Advanced Analysis of Marine Structures—Edition II

One of the key issues in the design of modern ship and offshore structures is the accurate prediction of strength under various load conditions, especially impact, ultimate and fatigue strength. The advanced analysis of marine structures is involved in the mechanical analyses of advanced materials such as alloys and composite materials, and strength analyses of novel structures such as sandwich structures, in order to render marine structures lightweight, safe and economical throughout their lifetimes. Accordingly, the Special Issue “Advanced Analysis of Marine Structures” was prepared to collect works relating to advanced analysis of marine structures in general. To continue that work, the present Special Issue, “Advanced Analysis of Marine Structures—Edition II”, was developed to include more works related to this topic.

The present Special Issue contains 14 articles: 3 papers on the impact response of ship structures, 3 papers related to the ultimate strength of ship structures, 1 paper dealing with the structural fatigue strength, 3 papers covering the various aspects of strength assessment of ship and offshore structures, 2 papers revolving around the structural load prediction and deformation monitoring, and 2 papers involved in the hydrodynamic analysis of marine devices.

The accurate prediction of ship structural damage due to collisions is a research focus in impact strength analysis. To enhance the predictive accuracy of failure criteria in the simulation of ship collisions, Liu et al. [1] studied the modified Mohr–Coulomb failure criterion for metals, utilizing experimental and numerical methods for parameter calibration.

The design of polar ship structures is often based on the rules and regulations of classification societies, but ice loading tends to be conservative and exhibits redundancy. Therefore, Xia et al. [2] evaluated the applicability of the empirical formula for ice load assessments by conducting a series of quasi-static indentation tests on scaled hull plates under laboratory-made ice blocks of different scales.

Slamming impact is a typical load on a ship bow, and the whipping induced by slamming can significantly increase ship loading. Thus, Lu et al. [3] carried out an experimental and numerical study on the water entry of rigid wedges with various deadrise angles. The drop height and deadrise angle were parametrically varied to investigate the effect of the entry velocity and wedge shape on the impact dynamics.

As the dynamic ultimate strength of ship structures is a hot topic in ship safety assessment, Zhang et al. [4] proposed a novel two-step approach for determining the dynamic ultimate load capacity of ship structures. The main idea behind the two-step approach is to determine the dynamic ultimate load capacity based on the static ultimate load capacity after accounting for impacts that cause strain on the ship structures.

Plated grillage with openings is a typical structural form in the superstructure of large passenger ships, and the deformation and stresses generated during the welding complicate the structural failure behavior. Chen et al. [5], therefore, used a new partitioned inherent strain method and nonlinear finite element method to simulate the welding and loading process, validated by experiments.

Since funnels have a non-typical structure in large passenger ships, Ao et al. [6] presented experimental and finite element investigations on the ultimate strength of the funnel structure of a large passenger ship subjected to wind pressure.

Offshore platforms can be used to launch rockets, so Xiong et al. [7] investigated fatigue crack propagation on the lower surface of rocket deflector troughs in offshore rocket launch platforms. They analyzed the fatigue crack propagation patterns in both the maximum stress and maximum deformation regions of the deflector channels under the combined conditions of high temperature and impact.

Safety assessments of ship cargo-securing systems is of significant importance in preventing casualties, vessel instability and economic losses. Li et al. [8], thus, adopted an independently designed cylindrical cargo securing scheme with supporting structures for investigation.

A subsea tunnel crossing an active fault zone is extremely susceptible to disasters, such as tunnel collapses, sudden water ingress and mud inrush. Therefore, Li et al. [9] conducted numerical simulations by employing different lining stiffnesses for tunnel excavation, as well as applying dynamic loads. The dynamic stability of a subsea tunnel crossing an active fault zone was thus evaluated by comparing and analyzing the lining’s displacement, peak acceleration and stress characteristics.

Bi-layer pipes, composed of an inner layer and an outer layer, have been widely used in offshore engineering. Guo et al. [10] derived the governing equation for a bi-layer pipe subjected to axisymmetric loadings, and the equation is used to develop stress concentration factor formulations for girth welds in bi-layer pipes.

As the real-time prediction of hull girder loads is of great significance for the safety of ship structures, Wang et al. [11] compared four recurrent neural network models and analyzed the effect of different levels of noise on the prediction accuracy of various load components.

Digital twins play a seminal role in the digital transformation and intelligent upgrade of ships, so Wei et al. [12] introduced a digital twin methodology for the real-time monitoring of ship structure deformation fields based on finite discrete strain data, and a visualization tool framework was developed using virtual reality technology.

The floatation capacity of seabed pipelines has been considered a key risk element during design. Therefore, Leng et al. [13] presented a two-dimensional coupled approach with an elastoplastic theory to study the floatation of pipelines with the combined loading of waves and currents.

A fish aggregating device is an essential supplementary structure used in fishing. Its hydrodynamic performance affects structural and environmental safety in the harsh marine environment. As such, Zhang et al. [14] examined the hydrodynamic performance of biodegradable drifting fish aggregating devices in oceanic currents using numerical modeling.

In summary, the articles presented in the present Special Issue cover broad research topics related to the advanced analysis of marine structures, guiding readers through the best analysis approach.