Real-time damage monitoring and load level monitoring method for fixed marine structure

Abstract

The invention relates to the technical field of ocean engineering, in particular to a fixed maritime work structure real-time damage monitoring and load level monitoring method, which comprises the following steps: arranging a strain sensor group, an acceleration sensor group, a tilt angle sensor group and an environmental load sensor group at key nodes of a structure, and acquiring strain, vibration and environmental load data in real time; constructing a structural digital twinborn model, deducing theoretical response and comparing the theoretical response with actually measured data, extracting a strain energy distortion rate and a frequency band energy entropy difference value, and constructing a damage sensitive factor; and based on the damage sensitive factor feedback correction model response, outputting a load danger coefficient. The method has the characteristics of high sensitivity, multi-source fusion and dynamic feedback, early damage identification and real-time risk early warning of the structure can be realized, and the service safety guarantee capability of the maritime work structure is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to methods for real-time damage monitoring and load level monitoring of fixed marine structures. Background Technology

[0002] Against the backdrop of the expanding development of marine energy and the construction of nearshore infrastructure, fixed marine structures, as crucial support systems for wind power generation devices, platform facilities, or transmission lines, directly impact the stability and economy of the entire engineering system through their operational safety. Serving for extended periods in the complex marine environment, fixed structures not only face continuous loads from multiple coupled sources such as waves, tides, and wind, but are also susceptible to cumulative damage from corrosion, fatigue, and loose connections. Therefore, constructing a monitoring system with multi-source sensing capabilities, real-time response analysis capabilities, and health status feedback capabilities has become a vital research direction for the full life-cycle safety management of marine structures.

[0003] However, existing structural monitoring technologies mostly rely on single strain or acceleration parameters, lacking systematic acquisition and collaborative analysis of environmental load information, making it difficult to form a complete load-response relationship chain. Furthermore, while some methods introduce finite element models for predictive simulation, they lack a closed-loop feedback mechanism with measured data, failing to effectively correct for nonlinear response shifts during structural state changes. In addition, traditional damage identification relies on static indicators, making it difficult to capture minute damage and assess real-time hazard levels under dynamic load scenarios, thus limiting the accuracy and timeliness of structural risk warnings. Summary of the Invention

[0004] This invention provides a method for real-time damage monitoring and load level monitoring of fixed marine structures.

[0005] A method for real-time damage monitoring and load level monitoring of fixed marine structures includes the following steps: S1: Install strain sensor groups, acceleration sensor groups, tilt sensor groups and environmental load sensor groups at key structural nodes, and start all sensor groups to collect data in real time. S2: Wave load spectrum, ocean current load vector and wind speed and direction data are collected by environmental load sensor group; at the same time, measured strain time history data are collected by strain sensor group and measured acceleration spectrum is collected by acceleration sensor group. S3: Input the obtained wave load spectrum, ocean current load vector and wind speed and direction data into the pre-calibrated structural digital twin model, and output the theoretical strain distribution cloud map and theoretical acceleration spectrum; S4: Compare the theoretical strain distribution cloud map with the measured strain time history data to calculate the strain energy distortion rate; at the same time, compare the theoretical acceleration spectrum with the measured acceleration spectrum to generate the frequency band energy entropy difference; fuse the strain energy distortion rate and the frequency band energy entropy difference to form the damage sensitivity factor; S5: Feedback the damage-sensitive factors into the structural digital twin model of S3 to correct the load-response mapping relationship and output the real-time load hazard factor.

[0006] Optionally, S1 includes: S11: Strain sensor groups are installed at the pile leg nodes, superstructure connection nodes and horizontal support nodes of the fixed marine structure to obtain the structural stress response in real time. S12: An accelerometer array is installed on the top platform, horizontal support components, and foundation of the structure to monitor the structural vibration response; S13: Install a tilt sensor group at the tilt-sensitive part of the structure to obtain information on structural attitude changes; S14: Install environmental load sensor groups on the windward and wave-facing sides of the structure to collect information on wind load, wave load and ocean current load acting on the structure. S15: Synchronously activate all sensor groups, establish a multi-channel data acquisition network, and initiate the real-time synchronous acquisition task of structural response and environmental load.

[0007] Optionally, S2 includes: S21: Real-time wave load spectrum data around the structure is collected using an environmental load sensor array to characterize wave frequency and amplitude characteristics. S22: Synchronously collect ocean current direction and velocity information to construct ocean current load vectors, which are used to characterize the resultant force of ocean currents on structures; S23: Collect wind speed and direction data, and record wind load time sequence based on the sampling period; S24: Use a strain sensor array to acquire measured strain time history data of multiple key nodes of the structure and record the stress change process; S25: Obtain measured acceleration spectrum data of the structure through an acceleration sensor array to reflect the frequency domain characteristics of the structure's vibration response.

[0008] Optionally, S3 includes: S31: Input the collected wave load spectrum, ocean current load vector and wind speed and direction data into the pre-built and calibrated structural digital twin model; S32: Utilize the structural digital twin model to perform time-varying mapping calculations between load input and structural response output, and deduce the theoretical strain distribution of the structure; S33: Based on the model simulation results, generate theoretical strain distribution cloud maps of key structural nodes to represent the response intensity and distribution characteristics of the structure under the current load. S34: Simultaneously outputs the theoretical acceleration spectrum as a reference value for the frequency response characteristics of the structure under specific load excitation; S35: Pair the theoretical response results with the subsequent measured results for input into the structural damage identification model.

[0009] Optionally, S4 includes: S41: Compare the theoretical strain distribution cloud map with the measured strain time history data to extract the structural response difference characteristics; S42: Based on the comparison results, assess the degree of spatial anomaly in strain energy of key structural components and identify potential damage zones; S43: Compare the theoretical acceleration spectrum with the measured acceleration spectrum in the frequency domain to extract the energy distribution difference characteristics; S44: Construct a frequency band energy entropy change index based on frequency domain characteristics to measure the degree of non-uniformity in structural vibration response; S45: Integrate the strain response characteristics and vibration frequency response characteristics to form a comprehensive damage sensitivity factor that can be used to sensitively identify the degree of damage.

[0010] Optionally, S5 includes: S51: The damage sensitivity factor is input as a feedback variable into the structural digital twin model to dynamically correct the mapping relationship between structural loading and response; S52: Based on the corrected mapping relationship, recalculate the response state of the structure under the current external load; S53: Calculate the load hazard factor of the current state of the structure based on the comparison between the response state and the allowable load limit standard. S54: Output the load hazard factor to the monitoring platform to guide the adjustment of structural safety management and operation and maintenance strategies; S55: Establish a continuous coupling feedback mechanism between load hazard coefficient and damage sensitivity factor to support subsequent long-term online monitoring tasks.

[0011] Optionally, the strain sensor group is a fiber optic strain sensor array, which has anti-electromagnetic interference capability and is suitable for marine corrosive environments.

[0012] Optionally, the acceleration sensor group includes a triaxial acceleration sensor array and is deployed on the top of the structure and the lateral members for high-frequency dynamic response capture.

[0013] Optionally, the structural digital twin model is jointly constructed using historical monitoring data, structural design parameters, and physical test results, and supports the function of automatic iterative correction based on damage factors.

[0014] The beneficial effects of this invention are: This invention establishes a multi-channel, high-frequency data acquisition network by deploying strain sensor groups, acceleration sensor groups, tilt sensor groups, and environmental load sensor groups at key locations such as pile leg nodes, superstructure connection nodes, and horizontal support nodes. This network can comprehensively perceive the mechanical response and attitude changes of fixed marine structures under different loads, and is particularly suitable for continuous health monitoring of structures that are in harsh marine environments for a long time. It overcomes the limitations of traditional point-based monitoring data and insufficient information resolution.

[0015] This invention inputs collected wave load spectrum, ocean current load vector, and wind speed and direction data into a structural digital twin model to deduce the theoretical strain distribution cloud map and theoretical acceleration spectrum of the structure. It then fuses and compares these data with measured strain time history data and measured acceleration spectrum to extract damage features such as strain energy distortion rate and frequency band energy entropy difference. This enables sensitive identification of early local damage or component stiffness degradation, significantly improving the resolution and robustness of structural damage detection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0019] It should be noted that embodiments referred to in the specification as "an embodiment," "an embodiment," "an exemplary embodiment," "some embodiments," etc., may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0020] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0021] like Figure 1 As shown, the method for real-time damage monitoring and load level monitoring of fixed marine structures includes the following steps: S1: Install strain sensor groups, acceleration sensor groups, tilt sensor groups, and environmental load sensor groups at key structural nodes, and activate all sensor groups for real-time data acquisition, specifically: S11: Strain sensor arrays are installed at the pile leg nodes, superstructure connection nodes, and horizontal support nodes of the fixed marine structure. These strain sensor arrays utilize fiber optic grating strain sensor arrays, whose high precision, corrosion resistance, and electromagnetic interference resistance ensure long-term stable recording of strain responses in critical structural components.

[0022] S12: An accelerometer array is installed on the top platform, lateral support components, and foundation anchorage of the structure. The selected accelerometers are triaxial high-frequency MEMS type, featuring wide bandwidth and high sensitivity, and can be used to capture the dynamic response behavior of the structure under changes in sea state or external impacts.

[0023] S13: Install tilt sensor groups in tilt-sensitive parts of the structure, such as the rising section of the jacket and the cantilever end of the main beam, to acquire changes in the structure's attitude in real time and help judge risks such as overall stiffness degradation or loosening of node connections.

[0024] S14: Install environmental load sensor groups, including wave pressure gauges, ocean current velocity meters, and wind speed and direction meters, on the windward and wave-facing sides of the structure to capture information on the main sources of external loads.

[0025] S15: Connect all the above sensor groups to the data acquisition platform through industrial Ethernet or fiber optic communication network, and set a unified sampling frequency to realize the multi-channel synchronous acquisition of structural response and environmental load.

[0026] S2: Wave load spectrum, ocean current load vector, and wind speed and direction data are collected using an environmental load sensor array; simultaneously, measured strain time history data are collected using a strain sensor array, and measured acceleration spectrum is collected using an acceleration sensor array. Specifically, this includes: S21: Using an environmental load sensor array, the wave load spectrum of the sea area is collected, and wave energy distribution curves are constructed through parameters such as wave height and period to reflect the periodic excitation characteristics of waves on the structure.

[0027] S22: Real-time acquisition of ocean current load vector, which consists of ocean current velocity and direction, reflecting the lateral force trend of the structure and the intensity of cross-sectional shear action.

[0028] S23: Collect wind speed and direction data and record the sequence of changes over time. Combine the wind load direction and structural orientation to establish a wind pressure time series model.

[0029] S24: The strain time history data of each key node is obtained by the strain sensor group, including the change sequence of tensile strain, compressive strain and shear strain, for subsequent model comparison.

[0030] S25: The measured acceleration spectrum of the structure is obtained through a triaxial accelerometer array. The time-domain vibration signal is converted into a frequency-domain response spectrum through short-time Fourier transform, and the dominant frequency, subharmonics and response intensity are identified.

[0031] S3: Input the obtained wave load spectrum, ocean current load vector, and wind speed and direction data into the pre-calibrated structural digital twin model, and output the theoretical strain distribution cloud map and theoretical acceleration spectrum, specifically: S31: Input the collected wave load spectrum, ocean current load vector, and wind speed and direction data into the pre-established structural digital twin model. This model is jointly constructed from a finite element model and an actual response database, and has the function of load-response coupled calculation.

[0032] A structural digital twin model maps external load inputs to structural response outputs, and its basic form can be expressed as: ; in, The structural response vector includes the theoretical strain distribution and the theoretical acceleration spectrum, which change with time. change, This is a structural digital twin mapping function that describes the mapping relationship between load input and response output. The environmental load input set includes: wave load spectrum Ocean current load vector Wind speed and direction data , This is the set of initial state variables for the structure, including structural geometric parameters, node connection stiffness, boundary conditions, etc. It is a set of structural material parameters, including elastic modulus, Poisson's ratio, density, damping coefficient, etc., used to determine the amplitude and frequency characteristics of the response.

[0033] S32: Perform time-varying excitation input and response output operations in the digital twin model to simulate the stress and vibration response process of the structure based on the type and magnitude of the input external load.

[0034] S33: Output the theoretical strain distribution cloud map of the key nodes of the structure. This cloud map expresses the magnitude and distribution characteristics of the strain response at the node through color gradient.

[0035] S34: The theoretical acceleration spectrum of the synchronous output structure, used to describe the vibration frequency distribution of different components under specific loads.

[0036] S35: The theoretical strain and theoretical spectrum serve as the benchmark response for subsequent comparison with measured data, and as an important reference for damage identification and parameter calibration.

[0037] S4: Compare the theoretical strain distribution cloud map with the measured strain time history data to calculate the strain energy distortion rate; simultaneously compare the theoretical acceleration spectrum with the measured acceleration spectrum to generate the frequency band energy entropy difference; fuse the strain energy distortion rate and the frequency band energy entropy difference to form the damage sensitivity factor, specifically: S41: Compare the theoretical strain distribution cloud map output by the structural digital twin model with the measured strain time history data node by node to identify the response deviation trend.

[0038] S42: Calculates strain energy distortion rate based on response deviation, used to quantify whether abnormal changes have occurred in the energy distribution inside the structure, commonly seen in early damage such as local cracks and loose connections.

[0039] S43: Compare the theoretical acceleration spectrum with the measured acceleration spectrum to extract frequency domain characteristic indicators such as the dominant frequency displacement and harmonic energy difference.

[0040] S44: Calculate the frequency band energy entropy difference based on frequency domain characteristics. This value is used to describe the changes in the concentration and dispersion of spectral energy and to reflect changes in structural stiffness or connection status.

[0041] S45: The difference between strain energy distortion rate and frequency band energy entropy is fused to form a single damage sensitivity factor, which is used to comprehensively represent the degree of deviation of the structural health status.

[0042] S5: Feedback the damage sensitivity factor into the structural digital twin model of S3 to correct the load-response mapping relationship and output the real-time load hazard factor, specifically: S51: Input the damage-sensitive factor into the structural digital twin model as a structural state feedback variable to iteratively correct the load-response mapping relationship of the model.

[0043] S52: Resimulate the structural response using the corrected model and update its current load-bearing capacity boundary.

[0044] S53: Compare the modified response with the marine structure design standard to calculate the load hazard factor under the current state, which reflects the relative safety margin of the structure.

[0045] The load hazard factor is calculated based on the comparison between the current response of the structure and its ultimate bearing capacity, and the expression is as follows: ; in, The load hazard factor measures the relative ratio between the structural response value and the allowable threshold. This represents the maximum response value in the structure at the current moment, which can be either the maximum strain or the maximum acceleration. Allowable limit response values ​​for structural design.

[0046] S54: Outputs the load hazard factor to the monitoring platform in real time, displays the risk level through a graphical interface, and assists in operation and maintenance decisions.

[0047] S55: Establish a dynamic coupling mechanism between damage sensitivity factors and load hazard coefficients, enabling the model to have online update and long-term monitoring capabilities, and making it suitable for rapid early warning in special scenarios such as extreme climate and seismic disturbances.

[0048] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for real-time damage monitoring and load level monitoring of fixed marine structures, characterized in that, Includes the following steps: S1: Install strain sensor groups, acceleration sensor groups, tilt sensor groups and environmental load sensor groups at key structural nodes, and start all sensor groups to collect data in real time. S2: Wave load spectrum, ocean current load vector and wind speed and direction data are collected by environmental load sensor group; at the same time, measured strain time history data are collected by strain sensor group and measured acceleration spectrum is collected by acceleration sensor group. S3: Input the obtained wave load spectrum, ocean current load vector and wind speed and direction data into the pre-calibrated structural digital twin model, and output the theoretical strain distribution cloud map and theoretical acceleration spectrum; S4: Compare the theoretical strain distribution cloud map with the measured strain time history data to calculate the strain energy distortion rate; at the same time, compare the theoretical acceleration spectrum with the measured acceleration spectrum to generate the frequency band energy entropy difference; fuse the strain energy distortion rate and the frequency band energy entropy difference to form the damage sensitivity factor; S5: Feedback the damage-sensitive factors into the structural digital twin model of S3 to correct the load-response mapping relationship and output the real-time load hazard factor.

2. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 1, characterized in that, S1 includes: S11: Strain sensor groups are installed at the pile leg nodes, superstructure connection nodes and horizontal support nodes of the fixed marine structure to obtain the structural stress response in real time. S12: An accelerometer array is installed on the top platform, horizontal support components, and foundation of the structure to monitor the structural vibration response; S13: Install a tilt sensor group at the tilt-sensitive part of the structure to obtain information on structural attitude changes; S14: Install environmental load sensor groups on the windward and wave-facing sides of the structure to collect information on wind load, wave load and ocean current load acting on the structure. S15: Synchronously activate all sensor groups, establish a multi-channel data acquisition network, and initiate the real-time synchronous acquisition task of structural response and environmental load.

3. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 2, characterized in that, S2 includes: S21: Real-time wave load spectrum data around the structure is collected using an environmental load sensor array to characterize wave frequency and amplitude characteristics. S22: Synchronously collect ocean current direction and velocity information to construct ocean current load vectors, which are used to characterize the resultant force of ocean currents on structures; S23: Collect wind speed and direction data, and record wind load time sequence based on the sampling period; S24: Use a strain sensor array to acquire measured strain time history data of multiple key nodes of the structure and record the stress change process; S25: Obtain measured acceleration spectrum data of the structure through an acceleration sensor array to reflect the frequency domain characteristics of the structure's vibration response.

4. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 3, characterized in that, S3 includes: S31: Input the collected wave load spectrum, ocean current load vector and wind speed and direction data into the pre-built and calibrated structural digital twin model; S32: Utilize the structural digital twin model to perform time-varying mapping calculations between load input and structural response output, and deduce the theoretical strain distribution of the structure; S33: Based on the model simulation results, generate theoretical strain distribution cloud maps of key structural nodes to represent the response intensity and distribution characteristics of the structure under the current load. S34: Simultaneously outputs the theoretical acceleration spectrum as a reference value for the frequency response characteristics of the structure under specific load excitation; S35: Pair the theoretical response results with the subsequent measured results for input into the structural damage identification model.

5. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 4, characterized in that, S4 includes: S41: Compare the theoretical strain distribution cloud map with the measured strain time history data to extract the structural response difference characteristics; S42: Based on the comparison results, assess the degree of spatial anomaly in strain energy of key structural components and identify potential damage zones; S43: Compare the theoretical acceleration spectrum with the measured acceleration spectrum in the frequency domain to extract the energy distribution difference characteristics; S44: Construct a frequency band energy entropy change index based on frequency domain characteristics to measure the degree of non-uniformity in structural vibration response; S45: Integrate the strain response characteristics and vibration frequency response characteristics to form a comprehensive damage sensitivity factor that can be used to sensitively identify the degree of damage.

6. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 5, characterized in that, S5 includes: S51: The damage sensitivity factor is input as a feedback variable into the structural digital twin model to dynamically correct the mapping relationship between structural loading and response; S52: Based on the corrected mapping relationship, recalculate the response state of the structure under the current external load; S53: Calculate the load hazard factor of the current state of the structure based on the comparison between the response state and the allowable load limit standard. S54: Output the load hazard factor to the monitoring platform to guide the adjustment of structural safety management and operation and maintenance strategies; S55: Establish a continuous coupling feedback mechanism between load hazard coefficient and damage sensitivity factor to support subsequent long-term online monitoring tasks.

7. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 6, characterized in that, The strain sensor group is a fiber optic strain sensor array, which has anti-electromagnetic interference capability and is suitable for marine corrosive environments.

8. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 7, characterized in that, The acceleration sensor group includes a triaxial acceleration sensor array and is deployed on the top of the structure and the lateral components for high-frequency dynamic response capture.

9. The method for real-time damage monitoring and load level monitoring of fixed marine structures according to claim 8, characterized in that, The structural digital twin model is constructed by combining historical monitoring data, structural design parameters and physical test results, and supports the function of automatic iterative correction based on damage factors.

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