Ship structure strain dynamic test data generation method

Abstract

The invention provides a hull structure strain dynamic test data generation method, which is applied to the technical field of hull structure strain test, and comprises the following steps: S1, arranging an optical fiber strain sensor and a first resistance strain sensor in a target test area of a test piece, arranging an optical fiber strain sensor and a first resistance strain sensor at the same measuring point on the test piece; s2, changing the temperature of the test piece, and when the temperature of the test piece is stabilized in the current target temperature range, loading the test piece according to the load gradient required by the test; s3, collecting first strain data and second strain data output by each sensor; s4, repeating the steps until the temperature change range of the test piece covers the temperature interval required by the test; and S5, performing data calibration on the corresponding second strain data by using the first strain data obtained in the step S4, and the strain test data generated by using the method is accurate and comprehensive, and can meet the requirement of performing stress compensation on the hull structure under the low-temperature condition.

Description

Technical Field

[0001] The present application relates to the technical field of stress and strain testing of hull structures, and in particular to a method for generating dynamic testing data of strain of hull structures. Background Art

[0002] The study of stress compensation of hull structures in low temperature environments is crucial to improving the safety and adaptability of ships. It helps to better understand and predict the stress state of the hull under low temperature conditions, and can provide important data support for stress monitoring and evaluation of ship structures. The stress-strain test on the hull structure can provide corresponding data support for the subsequent stress compensation of the hull structure. For example, the change in the strain value of the hull structure specimen under a certain temperature or load condition can be used to predict the possible failure form and location of the structure, and then the hull structure can be pre-stressed by means of structural reinforcement, prestressed construction, etc.

[0003] In the prior art, some researchers have studied the performance of EH36 steel used to build Arctic ships in the temperature range of 20°C to -60°C, simulating the stress-strain distribution of the hull structure when static loads are applied in a low-temperature environment. The stress-strain test of the hull structure by loading static loads not only has very complicated test conditions, but also cannot accurately simulate the dynamic response of the hull structure when the service environment changes, so it has certain limitations.

[0004] In the prior art, an applicant has proposed a Chinese patent with publication number CN117030298A, publication date 2023-11-10, and name “Ship Structure Extreme Loading Device and Method”, which uses fixed point strain gauges to monitor the strain data in the target area on the test piece. The range of stress and strain monitoring that the point strain gauge can perform on the test piece is too limited, so that the monitored data is often not comprehensive enough. The use of optical fiber strain sensors to measure the average strain value in a longer area on the test piece can expand the monitoring range to a certain extent. However, in a low temperature environment, the temperature sensitivity coefficient of the optical fiber strain sensor varies greatly, which can easily lead to deviations in the results of the sensor output, and thus make the collected data for subsequent stress compensation inaccurate.

[0005] Based on this, there is an urgent need for a method that can accurately collect stress change data in the target test area of ​​the specimen during loading under both high and low temperature conditions. Summary of the invention

[0006] In view of this, an embodiment of the present specification provides a method for generating dynamic test data of hull structure strain, comprising the following steps: S1, arranging an optical fiber strain sensor and a first resistance strain sensor in a target test area of ​​a test piece, and setting the optical fiber strain sensor and the first resistance strain sensor at the same measuring point on the test piece; S2, changing the temperature of the test piece, and when the temperature of the test piece is stable within the current target temperature range, loading the test piece according to the load gradient required by the test; S3, collecting the first strain data output by the first resistance strain sensor and the second strain data output by the optical fiber strain sensor when the test piece is loaded; S4, repeating steps (2) to (3) until the range of the test piece temperature change covers the temperature range required by the test, and obtaining the first strain data and the second strain data at different test piece temperatures; S5, using the first strain data obtained in step S4 to calibrate the corresponding second strain data to obtain matching measurement data and verify or correct the second strain data accordingly.

[0007] In order to further optimize the above scheme, the following technical measures are also taken:

[0008] As a preferred embodiment, the test piece includes a test section and clamping sections located at two ends of the test section, and the target test area is located on the test section of the test piece.

[0009] As a preferred implementation, in step S1, the optical fiber strain sensor is arranged at a central position of a test section of the specimen.

[0010] As a preferred embodiment, at least one pair of the first resistance strain sensors are arranged, and the at least one pair of first resistance strain sensors are symmetrically arranged with respect to the optical fiber strain sensor at the same measuring point.

[0011] As a preferred embodiment, the first strain data is a strain value ε output by the first resistance strain sensor. 0 , the second strain data is the central wavelength value λ output by the optical fiber strain sensor t , assuming that the temperature of the test piece is t°C, the step S5 specifically includes:

[0012] S5-1. According to the input-output relationship formula (1) of the optical fiber strain sensor, the K at different specimen temperatures is calculated by linear fitting. t and the value of Δa;

[0013] Δλ=K t *ε 0 +Δa (1)

[0014] Δλ=λ t -λ b

[0015] Δa=at -a 0

[0016] In the formula, a t is the zero point value of the optical fiber strain sensor at the specimen temperature t℃, a 0 is the zero point value of the optical fiber strain sensor at 0℃ specimen temperature, λ b K is the central wavelength of the optical fiber strain sensor at 0°C specimen temperature and without external load. t is the strain sensitivity coefficient of the optical fiber strain sensor at the specimen temperature t℃;

[0017] S5-2, the obtained temperature K of each specimen t The values ​​of and Δa are then quadratically fitted with the specimen temperature to obtain the strain sensitivity coefficient K based on temperature compensation. ετ and zero point change value Δa ετ Expression of

[0018] S5-3, the obtained K ετ and Δa ετ Substituting the expression into formula (1) we get the modified input-output formula (2),

[0019]

[0020] Then, the matching measurement data ε is calculated according to formula (2): 1 .

[0021] As a preferred embodiment, the method further includes the step of disposing a second resistance strain sensor on the surface of the specimen to serve as a reference for leveling the surface of the specimen.

[0022] As a preferred embodiment, the strain dynamic test is based on the following devices: a strain gauge, a fiber grating demodulator, a universal testing machine and a high and low temperature test chamber, the resistance strain sensor is connected to the strain gauge, the fiber optic strain sensor is connected to the fiber grating demodulator, the universal testing machine is used to load the specimen, and the high and low temperature test chamber is used to change the temperature of the specimen.

[0023] As a preferred embodiment, the following pre-test step is also included before loading the specimen: pre-apply an initial load to the specimen, observe whether the strain value of the strain sensor at the same measuring point is within the allowable error range, and if so, perform the step of loading the specimen after unloading; otherwise, unload, check and adjust, and re-pre-test.

[0024] As a preferred embodiment, it also includes a data preprocessing step, which includes filtering and denoising the first strain data and the second strain data collected in step S4 in sequence, and data screening based on the calibration value of each sensor itself.

[0025] As a preferred embodiment, the following steps are also included:

[0026] S6, sampling the first strain data and the second strain data obtained after executing step S5 using a set sampling frequency, screening out the strain data in a steady state under various temperature and load conditions, thereby compressing the data size;

[0027] S7. Classify the compressed data based on the type of output sensor, loading type, and specimen temperature to obtain the required sub-datasets.

[0028] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0029] In the embodiments of the present specification, an optical fiber strain sensor is used as the main measurement sensor to monitor the strain data, i.e., the second strain data, in the target test area as the load gradient changes at each temperature. At the same time, a first resistance strain sensor is used as a reference measurement sensor, and the strain data detected by the first resistance strain sensor at the same measuring point as the optical fiber strain sensor is used to calibrate the second strain data output by the optical fiber strain sensor to obtain matching measurement data, thereby verifying or correcting the second strain data output by the optical fiber strain sensor, so that the strain data results finally collected for hull structure stress compensation are more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the process of Example 1 in this application;

[0032] Figure 2 It is a schematic diagram of the structure of the tensile test piece in Example 1 of the present application;

[0033] Figure 3 Schematic diagram (I) of the layout of sensors on the tensile test piece in Example 1 of the present application;

[0034] Figure 4 Schematic diagram (II) of the layout of sensors on the tensile test piece in Example 1 of the present application;

[0035] Figure 5 is a schematic structural diagram of a bending test piece in Example 2 of the present application;

[0036] Figure 6 Schematic diagram (I) of the layout of sensors on the bending test piece in Example 2 of the present application;

[0037] Figure 7 Schematic diagram (II) of the layout of sensors on the bending test piece in Example 2 of the present application;

[0038] Figure 8 This is an example diagram of a sub-data set obtained after classification in Example 1 of the present application;

[0039] Fig. 9 This is an example diagram of a data set used for stress compensation of a hull structure under low temperature conditions in Embodiment 1 of the present application;

[0040] Fig.10 A basic flow chart of generating a stress compensation data set for a hull structure under low temperature conditions in Example 1 of the present application. DETAILED DESCRIPTION

[0041] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0042] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0043] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0044] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0045] Embodiment 1:

[0046] The embodiments of this specification propose a method for generating dynamic test data of hull structure strain, which aims to solve the problem of insufficient accuracy in generating and monitoring strain data in the target test area of ​​the structural specimen under high and low temperature conditions in the prior art. It not only realizes the accurate monitoring of strain data in the target test area of ​​the specimen under high and low temperature conditions, but also implements an effective data verification mechanism to ensure the accuracy and availability of the data.

[0047] refer to Figures 1 to 4 As shown, this embodiment first takes the tensile test process of the specimen as an example to illustrate. Figure 2 As shown, the tensile test piece is a 5 mm thick thin plate. In this embodiment, the loading direction of the test piece is consistent with the length direction of the test piece. The test piece includes a test section and clamping sections located at both ends of the test section. The clamping sections are installed in the fixture of the testing machine under the loading state. The method for generating dynamic test data of hull structure strain specifically includes the following steps:

[0048] S1. Arrange an optical fiber strain sensor and a first resistance strain sensor in a target test area of ​​a test piece, and set the optical fiber strain sensor and the first resistance strain sensor at the same measuring point on the test piece.

[0049] like Figure 3 As shown, the overall size of the specimen is 350×100 mm. On the front of the specimen, the optical fiber strain sensor A is arranged along the central axis of the specimen at the central position of the test section of the specimen in the length direction, which is the geometric symmetry center of the specimen. A first resistance strain sensor (A1, A2) is arranged on the left and right sides of the optical fiber strain sensor A, and the two are arranged symmetrically relative to the optical fiber strain sensor A.

[0050] like Figure 3 As shown, on the back of the specimen, the optical fiber strain sensor B is arranged at the geometric symmetry center of the specimen, and a first resistance strain sensor (B1, B2) is arranged on the upper and lower sides of the optical fiber strain sensor B, and the two are arranged symmetrically relative to the optical fiber strain sensor B.

[0051] like Figure 4As shown, on the front side of the specimen, the optical fiber strain sensor C2 is arranged at the geometric symmetry center of the specimen, and a first resistance strain sensor (C2-1, C2-2) is arranged on the left and right sides of the optical fiber strain sensor C2, and the two are arranged symmetrically relative to the optical fiber strain sensor C2.

[0052] like Figure 4 As shown, on the back of the specimen, the optical fiber strain sensor C1 is arranged at the geometric symmetry center of the specimen, and a first resistance strain sensor (C1-1, C1-2) is arranged on the left and right sides of the optical fiber strain sensor C1 and the two are arranged symmetrically relative to the optical fiber strain sensor C1.

[0053] By constructing a combined network based on strain sensors on the front and back of the specimen, the strain data generated on both surfaces of the specimen can be monitored and collected at the same time. At the same time, the operator can select the sensor model and specifications according to the specific test conditions, such as Figure 3 The optical fiber strain sensor A can adopt the BC-3100D sensor with high resolution and wide temperature adaptability range but large installation size, and the optical fiber strain sensor B can adopt the BA-OFS30 sensor with relatively small resolution and temperature adaptability range, but still able to meet the test requirements but with small installation size. The effect that can be achieved is that the sensor network composed of the optical fiber strain sensor A and the resistance strain sensor (A1, A2) on the front of the test piece is used as the measurement subject, and the sensor network composed of the optical fiber strain sensor B and the resistance strain sensor (B1, B2) on the back of the test piece is used as the measurement reference, so as to verify and analyze the results output by the measurement subject, and find out the source of the error generated by the sensor during the measurement process by comparing and analyzing the test results. At the same time, the optical fiber strain sensor B used as the measurement reference has a small installation size, high installation efficiency in the test, and relatively good stability, so the test efficiency can be improved.

[0054] Figure 4 The optical fiber strain sensors C1 and C2 are both bracket-type optical fiber strain sensors. During installation, the position of the sensor on the bracket can be continuously optimized and adjusted as needed, thereby achieving accurate detection of stress and strain data in the target test area. In addition, the bracket-type sensor has the advantages of high installation stability and long service life of the fiber grating. Operators can make specific choices based on test needs.

[0055] exist Figure 3 and Figure 4In the process, the target test area of ​​the test piece is preferentially set on the test section, because the boundary effect of the fixture has little effect on the test section, and the stress in the area where the test section is located along the loading direction has a good linear change, so the test result is less affected by the measurement error. Further, the target test area is located at the central position of the test section, that is, the optical fiber strain sensor and the first resistance strain sensor described in step S1 are both arranged at the central position. The central position (at the geometric symmetry center of the test piece on the tensile test piece) is almost a pure tensile section, which will not be affected by the boundary effect caused by the fixture or the support, ensuring the linear change of stress in the area, so that the results of the sensor output in the area are more accurate.

[0056] S2. Change the temperature of the specimen, and when the temperature of the specimen is stable within the current target temperature range, load the specimen according to the load gradient required by the test;

[0057] Specific operation process: In the test of this embodiment, the temperature range is -55℃~50℃, -55℃ is a temperature point, and every 10℃ interval from -50℃ is a temperature point. Use a high and low temperature test chamber to adjust the ambient temperature of the specimen, observe the specimen temperature measured by the temperature sensor, and wait for the specimen temperature to stabilize at the required temperature point, that is, the target temperature range, with an upper and lower fluctuation of no more than 1℃, for 5 minutes. Then, use a universal testing machine to apply a load to the specimen from 0 according to the required load gradient. After completing one loading, unload the testing machine, adjust the temperature to the next temperature point, and after the test chamber temperature stabilizes and the specimen temperature stabilizes at the required temperature point, continue to apply a load to the specimen from 0 according to the required load gradient.

[0058] S3, collecting first strain data output by the first resistance strain sensor and second strain data output by the optical fiber strain sensor when the specimen is loaded;

[0059] Specifically, the first resistance strain sensor on the test piece is connected to the strain gauge, and the first strain data output by the resistance strain sensor is collected through the strain gauge. The optical fiber strain sensor is connected to the optical fiber Bragg grating demodulator, and the second strain data output by the optical fiber strain sensor is collected through the optical fiber Bragg grating demodulator.

[0060] S4, repeating steps (2) to (3) until the temperature variation range of the specimen covers the temperature range required by the test, and obtaining the first strain data and the second strain data at different specimen temperatures;

[0061] S5. Using the first strain data obtained in step S4, calibrate the corresponding second strain data to obtain matching measurement data and verify or correct the second strain data accordingly.

[0062] Specifically, the first strain data is the strain value ε output by the first resistance strain sensor 0 , the second strain data is the central wavelength value λ output by the optical fiber strain sensor t , assuming that the temperature of the test piece is t°C, the step S5 specifically includes:

[0063] S5-1. According to the input-output relationship formula (1) of the optical fiber strain sensor, the K at different specimen temperatures is calculated by linear fitting. t and the value of Δa;

[0064] Δλ=K t *ε 0 +Δa (1)

[0065] Δλ=λ t -λ b

[0066] Δa=a t -a 0

[0067] In the formula, a t is the zero point value of the optical fiber strain sensor at the specimen temperature t℃, a 0 is the zero point value of the optical fiber strain sensor at 0℃ specimen temperature, λ b K is the central wavelength of the optical fiber strain sensor at 0°C specimen temperature and without external load. t is the strain sensitivity coefficient of the optical fiber strain sensor at the specimen temperature t℃;

[0068] S5-2, the obtained temperature K of each specimen t The values ​​of and Δa are then quadratically fitted with the specimen temperature to obtain the strain sensitivity coefficient K based on temperature compensation. ετ and zero point change value Δa ετ Expression of

[0069] S5-3, the obtained K ετ and Δa ετ Substituting the expression into formula (1) we get the modified input-output formula (2),

[0070]

[0071] Then, the matching measurement data ε is calculated according to formula (2): 1 .

[0072] by Fig. 9 The data set of optical fiber sensor A under -54°C is shown as an example, where the data in the "strain wavelength change" column shows the value of Δλ, and the data in the "resistance strain average value" column shows the value of ε 0The value of K corresponding to the optical fiber sensor A at -54℃ can be obtained by fitting the concentrated data. t and Δa, the K of the optical fiber sensor A at different temperatures was obtained by fitting in the same way. t and Δa. t By fitting K and Δa with temperature, we can get ετ and Δa ετ Substitute the expression into the modified compensation formula The compensated strain data can be obtained, that is, the matching measurement data ε 1 , based on which the central wavelength value λ output by the optical fiber strain sensor is t Verify or correct the output strain value.

[0073] Preferably, at least one pair of first resistance strain sensors are arranged, and the at least one pair of first resistance strain sensors are arranged symmetrically about the optical fiber strain sensor at the same measuring point. In this case, the first strain data is the strain average value ε output by the at least one pair of first resistance strain sensors. 0 .

[0074] Preferably, the method further includes the step of disposing a second resistance strain sensor on the surface of the specimen to serve as a reference for leveling the surface of the specimen.

[0075] like Figure 3 and 4 As shown, two opposite second resistance strain sensors (SG1, SG2) are arranged on the front or back side of the specimen along the width direction of the specimen, and a second resistance strain sensor SG3 is arranged at the geometric symmetry center of the other side of the specimen. A balancing bridge is connected before the test, and the corresponding output signal of the bridge is used to determine whether the specimen has been leveled.

[0076] like Figure 3 and 4 As shown, temperature sensors TGA, TGB and TGC for detecting the temperature of the test piece are also arranged on the surface of the test piece. In this embodiment, considering the size of the test piece, the accuracy of temperature measurement and the rationality of wiring, the temperature sensor is chosen to be arranged next to the strain sensor. In other implementations, it can also be arranged in other parts of the test piece, and this embodiment does not limit this.

[0077] It should be noted that the data generation method of this embodiment is based on the following devices: a strain gauge, a fiber Bragg grating demodulator, a universal testing machine, and a high and low temperature test chamber. The specific test steps or test steps are as follows:

[0078] (1) Prepare the test piece;

[0079] (2) Sensor selection and arrangement, that is, optical fiber strain sensors and resistance strain sensors are selected and arranged on the specimen according to the idea shown in step S1;

[0080] (3) Specimen installation and equipment adjustment, including:

[0081] (3-1) Install the test piece with the sensors arranged on the universal testing machine and place it in a high and low temperature test chamber;

[0082] (3-2) connecting the resistance strain sensor on the specimen to the strain gauge, and connecting the optical fiber strain sensor to the optical fiber Bragg grating demodulator;

[0083] (3-3) Start the test machine and adjust the test program, start the high and low temperature test chamber, set the chamber temperature to room temperature, and continue with the next step after the temperature in the chamber stabilizes;

[0084] (3-4) Pre-apply initial load for inspection, observe whether the strain values ​​of sensors at the same measuring point are consistent or within the allowable error range, and unload after meeting the requirements. If the strain data does not meet the requirements, unload for inspection and adjustment and re-pre-test;

[0085] (4) Formal testing and data records, including:

[0086] (4-1) Adjust the high and low temperature test chamber, set the chamber temperature to the initial target value, and continue to the next step after the temperature in the chamber stabilizes;

[0087] (4-2) Control the load applied by the test machine to gradually increase within the load range. Each time the load increases by one gradient, it is regarded as an observation point. The load of the test machine, the strain value output by the resistance strain gauge, the wavelength value and the strain value output by the fiber grating demodulator are recorded once. A total of 16 sets of data are recorded, and the test is repeated twice.

[0088] (5) Adjust the temperature of the high and low temperature test chambers to the corresponding temperatures respectively, and repeat steps (4-1)-(4-2).

[0089] (6) Record test data;

[0090] (7) Turn off the testing machine and high and low temperature test chamber.

[0091] In step (4-1), the temperature range is -55°C to 50°C, -55°C is a temperature point, and starting from -50°C, each interval of 10°C is a temperature point. Use a high and low temperature test chamber to adjust the ambient temperature of the specimen, observe the specimen temperature measured by the temperature sensor, and wait for the specimen temperature to stabilize at the required temperature point, that is, the target temperature range, with an upper and lower fluctuation of no more than 1°C. After 5 minutes, use a universal testing machine to apply a load to the specimen starting from 0 according to the required load gradient. After completing one loading, unload the testing machine, adjust the temperature to the next temperature point, and after the test chamber temperature stabilizes and the specimen temperature stabilizes at the required temperature point, continue to apply a load to the specimen starting from 0 according to the required load gradient.

[0092] like Fig.10 As shown in the figure, in the aforementioned strain test process, the original collected strain data needs to be cleaned through the data preprocessing step, that is, filtering and denoising processing and data screening processing, and then the output value of the optical fiber strain sensor is verified or calibrated by data calibration, so as to obtain data with stronger usability and higher accuracy. In order to obtain a data set for subsequent hull structure stress compensation, the following steps are also taken:

[0093] S6, a data compression step, i.e., sampling the first strain data and the second strain data obtained after executing step S5 at a set sampling frequency, screening out the strain data in a steady state under various temperature and load conditions, thereby compressing the data size; S7, a data classification step, i.e., classifying the compressed data based on the type of output sensor, loading type, and temperature parameters as classification basis to obtain the required sub-dataset.

[0094] like Figure 8 As shown, this embodiment takes the maximum loading load of 90KN and the load gradient interval of 3KN as an example to show the sub-dataset obtained after classification. According to the subsequent requirements for low-temperature stress compensation of hull structure, the sub-dataset is further processed to obtain a data set that can be used for stress compensation of hull structure under low-temperature conditions, wherein thermocouples A and B are used to detect the ambient loading temperature of the high and low temperature test box, the temperature wavelength change = measured temperature wavelength - initial temperature wavelength, and the strain wavelength change value Δλ and the resistance strain mean value ε 0 The calculations have been explained in the previous article and will not be repeated here.

[0095] Attached Fig. 9Some data sets used for stress compensation of hull structures under low temperature conditions, i.e., specimen temperature of -54°C, are shown. From the results, it can be seen that the temperature coverage of the data set has been expanded to -55°C to 50°C, and the increase in deformation types and load conditions has enriched the data concentration, data types and quantity. After the improvement, the accuracy and availability of the data have also been improved, proving the practical value of this method.

[0096] Embodiment 2:

[0097] This embodiment takes the four-point bending test process of the specimen as an example for explanation. Figure 5 , showing the structure of the bending specimen, where the bending specimen is a rectangular cross-section beam with an overall length of 600 mm, a cross-section width of 100 mm, and a height of 10 mm. The bending specimen includes a test section and support sections located at both ends of the test section, and the support sections are positioned on the support of the testing machine under loading.

[0098] like Figure 6 and 7 As shown, considering the linear variation of stress, the target test area is preferably in the test section of the specimen. Furthermore, the target test area is preferably set in the central position of the test section of the specimen.

[0099] like Figure 6 As shown, in this embodiment, on the front of the specimen, an optical fiber strain sensor A1 and its associated resistance strain sensors A1-1, A1-2, an optical fiber strain sensor B1 and its associated resistance strain sensors B1-1, B1-2 are arranged. Similarly, on the back of the specimen, an optical fiber strain sensor A2 and its associated resistance strain sensors A2-1, A2-2, an optical fiber strain sensor B2 and its associated resistance strain sensors B2-1, B2-2 are arranged.

[0100] like Figure 7 As shown, on the front of the specimen, an optical fiber strain sensor C1 and its associated resistance strain sensors C1-1, C1-2, an optical fiber strain sensor C2 and its associated resistance strain sensors C2-1, C2-2 are arranged. On the back of the specimen, an optical fiber strain sensor C3 and its associated resistance strain sensors C3-1, C3-2, an optical fiber strain sensor C4 and its associated resistance strain sensors C4-1, C4-2 are arranged.

[0101] In the bending test of the specimen, by using a sensor network consisting of two or more groups of optical fiber strain sensors and a first resistance strain sensor coordinated therewith arranged at a set distance in the bending area, the structural response of the bending specimen can be captured more comprehensively, that is, richer strain data can be provided.

[0102] In summary, in the above embodiments, by selecting high-precision and high-stability optical fiber strain sensors, the strain data in the target test area of ​​the test piece can be monitored under high and low temperature conditions, greatly reducing the impact of environmental factors on the accuracy of strain data collection. The strain data output by the optical fiber strain sensor is calibrated by the strain data of the resistance strain sensor at the same measuring point position, thereby verifying or correcting the strain data output by the optical fiber strain sensor, further ensuring the accuracy and availability of the data.

[0103] By expanding the temperature range of the specimen and encrypting the temperature gradient, combined with the use of multi-type and multi-gradient loading, the data types in the hull structure stress data set in this embodiment have been greatly enriched. This multi-dimensional testing method not only simulates the various temperature conditions that the hull may encounter in the actual marine environment, but also further increases the size of the data set through multiple measurements of multiple sensors. It not only improves the diversity of the data, but also enhances the reliability and representativeness of the data.

[0104] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, the description is relatively simple, and the relevant parts can be referred to the partial description of the previous embodiments.

[0105] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for generating dynamic test data of hull structure strain, characterized in that: The steps include: S1, deploying an optical fiber strain sensor and a first resistance strain sensor in a target test area of ​​a test piece, and arranging the optical fiber strain sensor and the first resistance strain sensor at the same measuring point on the test piece; S2. Change the temperature of the specimen, and when the temperature of the specimen is stable within the current target temperature range, load the specimen according to the load gradient required by the test; S3, collecting first strain data output by the first resistance strain sensor and second strain data output by the optical fiber strain sensor when the specimen is loaded; S4, repeating steps (2) to (3) until the temperature variation range of the specimen covers the temperature range required by the test, and obtaining the first strain data and the second strain data at different specimen temperatures; S5. Using the first strain data obtained in step S4, calibrate the corresponding second strain data to obtain matching measurement data and verify or correct the second strain data accordingly.

2. The method for generating dynamic test data of hull structure strain according to claim 1, characterized in that: The test piece comprises a test section and clamping sections located at two ends of the test section, and the target test area is located on the test section of the test piece.

3. The method for generating dynamic test data of hull structure strain according to claim 2, characterized in that: In step S1 , the optical fiber strain sensor is arranged at the central position of the test section of the specimen.

4. The method for generating hull structure strain dynamic test data according to claim 1, characterized in that: The first resistance strain sensors are arranged in at least one pair, and the at least one pair of first resistance strain sensors are arranged symmetrically with respect to the optical fiber strain sensor at the same measuring point.

5. The method for generating dynamic test data of hull structure strain according to claim 1, characterized in that: The first strain data is the strain value ε0 output by the first resistance strain sensor, and the second strain data is the center wavelength value λ output by the optical fiber strain sensor. t , assuming that the temperature of the test piece is t°C, the step S5 specifically includes: S5-1. According to the input-output relationship formula (1) of the optical fiber strain sensor, the K at different specimen temperatures is calculated by linear fitting. t and the value of Δa; Δλ=K t *ε0+Δa (1) Dλ=λ t -l b Δa=a t -a0 In the formula, a t is the zero point value of the optical fiber strain sensor at the test piece temperature of t℃, a0 is the zero point value of the optical fiber strain sensor at the test piece temperature of 0℃, λ b K is the central wavelength of the optical fiber strain sensor at 0°C specimen temperature and without external load. t is the strain sensitivity coefficient of the optical fiber strain sensor at the specimen temperature t℃; S5-2, the K t The values ​​of and Δa are then quadratically fitted with the specimen temperature to obtain the strain sensitivity coefficient K based on temperature compensation. ετ and zero point change value Δa ετ Expression of S5-3, the obtained K ετ and Δa ετ Substituting the expression into formula (1) we get the modified formula (2), Then the matching measurement data ε1 is calculated according to formula (2).

6. The method for generating dynamic test data of hull structure strain according to claim 1, 4 or 5, characterized in that: The method also includes the step of disposing a second resistance strain sensor on the surface of the specimen to serve as a reference for leveling the surface of the specimen.

7. The method for generating hull structure strain dynamic test data according to claim 1, characterized in that: The strain dynamic test is based on the following devices: a strain gauge, a fiber grating demodulator, a universal testing machine and a high and low temperature test chamber. The resistance strain sensor is connected to the strain gauge, the fiber optic strain sensor is connected to the fiber grating demodulator, the universal testing machine is used to load the specimen, and the high and low temperature test chamber is used to change the temperature of the specimen.

8. The method for generating hull structure strain dynamic test data according to claim 1 or 7, characterized in that: Before loading the specimen, the following pre-test step is also included: pre-applying an initial load to the specimen, observing whether the strain value of the strain sensor at the same measuring point is within the allowable error range, and if so, performing the step of loading the specimen after unloading, and otherwise, performing inspection and adjustment after unloading and re-pre-testing.

9. The method for generating hull structure strain dynamic test data according to claim 1, characterized in that: The step of data preprocessing is also included, and the step of data preprocessing includes filtering and denoising the first strain data and the second strain data collected in step S4 in sequence, and data screening based on the calibration value of each sensor itself.

10. The method for generating dynamic test data of hull structure strain according to claim 9, characterized in that: The following steps are also included: S6, sampling the first strain data and the second strain data obtained after executing step S5 using a set sampling frequency, screening out the strain data in a steady state under various temperature and load conditions, thereby compressing the data size; S7. Classify the compressed data based on the type of output sensor, loading type, and specimen temperature to obtain the required sub-datasets.

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