A method and system for self-adaptive thermal activation compensation of pre-tightening force of a deep-sea umbilical cable clamp

Abstract

The present application relates to the technical field of underwater equipment for deep-sea oil and gas development, and in particular to a deep-sea umbilical cable clamp pre-tightening force self-adaptive thermal activation compensation method and system. The method comprises the following steps: collecting multi-source information of a deep-sea umbilical cable clamp; calculating a contact pressure unevenness coefficient; calculating a pre-tightening force decay index; dividing a pre-tightening force decay grade based on the pre-tightening force decay index, and matching a thermal activation compensation mode according to the pre-tightening force decay grade; calculating an activation temperature and an activation time of a shape memory material according to the pre-tightening force decay index and the contact pressure unevenness coefficient; performing thermal activation on the shape memory material according to the activation temperature and the activation time; after the thermal activation compensation is completed, collecting a compensated pre-tightening force, calculating a compensation recovery rate based on the compensated pre-tightening force; and performing a closed-loop correction decision according to the compensation recovery rate. The present application realizes self-diagnosis and precise recovery of the pre-tightening force without manual intervention, and significantly improves the intelligent level and long-term service reliability of the deep-sea umbilical cable fixing system.

Description

Technical Field

[0001] This invention relates to the field of underwater equipment technology for deep-sea oil and gas development, and in particular to an adaptive thermal activation compensation method and system for the pre-tightening force of deep-sea umbilical cable clamps. Background Technology

[0002] During their service in kilometer-deep waters, deep-sea umbilical cables must be secured to underwater platforms or manifold supports using clamps, pipe clamps, and other restraint structures to limit axial slippage, lateral sway, and localized wear. If the clamps fail, the umbilical cable will break, production will be interrupted, and huge economic losses and safety hazards will result.

[0003] Currently, most mainstream deep-sea umbilical cable clamps employ a bolt-pre-tightened mechanical clamping structure, consisting of upper and lower clamping flaps, an inner liner, and fastening bolts. The clamping flaps hold the umbilical cable in place by the bolt pre-tightening force, and the cable is secured through the contact pressure and friction between the inner liner and the outer sheath. However, in the long-term service environment of the deep sea, the clamps are continuously subjected to the coupled effects of seawater temperature and pressure changes, wave and current impacts, platform movement, and the umbilical cable's own vibrations. The bolt connections gradually loosen due to repeated cyclic loading, and the inner liner and outer sheath undergo creep and compression relaxation under continuous pressure. This not only leads to a continuous decrease in overall clamping force but also uneven circumferential contact pressure distribution, potentially causing localized overpressure damage to the outer sheath or localized underpressure leading to umbilical cable slippage. Existing mainstream clamps are still purely passive mechanical structures, lacking online monitoring capabilities after installation, making it difficult to promptly identify the pre-tightening force decay state. Furthermore, underwater manual maintenance is extremely costly and risky, making it impossible to achieve active pre-tightening recovery during service. While some studies have introduced smart materials such as shape memory alloys and shape memory polymers, most of them only focus on material replacement and single thermal activation, without establishing a multi-factor integrated evaluation system for preload attenuation; general bolt preload technology is also not adapted to the special deep-sea working conditions where umbilical cable sheaths are sensitive to compression and load coupling.

[0004] Therefore, there is an urgent need to develop an adaptive pre-tightening recovery method and system for deep-sea umbilical cable clamps that integrates multi-source attenuation evaluation, graded thermal activation compensation, and closed-loop feedback correction, in order to solve the core problems of difficulty in identifying pre-tightening force attenuation and difficulty in actively repairing clamping force in existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for adaptive thermal activation compensation of pretension force in deep-sea umbilical cable clamps.

[0006] To achieve the above objectives, in a first aspect, the present invention provides an adaptive thermal activation compensation method for preload pretension of a deep-sea umbilical cable clamp, comprising: collecting preload information, contact pressure information, temperature information, and historical compensation counts of the deep-sea umbilical cable clamp; calculating a contact pressure non-uniformity coefficient based on the contact pressure information; calculating a preload attenuation index based on the preload information, the temperature information, the historical compensation counts, and the contact pressure non-uniformity coefficient; classifying preload attenuation levels based on the preload attenuation index, and matching corresponding thermal activation compensation modes according to the preload attenuation levels; calculating the activation temperature and activation time of the shape memory alloy fastening component and / or the shape memory polymer preload recovery zone based on the preload attenuation index and the contact pressure non-uniformity coefficient; thermally activating the shape memory alloy fastening component and / or the shape memory polymer preload recovery zone according to the activation temperature and the activation time; after the thermal activation compensation is completed, collecting the preload after compensation, calculating the compensation recovery rate based on the preload after compensation; and performing closed-loop correction decision based on the compensation recovery rate.

[0007] This invention enables multi-source sensing, accurate evaluation, graded compensation, and closed-loop recovery of the pre-tightening state of the clamp, fundamentally solving the problem of the inability to actively repair the attenuation of the pre-tightening force of deep-sea clamps.

[0008] Optionally, calculating the contact pressure non-uniformity coefficient based on the contact pressure information includes: The contact pressure non-uniformity coefficient Calculated using the following formula: ; in, The standard deviation of the pressure at multiple contact pressure measuring points uniformly arranged circumferentially along the inner lining of the deep-sea umbilical cable clamp is given. The average contact pressure at the multiple contact pressure measurement points is denoted as .

[0009] This invention quantifies the uniformity of circumferential pressure on umbilical cables, accurately identifies the risk of local underpressure or overpressure, and provides a key basis for evaluating preload attenuation.

[0010] Optionally, calculating the preload decay index based on the preload information, the temperature information, the historical compensation count, and the contact pressure non-uniformity coefficient includes: The preload attenuation index Calculated using the following formula: ; in, To compensate for the preload, This is the initial preload. The coefficient of non-uniformity of contact pressure. This is the absolute value of the preload decay rate normalized to the reference decay rate. This is the absolute value of the temperature change normalized to a reference temperature difference. This is the amount after normalizing the historical compensation count to the maximum allowed compensation count; , , , , This refers to the normalized weight or dimensional correction coefficient.

[0011] This invention integrates multi-dimensional attenuation factors to construct a comprehensive evaluation index, which reflects the actual service status of the clamp more comprehensively and accurately than a single preload index.

[0012] Optionally, the preload attenuation levels include a normal state, a first-level compensation state, a second-level compensation state, and a third-level compensation state. The step of classifying the preload attenuation levels based on the preload attenuation index and matching the corresponding thermal activation compensation mode according to the preload attenuation levels includes: when < At that time, the deep-sea umbilical cable clamp is in normal condition, requires no compensation, and returns to real-time monitoring; when ≤ < At this time, the deep-sea umbilical cable clamp is in the first-level compensation state, and only the shape memory alloy fastening component is activated to compensate for the pre-tightening force; when ≤ < At this time, the deep-sea umbilical cable clamp is in a secondary compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation. when ≥ At this time, the deep-sea umbilical cable clamp is in a level three compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation, and at least one of the following warning signals is output: loosening, pad failure, structural damage and overcompensation. in, , , The preset grading threshold is used.

[0013] This invention employs a graded compensation strategy based on the degree of attenuation to avoid undercompensation or overcompensation, thereby reducing energy consumption and extending the lifespan of shape memory materials.

[0014] Optionally, calculating the activation temperature of the shape memory alloy fastening assembly and / or the shape memory polymer preload recovery zone based on the preload decay index and the contact pressure non-uniformity coefficient includes: The activation temperature of the shape memory polymer pre-tightening recovery zone The formula is: ; Activation temperature of the shape memory alloy fastening assembly The formula is: ; in, The glass transition temperature of shape memory polymers. This refers to the temperature at which the austenitic phase transformation of shape memory alloys is completed. , , , , This is the temperature regulation coefficient; Pre-set safety constraints should be met during the compensation process: , , ; in, To preset the upper limit of the safe heating temperature, The maximum contact pressure after compensation. This is a preset upper limit for the allowable contact pressure of the outer sheath of the umbilical cable.

[0015] This invention adaptively calculates the activation temperature of the two materials to ensure sufficient phase transition and accurate compensation, while protecting the umbilical cable and clamp structure through multi-dimensional safety constraints.

[0016] Optionally, the activation time Calculated using the following formula: ; in, The preset base activation time, , , This is the preset time adjustment coefficient.

[0017] This invention precisely controls the heating time, avoiding insufficient heating leading to compensation failure or overheating causing energy waste and material damage.

[0018] Optionally, the step of performing thermal activation compensation on the shape memory alloy fastening component and / or the shape memory polymer pre-tightening recovery zone according to the activation temperature and the activation time includes: thermally activating the shape memory alloy fastening component and / or the shape memory polymer pre-tightening recovery zone according to the calculated activation temperature and the activation time, so that the shape memory alloy fastening component produces axial compensation and the shape memory polymer pre-tightening recovery zone produces radial recovery deformation, thereby restoring the clamping force of the deep-sea umbilical cable clamp on the deep-sea umbilical cable.

[0019] This invention controls the thermal activation process by precisely matching calculation parameters, achieving axial and radial dual-dimensional coordinated compensation, ensuring that the clamping force of the clip is restored in a targeted and efficient manner, and avoiding the limitations of a single compensation method.

[0020] Optionally, after the thermal activation compensation is completed, the preload force after compensation is collected, and the compensation recovery rate is calculated based on the preload force after compensation, including: when And when the deep-sea umbilical cable clamp has entered at least one of the first-level compensation state, the second-level compensation state, and the third-level compensation state, the compensation recovery rate is... The following relationship was used for calculation: ; in, To preset the preload loss threshold, To compensate for the preload.

[0021] This invention quantifies the compensation effect, provides an objective basis for closed-loop decision-making, and avoids the repeated execution of ineffective compensation.

[0022] Optionally, the step of performing closed-loop correction decision based on the compensation recovery rate includes: when Furthermore, if the contact pressure, temperature, and current do not exceed the preset threshold during the compensation process, the compensation is considered effective, the historical compensation count is incremented by 1, and the system returns to the real-time monitoring status. when If the number of consecutive compensation attempts does not reach the preset limit, the activation temperature and activation time for the next round are adjusted, and the next round of thermal activation compensation is executed. The adjustment method can be expressed as follows: ; ; in, The corrected activation temperature. This is the corrected activation time. This is the temperature feedback correction factor. For time feedback correction coefficient, The preset compensation recovery rate threshold; If the number of consecutive compensation attempts reaches the preset upper limit and the compensation recovery rate is still lower than the limit, If, during the compensation process, at least one of the factors of contact pressure, temperature, and current exceeds the preset threshold, heating will stop and an early warning signal will be output indicating that the deep-sea umbilical cable clamp is loose, the liner is in failure, the structure is damaged, or the compensation is over-compensated.

[0023] This invention achieves closed-loop feedback correction of the compensation effect, continuously optimizes activation parameters, provides timely warning of structural failure, and ensures long-term safe operation of the system.

[0024] Secondly, the present invention provides a deep-sea umbilical cable clamp preload adaptive thermal activation compensation system, comprising: a deep-sea umbilical cable clamp body for clamping a deep-sea umbilical cable; a shape memory polymer preload recovery zone disposed on the inner cavity contact surface, the clamp flap connection transition zone, or the preload force concentration zone of the deep-sea umbilical cable clamp body; a shape memory alloy fastening component disposed on the bolt connection part or the preload force transmission path of the deep-sea umbilical cable clamp body; and a sensor array for collecting preload force information, contact pressure information, and temperature information of the deep-sea umbilical cable clamp body. The invention provides a comprehensive hardware and software solution, integrating sensing, decision-making, execution, and feedback processes to achieve fully automatic adaptive recovery of the clamp pretension force. The contact pressure information measurement points are distributed along the contact arc surfaces of the upper and lower inner linings. A heating activation component is used to thermally activate the shape memory polymer pretension recovery zone and / or the shape memory alloy fastening component. A controller, comprising a data acquisition and filtering module, a contact pressure non-uniformity coefficient calculation module, a pretension force attenuation index calculation module, a graded compensation decision module, an activation parameter calculation module, a heating drive module, a recovery rate calculation module, and a closed-loop decision module, is used to execute the aforementioned adaptive thermal activation compensation method for deep-sea umbilical cable clamp pretension force. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a method for adaptive thermal activation compensation of pre-tightening force of deep-sea umbilical cable clamp according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the overall structure of a deep-sea umbilical cable clamp pretension force adaptive thermal activation compensation system according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the shape memory alloy fastening component structure according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the shape memory polymer pre-tightening recovery zone structure according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the controller framework flow according to an embodiment of the present invention. Detailed Implementation

[0030] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0031] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0032] Please see Figure 1 An embodiment of the present invention provides an adaptive thermal activation compensation method for the pretension force of a deep-sea umbilical cable clamp, the method comprising the following steps: S1. Collect information on the preload force, contact pressure, temperature, and historical compensation count of the deep-sea umbilical cable clamp.

[0033] Specifically, in this embodiment, the preload information includes, but is not limited to, the preload before compensation, the initial preload, and the preload decay rate. The preload before compensation can be obtained by the bolt axial force sensing unit, the contact pressure information can be obtained by the CNT pressure sensing layer, the temperature information can be obtained by the temperature sensor, and the historical compensation count can be obtained by the controller. In addition, the card body strain information also needs to be collected, which can be obtained by the FBG strain sensor. Among them, the contact pressure information includes, but is not limited to, the average contact pressure and the standard deviation of the contact pressure. The average contact pressure and the standard deviation of the contact pressure can be calculated based on the pressure data of multiple contact pressure measuring points. Multiple contact pressure measuring points are distributed along the contact arc surfaces of the upper and lower inner linings to reflect whether the circumferential pressure on the outer sheath of the umbilical cable is uniform.

[0034] Furthermore, before starting real-time monitoring and data acquisition, an initialization operation must be performed: after the clamp is installed, record the initial preload, initial ambient temperature, initial contact pressure distribution, and initial clamp strain value as benchmark parameters for subsequent preload attenuation calculation and compensation effect evaluation; at the same time, load the preset grading threshold, safety limit, and calibration coefficient.

[0035] S2. Calculate the contact pressure non-uniformity coefficient based on the contact pressure information.

[0036] Specifically, in this embodiment, the contact pressure non-uniformity coefficient Calculated using the following formula: ; in, The standard deviation of the pressure at multiple contact pressure measuring points uniformly arranged circumferentially along the inner lining of the deep-sea umbilical cable clamp is given. The average contact pressure at the multiple contact pressure measurement points is denoted as .

[0037] S3. Calculate the preload attenuation index based on the preload information, the temperature information, the number of historical compensations, and the contact pressure non-uniformity coefficient.

[0038] Specifically, in this embodiment, the preload attenuation index Calculated using the following formula: ; in, To compensate for the preload, This is the initial preload. The coefficient of non-uniformity of contact pressure. This is the absolute value of the preload decay rate normalized to the reference decay rate. This is the absolute value of the temperature change normalized to a reference temperature difference. This is the amount after normalizing the historical compensation count to the maximum allowed compensation count; , , , , This refers to the normalized weight or dimensional correction coefficient.

[0039] S4. Based on the preload attenuation index, preload attenuation levels are divided, and corresponding thermal activation compensation modes are matched according to the preload attenuation levels.

[0040] Specifically, in this embodiment, the preload attenuation levels include a normal state, a first-level compensation state, a second-level compensation state, and a third-level compensation state. when < At that time, the deep-sea umbilical cable clamp is in normal condition, requires no compensation, and returns to real-time monitoring; when ≤ < At this time, the deep-sea umbilical cable clamp is in the first-level compensation state, and only the shape memory alloy fastening component is activated to compensate for the pre-tightening force; when ≤ < At this time, the deep-sea umbilical cable clamp is in a secondary compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation. when ≥ At this time, the deep-sea umbilical cable clamp is in a level three compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation, and at least one of the following warning signals is output: loosening, pad failure, structural damage and overcompensation.

[0041] in, , , The preset grading threshold is used. The initial preload is... Based on the benchmark, the preload loss ratio was calculated separately. Coefficient of contact pressure non-uniformity Normalized decay rate Normalized temperature perturbation Normalized historical compensation times and compensation recovery rate Calibration: When the preload loss is small and When the pressure is below the first pressure non-uniformity threshold, determine the first-level compensation threshold. When the preload loss continues to increase, It is between the first and second pressure non-uniformity thresholds, or , When the disturbance range is reached, determine the secondary compensation threshold. When the preload loss increases significantly, Exceeding the second pressure unevenness threshold or Reaching a high disturbance range, or compensating for the recovery rate continuously below the compensation recovery rate threshold At that time, the three-level compensation threshold was determined. .

[0042] S5. Calculate the activation temperature and activation time of the shape memory alloy fastening component and / or the shape memory polymer preload recovery zone based on the preload attenuation index and the contact pressure non-uniformity coefficient.

[0043] Specifically, in this embodiment, the activation temperature of the shape memory polymer pre-tightening recovery region... The formula is: ; Activation temperature of the shape memory alloy fastening assembly The formula is: ; in, The glass transition temperature of shape memory polymers. This refers to the temperature at which the austenitic phase transformation of shape memory alloys is completed. , , , , This is the temperature regulation coefficient; Pre-set safety constraints should be met during the compensation process: , , ; in, To preset the upper limit of the safe heating temperature, The maximum contact pressure after compensation. This is a preset upper limit for the allowable contact pressure of the outer sheath of the umbilical cable.

[0044] Furthermore, the activation time Calculated using the following formula: ; in, The preset base activation time, , , This is the preset time adjustment coefficient.

[0045] In this way, the thermal activation process can be adaptively adjusted according to the degree of preload attenuation, the degree of contact pressure unevenness, and the number of historical compensation cycles.

[0046] S6. Perform thermal activation compensation on the shape memory alloy fastening assembly and / or the shape memory polymer pre-tightening recovery zone according to the activation temperature and the activation time.

[0047] Specifically, in this embodiment, based on the calculated activation temperature and activation time, the shape memory alloy fastening component and / or the shape memory polymer pre-tightening recovery zone are thermally activated, causing the shape memory alloy fastening component to generate axial compensation to compensate for the pre-tightening force attenuation at the bolt connection; and causing the shape memory polymer pre-tightening recovery zone to generate radial recovery deformation to compensate for the clamping force attenuation caused by inner liner compression relaxation, outer sheath creep, or decreased contact pressure, thereby restoring the clamping force of the deep-sea umbilical cable clamp on the deep-sea umbilical cable.

[0048] The axial compensation amount of the shape memory alloy fastening component and the radial recovery amount of the shape memory polymer pre-tightening recovery zone can be calibrated according to the size of the deep-sea umbilical cable clip, bolt specifications and liner compression amount. During the compensation process, each pressure measuring point is continuously monitored. When any contact pressure exceeds the preset upper limit of contact pressure or the temperature exceeds the preset upper limit of temperature after compensation, heating is stopped and at least one of the following warning signals is output: loosening, liner failure, structural damage and overcompensation warning.

[0049] S7. After the thermal activation compensation is completed, the pre-tightening force after compensation is collected, and the compensation recovery rate is calculated based on the pre-tightening force after compensation.

[0050] Specifically, in this embodiment, when When the deep-sea umbilical cable clamp has entered at least one of the three compensation states (Level 1, Level 2, and Level 3), the pre-tightening force after compensation is collected, and the compensation recovery rate is calculated based on the pre-tightening force, the post-compensation pre-tightening force, and the initial pre-tightening force. The following relationship was used for calculation: ; in, To preset the preload loss threshold, To compensate for the preload.

[0051] S8. Perform closed-loop correction decision based on the compensation recovery rate.

[0052] Specifically, in this embodiment, when Furthermore, if the contact pressure, temperature, and current do not exceed the preset threshold during the compensation process, the compensation is considered effective, the historical compensation count is incremented by 1, and the system returns to the real-time monitoring status. when If the number of consecutive compensation attempts does not reach the preset limit, the activation temperature and activation time for the next round are adjusted, and the next round of thermal activation compensation is executed. The adjustment method can be expressed as follows: ; ; in, The corrected activation temperature. This is the corrected activation time. This is the temperature feedback correction factor. For time feedback correction coefficient, This is the preset compensation recovery rate threshold.

[0053] If the number of consecutive compensation attempts reaches the preset upper limit and the compensation recovery rate is still lower than the limit, If, during the compensation process, at least one of the factors of contact pressure, temperature, and current exceeds the preset threshold, heating will stop and an early warning signal will be output indicating that the deep-sea umbilical cable clamp is loose, the liner is in failure, the structure is damaged, or the compensation is over-compensated.

[0054] The contact pressure distribution is obtained through a CNT pressure sensor. When any pressure measuring point exceeds the preset upper limit of contact pressure or the contact pressure non-uniformity coefficient exceeds the overpressure warning threshold, it is determined to be an over-threshold. The temperature is detected by a temperature sensor to activate the temperature. When it exceeds the preset upper limit of temperature, it is determined to be an over-threshold. The current is collected by the power supply circuit of the heating drive module. When it exceeds the preset threshold, it is determined to be an over-threshold.

[0055] The weighting coefficients in this embodiment to Threshold , , Recovery rate threshold Preset preload loss threshold The preset upper limit for the number of continuous compensation cycles, temperature adjustment coefficient, and time adjustment coefficient can all be calibrated based on the dimensions of the clip structure, the phase transition temperature of the shape memory alloy, the glass transition temperature of the shape memory polymer, the outer diameter of the umbilical cable, the operating water depth, the sea state, cyclic load tests, preload decay tests, and thermal activation compensation recovery tests. Among these, the preload decay index... Weighting coefficients in to , grading threshold , , , compensation recovery rate threshold The preset upper limit for the number of consecutive compensation cycles can be determined through calibration tests, including recording the initial preload after installation. Initial contact pressure distribution; applying different amplitudes of preload attenuation, temperature disturbance, and cyclic load, and simultaneously collecting data. , , , , and The changing data is used to finally complete the parameter calibration.

[0056] Please see Figure 2 In one optional embodiment, the present invention provides a deep-sea umbilical cable clamp pretension force adaptive thermal activation compensation system, comprising: a deep-sea umbilical cable clamp body 1 for clamping a deep-sea umbilical cable, which forms a clamping cavity for accommodating the deep-sea umbilical cable, the deep-sea umbilical cable being located at the clamping center.

[0057] Please see Figure 3 , Figure 3 The diagram shows the structure of the shape memory alloy fastening assembly 2. The shape memory alloy fastening assembly 2 is installed at the bolt connection or preload transmission path of the deep-sea umbilical cable clamp body 1. It includes a bolt 7, a nut 8, a shape memory alloy preload compensation washer 9, an upper connecting lug 10, a lower connecting lug 11, and a heat-activated zone 12. The shape memory alloy preload compensation washer 9 is installed on the preload transmission path formed by the bolt 7 and the nut 8. When the controller 6 determines that the clamp is in the first-level compensation state, the heat-activated zone 12 heats the shape memory alloy preload compensation washer 9, so that it has a restoring effect along the axial direction of the bolt 7 to compensate for the preload attenuation at the bolt 7 connection.

[0058] Please see Figure 4 , Figure 4 This is a schematic diagram of the shape memory polymer pre-tightening recovery zone 3. The shape memory polymer pre-tightening recovery zone 3 is disposed on the inner cavity contact surface, the transition area of ​​the clip connection, or the pre-tightening force concentration area of ​​the deep-sea umbilical cable clamp body 1. It includes an inner liner 13, a heating zone 14, and a thermal expansion zone 15. The inner liner 13 forms an arc surface contact with the outer sheath 16 of the umbilical cable. Before thermal activation, it serves as the contact layer of the inner liner 13 to bear the radial clamping load. The heating zone 14 is used to thermally activate the shape memory polymer material. After being heated, the thermal expansion zone 15 generates a recovery deformation in the direction of the outer sheath 16 of the umbilical cable to compensate for the attenuation of clamping force caused by the compression relaxation of the inner liner 13, the creep of the outer sheath 16 of the umbilical cable, or the decrease in contact pressure, thereby increasing the contact pressure between the inner liner 13 and the outer sheath 16 of the umbilical cable.

[0059] Sensor array 4 is used to collect the preload force information, contact pressure information, clamp strain and temperature information of the deep-sea umbilical cable clamp body 1, and the contact pressure information measuring points are distributed along the contact arc surface of the upper and lower inner linings; sensor array 4 includes, but is not limited to, FBG strain sensor, CNT pressure sensor, temperature sensor and bolt axial force sensing unit, and transmits sensing data and control signals through control connection line 5.

[0060] Heating activation component 7 is used to thermally activate the shape memory polymer pre-tightening recovery zone 3 and / or the shape memory alloy fastening component 2; the heating activation component 7 consists of... Figure 3 Thermal activation zone 12 in Figure 3 heating zone 14 and Figure 4The heating drive module 22 in the middle is used to thermally activate the shape memory alloy fastening component 2 and the shape memory polymer pre-tightening recovery zone 3 respectively.

[0061] Please see Figure 5 , Figure 5 This is a schematic diagram of the controller 6 framework. Controller 6 includes a data acquisition and filtering module 17, a contact pressure non-uniformity coefficient calculation module 18, a preload attenuation index calculation module 19, a graded compensation decision module 20, an activation parameter calculation module 21, a heating drive module 22, a recovery rate calculation module 23, and a closed-loop decision module 24, used to execute the aforementioned deep-sea umbilical cable clamp preload adaptive thermal activation compensation method. Specifically, the data acquisition and filtering module 17 receives data collected by the sensor array 4; the contact pressure non-uniformity coefficient calculation module 18 calculates the contact pressure non-uniformity coefficient; the preload attenuation index calculation module 19 calculates the preload attenuation index; and the graded compensation decision module 20 determines the preload attenuation index based on the data collected by the sensor array 4. The current state is displayed, and the compensation level is output. The activation parameter calculation module 21 calculates the target activation temperature, activation time, current and voltage, driving duration and heating rate according to the compensation level. The heating drive module 22 executes PWM control, current / voltage control and temperature closed-loop control to drive the heating activation component 7, so that the shape memory alloy fastening component 2 and / or the shape memory polymer pre-tightening recovery zone 3 implement thermal activation compensation. The recovery rate calculation module 23 and the closed-loop decision module 24 calculate the compensation recovery rate R, and determine whether to return to real-time monitoring, correct parameters or output an early warning based on the relationship between R and the preset threshold. The compensation effect is fed back to the activation parameter calculation module 21 for the next round of activation parameter correction, forming a closed-loop correction.

[0062] For those skilled in the art, the present invention is not limited to the specific details of the above embodiments. Under deep-sea service conditions, the threshold, heating power, and number of compensation cycles can be adjusted according to water depth, ambient temperature, ocean current vibration, umbilical cable outer diameter, allowable compressive stress of the outer sheath material, and clamp installation pre-tightening force; other specific forms can be used to implement the present invention without departing from the basic idea of ​​the invention.

[0063] In summary, this invention has the following beneficial effects: 1. By integrating multi-source sensor data such as preload, contact pressure, strain, temperature, and historical compensation counts, a comprehensive preload attenuation index is constructed, which can more comprehensively and accurately evaluate the actual loosening risk of deep-sea umbilical cable clamps in complex deep-sea environments; 2. Based on this attenuation index, different levels are classified and matched with differentiated compensation modes such as activating only shape memory alloy fastening components or jointly activating shape memory polymer preload recovery zones, to achieve precise matching between compensation intensity and attenuation degree, avoiding undercompensation and overcompensation, while reducing energy consumption and extending the life of smart materials; 3. Introducing a contact pressure non-uniformity coefficient distributed along the circumferential direction of the lining, while quantifying the circumferential pressure uniformity of the umbilical cable and providing a key basis for attenuation evaluation, incorporates the risk of local underpressure or overpressure into the adaptive calculation of activation parameters, which helps to restore uniform clamping and protect the outer sheath; 4. Based on the attenuation index and non-uniformity coefficient, two types of shape memory... 5. The system automatically adjusts the activation temperature and time of the shape memory material and applies multi-dimensional safety constraints such as upper temperature and upper contact pressure limits to ensure sufficient phase change, accurate compensation, and no damage to the umbilical cable and clamp structure; 6. After compensation, the system collects the pre-tightening force and calculates the compensation recovery rate to form a closed-loop correction decision. When the recovery rate does not meet the standard, the activation temperature and time are automatically adjusted for iterative compensation. Combined with the upper limit of continuous compensation times and safety threshold over-limit protection, the system promptly outputs warnings of loosening, pad failure, structural damage, and over-compensation, achieving dual protection of effective compensation and fault warning; 7. The entire system integrates the clamp body, shape memory functional area, sensor array, heating activation component, and multi-module controller to achieve full-process automation from multi-source sensing, attenuation evaluation, hierarchical decision-making, parameter calculation to closed-loop feedback. It can autonomously complete pre-tightening force diagnosis and adaptive recovery without manual underwater intervention, significantly improving the intelligence level, reliability, and long-term service safety of the deep-sea umbilical cable fixing system.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for adaptive thermal activation compensation of preload force in deep-sea umbilical cable clamps, characterized in that, include: Collect information on the preload force, contact pressure, temperature, and historical compensation counts of deep-sea umbilical cable clamps; Calculate the contact pressure non-uniformity coefficient based on the contact pressure information; The preload decay index is calculated based on the preload information, the temperature information, the historical compensation count, and the contact pressure non-uniformity coefficient. The preload attenuation level is divided based on the preload attenuation index, and the corresponding thermal activation compensation mode is matched according to the preload attenuation level. Based on the preload decay index and the contact pressure non-uniformity coefficient, calculate the activation temperature and activation time of the shape memory alloy fastening component and / or the shape memory polymer preload recovery zone; The shape memory alloy fastening assembly and / or the shape memory polymer pre-tightening recovery zone are thermally activated according to the activation temperature and the activation time. After the thermal activation compensation is completed, the preload force after compensation is collected, and the compensation recovery rate is calculated based on the preload force after compensation. A closed-loop correction decision is executed based on the stated compensation recovery rate.

2. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 1, characterized in that, The calculation of the contact pressure non-uniformity coefficient based on the contact pressure information includes: The contact pressure non-uniformity coefficient Calculated using the following formula: ； in, The standard deviation of the pressure at multiple contact pressure measuring points uniformly arranged circumferentially along the inner lining of the deep-sea umbilical cable clamp is given. The average contact pressure at the multiple contact pressure measurement points is denoted as .

3. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 1, characterized in that, The calculation of the preload decay index based on the preload information, the temperature information, the historical compensation count, and the contact pressure non-uniformity coefficient includes: The preload attenuation index Calculated using the following formula: ； in, To compensate for the preload, This is the initial preload. The coefficient of non-uniformity of contact pressure. This is the absolute value of the preload decay rate normalized to the reference decay rate. This is the absolute value of the temperature change normalized to a reference temperature difference. The number of historical compensation counts is the amount normalized to the maximum allowed number of compensation counts. , , , , This refers to the normalized weight or dimensional correction coefficient.

4. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 3, characterized in that, The preload attenuation levels include normal state, first-level compensation state, second-level compensation state, and third-level compensation state. The process of classifying the preload attenuation levels based on the preload attenuation index and matching corresponding heat activation compensation modes according to the preload attenuation levels includes: when < At that time, the deep-sea umbilical cable clamp is in normal condition, requires no compensation, and returns to real-time monitoring; when ≤ < At this time, the deep-sea umbilical cable clamp is in the first-level compensation state, and only the shape memory alloy fastening component is activated to compensate for the pre-tightening force; when ≤ < At this time, the deep-sea umbilical cable clamp is in a secondary compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation. when ≥ At this time, the deep-sea umbilical cable clamp is in a level three compensation state, and the shape memory alloy fastening component and the shape memory polymer pre-tightening recovery zone are activated for joint compensation, and at least one of the following warning signals is output: loosening, pad failure, structural damage and overcompensation. in, , , The preset grading threshold is used.

5. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 3, characterized in that, The step of calculating the activation temperature of the shape memory alloy fastening component and / or the shape memory polymer preload recovery zone based on the preload decay index and the contact pressure non-uniformity coefficient includes: The activation temperature of the shape memory polymer pre-tightening recovery zone The formula is: ； Activation temperature of the shape memory alloy fastening assembly The formula is: ； in, The glass transition temperature of shape memory polymers. This refers to the temperature at which the austenitic phase transformation of shape memory alloys is completed. , , , , This is the temperature regulation coefficient; Pre-set safety constraints should be met during the compensation process: ， ， ； in, To preset the upper limit of the safe heating temperature, The maximum contact pressure after compensation. This is a preset upper limit for the allowable contact pressure of the outer sheath of the umbilical cable.

6. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 3, characterized in that, The activation time Calculated using the following formula: ； in, The preset base activation time, , , This is the preset time adjustment coefficient.

7. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 1, characterized in that, The step of performing thermal activation compensation on the shape memory alloy fastening assembly and / or the shape memory polymer pre-tightening recovery zone according to the activation temperature and the activation time includes: Based on the calculated activation temperature and activation time, the shape memory alloy fastening component and / or the shape memory polymer pre-tightening recovery zone are thermally activated, causing the shape memory alloy fastening component to produce axial compensation and the shape memory polymer pre-tightening recovery zone to produce radial recovery deformation, thereby restoring the clamping force of the deep-sea umbilical cable clamp on the deep-sea umbilical cable.

8. The adaptive thermal activation compensation method for pre-tightening force of deep-sea umbilical cable clamps according to claim 3, characterized in that, After the thermal activation compensation is completed, the preload force after compensation is collected, and the compensation recovery rate is calculated based on the preload force after compensation, including: when And when the deep-sea umbilical cable clamp has entered at least one of the first-level compensation state, the second-level compensation state, and the third-level compensation state, the compensation recovery rate is... The following relationship was used for calculation: ； in, To preset the preload loss threshold, To compensate for the preload.

9. The adaptive thermal activation compensation method for pre-tightening force of a deep-sea umbilical cable clamp according to claim 5 or 6, characterized in that, The step of performing closed-loop correction decision based on the compensation recovery rate includes: when Furthermore, if the contact pressure, temperature, and current do not exceed the preset threshold during the compensation process, the compensation is considered effective, the historical compensation count is incremented by 1, and the system returns to the real-time monitoring status. when If the number of consecutive compensation attempts does not reach the preset limit, the activation temperature and activation time for the next round are adjusted, and the next round of thermal activation compensation is executed. The adjustment method can be expressed as follows: ； ； in, The corrected activation temperature. This is the corrected activation time. This is the temperature feedback correction factor. For time feedback correction coefficient, The preset compensation recovery rate threshold; If the number of consecutive compensation attempts reaches the preset upper limit and the compensation recovery rate is still lower than the limit, If, during the compensation process, at least one of the factors of contact pressure, temperature, and current exceeds the preset threshold, heating will stop and an early warning signal will be output indicating that the deep-sea umbilical cable clamp is loose, the liner is in failure, the structure is damaged, or the compensation is over-compensated.

10. A deep-sea umbilical cable clamp preload preload adaptive thermal activation compensation system, characterized in that, include: The body of the deep-sea umbilical cable clamp is used to hold the deep-sea umbilical cable. A shape memory polymer pre-tightening recovery zone is provided on the inner cavity contact surface, the card flap connection transition zone, or the pre-tightening force concentration zone of the deep-sea umbilical cable clamp body; Shape memory alloy fastening components are installed at the bolt connection points or on the preload transmission path of the deep-sea umbilical cable clamp body; A sensor array is used to collect information on the preload force, contact pressure, temperature, and historical compensation count of the deep-sea umbilical cable clamp body, and the contact pressure measurement points are distributed along the contact arc surfaces of the upper and lower inner linings. A heating activation component is used to thermally activate the shape memory polymer pre-tightening recovery zone and / or the shape memory alloy fastening component. The controller includes a data acquisition and filtering module, a contact pressure non-uniformity coefficient calculation module, a preload attenuation index calculation module, a graded compensation decision module, an activation parameter calculation module, a heating drive module, a recovery rate calculation module, and a closed-loop decision module, and is used to execute the deep-sea umbilical cable clamp preload adaptive thermal activation compensation method as described in any one of claims 1-9.

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