A method and system for intelligent assessment of ship structure safety

Abstract

The present invention discloses a method and system for intelligently evaluating the safety of ship structures. The method calculates the stress responses of key structural areas of a hull under different load conditions, different wave conditions and different speeds based on hydrodynamics and finite element software, establishes a basic stress response database, and establishes a data model to calculate and analyze the stress of key nodes of the hull in real time during actual ship operation. The above results are corrected through stress data of a stress monitoring system, and finally the stress state of the structure and fatigue life of key areas of the whole ship are diagnosed and predicted in real time, thereby realizing a comprehensive evaluation of the safety performance of the ship structure. The method also has corresponding early warning / alarm functions, etc., and can provide objective and reliable information to the crew in a timely manner, enhance the active prevention capability of the hull structure risk, improve the safety of ship operation, reduce maintenance costs and frequency, extend the service life of the ship, perform dimensionality reduction processing on data, and improve the real-time performance of stress calculation results.

Description

Technical Field

[0001] The present invention relates to a monitoring method and system, in particular to a ship structure safety intelligent assessment method and system, belonging to the technical field of ship health monitoring. Background Art

[0002] As ships become larger and larger, the requirements for hull structural strength are becoming higher and higher, and shipowners are paying more and more attention to hull structural strength and safety. At present, major classification societies are constantly promoting the top-level design of related smart ships and launching various smart ship symbols. For example, ABS has launched the smart hull structure smart symbol SMART (SHM). At present, the main means of hull structural health monitoring is still based on the installation of hull stress monitoring system. This system can only monitor the stress at the sensor installation point, and has no predictive and diagnostic properties for the structural safety of other key areas, and cannot achieve the intelligence required by classification societies.

[0003] Chinese patent publication number CN107406126A discloses a structural monitoring system for a ship's hull integrated with a navigation decision support system, which discloses relevant content for monitoring the hull's structure, but does not specifically disclose how to use relevant data for structural monitoring. In addition, since there is a large amount of relevant ship data involved in structural monitoring, the processing dimension is large, the data processing volume is large, and the calculation time is long, it is difficult to ensure that an effective response to structural stress can be made immediately. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for intelligent assessment of ship structure safety, which can perform real-time intelligent health monitoring of any structural point, reduce the amount of calculation for data processing, and improve the timeliness of structure monitoring.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for intelligently assessing ship structure safety comprises the following steps:

[0007] S1. Finite element fine mesh modeling is performed according to the actual structural shape of the key points of the ship. Each key point of the ship contains multiple fine meshes. The peak stress response function of each typical position of the key point of the ship under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β is calculated. The stress data of each fine mesh in the key point of the ship is extracted and a basic stress response database is established;

[0008] S2, wave radar inputs wave height H, period T, wave direction angle β in real time at each time interval, as well as draft D input by loading instrument and ship speed V input by GPS;

[0009] S3. According to the wave height H, period T, wave angle β input in real time by the wave radar at each time interval, the draft D input by the loader, and the speed V input by the GPS, the basic stress database obtained by the finite element method is used to find the adjacent wave height, period, wave angle, draft, and speed. Based on the actual input wave height, period, wave angle, draft, and speed of the radar during operation, the stress value is obtained using a multi-dimensional interpolation algorithm.

[0010] The final stress value σ is obtained by using a multidimensional interpolation algorithm for the wave height, period, wave angle, draft, and speed input by the system. Dimension reduction processing is performed during calculation to form a two-dimensional interpolation + three-dimensional interpolation algorithm. For the final stress value σ, the real-time draft D and speed V input by the loader are used for two-dimensional stress interpolation. The basic stresses σ1, σ2, σ3, and σ4 used for two-dimensional interpolation are obtained by using a three-dimensional difference algorithm based on the wave height H, wave angle β, and period T, respectively.

[0011] S4. For the given main wave information and secondary wave information, interpolate the main wave stress σ 主 and secondary wave stress σ 次 , superimpose the two stress values ​​to obtain the total predicted stress σ at the prediction point 预报 =σ 主 +σ 次 ;

[0012] S5, based on the stress input by the stress sensor in real time and the stress predicted at the location where the stress sensor is installed, the predicted stress obtained by interpolation calculation in the key area is corrected;

[0013] S6. After correcting the interpolated predicted stress of each key area, the stress history curve of each key structural area is obtained, and then the real-time stress is obtained;

[0014] S7. The actual predicted stress value σ max预报 and allowable stress value σ 许用 For comparison, R = σ max预报 / [σ 许用 ]*100%, use percentage to judge low risk, medium risk and high risk.

[0015] Furthermore, the step S3 is specifically as follows:

[0016] For the input wave height H, wave direction angle β, and period T, find the corresponding stresses for H1 and H2 that are close to the wave height H, the corresponding stresses for β1 and β2 that are close to the wave direction angle β, and the corresponding stresses for T1 and T2 that are close to the period T from the database. Here, H1 and H2 are two adjacent wave heights in the wave height list of the database adjacent to the wave height H, β1 and β2 are two adjacent wave direction angles in the wave direction angle list of the database adjacent to the wave direction angle β, T1 and T2 are two adjacent periods in the period list of the database adjacent to the period T, and H1 < H < H2, β1 < β < β2, T1 < T < T2; for the input draft D and ship speed V, find the corresponding stresses for D1 and D2 that are close to the draft D from the database. Here, D1 and D2 are two adjacent drafts in the draft list of the database adjacent to the draft D, and D1 < D < D2, and find the corresponding stresses for V1 and V2 that are close to the ship speed V. Here, V1 and V2 are two adjacent ship speeds in the ship speed list of the database adjacent to the ship speed V, and V1 < V < V2.

[0017] For wave height, period, wave direction angle, draft, and ship speed, use the multi-dimensional interpolation algorithm to obtain the stress value. Now there are a total of five-dimensional interpolations, which is quite difficult. First, perform dimensionality reduction to a two-dimensional interpolation + three-dimensional interpolation algorithm.

[0018] Perform two-dimensional stress interpolation for the real-time draft D and ship speed V input by the system, as Figure 2 shown. In the two-dimensional stress interpolation coordinate system, the horizontal axis of the coordinate is the draft D, the vertical axis of the coordinate is the ship speed V, and S1, S2, S3, and S4 are the areas of the four small rectangles divided by the required real-time interpolation stress σ, and S is the total area of the rectangle.

[0019] For the required stress σ, perform two-dimensional interpolation:

[0020]

[0021] Among them, σ1 is the stress value regarding D1 and V1, σ2 is the stress value regarding D1 and V2, σ3 is the stress value regarding D2 and V2, and σ4 is the stress value regarding D2 and V1;

[0022] And σ1, σ2, σ3, and σ4 are calculated through the three-dimensional interpolation algorithm.

[0023] For σ1, σ2, σ3, and σ4 in the above two-dimensional interpolation formula, first find the database stress based on the real-time input wave height H, wave direction angle β, and period T using the three-dimensional interpolation algorithm.

[0024] The calculation process of σ1 is as follows: Given the draft D1 and ship speed V1, for the real-time input wave height H, wave direction angle β, and period T, perform interpolation calculation to obtain σ1; as Figure 3As shown, in the three-dimensional interpolation coordinate system, wave height H, wave direction angle β, and period T are the three coordinate axes, V1, V2, V3, V4, V5, V6, V7, and V8 are the volumes of the eight small cuboids divided by the real-time interpolation stress σ1, and V is the total volume of the cuboids.

[0025] For σ1:

[0026]

[0027] Among them, σ11 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β1 found in the stress database; σ12 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β1 found in the stress database; σ13 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β2 found in the stress database; σ14 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β2 found in the stress database Value; σ15 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β1 found in the stress database; σ16 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β1 found in the stress database; σ17 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β2 found in the stress database; σ18 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β2 found in the stress database;

[0028] Similarly, we can get σ2, σ3, σ4;

[0029] Substitute σ1, σ2, σ3, and σ4 obtained by three-dimensional interpolation into the two-dimensional interpolation algorithm, and finally obtain the stress σ.

[0030] Furthermore, the step S5 is specifically as follows: the stress values ​​monitored in real time by the stress monitoring system monitoring point in each time interval are taken as the maximum value σ max测 Here, the stress sensor used is a long-base sensor, and the measured σ max测 The finite element model results at the monitoring point are specially processed to extract the longitudinal stress from the stress at the sensor installation point, that is, the longitudinal stress value is used here in the database, and the longitudinal stress prediction value obtained by interpolation at this point at each time is taken. The maximum value σ max预报 , the maximum stress σ at the monitoring point of the stress monitoring system max测 The maximum stress per minute σ obtained by interpolation here max预报 By calculating the ratio, we can get the correction factor σ of the predicted stress max测 / σ max预报=s, then the stress predicted at other key points is multiplied by the correction factor s for correction, σ 修正预报 =s*σ 预报 .

[0031] Furthermore, in step S6, the stress history curve of each key structural area uses the rain flow counting method to count stress cycles, uses the average cyclic stress to correct the cyclic stress amplitude, and performs fatigue calculation based on Miner's linear damage theory.

[0032] Furthermore, in step S7, the user sets appropriate percentages to determine low risk, medium risk, and high risk according to needs, and gives suggestions for corresponding risk conditions. When it is at medium risk, the alarm area is checked, and continuous attention is paid to it later, and text records are made. When it is at high risk, the heading angle is adjusted to reduce the stress level and thus reduce the risk of damage. If damage occurs, repairs are carried out.

[0033] A monitoring system for realizing an intelligent evaluation method for ship structure safety, comprising

[0034] Land-based processor, installed on land, used to install hydrodynamic and finite element software for computational processing;

[0035] The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β in advance, and establish a basic stress database;

[0036] Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions and collects wave load data in real time during the ship's voyage;

[0037] The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar;

[0038] Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed;

[0039] The ship-based processor is located in the ship's wheelhouse. It builds data models and performs calculations and analysis based on the input wave data, calculates and predicts the stress state and fatigue life of key area structures in real time, and evaluates the safety status of the hull structure.

[0040] The display, located in the ship's wheelhouse, shows the structural stress and accumulated fatigue damage in key areas of the hull;

[0041] The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

[0042] A monitoring system for realizing an intelligent evaluation method for ship structure safety, comprising

[0043] The land-based processor is used to install hydrodynamic and finite element software for calculation and processing, and to install stress database. Based on the stress database and the wave information transmitted by the wave analysis processor, a data model is established and dynamic stress range and peak stress calculation and analysis are performed. The stress state and fatigue life of the key area structure are calculated and predicted in real time, and the safety state of the hull structure is evaluated. The calculation results are transmitted to the data transmission communicator on the ship in real time.

[0044] The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different wave conditions in advance and establish a stress database;

[0045] Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions. It is used in the actual operation of the ship to collect wave load data in real time during the navigation process of the ship;

[0046] The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar;

[0047] Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed;

[0048] The data transmission communicator transmits the wave information processed by the wave analysis processor, GPS speed information, loading information and stress information collected by the stress sensor to the land-based server for real-time calculation and analysis, and receives the key area structural stress state and fatigue life prediction results transmitted by the land-based server;

[0049] The display, located in the ship's wheelhouse, displays the structural stress, cumulative fatigue damage status and diagnostic information of key areas of the hull transmitted from the land-based server;

[0050] The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

[0051] Furthermore, the wave radar includes a stern radar and a bow radar, the stern radar is arranged at the stern of the hull, and the bow radar is arranged at the bow of the hull.

[0052] Compared with the prior art, the present invention has the following advantages and effects: a method and system for intelligent assessment of ship structure safety of the present invention can perform real-time intelligent health monitoring of any structural point according to the stress database calculated in advance and the wave information collected by the wave radar, and correct the predicted stress by the stress measured by the stress detection system. The present invention performs dimensionality reduction processing on multi-dimensional propagation data and converts high-latitude data processing into multiple low-latitude data processing processes, which greatly reduces the amount of data processing calculation and the time required for data processing, so that the stress of the ship structure can be obtained more quickly and real-time response can be made; by real-time monitoring of the hull structure status information, a comprehensive assessment of the safety performance of the ship structure is achieved, and the stress level and fatigue life of the ship structure are predicted / alarmed in real time, etc., which can provide objective and reliable information to the crew in a timely manner, enhance the risk prevention capability of the hull structure, improve the safety of ship operation, reduce maintenance costs and frequency, and extend the service life of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 The present invention is a flow chart of a method for intelligently evaluating ship structure safety.

[0054] Figure 2 It is a schematic diagram of a two-dimensional interpolation coordinate system according to an embodiment of the present invention.

[0055] Figure 3 Schematic diagram of a three-dimensional interpolation coordinate system according to an embodiment of the present invention.

[0056] Figure 4 It is a schematic diagram of a stress monitoring interface of an embodiment of the present invention.

[0057] Figure 5 It is a schematic diagram of a fatigue monitoring interface according to an embodiment of the present invention.

[0058] Figure 6 It is a schematic diagram of Example 1 of a ship structure safety intelligent assessment system of the present invention.

[0059] Figure 7 It is a schematic diagram of Example 2 of a ship structure safety intelligent assessment system of the present invention.

[0060] Figure 8 It is a schematic diagram of the installation of the wave radar of the present invention.

[0061] Fig. 9 It is a schematic diagram of key area prediction points of a ship structure safety intelligent assessment method of the present invention. DETAILED DESCRIPTION

[0062] In order to elaborate on the technical scheme adopted by the present invention to achieve the predetermined technical purpose, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without paying creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0063] like Figure 1 As shown, a ship structure safety intelligent assessment method of the present invention specifically comprises the following steps:

[0064] S1. Finite element fine mesh modeling is performed according to the actual structural shape of the key points of the ship. Each key point of the ship contains hundreds of fine meshes. The peak stress response function of each typical position of the key point of the ship under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β is calculated. The stress data of each fine mesh in the key point of the ship is extracted and a basic stress response database is established.

[0065] Since the five influencing factors of draft D, speed V, wave height H, period T and wave direction angle β are taken into consideration, the stress data in the database will be more comprehensive and accurate, thereby improving the accuracy of the forecast results. Since the stress of each fine grid is extracted, the amount of data in the stress database is particularly large, and the call and query are particularly slow, which affects the immediacy of the analysis. The database is established in binary mode to greatly improve the speed of call and query.

[0066] S2. The wave radar inputs the wave height H, period T, wave direction angle β, draft D input by the loader, and speed V input by GPS in real time at each time interval.

[0067] The draft D input by the loading instrument reflects the loading condition of the ship and is an important factor affecting the safety of the ship structure. Especially for ultra-large container ships that load and unload cargo at multiple ports, different loading forms greatly affect the stress distribution of the hull structure.

[0068] S3. According to the wave height H, period T, wave angle β input by the wave radar in real time at each time interval, the draft D input by the loader, and the speed V input by the GPS, the basic stress database obtained based on the finite element method is used to find the adjacent wave height, period, wave angle, draft, and speed. Based on the actual input wave height, period, wave angle, draft, and speed of the radar during operation, the stress value is obtained using a multidimensional interpolation algorithm.

[0069] For the wave height, period, wave direction angle, draft, ship speed input to the system, the multi-dimensional interpolation algorithm is used to obtain the final stress value σ. During the calculation, dimensionality reduction processing is performed to form a two-dimensional interpolation + three-dimensional interpolation algorithm; for the final stress value σ, two-dimensional stress interpolation is performed on the real-time draft D and ship speed V input by the loading instrument; among them, the basic stress values σ1, σ2, σ3, and σ4 for two-dimensional interpolation are respectively obtained by three-dimensional difference algorithms using the wave height H, wave direction angle β, and period T.

[0070] Specifically, for the input wave height H, wave direction angle β, and period T, find the corresponding stresses of H1, H2 close to the wave height H, β1, β2 close to the wave direction angle β, and T1, T2 close to the period T from the database. Among them, H1 and H2 are two adjacent wave heights adjacent to the wave height H in the wave height list of the database, β1 and β2 are two adjacent wave direction angles adjacent to the wave direction angle β in the wave direction angle list of the database, T1 and T2 are two adjacent periods adjacent to the period T in the period list of the database, and H1 < H < H2, β1 < β < β2, T1 < T < T2; for the input draft D and ship speed V, find the corresponding stresses of D1, D2 close to the draft D and V1, V2 close to the ship speed V from the database. Among them, D1 and D2 are two adjacent drafts adjacent to the draft D in the draft list of the database, and D1 < D < D2, and V1 and V2 are two adjacent ship speeds adjacent to the ship speed V in the ship speed list of the database, and V1 < V < V2.

[0071] For the wave height, period, wave direction angle, draft, and ship speed, the stress value is obtained using the multi-dimensional interpolation algorithm. Now there are a total of five-dimensional interpolations, which is quite difficult. First, perform dimensionality reduction to a two-dimensional interpolation + three-dimensional interpolation algorithm.

[0072] For the real-time draft D and ship speed V input to the system, two-dimensional stress interpolation is performed, as Figure 2 shown. In the two-dimensional stress interpolation coordinate system, the horizontal axis of the coordinate is the draft D, the vertical axis of the coordinate is the ship speed V, and S1, S2, S3, and S4 are the areas of the four small rectangles into which the required real-time interpolation stress σ is divided, and S is the total area of the rectangle.

[0073] For the required stress σ, two-dimensional interpolation is performed:

[0074]

[0075] Among them, σ1 is the stress value with respect to D1 and V1, σ2 is the stress value with respect to D1 and V2, σ3 is the stress value with respect to D2 and V2, and σ4 is the stress value with respect to D2 and V1;

[0076] And σ1, σ2, σ3, and σ4 are calculated by the three-dimensional interpolation algorithm.

[0077] For σ1, σ2, σ3, and σ4 in the above two-dimensional interpolation formula, firstly, based on the real-time input wave height H, wave direction angle β, and period T, the database stress is found and obtained using a three-dimensional interpolation algorithm.

[0078] The calculation process of σ1 is as follows: when the draft D1 and the speed V1 are determined, the wave height H, wave angle β, and period T input in real time are interpolated to obtain σ1; Figure 3 As shown, in the three-dimensional interpolation coordinate system, wave height H, wave direction angle β, and period T are the three coordinate axes, V1, V2, V3, V4, V5, V6, V7, and V8 are the volumes of the eight small cuboids divided by the real-time interpolation stress σ1, and V is the total volume of the cuboids.

[0079] For σ1:

[0080]

[0081] Among them, σ11 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β1 found in the stress database; σ12 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β1 found in the stress database; σ13 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β2 found in the stress database; σ14 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β2 found in the stress database value; σ15 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β1 found in the stress database; σ16 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β1 found in the stress database; σ17 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β2 found in the stress database; σ18 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β2 found in the stress database.

[0082] Similarly, we can get σ2, σ3, σ4;

[0083] Substitute σ1, σ2, σ3, and σ4 obtained by three-dimensional interpolation into the two-dimensional interpolation algorithm, and finally obtain the stress σ.

[0084] S4. For the given main wave information and secondary wave information, interpolate the main wave stress σ 主 and secondary wave stress σ 次 , superimpose the two stress values ​​to obtain the total predicted stress σ at the prediction point 预报 =σ 主 +σ 次 .

[0085] S5. Based on the stress input by the stress sensor in real time and the stress predicted at the location where the stress sensor is installed, the predicted stress obtained by interpolation calculation in the key area is corrected.

[0086] The stress value monitored in real time by the stress monitoring system monitoring point in each time interval is taken as the maximum value σ max测 Here, the stress sensor used is a long-base sensor, and the measured σ max测 The finite element model results at the monitoring point are specially processed to extract the longitudinal stress from the stress at the sensor installation point, that is, the longitudinal stress value is used here in the database, and the longitudinal stress prediction value obtained by interpolation at this point at each time is taken. The maximum value σ max预报 , the maximum stress σ at the monitoring point of the stress monitoring system max测 The maximum stress per minute σ obtained by interpolation here max预报 By calculating the ratio, we can get the correction factor σ of the predicted stress max测 / σ max预报 =s, then the stress predicted at other key points is multiplied by the correction factor s for correction, σ 修正预报 =s*σ 预报 .

[0087] S6. After correcting the interpolated predicted stress in each key area, the stress history curve of each key structural area is obtained, and then the real-time stress is obtained. The stress history curve of each key structural area uses the rain flow counting method to count the stress cycles, uses the average cyclic stress to correct the cyclic stress amplitude, and performs fatigue calculation based on the Miner linear damage theory.

[0088] S7. The actual predicted stress value σ max预报 and allowable stress value σ 许用 For comparison, R = σ max预报 / [σ 许用 ]*100%, use percentage to judge low risk, medium risk and high risk. Users set appropriate percentages to judge low risk, medium risk and high risk according to their needs, and give suggestions on the corresponding risk status. When it is at medium risk, check the alarm area, continue to pay attention to it later, and make text records. When it is at high risk, adjust the heading angle to reduce the stress level and thus reduce the risk of damage. If damage occurs, repair it.

[0089] like Figure 4 The figure shows the comparison between the actual predicted stress value and the allowable stress value, R = σ max预报 / [σ 许用]*100%, use percentage to judge low risk, medium risk and high risk. For example, below 80% is low risk, 80%-90% is medium risk, and above 90% is high risk. Users can set appropriate percentages to judge as low risk, medium risk and high risk according to their needs.

[0090] like Figure 5 The figure shows how to judge low risk, medium risk and high risk based on the damage coefficient. For example, below 0.8 is low risk, 0.8-0.9 is medium risk, and above 0.9 is high risk. Users can set appropriate percentages to judge as low risk, medium risk or high risk according to their needs.

[0091] The monitoring system for realizing the intelligent ship structure safety assessment method of the present invention has two embodiments.

[0092] Embodiment 1:

[0093] like Figure 6 As shown, a monitoring system for realizing an intelligent evaluation method for ship structure safety comprises

[0094] Land-based processor, installed on land, used to install hydrodynamic and finite element software for computational processing;

[0095] The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β in advance, and establish a basic stress database;

[0096] Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions and collects wave load data in real time during the ship's voyage;

[0097] The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar;

[0098] Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed;

[0099] The ship-based processor is located in the ship's wheelhouse. It builds data models and performs calculations and analysis based on the input wave data, calculates and predicts the stress state and fatigue life of key area structures in real time, and evaluates the safety status of the hull structure.

[0100] The display, located in the ship's wheelhouse, shows the structural stress and accumulated fatigue damage in key areas of the hull;

[0101] The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

[0102] like Figure 8 As shown, the wave radar includes a stern radar 1 and a bow radar 2. The stern radar 1 is arranged at the stern of the hull, and the bow radar 2 is arranged at the bow of the hull. The ship-based processor 3, the wave analysis processor 4, the display 5, and the alarm 6 are arranged in the navigation room, and the stress monitoring sensor 7 is installed on the upper deck in the middle of the ship.

[0103] like Fig. 9 As shown, af is the prediction point of the key area, and point f is the installation point of the stress sensor.

[0104] The stress value monitored in real time by the stress monitoring system at the monitoring point f in each time interval is taken as the maximum value σ max测 ,,The stress sensor here uses a long-base sensor, and the measured stress is the longitudinal stress. The finite element model results at the monitoring point are specially processed when processing, and the longitudinal stress is extracted from the stress at the sensor installation point, that is, the longitudinal stress value is used in the database here, and the stress prediction value obtained by interpolation at each time interval of the monitoring point f is taken as the maximum longitudinal value σ max预报 , the maximum stress σ at the monitoring point of the stress monitoring system max测 The maximum stress per minute σ obtained by interpolation here max预报 By calculating the ratio, we can get the correction factor σ of the predicted stress max测 / σ max预报 =s, then the stress predicted at the key point ae is multiplied by the coefficient s for correction, σ 修正预报 =s*σ 预报 .

[0105] The hydrodynamic analysis software and finite element software are installed on the land-based processor, and the key structures of the hull under different wave conditions are simulated and analyzed in advance, and a stress database is established, and this database is transplanted into the ship-based processor in advance. The wave radar collects wave load data during the ship's navigation in real time, and inputs it into the wave analyzer for wave spectrum analysis to obtain the main wave and secondary wave components, and obtain the characteristic values ​​of the waves (wave height, wavelength, period, wave direction); the wave analysis processor inputs the wave information into the ship-based processor, and the ship-based processor combines the wave information obtained by the wave analysis processor, as well as the GPS speed information and the draft information of the loading instrument. Based on the stress database, the stress database is interpolated in real time to predict the stress response of the key area structure. Stress correction is performed based on the stress predicted at the monitoring point of the stress monitoring sensor and the actual stress obtained by the stress sensor to obtain the correction coefficient, and the predicted stress at other locations where stress sensors are not installed is corrected. According to the stress time history predicted in the key area, the rain flow counting method is used to statistically calculate the stress cycle, and the average cyclic stress is used to correct the cyclic stress amplitude. Fatigue analysis is performed based on Miner linear theory, and finally the safety status of the hull structure is evaluated. When the stress data or fatigue damage value of the monitored hull exceeds the target value, an alarm will be issued to remind the crew that the hull is at risk of damage, and further checks can be carried out or special attention can be paid during the next docking.

[0106] Embodiment 2:

[0107] like Figure 7 As shown, a monitoring system for realizing an intelligent evaluation method for ship structure safety comprises

[0108] The land-based processor is used to install hydrodynamic and finite element software for calculation and processing, and to install stress database. Based on the stress database and the wave information transmitted by the wave analysis processor, a data model is established and dynamic stress range and peak stress calculation and analysis are performed. The stress state and fatigue life of the key area structure are calculated and predicted in real time, and the safety state of the hull structure is evaluated. The calculation results are transmitted to the data transmission communicator on the ship in real time.

[0109] The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different wave conditions in advance and establish a stress database;

[0110] Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions. It is used in the actual operation of the ship to collect wave load data in real time during the navigation process of the ship;

[0111] The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar;

[0112] Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed;

[0113] The data transmission communicator transmits the wave information processed by the wave analysis processor, GPS speed information, loading information and stress information collected by the stress sensor to the land-based server for real-time calculation and analysis, and receives the key area structural stress state and fatigue life prediction results transmitted by the land-based server;

[0114] The display, located in the ship's wheelhouse, displays the structural stress, cumulative fatigue damage status and diagnostic information of key areas of the hull transmitted from the land-based server;

[0115] The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

[0116] like Figure 8 As shown, the wave radar includes a stern radar 1 and a bow radar 2. The stern radar 1 is arranged at the stern of the hull, and the bow radar 2 is arranged at the bow of the hull. The ship-based processor 3, the wave analysis processor 4, the display 5, and the alarm 6 are arranged in the navigation room, and the stress monitoring sensor 7 is installed on the upper deck in the middle of the ship.

[0117] like Fig. 9 As shown, af is the prediction point of the key area, and point f is the installation point of the stress sensor.

[0118] The stress value monitored in real time by the stress monitoring system at the monitoring point f in each time interval is taken as the maximum value σ max测 , the stress prediction value obtained by interpolation at each time interval of the monitoring point f, take the maximum value σ max预报 , the maximum stress σ at the monitoring point of the stress monitoring system max测 The maximum stress per minute σ obtained by interpolation here max预报 By calculating the ratio, we can get the correction factor σ of the predicted stress max测 / σ max预报 =s, then the stress predicted at the key point ae is multiplied by the coefficient s for correction, σ 修正预报 =s*σ 预报 .

[0119] The hydrodynamic analysis software and finite element software are installed on the land-based processor, and the key structures of the hull under different wave conditions are simulated and analyzed in advance to establish a stress database. The wave radar collects wave load data during the ship's navigation in real time, and inputs it into the wave analyzer for wave spectrum analysis to obtain the main and secondary wave components, and obtain the characteristic values ​​of the waves (wave height, wavelength, period, wave direction); the wave analysis processor inputs the wave information into the data transmission communicator, and transmits the wave information processed by the wave analysis processor to the land-based server. The land-based server performs multi-dimensional interpolation calculations on the stress database in real time based on the pre-installed stress database, combined with the wave information obtained by the wave analysis processor, as well as the GPS speed information and the loader draft information, and predicts the stress response of the key area structure. According to the stress predicted at the monitoring point of the stress monitoring sensor and the actual stress obtained by the stress sensor, the stress correction is performed to obtain the correction coefficient, and the predicted stress at other locations where the stress sensor is not installed is corrected. According to the stress time history predicted in the key area, the rain flow counting method is used to count the stress cycle, and the cyclic stress amplitude is corrected using the average cyclic stress. Fatigue analysis is performed based on Miner linear theory, and finally the safety status of the hull structure is evaluated. The land-based server transmits the structural stress of the key area, the cumulative fatigue damage status and diagnostic information to the data transmission communicator on the ship. When the stress data or fatigue damage value of the monitored hull exceeds the target value, an alarm is issued to remind the crew that the hull is at risk of damage, and further corresponding inspections can be made or focused on during the next docking repair.

[0120] The ship structure intelligent health monitoring system based on ship-based or land-based solutions establishes stress database and fatigue database based on finite element software and hydrodynamic software in advance, which can quickly predict stress and fatigue in actual ship operation and has strong timeliness. It can provide objective and reliable information to the crew in a timely manner, enhance the risk proactive prevention capability of the hull structure, improve the safety of ship operation, reduce maintenance costs and frequency, and extend the service life of the ship.

[0121] like Figure 6 The advantage of the embodiment 1 shown is that the wave data collected during the ship's voyage does not need to be transmitted to land, and can be analyzed directly on board. Figure 7 The advantage of the embodiment 2 shown is that the crew can directly obtain the calculation results transmitted from the land without having to operate professional software. Both the embodiment 1 and the embodiment 2 establish a stress database and a fatigue database based on the finite element software and the hydrodynamic software in advance, and perform real-time intelligent health monitoring on any structural point of interest in the actual operation of the ship, which can quickly predict stress and fatigue and has a strong timeliness. It avoids the hysteresis caused by using finite elements for calculation in the actual operation of the ship and the disadvantages of occupying a large amount of computing resources.

[0122] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for intelligent assessment of ship structure safety, characterized in that The following steps are involved: S1. Finite element fine mesh modeling is performed according to the actual structural shape of the key points of the ship. Each key point of the ship contains multiple fine meshes. The peak stress response function of each typical position of the key point of the ship under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β is calculated. The stress data of each fine mesh in the key point of the ship is extracted and a basic stress response database is established; S2, wave radar inputs wave height H, period T, wave direction angle β in real time at each time interval, as well as draft D input by loading instrument and ship speed V input by GPS; S3. According to the wave height H, period T, wave angle β input in real time by the wave radar at each time interval, the draft D input by the loader, and the speed V input by the GPS, the basic stress database obtained by the finite element method is used to find the adjacent wave height, period, wave angle, draft, and speed. Based on the actual input wave height, period, wave angle, draft, and speed of the radar during operation, the stress value is obtained using a multi-dimensional interpolation algorithm. The final stress value σ is obtained by using a multidimensional interpolation algorithm for the wave height, period, wave angle, draft, and speed input by the system. Dimension reduction processing is performed during calculation to form a two-dimensional interpolation + three-dimensional interpolation algorithm. For the final stress value σ, the real-time draft D and speed V input by the loader are used for two-dimensional stress interpolation. The basic stresses σ1, σ2, σ3, and σ4 used for two-dimensional interpolation are obtained by using a three-dimensional difference algorithm based on the wave height H, wave angle β, and period T, respectively. For the real-time draft D and speed V input by the system, two-dimensional stress interpolation is performed. In the two-dimensional stress interpolation coordinate system, the horizontal axis is the draft D, the vertical axis is the speed V, S1, S2, S3, S4 are the four small rectangular areas divided for the real-time interpolation stress σ, and S is the total area of ​​the rectangles; For the desired stress σ, perform two-dimensional interpolation: Among them, σ1 is the stress value about D1 and V1, σ2 is the stress value about D1 and V2, σ3 is the stress value about D2 and V2, and σ4 is the stress value about D2 and V1; And σ1, σ2, σ3, σ4 are calculated by a three-dimensional interpolation algorithm; For σ1, σ2, σ3, σ4 in the above two-dimensional interpolation formula, firstly, based on the real-time input wave height H, wave angle β, period T, the database stress is found and obtained using a three-dimensional interpolation algorithm; The calculation process of σ1 is as follows: the draft D1 and the speed V1 are determined, then the wave height H, wave angle β, and period T input in real time are interpolated to obtain σ1; in the three-dimensional interpolation coordinate system, the wave height H, wave angle β, and period T are used as the three coordinate axes, V1, V2, V3, V4, V5, V6, V7, and V8 are the volumes of the eight small cuboids divided by the real-time interpolation stress σ1, and V is the total volume of the cuboids; For σ1: Among them, σ11 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β1 found in the stress database; σ12 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β1 found in the stress database; σ13 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T2, and wave direction angle β2 found in the stress database; σ14 is the stress value corresponding to the draft D1, speed V1, wave height H1, period T1, and wave direction angle β2 found in the stress database Value; σ15 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β1 found in the stress database; σ16 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β1 found in the stress database; σ17 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T2, and wave direction angle β2 found in the stress database; σ18 is the stress value corresponding to the draft D1, speed V1, wave height H2, period T1, and wave direction angle β2 found in the stress database; Similarly, we can get σ2, σ3, σ4; Substitute σ1, σ2, σ3, and σ4 obtained by three-dimensional interpolation into the two-dimensional interpolation algorithm, and finally obtain the stress σ; S4. For the given main wave information and secondary wave information, interpolate the main wave stress σ 主 and secondary wave stress σ 次 , superimpose the two stress values ​​to obtain the total predicted stress σ at the prediction point 预报 =σ 主 +σ 次 ; S5, based on the stress input by the stress sensor in real time and the stress predicted at the location where the stress sensor is installed, the predicted stress obtained by interpolation calculation in the key area is corrected; S6. After correcting the interpolated predicted stress of each key area, the stress history curve of each key structural area is obtained, and then the real-time stress is obtained; S7. The actual predicted stress value σ max预报 and allowable stress value σ 许用 For comparison, R = σ max预报 / [σ 许用 ]*100%, use percentage to judge low risk, medium risk and high risk.

2. A ship structure safety intelligent assessment method according to claim 1, characterized in that: The step S5 is specifically as follows: the stress values ​​monitored in real time by the stress monitoring system monitoring point in each time interval are taken as the maximum value σ max测 Here, the stress sensor used is a long-base sensor, and the measured σ max测 The finite element model results at the monitoring point are specially processed to extract the longitudinal stress from the stress at the sensor installation point, that is, the longitudinal stress value is used here in the database, and the longitudinal stress prediction value obtained by interpolation at this point at each time is taken. The maximum value σ max预报 , the maximum stress σ at the monitoring point of the stress monitoring system max测 The maximum stress per minute σ obtained by interpolation here max预报 By calculating the ratio, we can get the correction factor σ of the predicted stress max测 / σ max预报 =s, then the stress predicted at other key points is multiplied by the correction factor s for correction, σ 修正预报 =s*σ 预报 .

3. A ship structure safety intelligent assessment method according to claim 1, characterized in that: In step S6, the stress history curve of each key structural area uses the rain flow counting method to count stress cycles, uses the average cyclic stress to correct the cyclic stress amplitude, and performs fatigue calculation based on the Miner linear damage theory.

4. A ship structure safety intelligent assessment method according to claim 1, characterized in that: In step S7, the user sets appropriate percentages to determine low risk, medium risk, and high risk according to needs, and gives suggestions for corresponding risk conditions. When it is at medium risk, the alarm area is checked, and continued attention is paid to it later, and text records are made. When it is at high risk, the heading angle is adjusted to reduce the stress level and thus reduce the risk of damage. If damage occurs, repairs are carried out.

5. A monitoring system for implementing the ship structure safety intelligent assessment method according to any one of claims 1 to 4, characterized in that: Include Land-based processor, installed on land, used to install hydrodynamic and finite element software for computational processing; The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different drafts D, different speeds V, different wave heights H, different wave periods T, and different wave angles β in advance, and establish a basic stress database; Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions and collects wave load data in real time during the ship's voyage; The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar; Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed; The ship-based processor is located in the ship's wheelhouse. It builds data models and performs calculations and analysis based on the input wave data, calculates and predicts the stress state and fatigue life of key area structures in real time, and evaluates the safety status of the hull structure. The display, located in the ship's wheelhouse, shows the structural stress and accumulated fatigue damage in key areas of the hull; The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

6. A monitoring system for implementing the ship structure safety intelligent assessment method according to any one of claims 1 to 4, characterized in that: Include The land-based processor is used to install hydrodynamic and finite element software for calculation and processing, and to install stress database. Based on the stress database and the wave information transmitted by the wave analysis processor, a data model is established and dynamic stress range and peak stress calculation and analysis are performed. The stress state and fatigue life of the key area structure are calculated and predicted in real time, and the safety state of the hull structure is evaluated. The calculation results are transmitted to the data transmission communicator on the ship in real time. The hydrodynamic analysis software and finite element software are installed on the land-based processor to simulate and analyze the key structures of the hull under different wave conditions in advance and establish a stress database; Wave radar, installed at the bow and stern of the ship, scans the wave information around the ship in all directions. It is used in the actual operation of the ship to collect wave load data in real time during the navigation process of the ship; The wave analysis processor, located in the ship's wheelhouse, performs spectral analysis on the wave data collected by the wave radar; Stress monitoring sensors are arranged on the upper deck in the middle of the ship to monitor the stress of the hull structure at the installation point, and to correct the structural stress predicted at other points where stress detection sensors are not installed; The data transmission communicator transmits the wave information processed by the wave analysis processor, GPS speed information, loading information and stress information collected by the stress sensor to the land-based server for real-time calculation and analysis, and receives the key area structural stress state and fatigue life prediction results transmitted by the land-based server; The display, located in the ship's wheelhouse, displays the structural stress, cumulative fatigue damage status and diagnostic information of key areas of the hull transmitted from the land-based server; The alarm is located in the wheelhouse and sounds an alarm when the stress data or fatigue damage value of the monitored hull exceeds the target value.

7. The monitoring system according to claim 6, characterized in that: The wave radar comprises a stern radar and a bow radar, the stern radar is arranged at the stern of the hull, and the bow radar is arranged at the bow of the hull.

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