Ship-ice Collision Research Articles

A Dynamic Bayesian Network model for ship navigation risk in the Arctic Northeast Passage

The melting of a significant amount of sea ice has enabled the commercial and normal operation of ships in the Arctic. However, the harsh natural environment, unique geographical location and complex navigational conditions pose a serious challenge to the safety of ships during navigation. Ship besetting in ice and ship-ice collision are identified as the most critical risks, potentially resulting in vessel damage, property loss, environmental harm, and even casualties. This study proposes a dynamic Bayesian network (DBN) model to assess and predict the risk of ship besetting in ice and ship-ice collision in five sea areas along the Arctic Northeast Passage. The proposed method comprehensively considers environmental, ship and human factors and incorporates multi-year (2013–2022) marine meteorological reanalysis data and expert knowledge. The developed model has seven time steps and can be updated based on past, current and future conditions. The results indicate that it can effectively reflect the distribution of ship navigation risks in various sea areas and has the capability to be updated in real-time, serving as a tool for guiding ship operations and navigation decisions. At the same time, this study confirms August and September are the optimal navigation periods for the Northeast Passage, and the East Siberian Sea presenting the highest navigation risk. Ice thickness, ice concentration, navigation experience, professional skills, ship speed and ship class are identified as the primary risk factors in the region.

Research on ship-ice collision model and ship-bow fatigue failure Mechanism based on elastic-plastic ice constitutive relation

Collisions between sea ice and ships can damage the hull structure and pose a threat to crew safety in severe cases. The modelling of ice materials is crucial, but it is difficult to study ice-ship interactions. In this study, an ice constitutive model including the temperature factor was verified through experiments and numerical simulations of uniaxial and triaxial compression. Furthermore, the effects of salinity and porosity on the compressive strength of ice were studied using experiments and numerical simulations. The mechanical behaviour of sea ice was then simulated using the constitutive model mentioned above. A numerical model of collisions between polar ships and sea ice was established to investigate the ice-breaking processes of ships under different working conditions. The collision force and the level of structural damage were obtained. The influences of the initial pore size, hull speed, bow angle, and bow shape on the collision force and structural damage in the ship-ice collision process were analysed. Finally, fatigue damage to the bow structure at different ice thicknesses and speeds was calculated. The present results provide a reference for the structural design and optimisation of polar ships to a certain extent and improve the theory of ship-ice collisions.

Underwater radiated noise numerical analysis of polar transport vessels under ship-ice-water-air coupling continuous icebreaking based on the S-ALE algorithm

With the gradual opening of the Arctic channel, the underwater radiated noise induced by the ship-ice collision cannot be ignored. However, the underwater radiated noise induced by ship-ice collision is significantly different from that of ships navigating in open water. To explore the response rule of transient underwater radiation noise induced by ship-ice collision, this paper proposes a simplified numerical analysis method of ship-ice collision-induced transient underwater radiated noise in the full frequency band by combining the explicit dynamic method and acoustic analysis method. The ship-ice-water-air coupled collision analysis method based on the S-ALE algorithm is used to simulate and verify the ice load in the process of ship-ice continuous collision at different speeds. Then, the frequency-domain acoustic analysis method is used to predict the transient underwater radiated noise response in the full frequency band under icebreaking excitation and evaluate it by referring to the steady-state underwater radiated noise standard. The results show that the simplified analysis method can effectively predict the transient underwater radiation noise under icebreaking excitation. Under the icebreaking excitation, the radiation shape is irregularly scattered and the radiation direction is concentrated towards the bottom and bow of the ship with the frequency increase. The influence range of transient underwater radiated noise is mainly within 1000 Hz at different speeds, and the variation in the ship's speed affects the amplitude of the sound power level and the smoothness of the periodic response. The synthesized total sound power levels are 172.56 dB (V = 2.0kn), 174.15 dB (V = 2.5kn), 175.70 dB (V = 3.0kn), and 182.49 dB (V = 4.0kn), respectively. According to the comparison with the evaluation standard, it is found that the transient underwater radiation noise induced by ship icebreaking has a greater impact on marine organisms. It should give more detailed requirements within 10–1000 Hz when using relevant standards to evaluate underwater radiated noise induced by polar icebreaking. This paper can provide a reference for the research of underwater radiated noise induced by ship-ice collision and the formulation of relevant standards.

A viscous investigation on the hydrodynamic coefficients and wave loads under the interaction of side-by-side cylinders in regular waves

The paper introduces a two-dimensional Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics (RANS CFD) model to investigate the effects of adjacently floating bodies on the hydrodynamic coefficients and wave loads acting on these bodies. The analysis considers two square cylinders with a narrow gap in way of the free water surface. The physical significance of subsections of the hydrodynamic coefficient matrix becomes evident when comparing coefficients obtained from oscillating-oscillating versus oscillating-fixed models. This understanding is significant, particularly in applications where only specific portions of the hydrodynamic coefficient matrix are utilized, such as in ship-ice collision scenarios (Jiang et al., 2023a). The correlation between wave loads and wave elevations reveals that the sway force and roll moment are associated with the disparity in wave elevation at both sides of each cylinder, while heave forces correlate with the averaged wave elevation on both sides of each cylinder. It is concluded that hydrodynamic interactions are sensitive to the displacement of a floater and accordingly can dominate added mass and damping effects.

Study on the peeling criterion of anti-ice and wear-resistant coating for polar ships and simulation analysis method of the ship-ice collision process

The wear-resistant coating on the hull surface can be peeled off under the collision between the ice during the navigation of polar ships. In this study, the damage and peeling of the anti-icing wear-resistant coating at different impact angles, impact speeds, and temperatures were simulated. The static icing adhesion shear strength and normal peel strength of the anti-ice wear-resistant coating were examined, and the coating peeling criterion with temperature term was proposed. Furthermore, the damage and peeling of the anti-ice wear-resistant coating at different impact angles, impact speeds, and temperatures were simulated numerically.

A Multi-Yield-Surface Plasticity State-Based Peridynamics Model and its Applications to Simulations of Ice-Structure Interactions

Due to complex mesoscopic and the distinct macroscopic evolution characteristics of ice, especially for its brittle-to-ductile transition in dynamic response, it is still a challenging task to build an accurate ice constitutive model to predict ice loads during ship-ice collision. To address this, we incorporate the conventional multi-yield-surface plasticity model with the state-based peridynamics to simulate the stress and crack formation of ice under impact. Additionally, we take into account of the effects of inhomogeneous temperature distribution, strain rate, and pressure sensitivity. By doing so, we can successfully predict material failure of isotropic freshwater ice,iceberg ice, and columnar saline ice. Particularly, the proposed ice constitutive model is validated through several benchmark tests, and proved its applicability to model ice fragmentation under impacts, including drop tower tests and ballistic problems. Our results show that the proposed approach provides good computational performance to simulate ship-ice collision.

A comprehensive method for causation analysis of ship-ice collision risk in Arctic waters.

The influence of harsh Arctic environmental factors has caused ship-ice collision accidents to become the main threat faced by navigating ships. It is necessary to quantify the causation of ship accidents and perform effective risk management and control measures to ensure ship navigation safety. This study proposes a Bayesian network (BN) model-based risk analysis method for ship-ice collision accidents, which is used to quantitatively analyze the key risk factors and primary risk causation paths of ship accidents. First, the fault tree analysis (FTA) method is proposed to constructing the BN structure model, and the BN parameter solution method is further established. Consequently, a triangular fuzzy and defuzzification method is developed to quantify uncertain expert knowledge. Then, the BN inference method is used to analyze the collision risk causation where the North Atlantic and Arctic waters meet. The results indicate that the main risk factors in Arctic waters come from the environment. There are four primary risk causation paths; the proposed management and control measures of the risk causation paths (A), (B), (C), and (D) can effectively reduce the navigation risk by 29.95%, 9.98%, 25.05%, and 3.99%, respectively; the combination of these four measures can reduce the navigation risk by 54.63%.The proposed method has positive guiding significance for ensuring the safety of ship navigation in Arctic waters.

Numerical investigation of an ice-breaking LNGC cargo containment system based on experimental verification

In recent years, the international situation becomes serious, which causes a shortage of energy supply. This trend makes the ice-breaking LNGC become potential because of the short transportation advantage of Arctic route. The new ship type brings a demand for the comprehensive safety assessment of LNGC cargo containment system (CCS), where the ice load should be further considered. The traditional CCS model with single insulation box and simply support condition may not accurately reflect the energy transfer mechanism and the dynamic response. In this study, the full-scale experiment is conducted and a refined CCS numerical model in the range of 3 × 3 insulation boxes is proposed. Firstly, the support structure from the inner hull is taken as the flexible boundary condition and the connection form between each component is taken into consideration. Subsequently, the numerical model is verified by the full-scale impact and modal experiment. The verification results show that the 3 × 3 analysis model has a larger effective response range and higher calculation accuracy. Finally, some simplified ship-ice collision scenarios are conducted to study the responses of CCS. The results show that the transverse girder plate is the main support structure of CCS under ship-ice collision. Then the insulation box is subjected to the ice load transferred from the inner hull structure via mastic rope, while being constrained by the coupler. The ice loads have a greater effect on the response of CCS than the structural design of insulation box.

Numerical analysis method of ship-ice collision-induced vibration of the polar transport vessel based on the full coupling of ship-ice-water-air

As the Arctic Channel continues to be developed, collisions between polar navigation vessels and sea ice are inevitable, which will directly affect structural safety and vibration comfort. However, the numerical analysis method of ship–ice collision-induced vibration is not perfect, and the effect of fluid coupling is not typically considered. In this paper, a simplified numerical analysis method for ship–ice collision-induced vibration is proposed, in which a reliable ice load is obtained by first performing ship–ice–water–air coupled collision calculations, followed by ship–ice–water coupled vibration calculations to obtain the vibration response of the structure. In addition, this paper investigates the full coupling method and the modeling ranges and meshing sizes involved in the analysis ship–ice collision-induced vibration, and the computational efficiencies of the traditional ALE algorithm and S-ALE algorithm are compared. The results indicate that the simplified simulation analysis method and gradient meshing model improve the calculation accuracy and efficiency in ship-ice collision and vibration response analysis. Moreover, the modeling range of the water and air models cannot be less than 6 times the ship width, 2 times the ship length, and 1 times the ship depth, and the S-ALE algorithm saves 47.86% time compared to the ALE algorithm. The research results in this paper can provide a reference for the numerical simulation of ship–ice collision-induced vibration.

Application of rigid-plastic theory method in ship-ice collision

The rigid-plastic theory is widely used to estimate structural plastic damage in ship collision and some other structural impact cases under the assumption that the impactor is an idealized rigid body. This paper aims to extend the rigid-plastic method in ship collision to ship-ice collision, considering the energy dissipation caused by ice failure in the collision process. Based on three types of assumed collision scenarios between ship plates and ice floes, an approximate analytical plastic damage prediction method for ship plate impacted by ice floe is proposed, combining the rigid-plastic theory method with the energy approach of ice crushing. The analytical results have good correlations with experimental and numerical results in predicting maximal collision forces, plastic deformations of plate and so on. The proposed analytical formulations can provide a useful and convenient tool for the estimation of plastic damage of ship plates subjected to ice floe impact.

CFD-DEM based full-scale ship-ice interaction research under FSICR ice condition in restricted brash ice channel

The CFD-DEM simulations are performed to investigate the suitable ship-ice contact model and research the full-scale ship-ice interaction characteristics in the restricted brash ice channel. The discrete element method has been coupled in the viscous flow CFD solver to establish the brash ice model, combining with the VOF model of Euler Multiphase flow to simulate the interaction between the ship and brash ice. The AFRAMAX oil tanker ice test in Hamburg Ship Model Basin (HSVA) has been taken as the research reference. Firstly, the computed mean total ice resistance of different density grids show the monotonic convergence and meet the experimental results well. Secondly, three ship-ice contact models are applied to simulate the ship-ice collision, and the maximum relative error of total ice resistance is within −5.5%. Thirdly, the parametric study of ice shape and restitution coefficient is researched, which shows the ice shape could be the vital factor affecting the simulated total ice resistance. Finally, The full-scale total ice resistance under Finnish-Swedish Ice Class Rules (FSICR) IA and IB ice conditions are compared and discussed among the experiment, FSICR method, Dobrovin's empirical method, and CFD-DEM simulations. Moreover, the characteristics of collision, accumulation, extrusion, rolling, and sliding in the ship-ice interaction process are well consistent with the observations in the ice tank test, which indicates the proposed full-scale CFD-DEM approach of direct evaluating the ship-brash ice interaction shows reasonable results and practical value.

쇄빙연구선 ARAON호의 국부 빙하중 추정을 위한 영향계수행렬의 보완

This paper focuses on the improvement of the influence coefficient matrix method for estimation of local ice load on the icebreaking research vessel ARAON. The influence coefficient matrix relates ice pressure on the hull plate to the measured/calculated hull strain/stress. Conventionally von Mises equivalent stresses representing hull stresses and ice pressure acting on the hull plate are utilized to assemble the influence coefficient matrix. Because of the three dimensional features of the ship-ice collision process, an enhanced method to assemble the influence coefficient matrix is derived considering ice loads in the X, Y, and Z direction simultaneously. Furthermore the location of ice loads acting on hull-plate may fall outside the measuring sensor area, and the enhanced influence coefficient matrix is modified to reduce the difference between the actual and the estimated ice loads by expanding the domain outward from the sensor area. The developed method for enhanced influence coefficient matrix is applied to IBRV ARAON during the 2019 Antarctic ice field test and the local ice loads in three directions are efficiently calculated compared to those by a conventional method.

Risk Reasoning from Factor Correlation of Maritime Traffic under Arctic Sea Ice Status Association with a Bayesian Belief Network

Sustainable growth should not only be beneficial to the shipping industry in the future, but is also an urgent need to respond to resource and environmental crises and strengthen shipping governance. Maritime traffic in Arctic waters is prone to encounter dangerous ice conditions, and it is essential to study the mechanism of ice collision risk formation in relation to ice conditions. Taking the ship-ice collision risk in Arctic waters as the research object, we propose a dynamic assessment model of ship-ice collision risk under sea ice status dynamic association (SDA) effect. By constructing the standard paradigm of risk factor dynamic association (DA) effect, taking SDA as the key association factor. Combing with other risk factors that affect ship-ice collision accidents, the coupling relationship between risk factors were analyzed. Then, using the Bayesian network method to build a ship-ice collision accident dynamic risk assessment model and combing with the ice monitoring data in summer Arctic waters, we screen five ships’ position information on the trans-Arctic route in August. The risk behavior of ship-ice collision accidents on the selected route under SDA is analyzed by model simulation. The research reveal that the degree of SDA is a key related factor for the serious ice condition and the possibility of human error during ship’s navigation, which significantly affects the ship-ice collision risk. The traffic in Arctic waters requires extra vigilance of the SDA effect from no ice threat to ice threat, and continuous ice threat. According to the ship-ice collision risk analysis under the SDA effect and without SDA effect, the difference in risk reasoning results on the five stations of the selected route are 32.69%, −32.33%, −27.64%, −10.26%, and −30.13% respectively. The DA effect can optimize ship-ice collision risk inference problem in Arctic waters.

An integrated risk assessment model for safe Arctic navigation

Abstract Safety is always the first concern for a ship’s navigation in the Arctic. Ships navigating in the Arctic may face two main accident scenarios, i.e., getting stuck in the ice and ship-ice collision. More specifically, excessive speed may cause severe hull damage, while a very low speed may lead to a high probability of getting stuck in the ice. Based on this multi-risk perspective, an integrated risk assessment model was proposed to obtain the overall risk using the Bayesian Network (BN), in which the probabilities of accident occurrence and the severities of the possible consequences for ships getting stuck in the ice and for ship-ice collision could be estimated. Then, the voyage data collected from Yong Sheng’s Arctic sailing in 2013 were inputted into the integrated risk assessment model to perform a case study. A sensitivity analysis was performed to validate the proposed model and reveal the inherent mechanisms behind these two accidental scenarios. The proposed model can be applied to identify the safe speed for Arctic navigation under various ice conditions, a duty that is traditionally performed by well-trained crew members, but which entails too many uncertainties. The results can, to some extent, provide useful suggestions for navigators. They are imperative in supporting decision-making to shape the Arctic policy and to enhance the safety of Arctic shipping.

A Dynamic Bayesian Network model for ship-ice collision risk in the Arctic waters

Extreme weather conditions of the Arctic and its icy waters pose high-risk potential for a range of marine accidents in the region. Ship-ice collision is the focus of this paper. A large number of vessels operating in the Arctic waters are at risk of ice damage due to ship-ice collisions. The damage may vary from a minor hull deformation to ruptures that could put the lives, assets, and environment at risk. To minimize the risk of ship-ice collision in Arctic waters, a simple yet robust model to make routine safety-driven operational decisions could help. The present study proposes a Dynamic Bayesian Network (DBN) model to fill this gap. The model assesses the operational risk of ship-ice collision in an ice prone region using the hypothetical form of observations. Low temperatures, Weather, Ice, Fog, Darkness, Blowing snow, Poor visibility, Ice strength, Ice drift, Types of ice, Ice concentration and Speed of the vessel are considered as the primary risk factors in the region. The estimated collision risk would provide an easy to use indicator for decisions concerning safe operations in ice such as maneuvering, route selection, and safe speed. A case study of an oil tanker navigating across the Barents Sea is presented to explain the proposed model.

A theoretical investigation of ship ice resistance in waters covered with ice floes

Accurate prediction of ship resistance in ice covered waters is important for ice-going ships. In this paper the resistance of a ship moving in waters covered with small ice floes is investigated. A simplified collision process is applied to model the ship-ice collision process such that the ship resistance can be theoretically determined with hydrodynamic interaction taken into consideration. Thin-ship approximation leads to simple formula predicting that ship resistance coefficient is proportional to squared ship velocity, beam-to-length ratio, ice thickness-to-length ratio and sea ice concentration. These conclusions are in perfect agreement with experimental test results. This in turn confirms the validity of the theory proposed in this paper.

Effect of Parameter Variation of Viscoplastic Sea Ice Material Model on Ship Ice Collision

Effect of Parameter Variation of Viscoplastic Sea Ice Material Model on Ship Ice Collision

Simulation of Ship-ice Collision Considering the Effect of Temperature

The full opening of the northern shipping line puts forward a great challenge for the safety of polar ships, the presence of floating ice increases the possibility of collision between ship and sea ice. However, due to the complex mechanical properties of sea ice, a reasonable description of its material constitutive relation is the main factor affecting the accusation of calculation and analysis. In this paper, a constitutive model of ice material considering the effect of temperature is presented, a user-defined subroutine is developed and embedded into the finite element software LS-DYNA. Based on this, the damage and deformation characteristics of the ship structure and ice is studied, and effects of collision scenario parameters are discussed. The results of this paper can provide reference for the design and manufacture of polar ships.

Simulation of Ship-ice Collision Considering the Effect of Temperature

Simulation of Ship-ice Collision Considering the Effect of Temperature

An operational risk analysis tool to analyze marine transportation in Arctic waters

The Arctic Ocean has drawn major attention in recent years due to its rich natural resources and shorter navigational routes. Arctic development and transportation involve significant risk caused by the unique features of this region, such as ice, severe operating conditions, unpredictable climatic changes, and remoteness. Considering the high degree of uncertainty in the performance of vessel operating systems and humans, robust risk analysis and management tools are required to provide decision-support to prevent accidents and ensure safety at sea. This paper proposes an Object-Oriented Bayesian Network model to dynamically predict ship-ice collision probability based on navigational and operational system states, weather and ice conditions, and human error. The model, when integrated with potential consequences, may help estimate risk. A case study related to oil tanker navigation on the Northern Sea Route (NSR) is used to show the application of the proposed model to predict oil tanker collision with sea ice.