Ocean engineering structure full-field stress monitoring method
By laying strain sensors on the marine engineering structure, establishing a finite element model and estimating the stress value of unmeasured positions using the Kriging model, the problem of inability to monitor initial static strain and local installation of strain sensors in the prior art is solved, and high accuracy and accuracy of full-field stress monitoring are achieved.
Patent Information
- Application Number
- CN202510500530.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-07-08
AI Technical Summary
The existing marine engineering structure cannot monitor the initial static strain value, which affects the accuracy of monitoring and evaluation, and the strain sensor can only be installed in a limited position, making it impossible to achieve full-field stress monitoring.
By arranging strain sensors on the marine engineering structure, the initial static strain value is obtained, the finite element model is established, the stress transfer function and the Kriging model are used to estimate the stress value at the unmeasured position, and the Kriging model is trained in combination with the measured stress values collected in real time to achieve full-field stress monitoring.
The accuracy of full-field stress calculation and monitoring and evaluation are improved, and the full-field stress monitoring of large-scale marine engineering structures is realized.
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Figure CN120274918A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of offshore engineering structures, and particularly to a method for monitoring the full-field stress of an offshore engineering structure. Background Art
[0002] As the core equipment in the field of ocean energy and resource development, large offshore engineering structures can bear a load capacity of hundreds of tons and are the key supports for large-scale development facilities such as oil and gas and electric energy. The working environment of offshore engineering structures is complex and diverse. During long-term operation, large deflection deformation and stress overrun will lead to structural failure. Once structural failure occurs, it will cause equipment damage and project interruption at least, and may even trigger a collapse accident, endangering personnel safety and resulting in economic losses of hundreds of millions of yuan.
[0003] In order to ensure the safe and reliable operation of large offshore engineering structures throughout their life cycle and prevent catastrophic consequences, it is necessary to monitor the health of the structures. For large offshore engineering structures, the main structural failure forms in the working state dominated by static loads are large deflection deformation and stress overrun of the structure. By installing strain sensors on offshore engineering structures, the stress changes of the structures can be captured, which is of great significance for monitoring the full-field stress distribution of the structures, analyzing the strength of offshore engineering structures, and evaluating the health status of the structures. Sticking strain sensors can achieve structural stress monitoring, but there are the following problems in actual engineering applications:
[0004] (1) The static strain of large offshore engineering structures accounts for a large proportion in the total strain, and strain sensors are usually pasted after the structure generates self-weight pre-strain. Therefore, the initial static strain value cannot be monitored, which seriously restricts the accuracy of monitoring and evaluation.
[0005] (2) Due to the constraints of on-site conditions, strain sensors can only be installed at limited positions on offshore engineering structures, and full-field stress monitoring of the structures cannot be achieved. Summary of the Invention
[0006] In order to solve the problems that the existing offshore engineering structures cannot monitor the initial static strain value, which affects the accuracy of monitoring and evaluation, and due to the constraints of on-site conditions, strain sensors can only be installed at limited positions on offshore engineering structures, and full-field stress monitoring of the structures cannot be achieved, the present invention proposes a method for monitoring the full-field stress of an offshore engineering structure, which can solve the above problems.
[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve:
[0008] A method for monitoring the full-field stress of an offshore engineering structure includes:
[0009] Step 1: Deploy strain sensors on the offshore engineering structure to obtain the measured stress value S of the offshore engineering structure only under its own weight o ;
[0010] Step 2: Apply loads F1 to F n with different weights on the ocean engineering structure, where F1 < F2 < … < F n , and obtain the corresponding measured stress values S1 to S n ;
[0011] Step 3: Establish a finite element model of the ocean engineering structure, and respectively obtain the simulation stress values output by the finite element model under no-load condition and when applying loads F1 to F n with different weights;
[0012] Step 4: Select the test position point Q and the untested position point P on the ocean engineering structure. Estimate the stress value at point P based on the measured stress value S i at point Q when applying the load F Qi as the measured stress value S i at point P when applying the load F Pi :
[0013] where i = 2, …, n, and K i is the stress transfer function between point Q and point P when applying the load F i , S Q1 is the measured stress value at point Q when applying the load F1, and S P1 is the measured stress value at point P when applying the load F1;
[0014] S Pi can also be expressed as:
[0015] where R i is the transfer coefficient between the measured stress value and the simulation stress value when applying the load F i , is the simulation stress value at point P output by the finite element model when applying the load F i , and is the simulation stress value at point P output by the finite element model when applying the load F1;
[0016] Calculate S Pi according to the above two expressions for S P1 ;
[0017] Calculate the actual stress value of point Q considering the initial static stress
[0018] i = 1, …, n, represents the simulation stress value at point Q output by the finite element model under no-load condition;
[0019] Calculate the actual stress value of point P considering the initial static stress
[0020] i = 1, …, n, represents the simulated stress value of point P output by the finite element model under the no-load state;
[0021] and are combined into the full-field actual stress value
[0022] According to the measured stress values S1~S n and the full-field actual stress value train the Kriging model.
[0023] Step five, collect the measured stress values at the test positions on the ocean engineering structure in real time and input them into the Kriging model. The Kriging model outputs the full-field stress value of the ocean engineering structure and conducts monitoring.
[0024] In some embodiments, in step one, the strain sensor is used to detect the strain response signal ε, and it further includes calculating the measured stress value S according to the strain response signal. Therefore:
[0025] S0 = Eε0;
[0026] where E is the elastic modulus and ε0 is the strain response signal of the ocean engineering structure detected by the strain sensor under the no-load state.
[0027] In some embodiments, in step three, the method for establishing the finite element model of the ocean engineering structure is: establish an initial finite element model of the ocean engineering structure from the drawings in the finite element simulation software, and set the material parameters and constraint conditions of the initial finite element model according to the ocean engineering structure.
[0028] In some embodiments, in step three, it further includes modifying the finite element model by the model modification method to make the response of the finite element model consistent with the actual structural response of the ocean engineering structure.
[0029] In some embodiments, in step four, the stress transfer function K i is calculated as follows:
[0030]
[0031] where i = 2, …, n, represents the simulated stress value of point Q output by the finite element model when the load F i is applied, represents the simulated stress value of point P output by the finite element model when the load F i is applied, Denote the loading load F i The simulated stress value of point Q output by the finite element model when Denote the loading load F i The simulated stress value of point P output by the finite element model when
[0032] In some embodiments, in step four, the transfer coefficient R i The calculation method is as follows:
[0033]
[0034] Wherein, Is the simulated stress value of point Q output by the finite element model when the loading load is F i The simulated stress value of point Q output by the finite element model when the loading load is F1 Is the simulated stress value of point Q output by the finite element model when the loading load is F1
[0035] In some embodiments, in step four, the measured stress values S1 to S n Are used as input data, and the actual stress value Is used as output data, and the Gaussian model is selected as the correlation function to train the Kriging model
[0036] In some embodiments, step four further includes:
[0037] The whole field of the offshore engineering structure is discretized into a number of discrete points, and the discrete points include a number of test position points and a number of unmeasured position points;
[0038] When calculating the actual stress value of each unmeasured position point, the test position point closest to the unmeasured position point is selected as point Q
[0039] In some embodiments, the loads F1 to F n Are evenly spaced and cover the design allowable load range of the offshore engineering structure
[0040] In some embodiments, the sampling frequency of the strain sensor is 20 - 50 Hz
[0041] Compared with the prior art, the advantages and positive effects of the present invention are: the full-field stress monitoring method for the offshore engineering structure of the present invention, by measuring the measured stress values at local positions, and establishing a finite element model of the offshore engineering structure, estimating the measured stress values of unmeasured position points according to the stress transfer relationship, and then taking into account the initial static stress, obtaining the actual stress values of each point respectively, training the Kriging model according to the actual stress values and the measured stress values, realizing the mapping relationship between the measured stress values and the response signals of the actual stress considering the initial static stress, and being able to invert the full-field stress of the offshore engineering structure through the measured stress data at local positions, so as to complete the full-field stress monitoring of the large offshore engineering structure
[0042] This solution can improve the accuracy of the full-field stress calculation by obtaining the initial static strain value of the offshore engineering structure in the unloaded state and using it to calculate the actual stress value, and further improve the accuracy of monitoring and evaluation.
[0043] After reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become clearer. Description of the Drawings
[0044] Figure 1 It is a simplified model diagram of an offshore engineering structure in an embodiment of the full-field stress monitoring method for offshore engineering structures proposed by the present invention;
[0045] Figure 2 It is a comparison diagram of the true value, fitting curve and inversion value at position 2-2 in an embodiment of the full-field stress monitoring method for offshore engineering structures proposed by the present invention;
[0046] Figure 3 It is a comparison diagram of the true value, fitting curve and inversion value at position 3-2 in an embodiment of the full-field stress monitoring method for offshore engineering structures proposed by the present invention. Detailed Embodiments
[0047] The following further describes in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.
[0048] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0049] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.
[0050] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0051] Embodiment 1: This embodiment proposes a method for full-field stress monitoring of marine engineering structures, including: step 1: deploying strain sensors on the marine engineering structure to obtain a measured stress value S of the marine engineering structure in an unloaded state. o .
[0052] See also Figure 1 As shown, this marine engineering structure is a ship crane A-frame, which generally includes a beam 3 and a column 2. Strain sensors can be set only on the beam 3 or the column 2. Since the stress directions of the beam 3 and the column 2 are different, in order to improve the comprehensiveness of the detection and make the detection results more accurate and comprehensive to reflect the stress conditions of the entire field, it is preferred to arrange strain sensors on both the beam 3 and the column 2.
[0053] Due to the limitation of assembly position and cost, it is impossible to distribute strain sensors throughout the entire marine engineering structure. Therefore, in order to solve this problem, this scheme deploys strain sensors at some locations to actually measure the stress values, and can estimate the stress values at locations where strain sensors are not deployed.
[0054] Since strain sensors cannot obtain the static stress caused by the deadweight of marine engineering structures, the measured S o is a number close to 0. In order to improve the strain response when different loads are applied in the subsequent steps, the change after the sensor is installed is measured by strain measurement, and the true stress is determined by combining the change and model estimation.
[0055] In some embodiments, 2-5 strain sensors are installed on the marine engineering structure, and the strain sensors are dispersed at different positions of the marine engineering structure as much as possible.
[0056] In some embodiments, the sampling frequency of the strain sensor is 20-50 Hz.
[0057] Step 2: Load F1~F on the marine engineering structure respectively. n Weight load, F1 <F2<…<F n , and obtain the corresponding measured stress values S1~S n. By applying loads of different weights to the offshore engineering structure and then detecting the stress conditions under different loads, the monitoring of the offshore engineering structure is made more comprehensive.
[0058] Step 3: Establish a finite element model of the offshore engineering structure, and respectively obtain the simulation stress values output by the finite element model under the no-load state and when loading the loads of F1 to F n weights
[0059] Step 4: Select the test position point Q and the untested position point P on the offshore engineering structure. According to the measured stress value S i of point Q at the time of loading the load F Qi estimate the stress value of point P, which is used as the measured stress value S i of point P at the time of loading the load F Pi .
[0060] where i = 2, …, n, and K i is the stress transfer function between point Q and point P at the time of loading the load F i , S Q1 is the measured stress value of point Q at the time of loading the load F1, and S P1 is the measured stress value of point P at the time of loading the load F1.
[0061] S Pi is also expressed as:
[0062] where R i is the transfer coefficient between the measured stress value and the simulation stress value at the time of loading the load F i , is the simulation stress value of point P output by the finite element model at the time of loading the load F i , is the simulation stress value of point P output by the finite element model at the time of loading the load F1.
[0063] According to the above two expressions for S Pi , calculate S P1 .
[0064] Calculate the actual stress value of point Q considering the initial static stress
[0065] i = 1, …, n, represents the simulation stress value of point Q output by the finite element model under the no-load state.
[0066] Calculate the actual stress value of point P considering the initial static stress
[0067] i = 1, …, n, represents the simulated stress value of point P output by the finite element model under the no-load state.
[0068] and are combined into the actual stress value of the whole field At this time is the actual stress value considering the initial static stress of the structure.
[0069] According to the measured stress values S1 to S n and the actual stress value of the whole field train the Kriging model.
[0070] Step Five, collect the measured stress values at the test positions on the offshore engineering structure in real time, and input them into the Kriging model. The Kriging model outputs the whole-field stress value of the offshore engineering structure and conducts monitoring.
[0071] The whole-field stress monitoring method for the offshore engineering structure in this embodiment estimates the measured stress values of the unmeasured position points according to the stress transfer relationship by measuring the measured stress values at the local positions and establishing the finite element model of the offshore engineering structure, and then takes the initial static stress into account to obtain the actual stress values of each point respectively. The Kriging model is trained according to the actual stress values and the measured stress values, realizing the mapping relationship between the measured stress values and the response signals of the actual stress considering the initial static stress. The whole-field stress of the offshore engineering structure can be deduced from the measured stress data at the local positions, thus completing the whole-field stress monitoring of the large offshore engineering structure.
[0072] This solution can improve the accuracy of the whole-field stress calculation by obtaining the initial static strain value of the offshore engineering structure under the no-load state and using it for the calculation of the actual stress value, and further improve the accuracy of monitoring and evaluation.
[0073] In some embodiments, in Step One, the strain sensor is used to detect the strain response signal ε, and the stress value is calculated by Eε. Therefore, this step also includes calculating the measured stress value according to the strain response signal, that is:
[0074] S0 = Eε0.
[0075] where E is the elastic modulus, and ε0 is the strain response signal of the offshore engineering structure detected by the strain sensor under the no-load state.
[0076] In some embodiments, in Step Two, it includes:
[0077] (11) Apply a load of weight F1 to the offshore engineering structure, collect the strain response signal of the offshore engineering structure in this state through the installed strain sensors, and calculate the stress value S1.
[0078] (12) Gradually increase the weight of the lifted load and repeat the above process. Apply loads of weights F2 to F n to the offshore engineering structure respectively, where F1 < F2 < … < F n , and obtain the stress values S2 to S n corresponding to the respective working conditions.
[0079] The measured stress values S1 to S n obtained at this time do not include the stress caused by the self-weight of the device and are not the actual stress, and need further processing.
[0080] In some embodiments, in step three, the method for establishing the finite element model of the offshore engineering structure is: establish an initial finite element model of the offshore engineering structure from the drawings of the offshore engineering structure in finite element simulation software, and set the material parameters and constraint conditions of the initial finite element model according to the offshore engineering structure.
[0081] In some embodiments, in step three, it further includes correcting the finite element model through a model correction method to make the response of the finite element model consistent with the actual structural response of the offshore engineering structure.
[0082] For the finite element model,
[0083] (21) Initially, no external load is applied to the offshore engineering structure, and the finite element model performs a static analysis on the structure to obtain the simulation stress including the test positions and untested positions on the offshore engineering structure.
[0084] (22) Apply loads of weights F1 to F n to the offshore engineering structure respectively. The load applied each time is the same as the load applied in step (12), and perform static analysis respectively to obtain the stress values
[0085] The simulation stress values obtained at this time are the theoretical stresses of the device, which are close to the actual stresses, but there will be some errors due to different environmental conditions and need to be corrected with the measured stresses.
[0086] In some embodiments, the loads F1 to F n are evenly spaced and cover the design allowable load range of the offshore engineering structure, so that the measured stress values S1 to S n and the simulation stress values can represent most cases.
[0087] In some embodiments, in step four, the stress relationship between two points, point P and point Q, is constructed from simulation data as follows:
[0088]
[0089] where i = 2, …, n, represents the simulated stress value of point Q output by the finite element model when the applied load is F i ; represents the simulated stress value of point P output by the finite element model when the applied load is F i ; represents the simulated stress value of point Q output by the finite element model when the applied load is F i ; represents the simulated stress value of point P output by the finite element model when the applied load is F i .
[0090] The stress transfer function K i can be calculated from the above formula.
[0091] Since the finite element model is consistent with the actual structural response, there is also a transfer function K i in the actual structure
[0092] In some embodiments, in step four, the calculation method of the transfer coefficient R i is as follows:
[0093]
[0094] where is the simulated stress value of point Q output by the finite element model when the applied load is F i ; is the simulated stress value of point Q output by the finite element model when the applied load is F1.
[0095] The relationship between the actual stress and the measured stress is where i = 1, …, n, and a similar relationship also exists at unmeasured locations
[0096] In some embodiments, in step four, the measured stress values S1 to S n are used as input data, and the actual stress values are used as output data. The Gaussian model is selected as the correlation function to train the Kriging model. After training, the Kriging model can automatically invert the actual stress based on the measured stress S j .
[0097] In some embodiments, step four further includes:
[0098] The whole field of the ocean engineering structure is discretized into a number of discrete points, which include a number of test position points and a number of untested position points.
[0099] When calculating the actual stress value of each untested position point, the test position point closest to the untested position point is selected as point Q.
[0100] In step five, through the installed strain sensors and the trained Kriging model, the full-field stress of the ocean engineering structure can be inversed. Since the Kriging model takes the measured stresses S1 to S n as input data and the actual stress as output data, a mapping relationship between the measured stress and the actual stress is established. When new measured stress S j is collected later, it is brought into the trained Kriging model, and the full-field stress of the ocean engineering structure is inversed through this mapping relationship, thus completing the full-field stress monitoring of the large ocean engineering structure.
[0101] Example two, as Figure 1 shown, is a simplified model of an ocean engineering structure, including a column 2 and a cross beam 3. The column 2 is 15 m high and has a wall thickness of 40 mm; the cross beam 3 is a circular tube with a length of 15 m, a diameter of 1.4 m, and a wall thickness of 50 mm. The weight 1 is a lifting load, and the stress change of the ocean engineering structure is changed by changing the weight of the weight 1.
[0102] Taking the situation without applying the weight 1 as the initial condition, weights of 20 t, 40 t, 60 t, 80 t, and 100 t are applied respectively as five working conditions to obtain the measured stresses and simulation stresses of the five working conditions. In addition, the measured stress when a weight of 130 t is applied is tested as a verification working condition.
[0103] Strain sensors are arranged at positions 2-1 and 3-1 after applying a 20-t load to simulate the existence of unknown initial stresses; strain sensors are not installed at positions 2-2 and 3-2 as inversion positions; strain sensors are installed at positions 2-3 and 3-3 when the weight 1 is not applied, and the measured stresses are used as the actual stresses including the initial stresses. These two positions are symmetric to 2-2 and 3-2 respectively, so they are used to compare with the inversion results of 2-2 and 3-2.
[0104] The whole verification process is carried out as follows:
[0105] Step 1: Without applying additional loads to the physical model, strain sensors are arranged at positions 2-3 and 3-3. After applying a 20t heavy object in Working Condition 1, strain sensors are arranged at positions 2-1 and 3-1, and the stress S1 at this time is recorded, including the measured stresses at the four positions. Then, the 20t heavy object is continuously increased, and the current stress is recorded until 100t is applied, completing Working Conditions 2 to 5 to obtain S2~S5. In addition, the stresses at positions 2-3 and 3-3 when a 130t heavy object is applied are measured and used as Working Condition 6 to verify the inversion results.
[0106] Establish a consistent finite element model, complete the same working condition settings, and record the simulation stresses for each working condition
[0107] Step 2: Select the test position 2-1 as the reference position, and construct the transfer function K between positions 2-1 and 2-2 through the simulation data i , and this transfer function also satisfies the actual structure. Use the loading load F at position 2-1 i and the transfer coefficient R between the measured stress value and the simulation stress value when measuring i . Then, combine K i with the two transfer functions and R i and the equations and to solve the actual stress at position 2-2 when the loading load F i is applied at the moment, and sequentially calculate the actual stresses for the five working conditions.
[0108] Select the test position 3-1 as the reference position, and similarly calculate the actual stresses at position 3-2 for each working condition.
[0109] Construct a Kriging model, use the measured stresses at positions 2-1 and 3-1 as inputs, the actual stresses at positions 2-2 and 3-2 as outputs, select the Gaussian model as the correlation function, and use the five working conditions to train the Kriging model.
[0110] Step 3: Put the measured stresses of Working Condition 6 at positions 2-1 and 3-1 into the trained Kriging model to obtain the actual stresses at positions 2-2 and 3-2 predicted by the model. The true values, fitting curves, and inversion values of position 2-2 for Working Condition 6 are as Figure 2 shown. The true values, fitting curves, and inversion values of position 3-2 for Working Condition 6 are as Figure 3 shown. Among them, Figure 2 , Figure 3 the true value refers to the measured stress value at position 2-2, the fitting curve refers to a curve fitted after training by the Kriging model, and the inversion value refers to the stress value calculated through the fitting curve. From Figure 2 , Figure 3It can be seen that the Kriging model can effectively fit the change trend of the actual stress, and the inversion value of the Kriging model is extremely close to the true value, indicating that the full-field stress monitoring method for large ocean engineering structures of the present invention can effectively reconstruct the full-field stress of the structure.
[0111] Certainly, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.
Claims
1. A full-field stress monitoring method for ocean engineering structures, characterized in that Including: Step 1: Deploy strain sensors on the ocean engineering structure to obtain the measured stress value S of the ocean engineering structure under the no-load state o ; Step 2: Apply loads of F1 to F n weights on the offshore engineering structure, where F1 < F2 < … < F n , and obtain the corresponding measured stress values S1 to S n ; Step 3: Establish a finite element model of the offshore engineering structure, and respectively obtain the simulation stress values output by the finite element model when it is in the no-load state and when a load of F1 to F n weight is applied Step 4: Select the test position point Q and the untested position point P on the offshore engineering structure, and according to the applied load F i The measured stress value S of point Q at a certain time Qi Estimate the stress value of point P, which is used as the applied load F i The measured stress value S of point P at a certain time Pi : where \(i = 2,\ldots,n\), \(K\) i is the load \(F\) i the stress transfer function between point \(Q\) and point \(P\), \(S\) Q1 is the measured stress value at point \(Q\) when the load is \(F_1\), \(S\) P1 is the measured stress value at point \(P\) when the load is \(F_1\); S Pi Also expressed as: Among them, R i is the transfer coefficient between the measured stress value and the simulated stress value when loading the load F i , is the simulated stress value of point P output by the finite element model when loading the load F i , is the simulated stress value of point P output by the finite element model when loading the load F1; Calculate S according to the above two equations about S Pi ; P1 ; The actual stress value of point Q considering the initial static stress is calculated i = 1, …, n, represents the simulated stress value of point Q output by the finite element model under no-load conditions; Calculate the actual stress value of point P considering the initial static stress where \(i = 1,\ldots,n\) represents the simulated stress value of point \(P\) output by the finite element model under no-load condition; and combined into the actual stress value of the whole field According to the measured stress values S1 to S n and the actual stress values of the whole field train the Kriging model; Step 5: Collect the measured stress values at the test positions on the offshore engineering structure in real time, and input them into the Kriging model. The Kriging model outputs the full-field stress values of the offshore engineering structure and conducts monitoring.
2. The full-field stress monitoring method for offshore engineering structures according to claim 1, characterized in that In Step 1, the strain sensor is used to detect the strain response signal ε, and it also includes calculating the measured stress value S based on the strain response signal. Therefore: S0 = Eε0; where E is the elastic modulus, and ε0 is the strain response signal of the offshore engineering structure detected by the strain sensor in the no-load state.
3. The full-field stress monitoring method for offshore engineering structures according to claim 1, characterized in that, In Step 3, the method for establishing the finite element model of the offshore engineering structure is as follows: Establish an initial finite element model of the offshore engineering structure in the finite element simulation software based on the drawing of the offshore engineering structure, and set the material parameters and constraint conditions of the initial finite element model according to the offshore engineering structure.
4. The full-field stress monitoring method for offshore engineering structures according to claim 3, characterized in that In Step 3, it also includes correcting the finite element model through a model correction method to make the response of the finite element model consistent with the actual structural response of the offshore engineering structure.
5. The full-field stress monitoring method for offshore engineering structures according to claim 1, wherein, In step 4, the stress transfer function K i is calculated as follows: where \(i = 2,\ldots,n\) represents the simulated stress value of point \(Q\) output by the finite element model i when the load \(F\) is applied, represents the simulated stress value of point \(P\) output by the finite element model i when the load \(F\) is applied, represents the simulated stress value of point \(Q\) output by the finite element model i when the load \(F\) is applied, represents the simulated stress value of point \(P\) output by the finite element model i when the load \(F\) is applied.
6. The full-field stress monitoring method for ocean engineering structures according to claim 5, characterized in that, In step 4, the transfer coefficient R i is calculated as follows: Wherein, is the simulated stress value of point Q output by the finite element model when the load F is applied, i and is the simulated stress value of point Q output by the finite element model when the load F1 is applied.
7. The full-field stress monitoring method for offshore engineering structures according to claim 6, wherein In Step 4, the measured stress values S1 to S n are used as input data, and the actual stress value is used as output data. The Gaussian model is selected as the correlation function to train the Kriging model.
8. The full-field stress monitoring method for ocean engineering structures according to claim 5, characterized in that, Step 4 also includes: Discretize the full field of the offshore engineering structure into a number of discrete points, and the discrete points include a number of test position points and a number of unmeasured position points; When calculating the actual stress values of each unmeasured position point, select the test position point closest to the unmeasured position point as point Q.
9. The full-field stress monitoring method for offshore engineering structures according to any one of claims 1-8, characterized in that, Loads F1 to F n Evenly spaced, covering the allowable load range for offshore engineering structure design.
10. The full-field stress monitoring method for ocean engineering structures according to any one of claims 1-8, characterized in that, The sampling frequency of the strain sensor is 20 - 50 Hz.