System for predicting fatigue life of offshore monopile structures

Abstract

The application discloses a marine single-pile structure fatigue life prediction system and relates to the technical field of single-pile structure monitoring. The marine single-pile structure fatigue life prediction system comprises a single-pile body, two support assemblies are fixedly connected to the outer surface of the single-pile body, a protection assembly is arranged outside the single-pile body, two climbing assemblies are arranged inside the protection assembly, the two climbing assemblies are symmetrically arranged, each of the two support assemblies comprises two support rods, and a plurality of climbing ladders are fixedly connected between the outer surfaces of every two adjacent support rods. The marine single-pile structure fatigue life prediction system can adjust the height of the protection assembly and the sensors installed inside the protection assembly on the outside of the single-pile body up and down, can make the single-pile body rise when the sea level rises, and can avoid the single-pile body from being soaked in seawater, thereby solving the problem that the existing prediction equipment is easily soaked in seawater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of single-pile structure monitoring, in particular to a fatigue life prediction system for offshore single-pile structures. BACKGROUND

[0002] An offshore single-pile structure is a type of foundation structure for offshore wind turbine generators, which is usually a large steel pile driven into the seabed to support the wind turbine generator. It can provide stable support for the wind turbine generator in the offshore environment, ensuring that it can withstand the weight of the wind turbine generator and various marine environmental loads such as wind, waves, and currents. However, due to the long-term bearing of complex and variable loads, including the cyclic action of wind loads and the impact of sea waves, these repeated actions will gradually cause micro-damage inside the material, and when accumulated to a certain extent, fatigue failure will occur.

[0003] In the prior art, in order to avoid major accidents caused by structural fatigue failure, ensure the long-term stable operation of the field, and prolong the service life of the field, it is necessary to predict the fatigue life of offshore single-pile structures. Accurate prediction can help to know the fatigue condition of the structure in advance, take timely measures to prevent potential risks, and ensure the safe operation of the offshore field. Since the installation of prediction equipment inside the single-pile structure is extremely costly, most cases will install prediction equipment outside the single-pile structure. However, the prediction equipment installed outside the single-pile structure is easily wetted by seawater, which is corrosive and can adversely affect the performance and service life of the prediction equipment.

[0004] Therefore, we propose a fatigue life prediction system for offshore single-pile structures to solve the problems mentioned above. SUMMARY

[0005] The present application aims to provide a fatigue life prediction system for offshore single-pile structures to solve the problem of adverse effects on the performance and service life of prediction equipment caused by installing prediction equipment outside the single-pile structure as mentioned in the background.

[0006] In order to achieve the above object, the present application provides the following technical scheme: offshore single pile structure fatigue life prediction system, including single pile body, the outer surface of the single pile body is fixedly connected with two support assemblies, the outer surface of the single pile body is provided with a protection assembly, the inner surface of the protection assembly is provided with two climbing assemblies, two climbing assemblies are symmetrically arranged, two support assemblies all include two support rods, the outer surface of every two adjacent support rods is fixedly connected with a plurality of climbing ladders; two climbing assemblies all include a fixing frame and a mounting plate, the outer surface of two fixing frames is rotatably connected with a rotating drum, the outer surface of two rotating drums is fixedly connected with a plurality of rotating leaves in the circumferential direction, the outer surface of each rotating leaf is fixedly connected with a positioning arc plate, the outer surface of one end of two rotating drums is fixedly connected with a fixed wheel, the top of two mounting plates is provided with a forward and reverse motor, the output shaft of two forward and reverse motors is fixedly connected with a driving wheel, the outer surface of two fixed wheels is movably connected with the outer surface of two driving wheels respectively; the outer surface of the rotating leaf is matched with the outer surface of the climbing ladder.

[0007] Preferably, the two ends of each support rod are welded with a support point column, and each support point column is fixedly connected to the outer surface of the single pile body.

[0008] Preferably, the other two outer surfaces of the single pile body are fixedly connected with a plurality of fixed point columns, and the outer surfaces of every two fixed point columns are welded with a limiting rod.

[0009] Preferably, the protection assembly includes a waterproof outer cover and a waterproof inner cover, the inner wall of the waterproof inner cover is fixedly connected with a plurality of limiting blocks, the outer surface of each limiting block is provided with two limiting holes, and every two limiting holes are divided into two groups, and the inner walls of each group of limiting holes are slidably connected with the outer surfaces of two limiting rods respectively.

[0010] Preferably, two climbing assemblies are fixedly installed on the inner wall of the waterproof inner cover, and the fixing frame and the mounting plate are fixedly connected with the inner wall of the waterproof inner cover.

[0011] Preferably, the top of the waterproof outer cover is fixedly connected with an outer inclined plate, the inner wall of the waterproof outer cover is fixedly connected with an inner drainage plate close to the outer inclined plate, and the bottom of the waterproof outer cover is provided with a first water guide plate.

[0012] Preferably, the top of the waterproof inner cover is fixedly connected with an inner inclined plate, and the bottom of the waterproof inner cover is provided with a second water guide plate.

[0013] Preferably, the inner wall of the waterproof cover is fixedly connected with a plurality of mounting blocks, and the outer surfaces of the mounting blocks are respectively provided with strain sensors, acceleration sensors, displacement sensors and inclination sensors.

[0014] Preferably, the strain sensors are used for measuring strain changes of key parts of the structure, the acceleration sensors are used for monitoring vibration characteristics of the structure to understand responses of the structure under dynamic loads, the displacement sensors are used for monitoring displacement changes of the structure, and the inclination sensors are used for understanding inclination degrees of the single-pile body.

[0015] Preferably, the strain sensors are used for measuring strain changes of key parts of the structure, the acceleration sensors are used for monitoring vibration characteristics of the structure to understand responses of the structure under dynamic loads, the displacement sensors are used for monitoring displacement changes of the structure, and the inclination sensors are used for understanding inclination degrees of the single-pile body.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. In use, the protection assembly and the sensors installed therein can be adjusted in height on the outside of the single-pile body through the climbing assembly, can be raised when the sea level rises, and can be prevented from being soaked in seawater. When the device for monitoring the sea level height detects that the seawater obviously rises, the control system controls the starting of the reversible motor to drive the driving runner, the fixed wheel and the rotating drum to rotate. At the same time, the rotating blades outside the rotating drum rotate, and the rotating direction is determined according to the climbing height. When rising, the side of the positioning arc plate first contacts the rung of the climbing ladder under the continuous rotation of the rotating drum. The rotating blades alternately contact the rung of the climbing ladder, so that the entire protection assembly can climb upward, thereby solving the problem that the prediction device is easily soaked in seawater.

[0018] 2. In use, the directions of the reversible motors in the two climbing assemblies are symmetrical, and do not interfere with each other during operation. When climbing to a safe height, the reversible motor is reversely operated, so that the hooks on one side of the rotating blades hook the rung of the climbing ladder to prevent the protection assembly from automatically falling down. After the position is hung, the reversible motor is paused and locked. When the protection assembly needs to move downward, the rotating blades are adjusted to be separated from the climbing ladder, and the position of the rotating blades is adjusted to a state in which the rotating blades cannot be hooked with the climbing ladder, so that the protection assembly can slide downward along the limiting rod. During sliding, the protection assembly relies on its own gravity, and the hooking arc-shaped part of the rotating blades and the rung of the climbing ladder continuously touch each other to play a role of friction deceleration, so that the protection assembly cannot directly and quickly fall down.

[0019] 3、In use, the strain sensor, acceleration sensor, displacement sensor and tilt sensor are installed alternately on the plurality of mounting blocks, and cooperate with each other, so as to achieve the effect of predicting the fatigue life of the offshore single pile structure. Since the single pile body is used at sea, it is often wetted by seawater. At this time, when the rain and splashing water at sea hits the surface of the protection assembly, it is blocked by the waterproof cover, and multiple layers of waterproof are used to prevent the seawater from damaging the sensor. The first layer of protection is the outer inclined plate, which slides the water outward. If a small amount of water enters the inside, the second layer of protection is the inner inclined plate, which also guides the water downward. The third layer of protection is the inner drainage plate, which guides the water vapor and water droplets to the side away from the sensor, preventing the sensor from being in a wet state for a long time. The water inside the waterproof cover and the waterproof inner cover flows out from the gap between the first water guide plate and the second water guide plate. Since the first water guide plate and the second water guide plate are in the shape of a bucket downward, the water inside can be drained in time. The protection assembly has a protective effect on the internal sensor. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a front view of the offshore single pile structure fatigue life prediction system of the present application;

[0021] Figure 2 It is a sectional view of the offshore single pile structure fatigue life prediction system of the present application;

[0022] Figure 3 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0023] Figure 4 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0024] Figure 5 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0025] Figure 6 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0026] Figure 7 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0027] Figure 8 It is a sectional view of the protection assembly part structure of the offshore single pile structure fatigue life prediction system of the present application;

[0028] In the drawings:

[0029] 1, single pile body; 2, protection assembly; 201, waterproof outer cover; 202, outer inclined plate; 203, inner drainage plate; 204, inner inclined plate; 205, waterproof inner cover; 206, mounting block; 207, limiting block; 208, limiting hole; 209, outer fixed block; 210, connecting block; 211, inner fixed block; 212, first water guide plate; 213, second water guide plate; 214, stud; 3, support assembly; 301, limiting rod; 302, fixed point column; 303, support point column; 304, support rod; 305, climbing ladder; 4, climbing assembly; 401, fixed frame; 402, rotating drum; 403, rotating blade; 404, fixed wheel; 405, conveyor belt; 406, driving pulley; 407, forward and reverse motor; 408, mounting plate; 409, positioning arc plate; 5, strain sensor; 6, acceleration sensor; 7, displacement sensor; 8, inclination sensor. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0031] Embodiment one

[0032] Reference Figures 1-8As shown, the present application provides technical solutions: offshore single pile structure fatigue life prediction system, including single pile body 1, the outer surface of single pile body 1 is fixedly connected with two support assemblies 3, the outside of single pile body 1 is provided with protection assembly 2, the inside of protection assembly 2 is provided with two climbing assemblies 4, two climbing assemblies 4 are symmetrically arranged, two support assemblies 3 all include two support rods 304, the outer surface between every two adjacent support rods 304 is fixedly connected with multiple climbing ladders 305;Two climbing assemblies 4 all include fixed frame 401 and mounting plate 408, the outer surface of two fixed frames 401 is all rotatably connected with rotary drum 402, the outer surface of two rotary drums 402 is all fixedly connected with multiple rotating leaves 403, the outer surface of one side of each rotating leaf 403 is all fixedly connected with positioning arc plate 409, the outer surface of one end of two rotary drums 402 is all fixedly connected with fixed wheel 404, the top of two mounting plates 408 is all provided with reversible motor 407, the output shaft of two reversible motors 407 is all fixedly connected with driving pulley 406, the outer surface of two fixed wheels 404 is respectively movably connected with the outer surface of two driving pulleys 406 with conveying belt 405;The outer surface of rotating leaf 403 is matched with the outer surface of climbing ladder 305, the two ends of each support rod 304 are all welded with support point column 303, each support point column 303 is all fixedly connected on the outer surface of single pile body 1, the outer surface of the other two sides of single pile body 1 is all fixedly connected with multiple fixed point columns 302, the outer surface between every two fixed point columns 302 is all welded with limiting rod 301, protection assembly 2 includes waterproof outer cover 201 and waterproof inner cover 205, the inner wall of waterproof inner cover 205 is fixedly connected with multiple limiting blocks 207, the outer surface of multiple limiting blocks 207 is all provided with two limiting holes 208, every two limiting holes 208 is divided into two groups, the inner wall of each group of limiting holes 208 is respectively slidably connected with the outer surface of two limiting rods 301, two climbing assemblies 4 are all fixedly installed on the inner wall of waterproof inner cover 205, fixed frame 401 and mounting plate 408 are all fixedly connected with the inner wall of waterproof inner cover 205.

[0033] In this embodiment, when in use, the protection assembly 2 and the sensors installed therein can be adjusted in height on the outside of the single-pile body 1 by the climbing assembly 4, and can be raised when the sea level rises, so as to avoid being soaked in seawater. When the device for monitoring the sea level height detects that the seawater rises significantly, the control system controls the starting of the reversible motor 407, so that the output shaft of the reversible motor 407 rotates, thereby driving the driving pulley 406 to rotate, and under the connection of the conveying belt 405, the fixed pulley 404 and the rotating drum 402 are further driven to rotate. At the same time, the rotating blades 403 outside the rotating drum 402 rotate, and the rotating direction is determined according to the climbing height. When rising, the side of the positioning arc plate 409 first contacts the rungs of the climbing ladder 305. Under the continuous rotation of the rotating drum 402, the rotating blades 403 alternately contact the rungs of the climbing ladder 305, so that the entire protection assembly 2 can climb upward, thereby solving the problem that the prediction device is easily soaked by seawater. The rotating directions of the reversible motors 407 in the two climbing assemblies 4 are symmetrical, and do not interfere with each other during operation. When climbing to a safe height, the reversible motor 407 is reversely operated, so that the hooks on one side of the rotating blades 403 hook the rungs of the climbing ladder 305, thereby preventing the protection assembly 2 from falling automatically. After the position is hung, the reversible motor 407 is paused and locked. When the protection assembly 2 needs to move downward, the rotating blades 403 are adjusted to be separated from the climbing ladder 305, and the position of the rotating blades 403 is adjusted to a state where the rotating blades 403 cannot be hooked with the climbing ladder 305, so that the protection assembly 2 can slide downward along the limiting rod 301. During sliding, the gravity of the protection assembly 2 is relied on, and the hooking arc-shaped part of the rotating blades 403 constantly touches the rungs of the climbing ladder 305, thereby playing a role of friction deceleration, and the protection assembly 2 will not directly and quickly fall.

[0034] Embodiment two

[0035] Figures 1-8As shown, the protection assembly 2 comprises a waterproof outer cover 201 and a waterproof inner cover 205, the inner wall of the waterproof inner cover 205 is fixedly connected with a plurality of limiting blocks 207, the outer surfaces of the plurality of limiting blocks 207 are each provided with two limiting holes 208, every two limiting holes 208 are divided into two groups, the inner walls of each group of limiting holes 208 are respectively in sliding connection with the outer surfaces of two limiting rods 301, the two climbing assemblies 4 are each fixedly installed on the inner wall of the waterproof inner cover 205, the fixing frame 401 and the mounting plate 408 are each fixedly connected with the inner wall of the waterproof inner cover 205, the top of the waterproof outer cover 201 is fixedly connected with an outer inclined plate 202, the inner wall of the waterproof outer cover 201 is fixedly connected with an inner drainage plate 203 near the outer inclined plate 202, the bottom of the waterproof outer cover 201 is provided with a first water guide plate 212, the top of the waterproof inner cover 205 is fixedly connected with an inner inclined plate 204, the bottom of the waterproof inner cover 205 is provided with a second water guide plate 213, the inner wall of the waterproof outer cover 201 is fixedly connected with a plurality of outer fixed blocks 209 near the bottom and the inner wall of the first water guide plate 212 is fixedly connected with a plurality of outer fixed blocks 209 near the top, the outer wall of the waterproof inner cover 205 is fixedly connected with a plurality of inner fixed blocks 211 near the bottom and the outer wall of the second water guide plate 213 is fixedly connected with a plurality of inner fixed blocks 211 near the top, every two adjacent outer fixed blocks 209 and every two adjacent inner fixed blocks 211 are connected through bolts, the top of the upper outer fixed block 209 and the top of the inner fixed block 211 are each fixedly connected with a threaded stud 214, the outer surfaces of every two adjacent threaded studs 214 are movably connected with a connecting block 210, and the outer surfaces of the threaded studs 214 are threadedly installed with nuts, the inner wall of the waterproof outer cover 201 is fixedly connected with a plurality of mounting blocks 206, the outer surfaces of the plurality of mounting blocks 206 are respectively provided with a strain sensor 5, an acceleration sensor 6, a displacement sensor 7 and an inclination sensor 8, the strain sensor 5 is used for measuring the strain change of the key part of the structure, the acceleration sensor 6 is used for monitoring the vibration characteristics of the structure so as to understand the response of the structure under dynamic load, the displacement sensor 7 is used for monitoring the displacement change of the structure, and the inclination sensor 8 is used for understanding the inclination degree of the single pile body 1.

[0036] In this embodiment, in use, the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 are all connected with an external control system, and the control and adjustment of them are completed by the control system, and the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 are alternately installed on the plurality of mounting blocks 206, and cooperate with each other, so as to achieve the effect of predicting the fatigue life of the offshore single pile structure, wherein the steps and principles for completing the single pile structure fatigue life prediction by using the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 are as follows: the first step is data acquisition, the strain data of the single pile under different loads and working conditions are measured by the strain sensor 5, the vibration acceleration information of the single pile structure is collected by the acceleration sensor 6, the displacement change of the single pile is obtained by the displacement sensor 7, and the inclination angle of the single pile is monitored by the tilt sensor 8, the second step is data analysis, the collected strain data are processed, the stress amplitude and the stress cycle number are calculated, the stress amplitude is a key factor of fatigue damage, the stress cycle number reflects the cumulative effect of the structure bearing load, the acceleration data are analyzed, the vibration characteristics of the single pile structure such as vibration frequency and amplitude are evaluated, so as to understand the dynamic response of the structure, the displacement data can be used to evaluate the overall deformation of the single pile, and whether the structural damage caused by excessive displacement exists is judged, and the inclination data are used to monitor the perpendicularity change of the single pile, and indirectly reflect the stability of the structure, the third step is to establish a fatigue model, based on the fatigue performance data of the material and the data obtained by the above collection and analysis, a fatigue life prediction model suitable for the single pile structure is established, the fourth step is fatigue life prediction, the actually measured data are input into the established fatigue model, and the fatigue life of the single pile structure is calculated, the fatigue failure is a process that the single pile structure gradually accumulates damage under the action of cyclic load until failure, the strain measured by the strain sensor 5 reflects the stress distribution and change in the structure, the vibration information captured by the acceleration sensor 6 helps to understand the dynamic response and energy transmission of the structure, the displacement monitored by the displacement sensor 7 can reflect the overall deformation of the structure, and the measurement result of the tilt sensor 8 reflects the stability of the structure, through comprehensive analysis of the data of these sensors, the stress, deformation and vibration of the single pile structure in the working process can be comprehensively understood, based on the fatigue characteristics of the material and the existing fatigue theory model, combined with the actual measurement data, calculation and analysis are carried out, so as to more accurately predict the fatigue life of the single pile structure, so that maintenance and repair measures can be taken in time, and the safety and reliability of the structure are ensured, since the single pile body 1 is used on the sea, it is often wetted by seawater, at this time, when the rainwater and splashed water on the sea hit the surface of the protective assembly 2, they are blocked by the waterproof cover 201, and multiple layers of waterproof are used to prevent the seawater from damaging the sensor, the first layer of protection is the outer inclined plate 202, which slides the water waves outward, if a small amount of water waves enter the inside, the second layer of protection is the inner inclined plate 204, the inclined surface of which also guides the water waves downward, the third layer of protection is the inner drainage plate 203,The water vapor and water droplets on the inner drainage plate 203 will be guided to the side away from the sensor, preventing the sensor from being in a wet state for a long time. The water inside the waterproof outer cover 201 and the waterproof inner cover 205 will flow out from the gap between the first water guide plate 212 and the second water guide plate 213. Since the structure of the first water guide plate 212 and the second water guide plate 213 is downwardly shaped like a bucket, the internal water can be promptly leaked out, and the protection assembly 2 has a protective effect on the internal sensor.

[0037] The method for using the device and the working principle: in use, the protection assembly 2 and the sensor installed inside can be adjusted in height on the outside of the single pile body 1 through the climbing assembly 4, which can rise with the sea level to avoid being immersed in seawater. When the device for monitoring the sea level height detects that the seawater rises obviously, the control system controls the starting of the reversible motor 407, so that the output shaft of the reversible motor 407 rotates, thereby driving the driving runner 406 to rotate, and under the connection of the conveying belt 405, the fixed wheel 404 and the rotating drum 402 are further driven to rotate. At the same time, the rotating blade 403 outside the rotating drum 402 rotates, and the rotating direction is determined according to the climbing height. When rising, the side of the positioning arc plate 409 first contacts the rung of the climbing ladder 305. Under the continuous rotation of the rotating drum 402, the rotating blade 403 alternately contacts the rung of the climbing ladder 305, so that the whole protection assembly 2 can climb upward. The rotating directions of the reversible motors 407 in the two climbing assemblies 4 are symmetrical, and they will not interfere with each other during operation. When climbing to a safe height, the reversible motor 407 runs in reverse, so that the hook on one side of the rotating blade 403 hooks the rung of the climbing ladder 305 to prevent the protection assembly 2 from falling automatically. After the position is hung, the reversible motor 407 is paused and locked. When the protection assembly 2 needs to move downward, the rotating blade 403 is adjusted to be separated from the climbing ladder 305, and the position of the rotating blade 403 is adjusted to a state where it cannot be hooked with the climbing ladder 305, so that the protection assembly 2 can slide downward along the limiting rod 301. During sliding, it relies on its own gravity, and the hooking arc-shaped part of the rotating blade 403 constantly touches the rung of the climbing ladder 305, which plays a role of friction deceleration, so that the protection assembly 2 will not fall directly and quickly. In use, the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the inclination sensor 8 are connected with the external control system, and the control and adjustment of them are completed by the control system. The strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the inclination sensor 8 are alternately installed on the multiple mounting blocks 206, and cooperate with each other to achieve the effect of predicting the fatigue life of the offshore single pile structure. The steps and principles for predicting the fatigue life of the single pile structure by using the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the inclination sensor 8 are as follows: the first step is data collection, the strain data of the single pile under different loads and working conditions are measured by the strain sensor 5, the vibration acceleration information of the single pile structure is collected by the acceleration sensor 6, the displacement change of the single pile is obtained by the displacement sensor 7, and the inclination angle of the single pile is monitored by the inclination sensor 8. The second step is data analysis, the collected strain data is processed, the stress amplitude and stress cycle number are calculated, the stress amplitude is a key factor of fatigue damage, the stress cycle number reflects the cumulative effect of the structure bearing load, the acceleration data is analyzed, and the vibration characteristics of the single pile structure, such as vibration frequency and amplitude, are evaluated to understand the dynamic response of the structure.The displacement data can be used to evaluate the overall deformation of the single pile, to determine whether there is excessive displacement leading to structural damage, and the inclination data is used to monitor the verticality change of the single pile, indirectly reflecting the stability of the structure. The third step is to establish a fatigue model based on the fatigue performance data of the material and the data obtained from the above collection and analysis, to establish a fatigue life prediction model suitable for the single pile structure. The fourth step is to predict the fatigue life. The actual measured data is input into the established fatigue model to calculate and predict the fatigue life of the single pile structure. Fatigue failure is a process of gradually accumulating damage until failure under the action of cyclic load. The strain measured by the strain sensor 5 reflects the stress distribution and change inside the structure. The vibration information captured by the acceleration sensor 6 helps to understand the dynamic response and energy transfer of the structure. The displacement monitored by the displacement sensor 7 can reflect the overall deformation of the structure. The measurement results of the inclination sensor 8 reflect the stability of the structure. By comprehensively analyzing the data of these sensors, the stress, deformation and vibration of the single pile structure during operation can be fully understood. Based on the fatigue characteristics of the material and the existing fatigue theory model, combined with the actual measurement data, the fatigue life of the single pile structure can be accurately predicted, so that maintenance and repair measures can be taken in time to ensure the safety and reliability of the structure. Since the single pile body 1 is used at sea, it is often wetted by seawater. At this time, when the rain and splashing water on the sea hit the surface of the protective assembly 2, they are blocked by the waterproof cover 201 and use multiple layers of waterproof. The first layer of protection is the outer inclined plate 202, which will slide the water outward. If a small amount of water enters the inside, the second layer of protection is the inner inclined plate 204, whose inclined surface also guides the water downward. The third layer of protection is the inner drainage plate 203. Water vapor and water droplets on the inner drainage plate 203 will be guided to the side away from the sensor, preventing the sensor from being in a wet state for a long time. The water inside the waterproof cover 201 and the waterproof inner cover 205 will flow out from the gap between the first water guide plate 212 and the second water guide plate 213. Since the structure of the first water guide plate 212 and the second water guide plate 213 is a downward bucket shape, the water inside can be drained in time.

[0038] The strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 are existing publicly disclosed devices for predicting the fatigue life of a single pile structure, so the specific structure and working principle thereof will not be described in detail here, and as known in the art, the strain sensor 5 mainly comprises a sensitive grid, a substrate, a lead wire and a cover sheet, the sensitive grid is the core part of the strain sensor 5, which is curved from a fine wire with a high resistance coefficient, can sense the strain of the component and convert it into a change in resistance, the substrate has the functions of accurately transmitting the strain on the component to the sensitive grid and having good insulation performance, moisture resistance and heat resistance, the lead wire is used to connect the sensitive grid with a measurement circuit, and the cover sheet has the function of protecting the sensitive grid, the working principle of the strain sensor 5 is based on the strain effect, that is, when the component is strained, the sensitive grid will also be deformed, thereby causing the resistance value to change, and by measuring the change in resistance, the strain of the component can be indirectly measured, the acceleration sensor 6 usually comprises a mass block, a damper, an elastic element, a sensitive element and an adaptive circuit, wherein the sensitive element can be capacitive, inductive, strain, piezoresistive or piezoelectric, and the working principle of the acceleration sensor 6 is based on Newton's second law, that is, when an object is subjected to acceleration, a corresponding inertial force will be generated, and the mass block in the sensor will be displaced under the action of the inertial force, and by measuring the displacement of the mass block or the size of the inertial force, the size of the acceleration can be indirectly measured, the internal structure of the displacement sensor 7 varies with the type, and common displacement sensors 7 include resistance type, optical type and ultrasonic type, and the working principle of the displacement sensor 7 is based on different physical principles, such as resistance change, optical interference and ultrasonic reflection, when the measured object is displaced, the sensor will detect the corresponding physical quantity change and convert it into an electrical signal output, the tilt sensor 8 usually comprises a cylindrical shell, a conductive rolling ball and two conductive elements, and the working principle of the tilt sensor 8 is based on gravity and conductivity, when the sensor is completely upright, the conductive rolling ball will fall to the bottom of the sensor and connect the two conductive elements, thereby allowing the current to flow, when the sensor is tilted, the conductive rolling ball will move away from the bottom, causing the circuit to be open, and the current cannot flow, and by detecting the on-off of the current, the tilt state of the sensor can be determined.

[0039] The wiring diagram of the forward and reverse motor 407, the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 in the application belongs to the common knowledge in the field, and the working principle thereof is a known technology, and the model thereof is selected according to actual use, so the control mode and wiring arrangement of the forward and reverse motor 407, the strain sensor 5, the acceleration sensor 6, the displacement sensor 7 and the tilt sensor 8 will not be explained in detail.

[0040] Although the present application has been described in detail with reference to the foregoing embodiments, the technical solutions recorded in the foregoing embodiments can be modified, or some of the technical features can be replaced by equivalent features, by those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fatigue life prediction system for marine monopile structures, comprising a monopile body (1), wherein two support components (3) are fixedly connected to the outer surface of the monopile body (1), a protective component (2) is provided on the outside of the monopile body (1), and two climbing components (4) are provided inside the protective component (2), the two climbing components (4) being symmetrically arranged, characterized in that: Both of the support components (3) include two support rods (304), and multiple climbing ladders (305) are fixedly connected between the outer surfaces of every two adjacent support rods (304); Both climbing components (4) include a fixed frame (401) and a mounting plate (408). The outer surfaces of both fixed frames (401) are rotatably connected to a rotating cylinder (402). Multiple rotating blades (403) are fixedly connected to the outer surfaces of both rotating cylinders (402) in the circumferential direction. A positioning arc plate (409) is fixedly connected to one side of the outer surface of each rotating blade (403). A fixed wheel (404) is fixedly connected to one end of the outer surface of both rotating cylinders (402). A forward and reverse motor (407) is provided on the top of both mounting plates (408). The output shafts of both forward and reverse motors (407) are fixedly connected to a drive wheel (406). A conveyor belt (405) is movably connected between the outer surfaces of the two fixed wheels (404) and the outer surfaces of the two drive wheels (406). The outer surfaces of the rotating blades (403) match the outer surfaces of the climbing ladder (305). The protective component (2) includes a waterproof outer cover (201) and a waterproof inner cover (205). The inner wall of the waterproof inner cover (205) is fixedly connected with a plurality of limiting blocks (207). The outer surface of each of the plurality of limiting blocks (207) has two limiting holes (208). Each pair of limiting holes (208) is divided into a group. The inner wall of each group of limiting holes (208) is slidably connected to the outer surface of two limiting rods (301). Both of the climbing components (4) are fixedly installed on the inner wall of the waterproof inner cover (205), and the fixing bracket (401) and the mounting plate (408) are fixedly connected to the inner wall of the waterproof inner cover (205); The top of the waterproof cover (201) is fixedly connected to an outer inclined plate (202), and the inner wall of the waterproof cover (201) is fixedly connected to an inner drainage plate (203) near the outer inclined plate (202). The bottom of the waterproof cover (201) is provided with a first water guide plate (212). The top of the waterproof inner cover (205) is fixedly connected to an inner inclined plate (204), and the bottom of the waterproof inner cover (205) is provided with a second water guide plate (213). Multiple outer fixing blocks (209) are fixedly connected to the inner wall of the waterproof outer cover (201) near the bottom and the inner wall of the first water guide plate (212) near the top. Multiple inner fixing blocks (211) are fixedly connected to the outer wall of the waterproof inner cover (205) near the bottom and the outer wall of the second water guide plate (213) near the top. Each pair of adjacent outer fixing blocks (209) and each pair of adjacent inner fixing blocks (211) are connected by bolts. Studs (214) are fixedly connected to the top of the upper outer fixing block (209) and the top of the inner fixing block (211). A connecting block (210) is movably connected between the outer surfaces of each pair of adjacent studs (214), and a nut is threaded on the outer surface of the stud (214). The inner wall of the waterproof cover (201) is fixedly connected with a plurality of mounting blocks (206), and the outer surfaces of the plurality of mounting blocks (206) are respectively provided with strain sensors (5), acceleration sensors (6), displacement sensors (7) and tilt sensors (8); The strain sensor (5) is used to measure the strain changes of key parts of the structure, the acceleration sensor (6) is used to monitor the vibration characteristics of the structure to understand the response of the structure under dynamic load, the displacement sensor (7) is used to monitor the displacement changes of the structure, and the tilt sensor (8) is used to understand the tilt degree of the single pile body (1).

2. The fatigue life prediction system for marine monopile structures according to claim 1, characterized in that: Each of the support rods (304) has a support point column (303) welded to both ends, and each of the support point columns (303) is fixedly connected to the outer surface of the monopile body (1).

3. The fatigue life prediction system for marine monopile structures according to claim 2, characterized in that: Multiple fixed point columns (302) are fixedly connected to the outer surfaces of the other two sides of the single pile body (1), and a limit rod (301) is welded between the outer surfaces of every two fixed point columns (302).

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