headspace. Tensile testing of dogbone coupons after the 14-day SRB immersion test indicated that more severe MIC pitting led to a higher ultimate strain loss by up to 23% (300 ml headspace) compared to the abiotic control, while the ultimate strength losses for all headspace volumes were quite small (3% and lower).
... The extensive experimental campaign of the ultimate strength of corroded box girders subjected to the pure vertical bending moment was conducted by Saad-Eldeen et al. [87][88][89][90][91][92][93]; the box girders were corroded in natural seawater with the acceleration by application of an electric current, as described in [94]. The observed reduction of capacity was significant and the structural behaviour was highly asymmetrical due to the uneven distribution of thickness reduction. ...
The present study reviews the recent advances in modelling and analyses the strength of corroded ship structures. Firstly, the time-variant methodologies that consider only the mean structural element thickness loss due to corrosion degradation are identified. Corrosion degradation is regarded as the phenomenon that causes uneven thinning of specimens. This has been captured by various researchers as the loss of mechanical properties of structural steel components. A review of the existing experimental and numerical studies shows significant interest in this field of study. The advances in modelling and analysis of structural behaviours of different ship structural components of larger sizes (including plates, stiffened plates and panels, and entire hull girders) are outlined. Research on the impact of general and pitting corrosion degradation is reviewed separately since the phenomena are different in terms of modelling and analysis. Additionally, recent advances concerning the reliability analysis of corroded ship structural components have also been reviewed. Finally, the general conclusions are drawn and future research topics are outlined.
... Garbatov and Saad-Eldeen et al. [15][16][17][18] studied the effect of corrosion on the mechanical properties of ship steel plates with a yield strength of 235 Mpa and found that modulus of elasticity, yield strength, tensile strength, and elongation after the fracture of the steel plate decreased with the increase in the degree of corrosion and corrosion made the steel plate more brittle; a new stress-strain relationship was proposed to consider the influence of corrosion and residual stress on the mechanical properties of the steel plate. Garbatov et al. [19] studied the same batch of corroded ship steel plates and found that the fatigue strength of the uncorroded sample was 86 Mpa and the fatigue strength of the corroded sample was between 50 MPa and 100 Mpa. ...
In order to study the influence of corrosion on the fatigue life of weathering steel bridges, firstly the nominal stress method is employed to identify the key fatigue details of a typical weathering-steel anchor box of a cable-stayed bridge and then, a multi-scale refined finite-element model for the weathering-steel anchor box is established. The established fatigue-life assessment method for corroded weathering steel is extended to the multi-scale model, the remaining fatigue life for the fatigue details under corrosion are predicted, and the influence of the initial pit size on the fatigue life of weathering steel structures is analyzed. The research results show that corrosion pits can be equated to the introduction of initial cracks in the structure, and the remaining fatigue life for key fatigue details is calculated when the initial crack size is 1 mm, 2 mm, and 3 mm of the fatigue life when the initial crack size is 0 mm, with results of 20.3%, 12.7%, and 11.5%, respectively. Therefore, the research results show that the corrosion pits are equivalent to the introduction of initial cracks in the structure and, even if the initial crack size is small, the fatigue life of the structure is greatly reduced. The fatigue-life assessment method for corroded weathering-steel structures established in this paper is based on the finite element method and fracture mechanics, which offer universal applicability and generalizability and make up for the lack of a fatigue-life assessment method for corroded weathering-steel bridges in service.
... Previously, many researchers have studied the impact of pitting corrosion on steel-based structures such as plates and hollow steel tubes [29][30][31]. A series of nonlinear analyses were carried out on steel plate elements with pitting corrosion wastage by Paik et al. [32], where the corrosion degree of steel was evaluated in terms of the ratio of the corroded surface area to the original plate surface area. ...
In recent years, concrete-filled steel tubular (CFST) columns are increasingly used in ocean construction, such as offshore towers and marine platforms. When used in harsh marine environments, the inevitable pitting corrosion poses a crucial threat to the outer surface of CFST and results in stress concentration, early local buckling as well as confinement reduction towards concrete. Relevant study is rarely seen given the complexity in experimental realization and numerical modelling of random pitting corrosion. This study aims to investigate the nonlinear performance of CFST columns with localized pitting corrosion damage. Advanced finite element modelling techniques are developed to simulate the localized corrosion pits with the consideration of its random nature in terms of sizes, depths and distributions. Previous test data are adopted to verify the developed model. The differences between the structural performance of CFST columns under pitting corrosion, uniform corrosion and uncorroded conditions are revealed. Comparison results demonstrate a more severe degradation caused by localized pitting corrosion. Finally, taking the characteristic of pitting corrosion into account, simplified design methods are proposed by modifying the existing methods in the current standards for calculating the post-corrosion strength of CFST columns.
... The corrosion influence on the load-carrying capacity of different structural elements was studied, both in the experimental and numerical domain considering different structural components, i.e., steel box girders in (Saad-Eldeen, et al., 2012, stiffened panels (Jurišić and Parunov, 2015;Shi, et al., 2018), stiffened plates Jurišić, et al., 2017;Woloszyk, et al., 2018;Woloszyk and Garbatov, 2019b), plates (Paik, et al., 2003;Jiang and Guedes Soares, 2012;Silva, et al., 2013;Zhang, et al., 2016) and beams (Wang, et al., 2020). Additionally, it was observed that the thickness reduction causes capacity loss, but in its action mechanical properties may also be significantly reduced Wang, et al., 2017). ...
The work is focused on the reliability of corroded stiffened plates subjected to compressive uniaxial load based on the progressive collapse approach as stipulated by the Common Structural Rules for Bulk Carriers and Oil Tankers, employing the limit state design. Two different cases have been investigated. In the first model, the corrosion degradation led to uniform thickness loss, whereas the mechanical properties were unchanged, as given in the Rules. In the second model, the plate thickness degradation was followed by mechanical properties reduction. The uncertainties related to the mechanical properties, thicknesses, and initial imperfections of the corroded stiffened plate were taken into account. Several initial design solutions of stiffened plates, as well as different severity levels of corrosion degradation were investigated. The results show that structural reliability significantly decreases with corrosion development, especially when in addition to the initial imperfections and corrosion plate thickness reduction, corroded plate surface roughness and the changes in the mechanical properties were considered. The uncertainties, their origins and confidence levels are discussed. It was found that non-linear time-dependent corrosion degradation accounting not only for the thickness reduction due to corrosion wastage but also the subsequent decrease of mechanical properties lead to a significant reduction in the reliability index. Additionally, it was defined that the reliability estimate is very sensitive to the uncertainties related to the initial thickness and the spread of corrosion degradation as a function of the time. Incorporating the probability of corrosion detection into the original reliability model introduces additional information about the validity of structural degradation that may lead to a higher beta reliability index estimate compared to the original model.
... The influence of corrosion on the mechanical behavior of steel bars is crucial; thus, it has drawn the attention of many researchers [2] [3] [4]. Pitting corrosion can considerably reduce the ultimate tensile strength of steel components [5] [6]. ...
Steel bars have been widely used in building structure and industrial equipment. For steel bars adopted in such structures, corrosion is inevitable, of which the pitting corrosion is one of the most common types. The tension capacity of steel bars is an important property utilized by steel structures; however, this property can be considerably deteriorated by corrosion. Hence, the tension capacity of corroded steel bars is investigated to determine the influence of corrosion. Stochastic numerical analysis is adopted, and the randomness of corrosion location is accurately considered. The relationship between tension capacity and mass loss ratio is the key research content. The influences of pit shape, corrosion thickness Tc, and constitutive model of steel on residual tension capacity are studied. An analytical method for predicting the value of Rmean is proposed.
... The impact of corrosion on the load-carrying capacity of different ship structural elements was studied, both experimentally and numerically. Experimental studies on the box girder, which simulate the real ship cross-section, were performed [5], [6]. It was found that corrosion degradation can cause a very significant reduction. ...
The work presented here investigates the structural response of cleaned corroded plates, subjected to compressive load in the presence of a locked crack, where the change of mechanical properties as a result of corrosion development and the cleaning process is also accounted for. A Finite Element model for assessing the compressive strength, considering geometric and material nonlinearities, is developed, and the analysed plates are compared with the available experimental data. An experimental design plan is generated using the Design of Experiments techniques, which quantifies the influence of the governing variables and their interactions with respect to the plate's ultimate compressive strength. With a limited number of observations, the most significant effects are identified. The corrosion degradation is revealed to be the most crucial effect leading to an effective strength reduction. It was found that, in the case of a corroded plate with a locked crack subjected to a compressive load, the most severe case is when the crack is transversely oriented. The strength reduction is slightly lower than when the corrosion degradation and the presence of a crack are considered to be a simple summation of these two effects but acting separately. The outcome of the analysis is the development of several empirical formulations that allow a fast estimation of the ultimate strength of a corroded plate, subjected to compressive load in the presence of a locked crack, accounting for different cleaning.
... It was reported that corrosion causes an annual loss of 2.4 trillion United States dollars, equal to 3% of world's gross domestic product (Velázquez et al., 2014). Pitting corrosion, among all types of corrosion, is the most common and dangerous as it is difficult to detect and can cause an insidious reduction in the strength of steel (Eldeen et al., 2012). The initiation and growth of pitting corrosion in marine environments are affected by many complex factors, such as seawater temperature, concentration of dissolved oxygen, water pH, and salinity (Guedes . ...
Pitting corrosion threatens the safety of steel structures by degrading material properties. In this paper, the effect of pitting damage on tensile behavior of Q345 and Q235 steels is studied experimentally and numerically. Material tensile tests were carried out on small steel specimens with artificially introduced corrosion pits of a cylindrical, semi-ellipsoidal, or conical shape, and used to validate their numerical models. Numerous numerical analyses were carried out to study the tensile properties and behavior of different steels due to varying pitting features in the pit shape and degree of volume loss (DOV) of corroded material. Results showed that pit shape influences the tensile properties of corroded steel significantly, depending on the ratio of pit diameter to pit depth. In the worst case, variation of pit shape could result in a difference of 7.58% in strength deterioration, and it could become worse if combined with the random nature of pit size, pit depth, and pitting distribution. An equivalent material model was proposed to correlate the reduction ratios of tensile properties with the DOV and pit shape. The ultimate strength of pitted plates can be predicted properly, using the equivalent material model instead of modelling the detailed corrosion pits.
