Method and system for predicting fatigue life of submarine cable considering influence of marine organisms inhabiting

Abstract

The application provides a submarine cable fatigue life prediction method and system considering the influence of marine biological colonization, and the method comprises the following steps: constructing a submarine cable model based on the inherent characteristics of the submarine cable; measuring the marine biological colonization state of the sea area to be predicted, and constructing a biological colonization state model; obtaining a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model; presetting marine condition parameters based on the marine state of the sea area to be predicted, simulating the submarine cable fatigue life prediction model, and obtaining submarine cable stress data; and performing fatigue damage analysis on the submarine cable according to the submarine cable stress data, obtaining the fatigue cumulative damage value under the marine condition, and predicting the fatigue life of the submarine cable. The method considers the influence of marine biological colonization in the process of predicting the fatigue life of the submarine cable, accurately predicts the fatigue life of the submarine cable, provides a strong reference for the transmission of marine energy, and can maximize the safe operation of the submarine cable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power, in particular to a submarine cable fatigue life prediction method and system considering the influence of marine biological colonization. BACKGROUND

[0002] In recent years, with the continuous increase of energy demand in coastal areas and the continuous deepening of marine development, submarine cables have become an indispensable core component in the fields of power transmission between land and islands, cross-sea communication, marine engineering and new energy development. Dynamic array inter-sea submarine power cables are needed for floating offshore renewable energy to connect to the power grid, and the development of these cables must improve their service life. Related research has found that fatigue is an important factor in determining service life, as these components must continuously withstand dynamic mechanical loads during their service life, but existing research on the fatigue life of submarine cables does not consider the influence of marine biological colonization. Since submarine cables are arranged in water, marine biological colonization on the cables will also affect the service life of these components, and the lack of consideration in this regard will inevitably lead to inaccurate prediction of the final fatigue life of submarine cables, making it difficult to provide effective reference for the transmission of marine energy and affecting the safe operation of submarine cables. SUMMARY

[0003] The present application aims to provide a submarine cable fatigue life prediction method and system considering the influence of marine biological colonization, to solve the above technical problems, to consider the influence of marine biological colonization in the process of predicting the fatigue life of submarine cables, to construct a submarine cable fatigue life prediction model, and to accurately predict the fatigue life of submarine cables, to provide a strong reference for the transmission of marine energy, and to maximize the safe operation of submarine cables.

[0004] To solve the above technical problems, the present application provides a submarine cable fatigue life prediction method considering the influence of marine biological colonization, comprising the following steps:

[0005] Constructing a submarine cable model based on the inherent characteristics of submarine cables;

[0006] Measuring the marine biological colonization state of the sea area to be predicted, and constructing a biological colonization state model;

[0007] Obtaining a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model;

[0008] Based on the marine state of the sea area to be predicted, presetting the marine condition parameters and simulating the submarine cable fatigue life prediction model to obtain submarine cable stress data;

[0009] According to the submarine cable stress data, fatigue damage analysis is performed on the submarine cable, the fatigue cumulative damage value under the marine condition is obtained, and the fatigue life of the submarine cable is predicted.

[0010] The scheme considers the marine organism inhabitation influence into the process of the submarine cable fatigue life prediction, thereby constructing a submarine cable fatigue life prediction model, realizing the accurate prediction of the submarine cable fatigue life, providing a powerful reference for the marine energy transmission, and maximizing the guarantee of the safe operation of the submarine cable.

[0011] Further, the marine organism inhabitation state of the to-be-predicted sea area is measured, and an organism inhabitation state model is constructed, specifically:

[0012] A plurality of regions are set according to different depths of the to-be-predicted sea area, and the marine organism inhabitation state of each region is measured;

[0013] Based on the marine organism inhabitation state of each region, a corresponding organism inhabitation state model is constructed.

[0014] Further, based on the marine organism inhabitation state of each region, a corresponding organism inhabitation state model is constructed, specifically:

[0015] Based on the marine organism inhabitation state of each region, a corresponding organism inhabitation mass density and organism inhabitation thickness are obtained;

[0016] According to the organism inhabitation mass density and the organism inhabitation thickness, a corresponding organism inhabitation state model is constructed.

[0017] Further, the submarine cable fatigue life prediction model is obtained based on the submarine cable model and the organism inhabitation state model, specifically:

[0018] According to the organism inhabitation state model, an organism inhabitation weight increase value and a resistance coefficient increase value at the current time are determined;

[0019] Based on the organism inhabitation weight increase value and the resistance coefficient increase value, the submarine cable surface resistance coefficient and the submarine cable weight of the submarine cable model are updated, so as to obtain the submarine cable fatigue life prediction model.

[0020] Further, the fatigue damage of the submarine cable is analyzed according to the submarine cable stress data, the fatigue cumulative damage value under the marine condition is obtained, and the submarine cable fatigue life is predicted, specifically:

[0021] The rainflow counting method is used to extract the stress cycle number and stress range from the submarine cable stress data;

[0022] According to the material of the submarine cable, the fatigue damage of the submarine cable is analyzed based on the Miner cumulative damage criterion and the S-N curve, and the fatigue cumulative damage value under the marine condition is obtained;

[0023] Based on the fatigue cumulative damage value, the submarine cable fatigue life is predicted.

[0024] The scheme can also accurately guide the operation and maintenance of the submarine cable and resource reservation, and effectively improve the operation and maintenance efficiency and avoid resource waste.

[0025] The application provides a submarine cable fatigue life prediction system considering the influence of marine biological colonization, comprising an initial model construction module, a biological colonization state model construction module, a model updating module, a model simulation module and a prediction module.

[0026] The initial model construction module is used to construct a submarine cable model based on the inherent characteristics of the submarine cable.

[0027] The biological colonization state model construction module is used to construct a biological colonization state model according to the measured biological colonization state of the sea area to be predicted.

[0028] The model updating module is used to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model.

[0029] The model simulation module is used to preset marine condition parameters based on the marine state of the sea area to be predicted and simulate the submarine cable fatigue life prediction model to obtain submarine cable stress data.

[0030] The prediction module is used to analyze the fatigue damage of the submarine cable according to the submarine cable stress data, obtain the fatigue cumulative damage value under the marine condition and predict the submarine cable fatigue life.

[0031] The system architecture is simple and easy to implement, and can be well combined with existing computer technology to implement the system architecture, which can consider the influence of marine biological colonization in the process of submarine cable fatigue life prediction, thereby constructing a submarine cable fatigue life prediction model and accurately predicting the fatigue life of the submarine cable, providing a strong reference for the transmission of marine energy and maximizing the safe operation of the submarine cable.

[0032] Further, the biological colonization state model construction module is used to construct a biological colonization state model according to the measured biological colonization state of the sea area to be predicted, specifically as follows.

[0033] The sea area to be predicted is divided into several regions according to different depths, and the marine biological colonization states measured in different regions are different.

[0034] Based on the marine biological colonization state of each region, a corresponding biological colonization state model is constructed.

[0035] Further, the biological colonization state model is constructed based on the marine biological colonization state of each region, specifically as follows.

[0036] Based on the marine biological colonization state of each region, the corresponding biological colonization mass density and biological colonization thickness are obtained.

[0037] According to the biological colonization quality density and the biological colonization thickness, a corresponding biological colonization state model is constructed.

[0038] Further, the model updating module is used to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model, specifically:

[0039] According to the biological colonization state model, a biological colonization weight increase value and a drag coefficient increase value at the current time are determined;

[0040] Based on the biological colonization weight increase value and the drag coefficient increase value, the submarine cable surface drag coefficient and the submarine cable weight of the submarine cable model are updated to obtain the submarine cable fatigue life prediction model.

[0041] Further, the prediction module is used to perform fatigue damage analysis on the submarine cable according to submarine cable stress data, obtain a fatigue cumulative damage value under the marine condition, and predict the submarine cable fatigue life, specifically:

[0042] The rainflow counting method is used to extract stress cycle times and stress ranges from the submarine cable stress data;

[0043] According to the material of the submarine cable, fatigue damage analysis is performed on the submarine cable based on the Miner cumulative damage criterion and the S-N curve to obtain a fatigue cumulative damage value under the marine condition;

[0044] Based on the fatigue cumulative damage value, the submarine cable fatigue life is predicted. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 A flowchart of a submarine cable fatigue life prediction method considering the influence of marine biological colonization is provided in an embodiment of the present application;

[0046] Figure 2 A rising cycle number extraction schematic diagram is provided in an embodiment of the present application;

[0047] Figure 3 A submarine cable fatigue life prediction system module connection diagram considering the influence of marine biological colonization is provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0049] Please refer to Figure 1 The embodiment provides a submarine cable fatigue life prediction method considering the influence of marine biological colonization, and comprises the following steps:

[0050] S1: constructing a submarine cable model based on inherent characteristics of the submarine cable;

[0051] S2: measuring marine biological colonization states of a sea area to be predicted, and constructing a biological colonization state model;

[0052] S3: obtaining a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model;

[0053] S4: presetting marine state parameters based on marine states of the sea area to be predicted, simulating the submarine cable fatigue life prediction model, and obtaining submarine cable stress data;

[0054] S5: performing fatigue damage analysis on the submarine cable according to the submarine cable stress data, obtaining a fatigue cumulative damage value under the marine state, and predicting the submarine cable fatigue life.

[0055] The embodiment considers the influence of marine biological colonization in the process of predicting the submarine cable fatigue life, thereby constructing a submarine cable fatigue life prediction model, realizing accurate prediction of the submarine cable fatigue life, providing a powerful reference for marine energy transmission, and maximizing the safe operation of the submarine cable.

[0056] It should be noted that the inherent characteristics of the submarine cable can include length, axial stiffness, bending stiffness, mass, structural damping coefficient and tangential flow resistance coefficient, and the submarine cable model can be constructed based on the inherent characteristics. The submarine cable model is an existing mathematical model, which is only updated based on the constructed biological colonization state model in the embodiment to obtain the submarine cable fatigue life prediction model, so as to finally achieve the purpose of predicting the submarine cable fatigue life.

[0057] Further, the measuring of the marine biological colonization states of the sea area to be predicted and the constructing of the biological colonization state model are specifically as follows:

[0058] A plurality of regions are set according to different depths of the sea area to be predicted, and marine biological colonization states of each region are measured;

[0059] Based on the marine biological colonization states of each region, a corresponding biological colonization state model is constructed.

[0060] In the embodiment, three states of the biological colonization can be measured and compared, including: the non-biological colonization state A1, the preliminary coverage state A2 and the full coverage state A3; wherein the non-biological colonization state A1 is taken as a reference, which is irrelevant to the selection of the area; the preliminary coverage state A2 indicates that the selected submarine cable is preliminarily covered by the biological colonization, and the full coverage state A3 indicates that the selected submarine cable is fully covered by the biological colonization, and the A2 and A3 are set because the biological colonization thickness varies with the depth of the sea, so the biological colonization state of the submarine cable can be set as two areas. Preferably, the area from the sea surface to the depth of 30m can be set as the first area, and a fixed value of the biological colonization thickness is used; the area below the depth of 30m can be set as the second area, and another fixed value of the biological colonization thickness is used.

[0061] In the embodiment, the biological colonization prediction of the specific position can also be provided according to the NORSOK standard, that is, without measuring the biological colonization state of the sea area to be predicted, only the latitude and longitude position of the sea area to be predicted is determined, the corresponding biological colonization state can be predicted, the operation efficiency is greatly improved, and the problem that some sea areas are difficult to measure in the field is avoided, and the application range of the method is improved.

[0062] Further, the biological colonization state of each area is used to construct a corresponding biological colonization state model, specifically:

[0063] Based on the biological colonization state of each area, the corresponding biological colonization mass density and biological colonization thickness are obtained;

[0064] The corresponding biological colonization state model is constructed according to the biological colonization mass density and the biological colonization thickness.

[0065] In the embodiment, the biological colonization state model includes a weight increase model and a drag coefficient increase model; wherein:

[0066] The weight increase model is specifically represented as:

[0067]

[0068] In the formula, ρ g is the biological colonization mass density, ρ s is the density of seawater, D n is the outer diameter of the submarine cable, ΔT g is the biological colonization thickness, μ is a surface constant (1.0 for the submarine cable), and g is the acceleration of gravity;

[0069] The drag coefficient increase model is specifically represented as:

[0070]

[0071] In the formula, CD The damping coefficient of the submarine cable.

[0072] Further, the submarine cable fatigue life prediction model is obtained based on the submarine cable model and the bio-attachment state model, specifically:

[0073] The bio-attachment weight increase value and the drag coefficient increase value at the current time are determined according to the bio-attachment state model;

[0074] The submarine cable surface drag coefficient and the submarine cable weight of the submarine cable model are updated based on the bio-attachment weight increase value and the drag coefficient increase value, so as to obtain the submarine cable fatigue life prediction model.

[0075] In the embodiment, the bio-attachment mass density and the bio-attachment thickness in the bio-attachment state model change over time, so the submarine cable model needs to be updated regularly to obtain the submarine cable fatigue life prediction model. In actual operation, the submarine cable model can be adjusted and updated at monthly intervals to modify the submarine cable surface drag coefficient and the submarine cable weight, and to optimize the submarine cable fatigue life prediction model for predicting the submarine cable fatigue life.

[0076] Further, in the process of simulating the submarine cable fatigue life prediction model based on the preset marine condition parameters of the sea area to be predicted and obtaining the submarine cable stress data, the marine condition parameters can be set according to actual needs, including wave height, peak wave period and sea state occurrence probability. Specifically, the JONSWAP wave generation program can be used to generate a wave file to realize the presetting of the marine condition. At the same time, the marine condition duration is set according to the needs, so as to simulate the submarine cable fatigue life prediction model in a specific time and obtain the submarine cable stress data.

[0077] Further, the fatigue damage analysis of the submarine cable is performed according to the submarine cable stress data, the fatigue cumulative damage value under the marine condition is obtained, and the submarine cable fatigue life is predicted, specifically:

[0078] The rainflow counting method is used to extract the stress cycle number and stress range from the submarine cable stress data;

[0079] According to the material of the submarine cable, the fatigue damage analysis of the submarine cable is performed based on the Miner cumulative damage criterion and the S-N curve to obtain the fatigue cumulative damage value under the marine condition;

[0080] The submarine cable fatigue life is predicted based on the fatigue cumulative damage value.

[0081] In the embodiment, the rainflow counting method is used to extract the stress cycle number and stress range from the submarine cable stress data, specifically:

[0082] (1) Extraction of peak-to-valley points

[0083] 1) Remove the continuous equal points in the submarine cable stress data, and retain one point;

[0084] 2) Remove the non-peak-to-valley points of the remaining data points. For the determination of whether a point belongs to a peak-to-valley point, the difference product method can be used. That is, for the non-first point P i after removing the continuous equal points, if (P i -P i-1 )(P i -P i+1 )<0, the above formula is established, and it is considered that this point is a non-peak-to-valley point and should be removed. For the first point, it is directly considered as a peak-to-valley point and no longer needs to be determined.

[0085] (2) Extraction of cycle number

[0086] The four-point rainflow counting principle is used for statistics: the maximum peak-to-valley value of the raindrop flow is recorded as a cycle; the part of the raindrop flow is deleted from the submarine cable stress data, and the rainflow counting method is repeated for the remaining submarine cable stress data until there is no remaining history. For example, if e < f < h < g, it is a full cycle fgf', as shown in Figure 2 , the amplitude S a = |f-g| / 2 and the average value S p = |f+g| / 2 can be obtained. Similarly, the descending type can be obtained.

[0087] Based on the above process, the Matlab software is used to realize the rainflow counting method to obtain the stress range and stress cycle number in the stress duration curve of the submarine cable, and then the fatigue load spectrum is obtained.

[0088] In this embodiment, according to the material of the submarine cable used, the fatigue damage analysis of the submarine cable is carried out based on the Miner cumulative damage criterion and S-N curve to obtain the fatigue cumulative damage value under the sea condition, wherein the cumulative damage value D i under the i-th sea condition can be expressed as:

[0089]

[0090] In the formula, p i represents the probability of occurrence under the i-th sea condition; n s represents the cycle number under the stress level S, wherein the stress level S is determined by the stress range, and the cycle number is determined by the stress cycle number; that is, the total fatigue cumulative damage value D is:

[0091]

[0092] It should be noted that, to determine the fatigue cumulative damage value of the submarine cable, stress cycle times and stress ranges need to be extracted from the stress data of the submarine cable obtained under several marine conditions, so as to obtain the total fatigue cumulative damage value in a certain time region, and the fatigue life of the submarine cable is predicted based on the value.

[0093] Further, to quickly realize the prediction of the fatigue life of the submarine cable, the software AQWA based on potential flow hydrodynamics can be used to obtain the damage calculation results of the submarine cable under different marine conditions by adding time domain response, and the damage critical values of the submarine cable with marine organisms under different sea conditions can be determined by comparing the results of the submarine cable without marine organisms and the submarine cable with marine organisms, so as to predict the life of the submarine cable after the marine organisms, and realize the regular maintenance of the submarine cable.

[0094] The submarine cable fatigue life prediction model constructed in the embodiment can set corresponding marine state parameters according to the actual situation of the sea area to be predicted, and based on the inherent characteristics of the submarine cable used in the sea area, the stress cycle times and the corresponding stress ranges of the submarine cable under different marine conditions after the marine organisms are analyzed by the rain flow counting method. According to the S-N curve, the total fatigue cumulative damage value is calculated, and finally the coupling response analysis is performed in the software SESAM to obtain the simulation matrix for life prediction of the submarine cable. Therefore, the fatigue life of the submarine cable after the marine organisms is studied, which further provides protection for the long-term stable operation of the submarine cable.

[0095] Please refer to Figure 3 The embodiment provides a submarine cable fatigue life prediction system considering the influence of marine organisms, which is used to realize a submarine cable fatigue life prediction method considering the influence of marine organisms, and includes an initial model construction module, a biological colonization state model construction module, a model updating module, a model simulation module and a prediction module.

[0096] The initial model construction module is used to construct a submarine cable model based on the inherent characteristics of the submarine cable.

[0097] The biological colonization state model construction module is used to construct a biological colonization state model according to the biological colonization state measured in the sea area to be predicted.

[0098] The model updating module is used to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model.

[0099] The model simulation module is used to preset marine state parameters based on the marine state of the sea area to be predicted and simulate the submarine cable fatigue life prediction model to obtain submarine cable stress data.

[0100] The prediction module is configured to perform fatigue damage analysis on the submarine cable according to submarine cable stress data, obtain a fatigue cumulative damage value under the marine condition, and predict the fatigue life of the submarine cable.

[0101] The system provided by the embodiment has a simple system architecture and is easy to implement, and can be well combined with existing computer technology. The system can consider the influence of marine organisms on the fatigue life prediction of the submarine cable, thereby constructing a fatigue life prediction model of the submarine cable, accurately predicting the fatigue life of the submarine cable, providing a strong reference for the transmission of marine energy, and maximizing the safe operation of the submarine cable.

[0102] Further, the biological colonization state model construction module is configured to construct a biological colonization state model according to the biological colonization state measured in the to-be-predicted sea area, and specifically:

[0103] The to-be-predicted sea area is divided into a plurality of regions according to different depths, and the biological colonization states measured in different regions are different;

[0104] Based on the biological colonization state of each region, a corresponding biological colonization state model is constructed.

[0105] Further, the biological colonization state model is constructed based on the biological colonization state of each region, and specifically:

[0106] Based on the biological colonization state of each region, a corresponding biological colonization mass density and a biological colonization thickness are obtained.

[0107] The biological colonization state model is constructed according to the biological colonization mass density and the biological colonization thickness.

[0108] Further, the model updating module is configured to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model, and specifically:

[0109] According to the biological colonization state model, a biological colonization weight increase value and a drag coefficient increase value at the current time are determined;

[0110] The submarine cable surface drag coefficient and the submarine cable weight of the submarine cable model are updated based on the biological colonization weight increase value and the drag coefficient increase value, to obtain the submarine cable fatigue life prediction model.

[0111] Further, the prediction module is configured to perform fatigue damage analysis on the submarine cable according to submarine cable stress data, obtain a fatigue cumulative damage value under the marine condition, and predict the fatigue life of the submarine cable, and specifically:

[0112] The rainflow counting method is used to extract stress cycle times and stress ranges from the submarine cable stress data.

[0113] According to the material of the submarine cable, fatigue damage analysis is performed on the submarine cable based on Miner cumulative damage criterion and S-N curve to obtain the fatigue cumulative damage value under the marine condition;

[0114] The fatigue life of the submarine cable is predicted based on the fatigue cumulative damage value.

[0115] The above is the preferred embodiment of the present application, it should be pointed out that, for those skilled in the technical field, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements also as the protection scope of the present application.

Claims

1. A method for predicting the fatigue life of a submarine cable taking into account the effect of marine organisms inhabiting, characterized in that, The method comprises the following steps: constructing a submarine cable model based on inherent characteristics of the submarine cable; measuring the marine biological colonization state of the sea area to be predicted, and constructing a biological colonization state model, specifically: setting a plurality of regions according to different depths of the sea area to be predicted, measuring the marine biological colonization state of each region, obtaining the corresponding biological colonization mass density and biological colonization thickness based on the marine biological colonization state of each region, and constructing the corresponding biological colonization state model according to the biological colonization mass density and the biological colonization thickness; obtaining a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model, specifically: determining the biological colonization weight increase value and the resistance coefficient increase value at the current time according to the biological colonization state model; updating the submarine cable surface resistance coefficient and the submarine cable weight of the submarine cable model based on the biological colonization weight increase value and the resistance coefficient increase value to obtain the submarine cable fatigue life prediction model; presetting marine condition parameters based on the marine state of the sea area to be predicted, and simulating the submarine cable fatigue life prediction model to obtain submarine cable stress data; 2. The method of predicting the fatigue life of a submarine cable taking into account the effect of marine organisms inhabiting according to claim 1, characterized in that, performing fatigue damage analysis on the submarine cable according to the submarine cable stress data, obtaining the fatigue cumulative damage value under the marine condition, and predicting the submarine cable fatigue life. The fatigue damage analysis on the submarine cable according to the submarine cable stress data, the fatigue cumulative damage value under the marine condition, and the prediction of the submarine cable fatigue life are specifically: extracting the stress cycle number and the stress range from the submarine cable stress data by using the rain flow counting method; performing fatigue damage analysis on the submarine cable based on the Miner cumulative damage criterion and the S-N curve according to the material of the submarine cable to obtain the fatigue cumulative damage value under the marine condition; 3. A system for predicting the fatigue life of a subsea cable taking into account the effect of marine organisms colonising the cable, characterised in that, predicting the submarine cable fatigue life based on the fatigue cumulative damage value. The method comprises an initial model construction module, a biological colonization state model construction module, a model updating module, a model simulation module, and a prediction module; wherein: the initial model construction module is used to construct a submarine cable model based on inherent characteristics of the submarine cable; the biological colonization state model construction module is used to construct a biological colonization state model according to the measured biological colonization state of the sea area to be predicted; the model updating module is used to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological colonization state model; the model simulation module is used to preset marine condition parameters based on the marine state of the sea area to be predicted, and simulate the submarine cable fatigue life prediction model to obtain submarine cable stress data; 4. The system for predicting the fatigue life of a subsea cable taking into account the effect of marine organisms according to claim 3, characterized in that, the prediction module is used to perform fatigue damage analysis on the submarine cable according to the submarine cable stress data, obtain the fatigue cumulative damage value under the marine condition, and predict the submarine cable fatigue life. The biological colonization state model construction module is used to construct a biological colonization state model according to the measured biological colonization state of the sea area to be predicted, specifically: the sea area to be predicted is set into a plurality of regions according to different depths, and the marine biological colonization state measured in different regions is different; 5. A system for predicting the fatigue life of a subsea cable taking into account the effect of marine organisms inhabiting the same, according to claim 4, characterized in that, a corresponding biological colonization state model is constructed based on the marine biological colonization state of each region. The corresponding biological colonization state model is constructed based on the marine biological colonization state of each region, specifically: Based on the marine organism settlement state of each region, the corresponding biological settlement mass density and biological settlement thickness are obtained; According to the biological settlement mass density and the biological settlement thickness, a corresponding biological settlement state model is constructed.

6. A system for predicting the fatigue life of a subsea cable taking into account the effect of marine organisms colonisation according to any one of claims 3 to 5, characterised in that, The model updating module is configured to obtain a submarine cable fatigue life prediction model based on the submarine cable model and the biological settlement state model, specifically: According to the biological settlement state model, the biological settlement weight increase value and the resistance coefficient increase value at the current time are determined; Based on the biological settlement weight increase value and the resistance coefficient increase value, the submarine cable surface resistance coefficient and the submarine cable weight of the submarine cable model are updated to obtain the submarine cable fatigue life prediction model.

7. A system for predicting the fatigue life of a subsea cable taking into account the effect of marine organisms colonising the cable according to claim 6, characterised in that, The prediction module is configured to perform fatigue damage analysis on the submarine cable according to the submarine cable stress data, obtain the fatigue cumulative damage value under the marine condition, and predict the submarine cable fatigue life, specifically: The rainflow counting method is used to extract the stress cycle number and stress range from the submarine cable stress data; According to the material of the submarine cable, the fatigue damage analysis on the submarine cable is performed based on the Miner cumulative damage criterion and the S-N curve to obtain the fatigue cumulative damage value under the marine condition; Based on the fatigue cumulative damage value, the submarine cable fatigue life is predicted.

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