A method and system for early warning failure of offshore buoy connection bolts

Abstract

The present invention relates to the field of marine engineering technology and navigation security, and specifically to a method and system for early warning of failure of offshore buoy connection bolts. The early warning method comprises the following steps: obtaining basic parameters of loosening, breaking and corrosion of offshore buoy connection bolts; using the basic parameters to construct an assessment model for assessing the risk of bolt failure; setting a risk factor threshold of the bolt through the assessment model; assessing the failure risk of the bolt based on the risk factor threshold; and realizing early warning of failure of offshore buoy connection bolts according to the result of the assessment. The present invention comprehensively considers the failure risks of bolt loosening, breaking and corrosion, and realizes comprehensive, refined and accurate early warning of failure of offshore buoy connection bolts, which is conducive to targeted repair and maintenance of bolts or buoy structures, greatly reduces the cost of manual inspections, improves maintenance efficiency and accuracy, and ensures the long-term stable operation of offshore buoys.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology and navigation security, and in particular to a method and system for early warning failure of marine buoy connection bolts. Background Art

[0002] As an important navigation aid and monitoring equipment, the stability and safety of offshore buoys are directly related to the smooth progress of maritime traffic, fishery activities and marine environmental monitoring. The connection bolts of offshore buoys are the key part of their stability and safety. Once the bolts fail, the buoy structure may become loose, tilted or even disintegrated, further causing the failure of the navigation mark, thus causing serious safety accidents. Therefore, it is particularly important to judge the status of the buoy connection bolts in advance.

[0003] In the prior art, a bolt failure early warning method is proposed. The method is based on a multivariate logistic regression model and a convolutional neural network model, and detects the bolt preload and bolt fatigue cracks through ultrasound, thereby improving the efficiency and reliability of early warning. However, there are still some shortcomings. First, since the unloosened bolt may not have obvious changes in preload and cracks before overload fracture and brittle fracture, it is difficult to accurately detect the non-fatigue failure of the bolt; second, since the bolt can produce cracks when it is subjected to external stress, brittle stress induced by internal hydrogen permeation, and environmental corrosion, it is difficult to obtain the specific cause of the bolt failure through the cracks; third, since the bolt preload state and crack state can only determine the bolt loosening failure and fatigue failure, it is difficult to determine other failure forms such as bolt overload failure, hydrogen-induced failure and corrosion failure, resulting in limitations in the early warning of bolt failure; fourth, the factors that cause bolt fracture, loosening and corrosion failure are not comprehensively considered, making it difficult to achieve targeted maintenance, which can easily cause secondary or even multiple failures of the bolt, further increasing the maintenance cost. At present, there is not much research on the failure of offshore buoy connection bolts, and there is no specific comprehensive, detailed and accurate early warning method for the failure of offshore buoy connection bolts. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a method and system for early warning of failure of connecting bolts of an offshore buoy.

[0005] On the one hand, the method includes the following steps: obtaining basic parameters of loosening, breaking and corrosion of offshore buoy connection bolts; using the basic parameters, constructing an assessment model for assessing the risk of bolt failure; setting a risk factor threshold of the bolt through the assessment model; assessing the failure risk of the bolt based on the risk factor threshold; and realizing early warning of the failure of offshore buoy connection bolts according to the results of the assessment. The present invention comprehensively considers the influencing factors of the failure of offshore buoy connection bolts, constructs a targeted assessment model for assessing the risk of bolt failure, and further uses the assessment model to realize a comprehensive, refined and accurate early warning of the failure of offshore buoy connection bolts.

[0006] Optionally, the basic parameters for obtaining the fracture, loosening and corrosion of the offshore buoy connection bolts include: obtaining the environmental parameters for the loosening, fracture and corrosion of the offshore buoy connection bolts, the environmental parameters including the corrosive factor, stress state, temperature, humidity, wave surface relative height, wave surface phase and hydrogen concentration of the environment; obtaining the self parameters for the loosening, fracture and corrosion of the offshore buoy connection bolts, the self parameters including the geometric dimensions, service life, corrosion resistance factor, aging rate factor, tensile strength, critical hydrogen concentration and hydrogen diffusion rate of the bolts. By obtaining the environmental parameters and self parameters for the loosening, fracture and corrosion of the offshore buoy connection bolts, the present invention can more comprehensively evaluate the safety status of the offshore buoy connection bolts, and provide a scientific basis for preventing failures and ensuring the smooth progress of activities such as ocean monitoring or energy collection.

[0007] Optionally, the use of the basic parameters to construct an assessment model for assessing the risk of bolt failure includes: using the basic parameters to construct a corrosion risk assessment model for assessing the risk of bolt failure; using the basic parameters to construct a fracture risk assessment model for assessing the risk of bolt failure; using the basic parameters to construct a loosening risk assessment model for assessing the risk of bolt failure. The present invention constructs three assessment models for the failure risk of offshore buoy connection bolts: a corrosion risk assessment model, a fracture risk assessment model, and a loosening risk assessment model; the assessment model accurately quantifies and analyzes the corrosion risk, fracture risk, and loosening risk of bolts under different environmental conditions, which not only helps to identify potential safety hazards in advance, but also guides the formulation of effective maintenance strategies to ensure the stable operation of the buoy system; through the comprehensive use of the assessment model, the safety management level of offshore facilities can be significantly improved to ensure the smooth progress of marine activities.

[0008] Optionally, the corrosion risk assessment model satisfies the following expression:

[0009]

[0010] in, represents the bolt corrosion risk factor, Indicates the environmental corrosiveness factor, Indicates the bolt corrosion resistance factor, Indicates temperature, represents the magnitude of stress, Indicates humidity, Indicates the ratio of bolt length to diameter. represents the aging rate factor, Indicates the service life of the bolt. , , , The corrosion risk assessment model constructed by the present invention is not only highly scientific and accurate, but also can flexibly adjust parameters according to different environmental conditions to ensure the reliability and applicability of the assessment results, providing an important reference for the anti-corrosion design, material selection and regular maintenance of marine facilities such as offshore buoys.

[0011] Optionally, the use of the basic parameters to construct a fracture risk assessment model for assessing the failure risk of bolts includes: using the basic parameters to construct a stress risk assessment model for bolts; using the basic parameters to construct a hydrogen embrittlement risk assessment model for bolts; using the basic parameters to construct an overload risk assessment model for bolts. The present invention constructs a stress risk assessment model, a hydrogen embrittlement risk assessment model and an overload risk assessment model for bolts based on the bolt's own parameters and environmental parameters respectively; the stress risk assessment model, the hydrogen embrittlement risk assessment model and the overload risk assessment model focus on the performance of bolts under different failure mechanisms, such as fatigue fracture caused by stress concentration, hydrogen embrittlement caused by hydrogen penetration, and overload fracture exceeding the material strength limit; through refined simulation and calculation, the assessment model can accurately assess the failure risk of bolts under different circumstances, provide a scientific basis for the safety design, risk assessment and maintenance strategy formulation of marine buoys and bolted structures, and ensure the reliability and durability of the buoy system in a complex marine environment.

[0012] Optionally, the stress risk assessment model satisfies the following expression:

[0013]

[0014] in, Indicates the risk factor of alternating stress to which the bolt is subjected, represents the mapping function, represents the maximum processing function, Indicates The frequency corresponding to the alternating stress is Indicates The average water surface height of the secondary wave surface, Indicates The initial phase of the secondary wavefront, represents the strain hysteresis phase, Indicates that the frequency is The alternating stress amplitude at the time; the hydrogen embrittlement risk assessment model satisfies the following expression:

[0015]

[0016] in, Indicates the risk factor of hydrogen embrittlement inside the bolt, is the hydrogen concentration in the environment, represents the critical hydrogen concentration of the bolt, is the stress on the bolt, is the tensile strength of the bolt, is the ambient temperature, is the diffusion rate of hydrogen inside the bolt, It’s exposure time. is the characteristic diffusion time of hydrogen inside the bolt, , , is the weight coefficient of bolt material, stress and time factors; the overload risk assessment model satisfies the following expression:

[0017]

[0018] in, represents the risk factor of bolt fracture overload, Indicates the real-time preload. represents the workload, represents the ultimate tensile strength, represents the fracture toughness, represents the initial toughness, represents the environmental correction factor, represents the degradation coefficient, Represents the weight coefficient. The stress risk assessment model constructed by the present invention is used to analyze the failure risk of bolts when they are affected by external alternating stress; the hydrogen embrittlement risk assessment model constructed is used to analyze the failure risk of bolts when they are affected by internal hydrogen; the overload risk assessment model constructed is used to analyze the failure risk of bolts under overload conditions; the stress risk assessment model, hydrogen embrittlement risk assessment model and overload risk assessment model provide a reference for analyzing the failure risk of bolts, promote the in-depth development of fracture mechanics, and lay a solid foundation for improving the safety and reliability of marine buoy structures.

[0019] Optionally, the loose risk assessment model satisfies the following expression:

[0020]

[0021] in, represents the bolt loosening risk factor, Indicates the real-time preload. represents the initial preload, Indicates the ambient temperature, Indicates the ambient humidity. The loosening risk assessment model constructed by the present invention can not only efficiently and accurately reflect the loosening state of the buoy connection bolts, but also identify signs of loosening at an early stage to avoid structural performance degradation and safety hazards caused by loosening; in addition, the model also promotes the intelligent development of loosening monitoring technology, provides strong support for remote monitoring, automatic early warning and intelligent maintenance, and is of great significance for improving the safety and reliability of marine buoy structures.

[0022] Optionally, setting the risk factor threshold of the bolt through the evaluation model includes: setting the risk factor threshold of bolt corrosion through a corrosion risk evaluation model for evaluating the risk of bolt failure; setting the risk factor threshold of bolt fracture through a fracture risk evaluation model for evaluating the risk of bolt failure; setting the risk factor threshold of bolt loosening through a loosening risk evaluation model for evaluating the risk of bolt failure. The present invention sets a corresponding risk factor threshold for the evaluation model of the bolt; the setting of the risk factor threshold not only provides a scientific basis for the real-time monitoring and evaluation of the bolt status, but also ensures the effective management of the safety of the buoy structure, constitutes an important line of defense for preventing bolt failure and ensuring the integrity of the buoy structure, and has a far-reaching impact on improving the overall performance and reliability of the buoy structure.

[0023] Optionally, the assessing the risk of the bolt based on the risk factor threshold comprises:

[0024] Based on the risk factor threshold and actual risk factor of bolt loosening, the loosening risk of the bolt is evaluated; based on the risk factor threshold and actual risk factor of bolt breakage, the breakage risk of the bolt is evaluated; based on the risk factor threshold and actual risk factor of bolt corrosion, the corrosion risk of the bolt is evaluated. The present invention accurately judges the status of the bolt in different risk dimensions by comparing the actual risk factor with the respective risk factor thresholds, and timely identifies potential safety hazards; this multi-dimensional risk assessment method not only enhances the accuracy and reliability of risk assessment, but also provides strong support for the implementation of preventive maintenance and optimization of maintenance strategies for bolts, further ensuring that the bolts are always in a controlled state, and building a solid line of defense for the safe and stable operation of the buoy structure.

[0025] In the second aspect, the present invention provides a failure warning system for a buoy connection bolt at sea, including a collection device, an input device, a processor, an output device and a memory, wherein the collection device, the input device, the processor, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the method for warning the failure of a buoy connection bolt at sea. The failure warning system for a buoy connection bolt at sea provided by the present invention has high integration and compact structure, and can realize real-time and accurate monitoring of the bolt status of the key connection parts of the buoy; the system can warn of the possible failure risks of loosening, breaking or corrosion of the bolts in advance by integrating advanced monitoring technology and intelligent analysis algorithms, and effectively avoids the problems of damage to the buoy structure and interruption of data transmission caused by bolt failure; in addition, the system also has the characteristics of automation and intelligence, which can greatly reduce the cost of manual inspection, improve maintenance efficiency and accuracy, ensure the long-term stable operation of the buoy at sea, and provide reliable protection for marine environmental monitoring, shipping safety and scientific research activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a method for early warning failure of a connection bolt of an offshore buoy according to an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the state of a marine buoy according to an embodiment of the present invention;

[0028] Figure 3 It is a schematic structural diagram of a failure warning system for connecting bolts of an offshore buoy according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0030] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0031] See also Figure 1 The embodiment of the present invention provides a method for early warning failure of a connection bolt of an offshore buoy, the method comprising the following steps:

[0032] S1. Obtain the basic parameters of loosening, fracture and corrosion of offshore buoy connection bolts.

[0033] Wherein, step S1 comprises the following steps:

[0034] S11. Obtain environmental parameters for loosening, breakage and corrosion of offshore buoy connection bolts.

[0035] Specifically, the method comprises the following steps:

[0036] S111. Obtain the ambient temperature.

[0037] In the process of obtaining the ambient temperature, the devices used include but are not limited to temperature sensors and thermocouples.

[0038] In one embodiment, a temperature sensor is installed near or on the bolt, and the temperature data is read through a data acquisition system or a reading device connected to the temperature sensor.

[0039] In another embodiment, a thermocouple is installed near or on the bolt to ensure that the temperature sensing element of the thermocouple can fully contact and accurately reflect the temperature around the bolt, and the temperature data is read through a data acquisition system or reading device connected to the thermocouple.

[0040] S112. Obtain the ambient humidity.

[0041] In the process of obtaining the ambient humidity, the devices used include but are not limited to humidity sensors.

[0042] In one embodiment, a humidity sensor is installed near the bolt installation location or in a representative environmental area, and humidity data is read in real time through a data acquisition system or a reading device connected to the sensor.

[0043] S113. Obtain environmental corrosivity factor.

[0044] The methods for obtaining environmental corrosiveness factors include, but are not limited to, environmental analysis, experimental testing, and consulting standards and specifications.

[0045] In one embodiment, the composition of the corrosive medium in the environment surrounding the bolt is analyzed, the corrosive medium including but not limited to seawater and marine atmosphere.

[0046] Furthermore, concentration, temperature and humidity detectors are used to obtain parameters such as the concentration of the corrosive medium, the ambient temperature and humidity.

[0047] Furthermore, by means of data processing, an environmental corrosion factor for evaluating the corrosion effect of the corrosive medium on the bolts is obtained, and the environmental corrosion factor satisfies the following expression:

[0048]

[0049] in, Indicates the environmental corrosiveness factor, Indicates the concentration of corrosive media, which is mainly obtained by calculating the concentration of corrosive media in seawater. Indicates temperature, Indicates humidity, , , , They are constants obtained by fitting the experimental data, and they reflect the weight of the influence on the corrosive factor.

[0050] In another embodiment, an accelerated corrosion test, such as a salt spray test, is performed by simulating the actual working environment of the bolt to obtain corrosion data of the bolt under different conditions. At the same time, an electrochemical test method is used to evaluate the corrosion tendency and rate of the bolt to obtain an environmental corrosivity factor.

[0051] In another embodiment, the industry standard, national standard or international standard of the buoy connection bolts is referred to understand the corrosion performance and anti-corrosion requirements of the bolts in different environments, so as to obtain the environmental corrosion factor.

[0052] S114. Obtain environmental stress status.

[0053] The obtaining of the environmental stress state includes obtaining the environmental stress magnitude and obtaining the environmental stress frequency. The method for obtaining the environmental stress magnitude includes but is not limited to a resistance strain method, a magnetoelastic method, an ultrasonic method and an X-ray diffraction method.

[0054] In one embodiment, the resistance strain method is used to estimate the stress of the bolt by measuring the resistance change generated when the bolt is subjected to force. The advantages of this method are simple operation, low cost, and suitable for preliminary stress detection.

[0055] In another embodiment, a magnetoelastic method is used to detect the stress magnitude by utilizing the magnetoelastic effect generated when the bolt is subjected to force in a magnetic field. The advantages of this method are non-contact, non-destructive, and high measurement accuracy.

[0056] In another embodiment, the internal stress is detected by transmitting ultrasonic waves to the bolt and receiving the reflected signal. The advantages of this method are high measurement accuracy, wide application range, and non-contact measurement.

[0057] The method of obtaining the environmental stress frequency includes but is not limited to a vibration monitoring method.

[0058] In one embodiment, by installing a vibration sensor on the bolt or a nearby structure and monitoring its vibration frequency and amplitude, the dynamic stress frequency to which the bolt is subjected can be indirectly reflected.

[0059] S115. Obtain the relative height of the wave surface.

[0060] The methods for obtaining the wave surface height include but are not limited to a wave buoy equipped with an acceleration sensor method and a Beidou wave buoy method.

[0061] In one embodiment, the Beidou wave buoy method is used.

[0062] Specifically, install the Beidou receiver on the buoy and ensure that it can receive satellite signals normally.

[0063] Furthermore, when the buoy is affected by external forces such as wind load, wave load and impact that can produce water surface fluctuations, the buoy rises and falls with the waves, and the Beidou receiver measures the three-dimensional position information of the buoy in real time.

[0064] Furthermore, by comparing the position information at different time points, the vertical displacement of the buoy, that is, the relative height of the wave surface, is calculated.

[0065] S116. Obtain the wavefront phase.

[0066] The obtaining of the wavefront phase includes but is not limited to obtaining the initial phase of the wavefront and obtaining the hysteresis phase caused by stress.

[0067] The method of obtaining the initial phase of the wavefront includes but is not limited to a waveform fitting method.

[0068] In one embodiment, the wavefront data is fitted using a mathematical method to obtain an expression of the waveform. The mathematical method includes but is not limited to Fourier transform and wavelet transform, and the expression includes parameters such as amplitude, frequency, and phase.

[0069] The method of obtaining the hysteresis phase caused by stress includes but is not limited to a wavefront data position comparison method, a theoretical model method and a phase unwrapping algorithm.

[0070] In another embodiment, a wavefront data comparison method is used to obtain wavefront data at different times using a wavefront data detector. By calculating the phase difference of the wavefront data at different times of the buoy, the hysteresis phase of the wavefront during the propagation process can be estimated.

[0071] S117. Obtain hydrogen concentration.

[0072] The obtaining of hydrogen concentration refers to obtaining the hydrogen concentration of the environment around the bolt, and the method of obtaining the hydrogen concentration includes but is not limited to the environmental monitoring method.

[0073] In one embodiment, a dedicated hydrogen concentration sensor is installed near the buoy connection bolts to monitor the hydrogen concentration in the surrounding environment in real time. The hydrogen concentration sensor generally has high sensitivity and accuracy and can quickly respond to changes in hydrogen concentration in the environment.

[0074] S12. Obtain the inherent parameters of loosening, breaking and corrosion of the connecting bolts of the offshore buoy.

[0075] Specifically, the method comprises the following steps:

[0076] S121. Obtain the geometric dimensions of the bolt.

[0077] The method of obtaining the geometric dimensions of the bolt includes but is not limited to a caliper and a thread gauge.

[0078] In one embodiment, a caliper and a thread gauge are used to measure the diameter and length of the bolt, wherein the diameter of the bolt includes the diameter of the thread and the diameter of the bolt head.

[0079] Specifically, the length of the bolt is measured using a caliper, which is the straight-line distance from the top of the bolt head to the end of the thread.

[0080] Furthermore, the diameter of the bolt head and the diameter of the thread are measured using a thread gauge.

[0081] S122. Obtain the service life of the bolt.

[0082] The method of obtaining the service life of the bolt includes but is not limited to consulting product specifications and technical documents, material performance testing, and model analysis.

[0083] In one embodiment, the service life of the bolt is obtained by referring to the product specification sheet, technical manual or data sheet provided by the bolt manufacturer. These documents usually provide information about the bolt material, performance, working environment recommendation and expected life or service life.

[0084] In another embodiment, the service life of the bolt is obtained by performing material performance tests on the bolt, such as chemical composition analysis, mechanical performance tests (such as tensile tests, hardness tests), etc. These tests can provide an in-depth understanding of the material characteristics and mechanical properties of the bolt, and provide a scientific basis for evaluating the service life of the bolt.

[0085] In another embodiment, the stress distribution, temperature field, etc. of the bolt in the actual working environment are simulated by finite element analysis software to predict its fatigue life and service life. This method can more accurately simulate the performance of the bolt under complex working conditions.

[0086] S123. Obtain the bolt corrosion resistance factor.

[0087] The method for obtaining the bolt corrosion resistance factor includes but is not limited to laboratory testing and reference standards and specifications.

[0088] In one embodiment, a suitable test method is selected according to the material of the bolt, the use environment and the expected corrosion type (such as uniform corrosion, pitting corrosion, stress corrosion, etc.). Common test methods include salt water immersion accelerated test, electrochemical test, stress corrosion test, etc.

[0089] Furthermore, representative bolt samples are selected to ensure that the sample surface is free of defects and contamination and meets the test requirements.

[0090] Furthermore, the bolt samples are subjected to corrosion tests according to the selected test method, and various parameters during the test, such as the concentration of the corrosive medium, temperature, time, etc., are recorded.

[0091] Furthermore, the test data is collated and analyzed to calculate key indicators such as corrosion rate and corrosion depth. Based on these data, the corrosion resistance of the bolts is evaluated and the corrosion resistance factor is calculated.

[0092] In another embodiment, industry standards, national standards or international standards related to the corrosion resistance of bolts are consulted. These standards generally contain specific requirements, test methods and evaluation criteria for the corrosion resistance of bolts.

[0093] Furthermore, the bolt performance to be evaluated is compared with the requirements in the standard, with particular attention paid to indicators related to corrosion resistance, such as corrosion rate, corrosion depth, etc.

[0094] Further, according to the comparison results, it is determined whether the corrosion resistance of the bolt meets the standard requirements. If it does, the corrosion resistance factor of the bolt can be determined according to the evaluation method or recommended value in the standard, and the corrosion resistance factor satisfies the following expression:

[0095]

[0096] in, Indicates the corrosion resistance factor of the bolt, is the corrosion rate, Indicates the depth of corrosion.

[0097] S124. Obtain the bolt aging rate factor.

[0098] The method for obtaining the bolt aging rate factor includes but is not limited to laboratory testing and reference standards and specifications.

[0099] In one embodiment, representative bolt samples are selected to ensure that the samples are consistent with the actual bolts in terms of material composition, heat treatment state, surface treatment, etc. The samples are also pre-treated as necessary, such as cleaning, drying, weighing, etc., to facilitate accurate comparison of subsequent test results.

[0100] Furthermore, the bolt samples were subjected to aging tests, and various parameters during the test were recorded, such as temperature, humidity, concentration of corrosive media, stress state, etc. The aging phenomena of the bolt samples, such as surface corrosion, crack extension, weight change, etc., were regularly observed and recorded.

[0101] Furthermore, the test data is sorted and analyzed multiple times to calculate the aging rate factor of the bolt, which satisfies the following expression:

[0102]

[0103] in, represents the aging rate factor, Indicates temperature, Indicates humidity, Indicates the concentration of corrosive medium, represents the vibration frequency of stress, Represents the weight coefficient.

[0104] S125. Obtain the tensile strength of the bolt.

[0105] The method of obtaining the tensile strength of the bolt includes but is not limited to laboratory testing and reference standards and specifications.

[0106] In one embodiment, representative bolt samples are selected to ensure that the samples meet the test requirements in terms of material composition, heat treatment status, size, etc.

[0107] Further, prepare the tensile testing machine to ensure that the equipment is in good working condition and meets the requirements of relevant test standards. At the same time, install the bolt sample in the fixture of the tensile testing machine to ensure that the sample is evenly tensile. Adjust the position of the fixture so that the axis of the bolt is consistent with the direction of tension.

[0108] Furthermore, the tensile testing machine is started to gradually increase the tensile force applied to the sample. During the test, the tensile force needs to be applied stably, and the change in tensile force and the degree of deformation of the sample need to be recorded. The tensile force is continued to be increased until the sample breaks. At this point, the tensile testing machine will record the maximum tensile force before the sample breaks, i.e. the tensile limit load.

[0109] Further, the tensile strength of the bolt is calculated according to the tensile limit load and the diameter of the sample, and the tensile strength satisfies the following expression:

[0110]

[0111] in, is the tensile strength of the bolt, is the cross-sectional diameter of the bolt, is the tensile limit load of the bolt.

[0112] S126. Obtain the critical hydrogen concentration of the bolt.

[0113] The method for obtaining the critical hydrogen concentration of the bolt includes but is not limited to a physical method, an electrochemical method and a bubble method.

[0114] In one embodiment, a physical method is used to obtain the critical hydrogen concentration of the bolt.

[0115] Specifically, representative samples are taken from the bolts to ensure that the samples reflect the overall hydrogen content of the bolts.

[0116] Furthermore, the hydrogen atomic content is determined by melting the sample at high temperature and using vacuum extraction technology. This method has high technical requirements and is usually used for precision measurements.

[0117] Furthermore, the critical hydrogen concentration of the bolt is evaluated based on the measured hydrogen content data combined with the hydrogen embrittlement sensitivity data of the bolt material.

[0118] S127. Obtain the hydrogen diffusion rate in the bolt.

[0119] The method for obtaining the hydrogen diffusion rate of the bolt includes but is not limited to an experimental measurement method and a theoretical calculation method.

[0120] In one embodiment, the hydrogen diffusion rate of the bolt is obtained by experimental measurement.

[0121] Specifically, select representative bolt samples to ensure that their material, size, heat treatment status, etc. meet the test requirements.

[0122] Furthermore, the samples are subjected to necessary pretreatment, such as cleaning, removal of surface coatings or oxides, etc.

[0123] Furthermore, a certain amount of hydrogen is introduced into the bolt sample by using methods such as electrochemical hydrogen charging and thermal desorption. At the same time, the conditions for introducing hydrogen (such as temperature, pressure, and time) are controlled to ensure that the distribution and content of hydrogen in the sample meet the test requirements.

[0124] Furthermore, the sample is placed in a specific environment (such as a constant temperature and pressure chamber) to allow hydrogen to diffuse freely inside the sample; at different time points, appropriate methods (such as mass spectrometer, thermal desorption spectrometer, etc.) are used to detect the hydrogen content on the sample surface to reflect the diffusion of hydrogen inside the sample.

[0125] Furthermore, according to the experimental data, a curve of hydrogen content changing with time is drawn; by analyzing the curve, the diffusion rate of hydrogen in the bolt sample is calculated, and the diffusion rate satisfies the following expression:

[0126]

[0127] in, represents the hydrogen diffusion rate in the bolt, Indicates the hydrogen content, Represents the diffusion time.

[0128] S2. Using the basic parameters, an assessment model for assessing bolt failure risk is constructed.

[0129] Wherein, step S2 further comprises the following steps:

[0130] S21. Using the basic parameters, a corrosion risk assessment model for assessing the risk of bolt failure is constructed.

[0131] In one embodiment, a corrosion risk assessment model for bolts is constructed by considering various factors affecting bolt corrosion. The corrosion risk assessment model satisfies the following expression:

[0132]

[0133] in, represents the bolt corrosion risk factor, Indicates the environmental corrosiveness factor, Indicates the bolt corrosion resistance factor, Indicates temperature, represents the magnitude of stress, Indicates humidity, Indicates the ratio of bolt length to diameter. represents the aging rate factor, Indicates the service life of the bolt. , , , , Represents the weight coefficient. The model comprehensively considers the external and internal influencing factors of bolt corrosion and can more comprehensively evaluate the corrosion behavior of bolts.

[0134] S22. Using the basic parameters, construct a fracture risk assessment model for assessing the risk of bolt failure;

[0135] Wherein, step S22 further includes the following steps:

[0136] S221. Utilize the basic parameters to construct a stress risk assessment model for bolts.

[0137] In one embodiment, the external stress on the buoy is linked to the change of water waves, and then the stress is transmitted and analyzed to further obtain the stress risk factor on the bolt; the external stress includes but is not limited to the stress caused by wind load, wave load and collision; the stress risk assessment model satisfies the following expression:

[0138]

[0139] in, Indicates the risk factor of alternating stress to which the bolt is subjected, represents the mapping function, represents the maximum processing function, Indicates The frequency corresponding to the alternating stress is Indicates The average water surface height of the secondary wave surface, Indicates The initial phase of the secondary wavefront, represents the strain hysteresis phase, Indicates that the frequency is The alternating stress amplitude at .

[0140] It should be noted that the mapping function The main function is to map the external force response time history of the buoy to the external force response time history of the bolt.

[0141] Specifically, the data set of the buoy subjected to external stress is:

[0142]

[0143] The data set of external transmission stress on the bolt is:

[0144]

[0145] It can be found that the mapping function Only the data of the amplitude and frequency of the external alternating stress on the buoy are converted to obtain the amplitude and frequency of the external alternating stress on the bolt, and the other data remain unchanged. Among them, the stress and frequency on the bolt will be affected by the material structure of the bolt, the material of the buoy and the transmission distance. arrive as well as arrive The conversion relationship can be obtained by measuring a large amount of data and then performing fitting analysis on the data.

[0146] It should be noted that the maximum processing function The main function is to obtain the maximum value of the alternating stress response time history of the bolt.

[0147] Specifically, by maximizing the processing function The results of the processing are as follows:

[0148]

[0149] Among them, the maximum processing function Only for The data that needs to be maximized is processed.

[0150] S222. Using the basic parameters, a hydrogen embrittlement risk assessment model for bolts is constructed.

[0151] In one embodiment, by comprehensively considering the concentration of hydrogen near the bolt, its own bearing capacity and the influence of the external environment, a hydrogen embrittlement risk assessment model of the bolt is constructed, and the hydrogen embrittlement risk assessment model satisfies the following expression:

[0152]

[0153] Among them, among them, Indicates the risk factor of hydrogen embrittlement inside the bolt, is the hydrogen concentration inside the bolt, represents the critical hydrogen concentration of the bolt, is the stress on the bolt, is the tensile strength of the bolt, is the ambient temperature, is the diffusion rate of hydrogen inside the bolt, It’s exposure time. is the characteristic diffusion time of hydrogen inside the bolt, , , is the weight coefficient of bolt material, stress and time factors.

[0154] It should be noted that each weight coefficient can be obtained by fitting the data. In addition, the hydrogen concentration inside the bolt is difficult to detect, and a corresponding relationship can be found between the hydrogen concentration in the environment and the hydrogen concentration inside the bolt. The hydrogen concentration inside the bolt can be obtained by only detecting the hydrogen concentration in the environment.

[0155] Specifically, introduce a training function , satisfying the following expression:

[0156]

[0157] in, is the hydrogen concentration in the air near the bolt. Through this training function, the corresponding relationship between the hydrogen concentration inside the bolt and the environment when the bolt is in different states is captured. This corresponding relationship can be obtained through data fitting.

[0158] S223. Utilize the basic parameters to construct a bolt overload risk assessment model.

[0159] In one embodiment, by considering the bolt preload, tensile strength, toughness and other factors, a bolt overload risk assessment model is constructed, and the overload risk assessment model satisfies the following expression:

[0160]

[0161] in, represents the risk factor of bolt fracture overload, Indicates the preload force, represents the workload, represents the ultimate tensile strength, represents the fracture toughness, represents the initial toughness, represents the environmental correction factor, represents the degradation coefficient, Represents the weight coefficient.

[0162] It should be noted that the environmental correction factor satisfies the following expression:

[0163]

[0164] in, Indicates the ambient temperature, Represents the ambient humidity. The degradation coefficient satisfies the following expression:

[0165]

[0166] in, Indicates the maximum reaction force value. The maximum reaction force value refers to the maximum reaction force generated by the bolt to resist the overload when the external load exceeds its design allowable range. The maximum reaction force value can be determined by simulation analysis through finite element analysis (FEA) or other mechanical analysis tools.

[0167] In addition, fracture toughness is the ability of a bolt to resist fracture during crack propagation. It describes the minimum energy or stress intensity factor required for crack propagation when a crack exists in the bolt. Therefore, in this expression Defined as the minimum stress to which the bolt is subjected when cracks first begin to form; Defined as the minimum stress to which an initial crack propagates.

[0168] S23. Using the basic parameters, a loosening risk assessment model for evaluating the performance of connecting bolts is constructed.

[0169] In one embodiment, by considering various parameters that cause bolt loosening, a loosening risk assessment model of the bolt is constructed, and the loosening risk assessment model satisfies the following expression:

[0170]

[0171] in, represents the bolt loosening risk factor, Indicates the real-time preload. represents the initial preload, Represents the environmental correction factor. The expression that satisfies has been introduced in step S223, therefore, the looseness risk assessment model can be further transformed into:

[0172]

[0173] in, Indicates the ambient temperature, Indicates the ambient humidity.

[0174] It should be noted that the real-time preload refers to the preload along the axial line of the bolt actually generated between the bolt and the connected parts during the process of tightening the bolt at different time points; the initial preload refers to the preload along the axial line of the bolt generated between the bolt and the connected parts during the initial tightening of the bolt; both the real-time preload and the ideal preload can be measured by pressure sensors.

[0175] S3. Using the evaluation model, a risk factor threshold of the bolt is set.

[0176] Wherein, step S3 further comprises the following steps:

[0177] S31. Set a risk factor threshold for bolt corrosion using a corrosion risk assessment model used to assess bolt failure risk.

[0178] Wherein, step S31 further includes the following steps:

[0179] S311. Perform model training on the corrosion risk assessment model.

[0180] In one embodiment, a data set of influencing factors related to bolt corrosion risk factors is obtained through experimental testing and data review, as shown below:

[0181]

[0182] This data set contains a large amount of test data. Based on these test data, fitting processing can be performed to obtain the weight coefficient of the corrosion risk assessment model.

[0183] Furthermore, by substituting the weight coefficient obtained by solving into the corrosion risk assessment model, an optimization model of the corrosion risk assessment model can be obtained.

[0184] S312. According to the results of the model training, a risk factor threshold of bolt corrosion is set.

[0185] In one embodiment, the situation that the bolt corrosion causes the connection function between the buoy and the bolt to fail is considered. The situation may be that the bolt breaks or the bolt loosens.

[0186] Specifically, while keeping other external factors stable, only the effect of corrosion on the function of the bolts is considered. As the degree of corrosion deepens, the connection function between the buoy and the bolts is further observed. When the bolt connection function fails, the specific data of the relevant parameters of the optimization model are recorded, and then the specific data are substituted into the optimization model to solve and obtain the corrosion risk factor, which is recorded as .

[0187] It should be noted that in order to ensure that the hidden dangers of bolt corrosion risk can be discovered in time and corresponding measures can be taken, a corrosion safety factor is set, which is recorded as The safety factor is less than is set to one tenth of the

[0188] Therefore, the risk factor threshold for bolt corrosion is set as follows:

[0189]

[0190] S32. A risk factor threshold for bolt fracture is set using a fracture risk assessment model for assessing bolt failure risk.

[0191] The fracture risk assessment model for assessing the failure risk of bolts includes a stress risk assessment model, a hydrogen embrittlement risk assessment model and an overload risk assessment model.

[0192] In one embodiment, referring to the method of step S31, model training is performed on the stress risk assessment model, the hydrogen embrittlement risk assessment model and the overload risk assessment model. For example, the stress risk assessment model is trained, and only the influence of the corresponding parameter data of the model on the stress analysis result is considered.

[0193] It should be noted that the difference between the bolt fracture risk assessment model and the corrosion risk assessment model is that the fracture risk assessment model contains three sub-models, and if one of the models reaches the risk condition, it will cause the buoy connection bolt to fail. Therefore, it is only necessary to find the minimum threshold corresponding to the risk factors of the three sub-models to determine the bolt failure function.

[0194] Specifically, referring to the method of step S31, the risk factors of the three sub-models when the bolt connection fails are determined. The risk factor of the stress risk assessment model when the bolt connection fails is recorded as The risk factor of the hydrogen embrittlement risk assessment model when the bolt connection fails is recorded as The risk factor of the overload risk assessment model when the bolt connection fails is recorded as .

[0195] Furthermore, the minimized risk factor is obtained as follows:

[0196]

[0197] Similarly, in order to ensure early warning and timely maintenance of bolts, a fracture safety factor is set The fracture safety factor is less than is set to one tenth of the

[0198] Furthermore, a risk factor threshold of the fracture risk assessment model is determined. The risk factor threshold is:

[0199]

[0200] S33. A risk factor threshold for bolt loosening is set using a loosening risk assessment model for assessing bolt failure risk.

[0201] In one embodiment, referring to the method of step S31, the bolt loosening assessment model is trained, and only the influence of the corresponding parameter data of the model on the loosening analysis result is considered.

[0202] When the bolt connection function fails, the loosening risk factor is recorded as , then press Set a loose safety factor of one tenth .

[0203] Furthermore, a risk factor threshold of the loose risk assessment model is determined. The risk factor threshold is:

[0204]

[0205] S4. Based on the risk factor threshold, assess the risk of the bolt.

[0206] Wherein, step S4 further comprises the following steps:

[0207] S41. Evaluate the corrosion risk of bolts based on the risk factor threshold and actual risk factor of bolt corrosion.

[0208] In one embodiment, the bolt corrosion risk factor obtained from the actual data is compared with the corrosion risk factor threshold. The actual risk factor is defined as .

[0209] when When the bolts are tightened, there is a risk of failure due to corrosion.

[0210] when There is no risk of bolt failure due to corrosion.

[0211] It should be noted that this method only determines whether the corrosion of the bolts poses a risk of failure.

[0212] S42. Evaluate the risk of bolt fracture based on the risk factor threshold and actual risk factor of bolt fracture.

[0213] In one embodiment, the bolt fracture risk factor obtained from the actual data is compared with the fracture risk factor threshold. The actual risk factor is defined as .

[0214] when There is a risk of bolt breakage and failure.

[0215] when There is no risk of bolt breakage and failure.

[0216] It should be noted that this method only determines whether the fracture of the bolt poses a risk of causing failure.

[0217] S43. Based on the risk factor threshold and actual risk factor of loosening of the connecting bolts, the loosening risk of the connecting bolts is assessed.

[0218] In one embodiment, the bolt loosening risk factor obtained from the actual data is compared with the loosening risk factor threshold. The actual risk factor is defined as .

[0219] when There is a risk that the bolts will loosen and cause failure.

[0220] when There is no risk of the bolts loosening and causing failure.

[0221] It should be noted that this method is only used to determine whether the loosening of the bolts poses a risk of causing failure.

[0222] S5. Based on the results of the evaluation, an early warning of failure of the connecting bolts of the offshore buoy is achieved.

[0223] In one embodiment, a reasonable warning mode is set according to the risk assessment results of bolt corrosion, breakage and loosening. Because bolt corrosion, breakage and loosening can each lead to functional failure of the buoy connection bolts, three types of warning modes can be set. The details are as follows:

[0224] When the bolt has the risk of failure due to corrosion, a corrosion failure risk warning signal is issued, which is issued by a red flashing alarm light.

[0225] When the bolt has the risk of breaking and causing failure, a breakage failure risk warning signal is generated, and the breakage failure risk warning signal is issued by a yellow flashing alarm light.

[0226] When there is a risk of the bolt becoming loose and causing failure, a loosening failure risk warning signal is generated, which is issued by a blue flashing alarm light.

[0227] It should be noted that as long as one of the warning signals is received, it means that there is a risk of bolt failure, which is very likely to affect the buoy structure. The impact of bolt failure on the buoy structure includes but is not limited to the tilt of the buoy. For the tilted state and normal state of the buoy, such as Figure 2 As shown, Figure 2 (a) (b) show the normal state of the buoy, and (c) (d) show the tilted state of the buoy due to bolt failure.

[0228] By judging the early warning signals of bolt failure risk, it is helpful to timely determine what type of failure risk exists in the connection between the buoy and the bolt, so as to carry out targeted repair and maintenance of the buoy and the bolt.

[0229] See also Figure 3 , Figure 3The present invention is a schematic diagram of the structure of a failure warning system for a connection bolt of an offshore buoy in an embodiment of the present invention. The system includes a collection device, an input device, a processor, an output device and a memory, the collection device, the input device, the processor, the output device and the memory are interconnected, the system uses the failure warning method for a connection bolt of an offshore buoy, the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

[0230] In this embodiment, the acquisition equipment uses a variety of instruments, including but not limited to pressure sensors, temperature sensors, humidity sensors, wavefront monitors and concentration monitors; the acquisition equipment is used to collect data information such as stress state, temperature, humidity, corrosive medium concentration, wavefront relative height, wavefront phase and hydrogen concentration.

[0231] The input device uses a touch screen, which is mainly used to input data information such as bolt geometry, service life, corrosion factor, corrosion resistance factor, aging rate factor, tensile strength, critical hydrogen concentration, hydrogen diffusion rate, corrosion risk factor threshold, fracture risk factor threshold and loosening risk factor threshold.

[0232] The processor, as the core of the system, includes a calculation module and an evaluation module;

[0233] Specifically, the calculation module has many built-in algorithm models, including a bolt corrosion failure model, three sub-models of fracture failure, and a loosening failure model, which are mainly used to train and analyze the bolt failure model and obtain risk factors for evaluating bolt failure;

[0234] The evaluation module has a built-in comparison algorithm, which is mainly used to compare the corrosion risk factor, fracture risk factor, and loosening risk factor of bolt failure with the corresponding corrosion risk factor threshold, fracture risk factor threshold, and loosening risk factor threshold, and send the comparison result to the output device.

[0235] The output device includes a display screen, a warning light and a loud speaker;

[0236] Specifically, the display screen is used to display the result of the processor processing, and the result includes "abnormal, there is a risk of bolt corrosion failure", "abnormal, there is a risk of bolt breakage failure", "abnormal, there is a risk of bolt loosening failure", and "normal";

[0237] The warning lights include a red flashing warning light, a yellow flashing warning light and a blue flashing warning light; the red flashing warning light is used to warn of the risk of bolt corrosion failure, the yellow flashing warning light is used to warn of the risk of bolt breakage failure, and the blue flashing warning light is used to warn of the risk of bolt loosening failure;

[0238] The large horn functions when the buoy connection bolts are "abnormal".

[0239] The memory adopts a high-speed solid-state hard disk, which has the characteristics of fast reading and writing speed, large capacity and high reliability. It is mainly used to store the original data obtained by the input device and the acquisition device and the result data processed by the processor, and can meet the needs of large data storage.

[0240] In summary, the method for early warning of failure of connection bolts of offshore buoys provided by the present invention comprehensively considers the factors affecting the failure of connection bolts of offshore buoys, constructs a targeted assessment model for assessing the risk of bolt failure, and further utilizes the assessment model to achieve comprehensive, refined and accurate early warning of failure of connection bolts of offshore buoys. The early warning system corresponding to the early warning method can realize real-time and accurate monitoring of the bolt status of key connection parts of the buoy; by integrating advanced monitoring technology and intelligent analysis algorithms, it can provide early warning of possible failure risks such as loosening, breaking or corrosion of bolts, effectively avoiding problems such as damage to the buoy structure and interruption of data transmission caused by bolt failure; it has the characteristics of automation and intelligence, can greatly reduce the cost of manual inspection, improve maintenance efficiency and accuracy, ensure the long-term stable operation of offshore buoys, and provide reliable protection for shipping safety, marine environmental monitoring and scientific research activities.

[0241] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for early warning of failure of offshore buoy connection bolts, characterized in that: The method comprises the following steps: Obtaining basic parameters for loosening, breaking and corrosion of offshore buoy connection bolts, wherein the basic parameters include environmental parameters and self parameters, wherein the environmental parameters include environmental corrosive factors, stress state, temperature, humidity, wave surface relative height, wave surface phase and hydrogen concentration, and the self parameters include geometric dimensions, service life, corrosion resistance factor, aging rate factor, tensile strength, critical hydrogen concentration and hydrogen diffusion rate of the bolts; Using the basic parameters, an assessment model for assessing the risk of bolt failure is constructed, wherein the assessment model includes a corrosion risk assessment model, a fracture risk assessment model, and a loosening risk assessment model. The fracture risk assessment model includes a stress risk assessment model, a hydrogen embrittlement risk assessment model, and an overload risk assessment model. The corrosion risk assessment model satisfies the following expression: in, represents the bolt corrosion risk factor, Indicates the environmental corrosiveness factor, Indicates the bolt corrosion resistance factor, Indicates temperature, represents the stress magnitude, Indicates humidity, Indicates the ratio of bolt length to diameter. represents the aging rate factor, Indicates the service life of the bolt. , , , , represents the weight coefficient; By using the evaluation model for evaluating the failure risk of bolts, a risk factor threshold of the bolts is set; Based on the risk factor threshold, evaluating the failure risk of the bolt; Based on the results of the evaluation, early warning of failure of offshore buoy connection bolts is achieved.

2. A method for early warning of failure of offshore buoy connection bolts according to claim 1, characterized in that: The stress risk assessment model satisfies the following expression: in, Indicates the risk factor of alternating stress to which the bolt is subjected, represents the mapping function, represents the maximum processing function, Indicates The frequency corresponding to the alternating stress is Indicates The relative height of the secondary wave surface, Indicates The initial phase of the secondary wavefront, represents the strain hysteresis phase, Indicates that the frequency is The alternating stress amplitude at represents the exposure time; the hydrogen embrittlement risk assessment model satisfies the following expression: in, Indicates the risk factor of hydrogen embrittlement inside the bolt, is the hydrogen concentration in the environment, represents the critical hydrogen concentration of the bolt, is the stress on the bolt, is the tensile strength of the bolt, is the ambient temperature, is the diffusion rate of hydrogen inside the bolt, It’s exposure time. is the characteristic diffusion time of hydrogen inside the bolt, , , is the weight coefficient of bolt material, stress and time factors; the overload risk assessment model satisfies the following expression: in, represents the risk factor of bolt fracture overload, Indicates the real-time preload. represents the workload, represents the ultimate tensile strength, represents the fracture toughness, represents the initial toughness, represents the environmental correction factor, represents the degradation coefficient, Represents the weight coefficient.

3. The method for early warning of failure of an offshore buoy connection bolt according to claim 1, characterized in that: The looseness risk assessment model satisfies the following expression: in, represents the bolt loosening risk factor, Indicates the real-time preload. represents the initial preload, Indicates the ambient temperature, Indicates the ambient humidity.

4. The method for early warning of failure of an offshore buoy connection bolt according to claim 1, characterized in that: The step of setting the risk factor threshold of the bolt by using the evaluation model includes: The risk factor threshold of bolt corrosion is set by using the corrosion risk assessment model used to assess the risk of bolt failure; By using a fracture risk assessment model for assessing the risk of bolt failure, a risk factor threshold for bolt fracture is set; The risk factor threshold of bolt loosening is set by using the loosening risk assessment model used to assess the risk of bolt failure.

5. The method for early warning of failure of offshore buoy connection bolts according to claim 1, characterized in that: The evaluating the failure risk of the bolt based on the risk factor threshold comprises: Based on the risk factor threshold and actual risk factor of bolt loosening, the loosening failure risk of bolts is assessed; Based on the risk factor threshold and actual risk factor of bolt fracture, the risk of bolt fracture failure is evaluated; Based on the risk factor threshold and actual risk factor of bolt corrosion, the corrosion failure risk of bolts is evaluated.

6. An offshore buoy connection bolt failure warning system, the system using an offshore buoy connection bolt failure warning method according to any one of claims 1 to 5, characterized in that: The system includes an acquisition device, an input device, a processor, an output device and a memory, wherein the acquisition device, the input device, the processor, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

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