Optical fiber compression resistance testing method and testing device thereof

Abstract

The invention discloses an optical fiber compression resistance testing method and a testing device thereof. The optical fiber compression resistance testing method comprises the following steps: providing an optical fiber sample; initial state parameters of the optical fiber sample are obtained in a preset test environment, the initial state parameters comprise a signal initial attenuation value of the optical fiber sample and an initial damage state of a coating layer of the optical fiber sample, and the initial damage state comprises an initial damage degree and an initial damage type; performing a cyclic test on the compression resistance of the optical fiber sample in a preset test environment, and evaluating the compression resistance of the optical fiber sample; and evaluating the elastic deformation range, the permanent deformation rate and the recovery rate of the tested optical fiber sample in the preset test environment. By adopting the technical scheme, multiple tests of the compression resistance of the optical fiber in the preset environment are realized, the test accuracy of the compression resistance of the optical fiber is improved, the comprehensive evaluation of the compression resistance of the optical fiber is realized, and the problem that the mechanical performance and the transmission performance and the compression resistance of the optical fiber cannot be synchronously tested is solved.

Description

Technical Field

[0001] This invention relates to the field of optical fiber testing technology, and in particular to a method and apparatus for testing the compressive strength of optical fibers. Background Technology

[0002] The fiber coating is a crucial structure protecting the optical fiber. The thickness and selection of the inner and outer coatings are extremely important for the fiber's long-term use. Appropriate coating material selection and thickness can ensure that the additional loss of the fiber is not significant when subjected to large compressive stresses in a short period. Therefore, the fiber coating plays a decisive role in the mechanical and transmission performance of the optical fiber. With the widespread application of optical fibers in complex environments such as deep-sea communication, aerospace, and rail transportation, the compressive strength of the fiber coating has become an important indicator for evaluating the reliability of optical fibers.

[0003] Existing methods apply pressure with a pressure plate and measure changes in optical power. However, the optical signal of this method is susceptible to interference, has limited testing accuracy, and cannot directly observe the damage state of the coating. While methods that apply lateral pressure to the fiber by suspending a counterweight at the end of the fiber at a constant speed and placing it on a pressure rod can directly observe whether the coating is damaged, the testing process is complex and can only assess lateral pressure performance. Existing technologies suffer from poor repeatability in fiber compressive strength testing, low testing accuracy, and a lack of comprehensive fiber performance evaluation. Summary of the Invention

[0004] This invention provides a method and apparatus for testing the compressive strength of optical fibers. By performing cyclic testing on the compressive strength of optical fibers and evaluating the overall performance of optical fibers under a preset environment, the accuracy of testing the compressive strength of optical fibers is improved, and the problem of not being able to simultaneously test the mechanical properties and transmission performance compressive strength of optical fibers is solved.

[0005] In a first aspect, embodiments of the present invention provide a method for testing the compressive strength of optical fibers, the method comprising:

[0006] Provide fiber optic samples;

[0007] The initial state parameters of the optical fiber sample are obtained under a preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0008] Cyclic tests on the compressive strength of the optical fiber samples were conducted under a preset test environment to evaluate the compressive strength of the optical fiber samples.

[0009] Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber samples after testing under a preset test environment.

[0010] Optionally, the fiber optic sample is subjected to cyclic testing of its compressive strength under a preset test environment to evaluate its compressive strength, including:

[0011] Set the pressure range and number of test cycles;

[0012] Based on the cyclic test pressure range and the number of cyclic tests, the compressive strength of the optical fiber samples is tested under a preset test environment.

[0013] Optionally, based on the cyclic test pressure range and the number of cyclic tests, the fiber optic sample is subjected to compressive strength testing under a preset test environment, including:

[0014] The optical fiber sample is placed on the tensile testing module, and the pressure is applied step by step according to the preset pressure loading step value and preset pressure holding time.

[0015] The signal attenuation value, real-time attenuation state of the coating layer of the optical fiber sample, pressure value and strain state of the optical fiber sample are monitored after the preset pressure is maintained for a preset time. The correspondence between signal attenuation value and time, the image sequence of coating layer damage evolution and the correspondence between pressure and time are obtained.

[0016] The sensitivity of the optical fiber sample to pressure is evaluated based on the correlation between signal attenuation value and time; the compressive strength of the optical fiber sample is evaluated based on the image sequence of coating damage evolution; and the real-time pressure that the optical fiber sample can withstand is obtained based on the correlation between pressure and time.

[0017] Optionally, the sensitivity of the fiber optic sample to pressure can be evaluated based on the correlation between signal attenuation and time, including:

[0018] Calculate the average signal attenuation value of the optical fiber sample under various pressure levels;

[0019] Data whose signal attenuation value in the optical fiber sample deviates from a preset deviation value are filtered out.

[0020] The signal attenuation change rate of the optical fiber sample is calculated based on the average attenuation value of the optical fiber sample under filtered multi-level pressure, and the sensitivity of the optical fiber sample to pressure is evaluated based on the attenuation change rate.

[0021] The compressive strength of optical fiber samples was assessed based on a sequence of image data showing the damage evolution of the coating layer, including:

[0022] By comparing the image sequence of coating damage evolution of optical fiber samples with the initial damage state of the coating of optical fiber samples, the real-time damage degree of the coating of optical fiber samples is determined, and the compressive strength of optical fiber samples is evaluated based on the real-time damage degree of the coating of optical fiber samples.

[0023] Optionally, the fiber compressive strength test method may also include: measuring the ultimate compressive strength that the fiber sample can withstand and evaluating the additional loss of the fiber sample.

[0024] Optionally, the ultimate stress that the fiber optic sample can withstand is measured, and the additional loss of the fiber optic sample is evaluated, including:

[0025] The first pressure value is measured when the coating of the optical fiber sample has a crack or peel exceeding a preset length, the second pressure value is measured when the rate of change of the signal attenuation value of the optical fiber sample exceeds a preset rate of change, or the third pressure value is measured when the optical fiber sample breaks, and the first pressure value, the second pressure value, or the third pressure value is determined to be the ultimate pressure that the optical fiber sample can withstand.

[0026] The signal attenuation increment of the optical fiber sample under the ultimate pressure is measured, and the additional loss of the optical fiber sample is evaluated based on the signal attenuation increment under the ultimate pressure.

[0027] Optionally, the elastic deformation range, permanent deformation rate, and recovery rate of the fiber optic sample after testing under a preset test environment are evaluated, including:

[0028] After the optical fiber sample is tested under the preset test environment, the elastic deformation range of the optical fiber sample is evaluated based on the deformation range of the coating layer that is fully recovered; the permanent deformation rate of the optical fiber sample is evaluated based on the ratio of the retained deformation of the coating layer to the initial length; and the recovery rate of the optical fiber sample is evaluated based on the percentage of signal attenuation that recovers to the initial value.

[0029] Optionally, the initial state parameters of the optical fiber sample are obtained under a preset test environment, including:

[0030] Place the optical fiber sample in the tensile testing module and ensure that the optical fiber sample is in a straight state;

[0031] Connect the optical fiber sample to the optical fiber attenuation test module;

[0032] The initial attenuation value of the optical fiber sample was measured and recorded, and the initial damage state of the coating layer of the optical fiber sample was monitored and recorded.

[0033] Optionally, testing the initial state of the fiber optic sample under a preset test environment also includes:

[0034] The initial state of the optical fiber sample is tested under a temperature test environment, and / or the initial state of the optical fiber sample is tested under a humidity test environment.

[0035] Secondly, embodiments of the present invention provide an optical fiber compressive strength testing device, which is applied to an optical fiber compressive strength testing method. The device includes: a tensile testing module, an optical fiber attenuation testing module, and a control module.

[0036] The tensile testing module includes an image acquisition unit, which is used to measure the initial damage state of the coating layer of the optical fiber sample under a preset test environment. The initial damage state includes the initial damage degree and the initial damage type.

[0037] The fiber optic attenuation test module is connected to the fiber optic sample and is used to measure the initial signal attenuation value of the fiber optic sample under a preset test environment.

[0038] The control module is electrically connected to the tensile testing module and the fiber attenuation testing module respectively. It is used to perform cyclic testing of the compressive strength of the fiber sample under a preset test environment, evaluate the compressive strength of the fiber sample, and evaluate the elastic deformation range, permanent deformation rate and recovery rate of the fiber sample after the test is completed under the preset test environment.

[0039] This invention provides a method for testing the compressive strength of optical fibers. After providing an optical fiber sample, the method acquires the initial signal attenuation value, the initial damage level of the coating layer, and the initial damage type of the optical fiber sample under a preset test environment. The compressive strength of the optical fiber sample is then subjected to cyclic testing under the preset test environment to evaluate its compressive strength. After the test is completed under the preset test environment, the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample are evaluated. This technical solution enables cyclic testing of optical fiber compressive strength under a preset environment, improving the accuracy of the test and achieving a comprehensive evaluation of the optical fiber compressive strength. It solves the problems of not being able to simultaneously test the mechanical properties and transmission performance compressive strength of optical fibers, and the problems of single and poor repeatability in optical fiber performance testing. Attached Figure Description

[0040] Figure 1 This is a flowchart of the first optical fiber compressive strength test method provided in the embodiments of the present invention;

[0041] Figure 2 This is a flowchart of the second optical fiber compressive strength test method provided in this embodiment of the invention;

[0042] Figure 3 This is a flowchart of the third optical fiber compressive strength test method provided in the embodiments of the present invention;

[0043] Figure 4 This is a flowchart of the fourth optical fiber compressive strength test method provided in the embodiments of the present invention;

[0044] Figure 5 This is a flowchart of the fifth optical fiber compressive strength test method provided in the embodiments of the present invention;

[0045] Figure 6 This is a flowchart of the sixth optical fiber compressive strength test method provided in the embodiments of the present invention;

[0046] Figure 7 This is a flowchart of the seventh optical fiber compressive strength test method provided in the embodiments of the present invention;

[0047] Figure 8 This is a schematic diagram of an optical fiber compressive strength testing device provided in an embodiment of the present invention.

[0048] In this embodiment of the invention, the reference numerals and corresponding feature names are as follows:

[0049] 10-Tensile testing module, 11-Image acquisition unit, 12-Sensing unit, 20-Fiber optic attenuation testing module, 30-Control module, 40-Temperature measurement module, 50-Humidity measurement module. Detailed Implementation

[0050] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0051] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "upper" or "lower" of another element, it can be formed not only directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] Figure 1This is a flowchart of the first optical fiber compressive strength test method provided in this embodiment of the invention. This embodiment is applicable to situations where the compressive strength of optical fibers needs to be accurately tested and comprehensively evaluated under various environments. Figure 1 As shown, the optical fiber compressive strength testing method provided in this embodiment of the invention includes:

[0054] S110, Provide optical fiber samples.

[0055] Specifically, optical fiber samples typically consist of bare fiber, an inner coating, and an outer coating. The inner coating is generally soft and has a low modulus, while the outer coating is generally hard and has a high modulus. The inner coating protects the bare fiber from stress, while the outer coating protects the fiber from external impacts. Before the fiber's compressive strength test begins, an optical fiber sample meeting the test requirements is provided. The specifications of the selected optical fiber sample are determined according to the test requirements, and this embodiment of the invention does not impose any limitations on this.

[0056] S120. Obtain the initial state parameters of the optical fiber sample under the preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0057] Specifically, the initial state parameters of the optical fiber sample are obtained under a preset test environment. The preset test environment can be understood as a precisely controllable test environment constructed to conduct target performance tests on the sample under test, such as the compressive strength test of the optical fiber sample, providing a near-realistic application scenario for performance testing. The initial state parameters can be understood as the baseline performance parameters and physical state parameters of the sample under test in its natural state without external force interference.

[0058] The initial state parameters include: the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the degree and type of initial damage. The initial signal attenuation value of the optical fiber sample can be understood as the power loss caused by factors such as material absorption, bending loss, or connection loss when light energy propagates in the optical fiber under natural conditions. The initial damage state of the coating layer of the optical fiber sample can be understood as the phenomenon of structural integrity damage or functional failure of the optical fiber coating layer under natural conditions. The initial damage state includes the degree and type of initial damage.

[0059] For example, the degree of initial damage includes, but is not limited to, the crack length or crack depth of the coating layer of the provided optical fiber sample, and the type of initial damage includes, but is not limited to, microcracks, delamination damage and penetration damage on the coating layer of the provided optical fiber sample. The embodiments of the present invention do not limit this.

[0060] S130. Perform a cyclic test on the compressive strength of the optical fiber sample under a preset test environment to evaluate the compressive strength of the optical fiber sample.

[0061] Specifically, the cyclic testing of compressive strength can be understood as performing repeated tests on the fiber optic sample based on the current preset testing environment, by setting different test parameters for each test, to ensure the accuracy of the test results. After each test, the compressive strength of the fiber optic sample is evaluated.

[0062] For example, in high and low temperature environments, the compressive strength of optical fiber samples is tested by applying different pressures. The number of cycles is set to 50, and the pressure increment for each cycle is 20% of the initial pressure. In each cycle, the signal attenuation value and the damage state of the coating layer of the tested optical fiber sample are recorded to evaluate the compressive strength of the tested optical fiber sample.

[0063] S140. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0064] Specifically, the elastic deformation range of an optical fiber sample can be understood as the deformation range that the sample can fully recover after the external force is removed following testing under a preset test environment. The permanent deformation rate can be understood as the percentage of unrecoverable deformation remaining after the external force is removed from the total deformation of the optical fiber sample after it has withstood external force exceeding its elastic limit; it reflects the degree of plastic damage caused by external force. The recovery rate can be understood as the percentage of recoverable attenuation increment relative to the total attenuation increment after the optical fiber sample has been subjected to pressure and experienced signal attenuation increase, and then all pressure is removed and the sample is allowed to settle to stable conditions. If the optical fiber sample only undergoes elastic deformation, the attenuation value can essentially return to its initial level after the pressure is removed. However, if the pressure exceeds the elastic limit and structural damage such as coating cracking occurs, the attenuation recovery rate will decrease significantly.

[0065] After testing under the preset environment, the three key performance indicators of the optical fiber sample—elastic deformation range, permanent deformation rate, and recovery rate—are quantitatively tested and evaluated to comprehensively assess the optical fiber's compressive strength.

[0066] The fiber optic compressive strength testing method provided in this invention obtains the initial signal attenuation value, initial damage level, and initial damage type of the fiber optic sample's coating under a preset test environment after providing the fiber optic sample. Cyclic compressive strength testing is then performed on the fiber optic sample under the preset test environment to evaluate its compressive strength. After the test is completed under the preset test environment, the elastic deformation range, permanent deformation rate, and recovery rate of the fiber optic sample are evaluated. This technical solution enables cyclic testing of fiber optic compressive strength under a preset environment, improving the accuracy of fiber optic compressive strength testing and achieving a comprehensive evaluation of fiber optic compressive strength. It solves the problems of not being able to simultaneously test the mechanical properties and transmission performance compressive strength of optical fibers, and the problems of single and poor repeatability in fiber optic performance testing.

[0067] Figure 2 This is a flowchart of the second optical fiber compressive strength test method provided in this embodiment of the invention. This embodiment elaborates in detail the specific process of cyclically testing the compressive strength of optical fiber samples under a preset test environment as described in the above embodiments. Figure 2 As shown, the method specifically includes:

[0068] S210, Provide optical fiber samples.

[0069] S220. Obtain the initial state parameters of the optical fiber sample under a preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0070] S230, Set the pressure range and number of cycles for the test.

[0071] Specifically, based on actual testing requirements, the cyclic test pressure range and the number of cyclic tests are set. The cyclic test pressure range can be understood as the pressure to be applied to the fiber optic sample under test for each cycle of testing, and the number of cyclic tests can be understood as the number of times the test needs to be repeated.

[0072] For example, the cyclic test pressure range can be set to 20%-80% of the maximum pressure that the fiber optic sample can withstand, and the number of cyclic tests can be set to 10-10000 times. This embodiment of the invention does not limit this.

[0073] S240. Based on the cyclic test pressure range and the number of cyclic tests, the compressive strength of the optical fiber sample is tested under a preset test environment.

[0074] Specifically, after setting an appropriate cyclic test pressure range and the number of cyclic tests, the fiber optic sample is subjected to a compressive strength test under a preset test environment based on the set cyclic test pressure range and the number of cyclic tests. In each cyclic test, the signal attenuation value and the damage state of the coating layer of the tested fiber optic sample are recorded. The compressive strength of the tested fiber optic sample is evaluated based on the signal attenuation value and the damage state of the coating layer.

[0075] For example, the optical fiber sample under test is subjected to a temperature cycling test environment of -60℃ to 23℃, with 100 cycles and a cycle test pressure range of 20N-80N. After each test, the signal attenuation value of the optical fiber sample and the damage state of the coating layer of the tested optical fiber sample are recorded.

[0076] S250. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0077] The fiber optic compressive strength testing method provided in this invention sets a cyclic test pressure range and the number of test cycles, and then performs compressive strength testing on fiber optic samples under a preset test environment based on this range and cycle count. By simulating the external pressure repeatedly subjected to optical fibers in practical applications, combined with preset environmental conditions, it achieves accurate verification of the long-term compressive strength reliability of optical fibers. Setting a clear cyclic pressure range and cycle count avoids irreversible damage to the optical fiber, providing precise test conditions for compressive strength testing. This solves the problem that single compressive strength tests yield inaccurate results and cannot reflect the long-term reliability of optical fibers.

[0078] Figure 3 This is a flowchart of the third optical fiber compressive strength test method provided in this embodiment of the invention. Figure 3 Based on the above embodiments, the specific test steps for testing the compressive strength of optical fiber samples are described in detail. For example... Figure 3 As shown, the method specifically includes:

[0079] S310, Provide fiber optic samples.

[0080] S320. Obtain the initial state parameters of the optical fiber sample under the preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0081] S330, Set the cyclic test pressure range and the number of cyclic tests.

[0082] S340. Place the optical fiber sample on the tensile testing module and apply pressure step by step according to the preset pressure loading step value and preset pressure holding time.

[0083] Specifically, the tensile testing module can be understood as a high-precision testing device used to accurately determine the tensile, compressive, and bending properties of materials. For example, the tensile testing module includes, but is not limited to, a precision electronic tensile testing machine; this embodiment of the invention does not impose such limitations. The optical fiber sample is placed on the tensile testing module, and the pressure is gradually increased according to preset pressure loading steps and preset pressure holding times. The pressure loading rate and maximum test pressure can be set according to the type of optical fiber sample to be measured.

[0084] Specifically, the preset pressure loading step value can be understood as the preset pressure increment for each stage. For example, the pressure loading step value for each stage can be the estimated maximum pressure that the optical fiber can withstand (5%-10%) or the pressure can be applied step by step according to the loading sequence of 1N, 2N, 3N to the maximum force to be verified. This embodiment of the invention does not limit this.

[0085] The preset pressure holding time can be understood as the pre-set pressurization time of each pressure level on the optical fiber sample. For example, the pressure holding time of each pressure level can be set to 5-10 minutes to ensure that the tested optical fiber sample reaches a stable state. This embodiment of the invention does not limit this.

[0086] S350: Monitor the signal attenuation value of the optical fiber sample, the real-time attenuation state of the coating layer of the optical fiber sample, the pressure value on the optical fiber sample, and the strain state of the optical fiber sample after maintaining the preset pressure for a preset time, and obtain the correspondence between the signal attenuation value and time, the image sequence of coating layer damage evolution, and the correspondence between pressure and time.

[0087] Specifically, after each pressure loading reaches a preset pressure and is maintained at that pressure for a preset time, the signal attenuation value of the optical fiber sample is monitored by the optical fiber attenuation test module. Simultaneously, the tensile test module detects the real-time attenuation state of the coating layer of the optical fiber sample through the image acquisition unit, and detects the pressure value and strain state of the optical fiber sample through the sensing unit. The sampling frequency can be set to greater than 100Hz to ensure that instantaneous signals of pressure changes can be captured; this embodiment of the invention does not impose any limitations on this. The control module obtains the correspondence between the signal attenuation value and time based on the signal attenuation value of the optical fiber sample, the correspondence between pressure and time based on the pressure value and strain state of the optical fiber sample, and obtains a sequence of coating layer damage evolution images based on the real-time attenuation state of the coating layer of the optical fiber sample.

[0088] For example, the correspondence between signal attenuation value and time, and the correspondence between pressure and time, include but are not limited to the form of signal attenuation value-time curve and pressure-time curve, and the embodiments of the present invention do not limit this.

[0089] The signal attenuation value of the optical fiber sample can be understood as the power loss data generated by the optical fiber sample after being held under a preset pressure for a preset time. The real-time attenuation state of the coating layer of the optical fiber sample can be understood as the damage and aging state of the coating layer of the optical fiber sample after being held under a preset pressure for a preset time. The strain state of the optical fiber sample can be understood as the relative change in length of the optical fiber sample from its initial length after being held under a preset pressure for a preset time.

[0090] S360. Evaluate the sensitivity of the optical fiber sample to pressure based on the correspondence between signal attenuation value and time; evaluate the compressive strength of the optical fiber sample based on the image sequence of coating damage evolution; and obtain the real-time pressure that the optical fiber sample can withstand based on the correspondence between pressure and time.

[0091] Specifically, the sensitivity of optical fiber samples to pressure is evaluated by the correlation between signal attenuation and time. The sensitivity of the optical fiber sample to pressure can be expressed as the change in signal attenuation under unit pressure. If the change in signal attenuation is small after the optical fiber sample has been subjected to significant pressure or multiple pressure cycles, the optical fiber sample maintains stable transmission performance, indicating low pressure sensitivity and strong pressure resistance. Conversely, if the change in signal attenuation is large after the optical fiber sample has been subjected to significant pressure or multiple pressure cycles, the optical fiber sample is highly sensitive to pressure and has weak pressure resistance.

[0092] The compressive strength of optical fiber samples is evaluated based on the coating damage evolution image sequence. After the optical fiber sample is subjected to a large pressure or multiple pressure cycles in a preset environment, the damage state of the optical fiber sample observed by the coating damage evolution image sequence generated by the control module is compared with the initial damage state of the coating layer of the optical fiber sample to determine the compressive performance of the tested optical fiber sample.

[0093] At the same time, the pressure that the optical fiber sample is subjected to in real time can be obtained based on the correspondence between pressure and time. The test parameters can be reasonably controlled according to the current pressure value and the state of the optical fiber sample to avoid the problem of test failure caused by applying too much or too little pressure to the optical fiber sample.

[0094] Optionally, the sensitivity of the fiber optic sample to pressure can be evaluated based on the correlation between signal attenuation and time, including:

[0095] Calculate the average signal attenuation value of the optical fiber sample under various pressure levels.

[0096] Specifically, based on the signal attenuation values ​​of the fiber optic samples obtained at each pressure level, the average attenuation value of the fiber optic samples at each pressure level is calculated. The average attenuation value can be understood as the ratio of the sum of the attenuation values ​​at each pressure level to the number of times the attenuation value occurs.

[0097] Data whose signal attenuation value in the fiber optic sample deviates from a preset deviation value are filtered out.

[0098] Specifically, the average attenuation value of the signal attenuation value of the optical fiber sample is used as the benchmark. Attenuation values ​​that deviate from the average attenuation value by more than ±10% are considered abnormal data points and are filtered out to ensure test accuracy.

[0099] The signal attenuation change rate of the optical fiber sample is calculated based on the average attenuation value of the optical fiber sample under filtered multi-level pressure, and the sensitivity of the optical fiber sample to pressure is evaluated based on the attenuation change rate.

[0100] Specifically, the signal attenuation change rate of the optical fiber sample is calculated based on the average attenuation value of the sample under filtered multi-stage pressure. The attenuation change rate can be understood as the ratio of the change in signal attenuation value at a certain stage during the pressure loading process to the corresponding change in pressure or time. A smaller signal attenuation change rate indicates lower sensitivity to pressure and stronger compressive strength of the optical fiber.

[0101] By calculating the average signal attenuation value of the fiber optic sample under various pressure levels, and then filtering out data where the deviation of the signal attenuation value exceeds a preset deviation value, abnormal data processing is completed. Next, based on the filtered average signal attenuation value of the fiber optic sample under multiple pressure levels, the signal attenuation change rate of the fiber optic sample is calculated, and the pressure sensitivity of the fiber optic sample is evaluated based on the attenuation change rate. This ensures the accuracy of the calculated signal attenuation change rate of the fiber optic sample, improves the accuracy and reliability of the pressure sensitivity assessment of the fiber optic sample, and solves the problem of inaccurate pressure sensitivity assessment of fiber optic samples.

[0102] The compressive strength of optical fiber samples was assessed based on a sequence of image data showing the damage evolution of the coating layer, including:

[0103] By comparing the image sequence of coating damage evolution of optical fiber samples with the initial damage state of the coating of optical fiber samples, the real-time damage degree of the coating of optical fiber samples is determined, and the compressive strength of optical fiber samples is evaluated based on the real-time damage degree of the coating of optical fiber samples.

[0104] Specifically, the damage evolution image sequence of the fiber optic sample's coating is compared with the initial damage state of the coating. If the damage to the fiber optic sample's coating worsens, the increase in crack length or depth compared to the initial state exceeds a preset value, or a new type of damage appears, it indicates that the fiber optic sample has weak compressive strength. If no obvious damage to the coating is observed in the coating damage evolution image sequence, it indicates that the tested fiber optic sample has strong compressive strength.

[0105] By comparing the damage evolution image sequence of the fiber optic sample's coating with the initial damage state of the coating, the degree of damage to the fiber optic sample after pre-set pressure measurement can be intuitively obtained. This allows for a direct assessment of the compressive strength of the tested fiber optic sample, improving the testing efficiency of the fiber optic sample's compressive performance.

[0106] S370. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0107] The fiber optic compressive strength testing method provided in this invention applies pressure in stages according to preset pressure loading steps and preset pressure holding times. It monitors the signal attenuation value, real-time attenuation state of the fiber optic coating, pressure value, and strain state of the fiber optic sample after holding the preset pressure for a preset time. It obtains the correspondence between signal attenuation value and time, the image sequence of coating damage evolution, and the correspondence between pressure and time. The sensitivity of the fiber optic sample to pressure is assessed based on the correspondence between signal attenuation value and time, the compressive strength of the fiber optic sample is assessed based on the image sequence of coating damage evolution, and the real-time pressure withstand capability of the fiber optic sample is obtained based on the correspondence between pressure and time, thus evaluating the compressive strength performance of the fiber optic sample. This allows personnel to intuitively obtain test results, improving the testing efficiency of fiber optic compressive strength performance and enabling refined verification of fiber optic compressive strength performance, thereby improving the reliability of test results. Simultaneously capturing changes in signal attenuation and damage evolution of the fiber optic cable enables multi-dimensional synchronous monitoring of changes in fiber optic coating damage evolution and transmission performance, avoiding the problem of only knowing the attenuation anomaly without knowing the cause of the damage. It solves the problems of traditional one-time loading methods that cannot observe the fiber optic sample coating damage process in real time and the instability of test data.

[0108] Figure 4 This is a flowchart of the fourth optical fiber compressive strength testing method provided in this embodiment of the invention. As another optional implementation method of this invention, such as... Figure 4 As shown, the fiber optic compressive strength test method also includes:

[0109] S410, provides fiber optic samples.

[0110] S420. Obtain the initial state parameters of the optical fiber sample under the preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0111] S430, Set the cyclic test pressure range and the number of cyclic tests.

[0112] S440. Place the optical fiber sample on the tensile testing module and apply pressure step by step according to the preset pressure loading step value and preset pressure holding time.

[0113] S450: Measure the ultimate stress that the optical fiber sample can withstand and evaluate the additional loss of the optical fiber sample.

[0114] Specifically, the ultimate pressure withstand capability of an optical fiber sample can be understood as the maximum pressure threshold that it can withstand under a preset test environment without causing irreversible structural damage or abrupt degradation in transmission performance. For example, the ultimate pressure withstand capability of an optical fiber sample is 120N. When the pressure withstand by the optical fiber sample is below 120N, the structure and transmission performance of the optical fiber remain stable. When the pressure withstand by the optical fiber sample exceeds 120N, the optical fiber sample will experience irreversible failure. The additional loss of the optical fiber sample can be understood as the increase in signal attenuation under the ultimate pressure withstand capability.

[0115] S460. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0116] The fiber optic compressive strength testing method provided in this invention measures the ultimate compressive strength of an optical fiber sample and evaluates its additional loss. This allows for the assessment of the impact of mechanical deformation on optical transmission performance, ensuring that the mechanical and optical properties of the fiber are matched. By using the ultimate compressive strength as the mechanical criterion and the additional loss threshold as the optical criterion, a standardized comprehensive evaluation system for fiber optic compressive strength is established, solving the problem of the lack of a standardized comprehensive evaluation system in fiber optic compressive strength testing.

[0117] Optional, Figure 5 This is a flowchart of the fifth optical fiber compressive strength test method provided in this embodiment of the invention. Figure 5 The specific methods for measuring the ultimate stress that optical fiber samples can withstand and evaluating the additional loss of the optical fiber samples are described in detail. For example... Figure 5 As shown, the method includes:

[0118] S510, provides fiber optic samples.

[0119] S520. Obtain the initial state parameters of the optical fiber sample under the preset test environment. The initial state parameters include: the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0120] S530, set the pressure range and number of cycles for the test.

[0121] S540. Place the optical fiber sample on the tensile testing module and apply pressure step by step according to the preset pressure loading step value and preset pressure holding time.

[0122] S550. Measure the first pressure value corresponding to the appearance of a crack or peel exceeding a preset length in the coating of the optical fiber sample, the second pressure value corresponding to the change rate of the signal attenuation value of the optical fiber sample exceeding a preset change rate value, or the third pressure value corresponding to the breakage of the optical fiber sample, and determine the first pressure value, the second pressure value, or the third pressure value as the ultimate pressure that the optical fiber sample can withstand.

[0123] Specifically, the real-time attenuation state of the coating layer of the optical fiber sample, the signal attenuation value of the optical fiber sample, the pressure value on the optical fiber sample, and the strain state of the optical fiber sample are monitored after the preset pressure is maintained for a preset time. When a crack or peeling exceeding a preset length is observed in the coating layer of the optical fiber sample, the pressure value borne by the optical fiber sample at this time is recorded as the first pressure value.

[0124] When the rate of change of signal attenuation of the optical fiber sample exceeds a preset rate of change, the pressure value borne by the optical fiber sample at this time is recorded as the second pressure value. For example, if the rate of change of signal attenuation of the optical fiber sample suddenly exceeds 0.1dB during the pressure loading process, the pressure value borne by the optical fiber sample at this time is recorded.

[0125] When a fiber optic sample is observed to break, the pressure value that the fiber optic sample experiences at this time is recorded as the third pressure value. The first pressure value, the second pressure value, or the third pressure value is the ultimate pressure that the fiber optic sample can withstand.

[0126] S560. Measure the signal attenuation increment of the optical fiber sample under the ultimate pressure, and evaluate the additional loss of the optical fiber sample based on the signal attenuation increment under the ultimate pressure.

[0127] Specifically, after determining the ultimate stress tolerance of the optical fiber sample, the signal attenuation increment under this stress is measured. The signal attenuation increment can be understood as the absolute change between the initial attenuation per unit length of the optical fiber before testing and the attenuation per unit length after testing. The additional loss of the optical fiber sample is then assessed based on the signal attenuation increment under the ultimate stress tolerance.

[0128] For example, if the measured ultimate pressure of the optical fiber sample is 120N, the initial attenuation of the optical fiber sample before testing is 0.18dB / km, and the attenuation of the optical fiber sample under the ultimate pressure is 0.19dB / km, then the additional loss of the tested optical fiber sample is 0.01dB / km.

[0129] S570. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0130] The fiber optic compressive strength testing method provided in this invention determines the ultimate withstand pressure of the fiber optic sample when the coating layer develops cracks or peels exceeding a preset length, when the rate of change of signal attenuation exceeds a preset rate of change, or when the fiber optic sample breaks. Then, the signal attenuation increment under the ultimate withstand pressure is measured, and the additional loss of the fiber optic sample is evaluated based on this increment. By determining the ultimate withstand pressure through multiple phenomena of the fiber optic sample, the accuracy of the ultimate pressure determination is achieved, avoiding the limitations of single-index determination and solving the problem of misjudgment caused by single-index determination. By simultaneously recording the signal attenuation increment under the ultimate withstand pressure to measure the additional loss of the fiber optic sample, the correlation analysis of mechanical and optical properties is realized, and a standardized comprehensive evaluation system for fiber optic compressive strength is established, solving the problem of the lack of a standardized comprehensive evaluation system in fiber optic compressive strength testing.

[0131] Figure 6 This is a flowchart of the sixth optical fiber compressive strength testing method provided in this embodiment of the invention. Based on the above-mentioned optional implementation methods, this embodiment elaborates in detail on the specific evaluation methods for the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under a preset test environment. Figure 6 As shown, the method includes:

[0132] S610, provides fiber optic samples.

[0133] S620. Obtain the initial state parameters of the optical fiber sample under a preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type.

[0134] S630. Perform cyclic testing on the compressive strength of the optical fiber sample under a preset test environment to evaluate the compressive strength of the optical fiber sample.

[0135] S640. After the optical fiber sample is tested under the preset test environment, evaluate the elastic deformation range of the optical fiber sample based on the deformation range of the coating layer of the optical fiber sample that is fully recovered; evaluate the permanent deformation rate of the optical fiber sample based on the ratio of the retained deformation amount of the coating layer of the optical fiber sample to the initial length; evaluate the recovery rate of the optical fiber sample based on the proportion of the signal attenuation of the optical fiber sample that recovers to the initial value.

[0136] Specifically, after the optical fiber sample is tested under a preset test environment, the elastic deformation range of the optical fiber sample is evaluated based on the deformation range of the fully recovered coating. The elastic deformation range reflects the deformation resistance of the optical fiber. The wider the fully recovered deformation range of the optical fiber sample, the greater the elastic deformation range of the optical fiber sample. This indicates that the optical fiber can maintain its structural integrity under large external forces and is less prone to microcracks or coating damage due to deformation.

[0137] Specifically, the permanent deformation rate of an optical fiber sample is evaluated based on the ratio of the retained deformation of the coating to its initial length. The permanent deformation rate reflects the degree of plastic damage caused by external force. The smaller the ratio of the remaining permanent deformation after the removal of the external force to the maximum total deformation under the external force, the less plastic damage the optical fiber sample experienced. For example, if the permanent deformation rate is less than or equal to 2% after the optical fiber is subjected to a pressure of 100N, it indicates that the optical fiber sample has no significant plastic damage.

[0138] Specifically, the recovery rate of an optical fiber sample is evaluated based on the percentage of signal attenuation that recovers to its initial value. A higher percentage indicates better resilience in transmission performance after being subjected to pressure. For example, a graded pressure loading test was performed on the optical fiber sample. When the pressure reached 100N, the pressure was removed, and the sample was allowed to stabilize. A signal attenuation recovery rate of 98% was calculated, indicating that the optical fiber exhibits excellent resilience in transmission performance after being subjected to pressure.

[0139] The fiber optic compressive strength testing method provided in this invention evaluates the elastic deformation range of the fiber optic sample based on the deformation range fully recovered by the coating layer after testing under a preset test environment. It also evaluates the permanent deformation rate based on the ratio of the retained deformation of the coating layer to the initial length, and assesses the recovery rate based on the percentage of signal attenuation that recovers to its initial value. This establishes a multi-dimensional system for evaluating fiber optic sample performance, enabling a comprehensive assessment of both mechanical and transmission properties, thus improving the comprehensiveness and accuracy of product performance evaluation. It avoids the inaccuracies inherent in single-dimensional evaluations and solves the problem that existing technologies cannot provide end-to-end performance evaluation data for optical fibers, making it difficult to support product optimization.

[0140] Figure 7 This is a flowchart of the seventh optical fiber compressive strength testing method provided in this embodiment of the invention. This embodiment elaborates in detail the specific process of obtaining the initial state parameters of the optical fiber sample under a preset test environment in each of the above optional embodiments. Figure 7 As shown, the method includes:

[0141] S710, provides fiber optic samples.

[0142] S720. Place the fiber optic sample in the tensile testing module and ensure the fiber optic sample is in a straight state.

[0143] Specifically, the fiber optic sample is placed in a standard environmental condition to eliminate residual stress. One side of the fiber optic sample to be tested is aligned with the test baseline and fixed to the tensile testing module with a label. The fiber optic sample is then straightened, and the other end of the fiber optic sample is also fixed to ensure that the fiber is in a naturally straight state. For example, the standard environment can be an experimental environment with a temperature controlled at 21℃-25℃ and a relative humidity controlled at 50±5%.

[0144] It should be noted that the length of the optical fiber sample to be tested is not limited in the embodiments of the present invention.

[0145] S730 connects the optical fiber sample to the optical fiber attenuation test module.

[0146] Specifically, the coating layers at both ends of the optical fiber sample are removed using an optical fiber stripper to expose the bare fiber segments. The stripping length is set according to the testing requirements, and this embodiment of the invention does not impose any limitations on it. When removing the coating layers at both ends of the optical fiber sample, the operation must be carried out at a uniform speed and smoothly to avoid inducing micro-cracks in the optical fiber sample under test. The bare fiber segments are cleaned to ensure the cleanliness of the bare fiber surface. The exposed bare fiber portions at both ends of the optical fiber sample are then connected to the optical fiber attenuation testing module.

[0147] The methods for cleaning bare fiber segments include, but are not limited to, wiping the bare fiber segments three times in one direction with a cotton swab soaked in alcohol.

[0148] S740. Measure and record the initial attenuation value of the optical fiber sample, and simultaneously monitor and record the initial damage state of the coating layer of the optical fiber sample.

[0149] Specifically, the initial attenuation value of the fiber optic sample is measured and recorded using the fiber optic attenuation testing module, serving as a benchmark for subsequent comparison. The initial damage state of the coating layer of the fiber optic sample is acquired and recorded using the image acquisition unit in the tensile testing module to determine existing damage.

[0150] The initial damage state includes the initial damage degree and the initial damage type, and the initial damage type includes, but is not limited to, defects and scratches.

[0151] S750. Cyclic tests are conducted on the fiber optic sample under a preset test environment to evaluate its compressive strength.

[0152] S760. Evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment.

[0153] The fiber optic compressive strength testing method provided in this invention involves placing the fiber optic sample in a tensile testing module with the sample in a straight state, connecting the sample to a fiber optic attenuation testing module, measuring and recording the initial attenuation value of the fiber optic sample using the attenuation testing module, and simultaneously monitoring and recording the initial damage state of the coating layer of the fiber optic sample using the tensile testing module. This method obtains the initial state parameters of the fiber optic sample, ensuring consistency in the initial state, eliminating test interference and contamination factors, and ensuring the accuracy and reliability of the initial test data. This provides a reliable benchmark for comparing the results of subsequent cyclic tests of fiber optic compressive strength. It solves the problem of unreliability and failure in subsequent fiber optic compressive strength testing due to inaccurate initial state measurements.

[0154] Optionally, the initial state parameters of the optical fiber sample tested under the preset test environment may also include: the initial state parameters of the optical fiber sample tested under the temperature test environment, and / or, the initial state parameters of the optical fiber sample tested under the humidity test environment.

[0155] Specifically, when testing the initial state parameters of the optical fiber sample under temperature testing conditions, the optical fiber sample is first placed in the temperature testing module 40 (e.g., Figure 8 As shown, the fiber optic sample is inserted through the temperature testing module 40 at both ends. One side of the fiber optic sample is fixed to the tensile testing module by a label. The fiber optic sample is straightened, and the other end is similarly fixed to ensure the fiber is in a naturally straight state. The coating layer at both ends of the fiber optic sample is removed using a fiber stripper to expose the bare fiber section. During the removal of the coating layer, the action must be uniform and smooth to avoid micro-cracks in the fiber optic sample under test. The bare fiber section is cleaned to ensure the cleanliness of the fiber surface. The exposed bare fiber sections at both ends of the fiber optic sample are connected to the fiber attenuation testing module.

[0156] The temperature is set step by step in preset temperature increments, and each temperature is held for a preset time. The initial attenuation value of the optical fiber sample is measured and recorded after holding at different preset temperatures for a preset time. At the same time, the damage state of the coating layer of the optical fiber sample is monitored and recorded.

[0157] For example, the temperature testing module 40 sets preset temperatures sequentially according to the temperature distribution of -60℃, 23℃, 150℃, and 23℃, and each temperature level is maintained for a preset time of 2 hours. This embodiment of the invention does not impose any restrictions on this.

[0158] When testing the initial state parameters of an optical fiber sample under a humidity testing environment, the optical fiber sample is placed in the humidity testing module 50 (e.g., ...). Figure 8 As shown in the figure, set the temperature and humidity conditions, and keep the optical fiber sample under the temperature and humidity conditions for a preset time.

[0159] After maintaining the fiber optic sample under preset temperature and humidity conditions for a predetermined time, fix one end to the tensile testing module. Straighten the fiber optic sample, then fix the other end in the same way, ensuring the fiber is in a naturally straight state. Remove the coating from both ends of the fiber optic sample using a fiber stripper to expose the bare fiber. During the removal of the coating, maintain a uniform and smooth movement to avoid inducing micro-cracks in the fiber optic sample. Clean the bare fiber section, ensuring the surface is clean. Connect the exposed bare fiber sections at both ends of the fiber optic sample to the fiber attenuation testing module.

[0160] The initial attenuation value of the optical fiber sample was measured and recorded after being kept at different preset humidity levels for a preset time. At the same time, the damage state of the coating layer of the optical fiber sample was monitored and recorded.

[0161] For example, the optical fiber sample is placed in the humidity testing module 50, the temperature is set to 85°C, the humidity is set to 85%RH, and the preset time is set to 240 hours. After 240 hours, the optical fiber sample is removed from the humidity testing module 50 and the initial state parameters are measured.

[0162] After testing the initial state parameters of the optical fiber samples under temperature and / or humidity conditions, cyclic tests of compressive strength were performed on the optical fiber samples under temperature and / or humidity conditions to evaluate their compressive strength. Following each cyclic test of compressive strength under temperature and / or humidity conditions, the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber samples were evaluated.

[0163] The temperature testing module 40 and humidity testing module 50 include, but are not limited to, high and low temperature test chambers and damp heat chambers or temperature, humidity and pressure three-dimensional test chambers. This embodiment of the invention does not impose any restrictions on them. By using a three-dimensional test chamber, temperature, humidity and pressure can be controlled synchronously, realizing real-time coupling of temperature, humidity and pressure, and avoiding the environmental parameter lag effect caused by segmented simulation of temperature and humidity treatment first and then pressure testing.

[0164] The fiber optic compressive strength testing method provided by this invention evaluates the compressive strength of fiber optic samples by measuring the initial state parameters of the samples under temperature and / or humidity testing environments, and by conducting cyclic tests on the samples under these same environments. By simulating the natural aging of optical fibers in high, low temperature, and humidity environments during actual applications, this method achieves accurate verification of the compressive strength of the fiber coating under complex working conditions through multi-environmental parameter evaluation. This meets the usage requirements of optical fibers in different application scenarios and solves the problem of insufficient coverage of complex scenarios in fiber optic compressive strength testing.

[0165] Based on the same inventive concept, this invention also provides an optical fiber compressive strength testing device. Figure 8 This is a schematic diagram of an optical fiber compressive strength testing device provided in an embodiment of the present invention. This device can apply any of the optical fiber compressive strength testing methods provided in the above-described optional embodiments. For example... Figure 8 As shown, the device includes: a tensile testing module 10, an optical fiber attenuation testing module 20, and a control module 30. The tensile testing module 10 includes: an image acquisition unit 11, which is used to measure the initial damage state of the coating layer of the optical fiber sample under a preset test environment. The initial damage state includes the initial damage degree and the initial damage type. The optical fiber attenuation testing module 20 is connected to the optical fiber sample and is used to measure the initial signal attenuation value of the optical fiber sample under a preset test environment. The control module 30 is electrically connected to the tensile testing module 10 and the optical fiber attenuation testing module 20 respectively. It is used to perform cyclic testing of the compressive strength of the optical fiber sample under a preset test environment, evaluate the compressive strength of the optical fiber sample, and evaluate the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after the test is completed under the preset test environment.

[0166] In this embodiment, the optical fiber compressive strength testing device includes a tensile testing module 10, an optical fiber attenuation testing module 20, and a control module 30. The tensile testing module 10 can be understood as a mechanical testing device used to accurately measure the tensile, bending, or peel performance of materials. Exemplarily, the tensile testing module 10 includes, but is not limited to, a precision electronic tensile testing machine, a universal testing machine, and a pneumatic pressure loading device; this embodiment of the invention does not impose any limitations on these. Compared to a precision electronic tensile testing machine, a universal testing machine offers higher load accuracy, reaching ±0.001N, and can achieve lower loading rates (0.01N / s), making it suitable for capturing microcrack damage below 5μm. However, its equipment cost is higher, and its operation is more complex, with a longer test time compared to a precision electronic tensile testing machine. A pneumatic pressure loading device has low equipment cost and a fast loading response speed, making it suitable for dynamic pressure impact testing; however, its load accuracy is low, it cannot achieve stable low-speed loading, and the error in the ultimate pressure tolerance of the test is greater than 5%.

[0167] Specifically, the tensile testing module 10 includes an image acquisition unit 11. The image acquisition unit 11 can be understood as a component capable of capturing and image-taking images of the microscopic changes on the surface of the optical fiber sample in real time and visually. Exemplarily, the image acquisition unit 11 includes, but is not limited to, a high-magnification optical microscope, a laser confocal microscope, and a high-speed camera system; this embodiment of the invention does not impose limitations on these. The high-magnification optical microscope can accurately capture microcracks less than 50 μm in length on the surface of the optical fiber coating. The laser confocal microscope can eliminate out-of-focus interference through point-by-point scanning, acquire the three-dimensional morphology of the surface / section of the optical fiber coating, quantify the depth and peeling area of ​​microcracks, and intuitively reflect the damage evolution of the optical fiber sample. The high-speed camera system records the instantaneous damage of the dynamic deformation of the optical fiber sample coating during pressure loading, quantifies the damage propagation rate through an image analysis device, captures the dynamic damage process, and avoids the lag of static observation.

[0168] Specifically, the image acquisition unit 11 is located inside the tensile testing module 10, and the test platform of the tensile testing module 10 is transparent. The image acquisition unit 11 clearly acquires the initial damage level and type of the coating layer of the optical fiber sample to be measured under a preset test environment through the test platform of the tensile testing module 10. This data is then used to obtain the real-time attenuation state of the coating layer of the optical fiber sample during cyclic testing of its compressive strength under the preset test environment. The tensile testing module 10 also includes a sensing unit 12, which can be understood as a functional unit integrating multiple physical quantity detection sensors and data acquisition modules, capable of acquiring the mechanical and environmental parameters borne by the optical fiber sample in real time. During cyclic testing of the compressive strength of the optical fiber sample under the preset test environment, the sensing unit 12 acquires the pressure value and strain state of the optical fiber sample.

[0169] Furthermore, the sensing unit 12 may also include an acoustic emission sensor, which is electrically connected to the image acquisition unit 11. The acoustic emission sensor monitors the acoustic emission signal released when the coating of the optical fiber sample cracks. The presence or absence of the acoustic emission signal triggers the image acquisition unit 11 for visual monitoring, reducing the operator's continuous observation workload and ineffective observation time.

[0170] The fiber optic attenuation testing module 20 can be understood as a device capable of measuring the dynamic change in optical signal transmission attenuation value of an optical fiber sample in real time and with high accuracy during stress or environmental changes. Exemplarily, the fiber optic attenuation testing module 20 includes, but is not limited to, an optical time domain reflectometer (OTDR) and a polarization mode dispersion (PMD) meter; this embodiment of the invention does not impose limitations on these. The PMD meter monitors the polarization mode dispersion coefficient of the optical fiber sample in real time during pressure loading. When the sudden change in the polarization mode dispersion coefficient exceeds 0.02 ps / ... When the coating of the optical fiber sample is damaged, it is determined that the damage is present. Compared with OTDR, polarization mode dispersion tester can capture micro-deformation damage that OTDR monitoring cannot detect, but the equipment cost is high, and the correlation between polarization mode dispersion changes and damage requires additional calibration, making it unsuitable for low-cost testing of ordinary communication optical fibers.

[0171] Specifically, the fiber optic attenuation test module 20 is connected to the fiber optic sample and is used to measure the initial signal attenuation value of the fiber optic sample under a preset test environment, and to obtain the signal attenuation value of the fiber optic sample during the cyclic test of the fiber optic sample's compressive strength under the preset test environment.

[0172] The control module 30 is electrically connected to the tensile testing module 10 and the fiber attenuation testing module 20, respectively, and is used to perform cyclic testing of the compressive strength of the fiber sample under a preset test environment. The control module 30 can be understood as a control device that calculates parameters and displays outputs based on preset logic, external input signals, or real-time monitoring data. For example, the control module 30 includes, but is not limited to, a computer; this embodiment of the invention does not impose such limitations.

[0173] The control module 30 generates a correlation between signal attenuation value and time based on the signal attenuation value of the optical fiber sample acquired by the optical fiber attenuation test module 20. It also generates a coating damage evolution image sequence and a correlation between pressure and time based on the real-time attenuation state of the coating layer of the optical fiber sample acquired by the tensile test module 10. Simultaneously, it generates a correlation between pressure and time based on the pressure value on the optical fiber sample. The pressure sensitivity of the optical fiber sample is evaluated based on the correlation between signal attenuation value and time. The compressive strength of the optical fiber sample is evaluated based on the coating damage evolution image sequence. The real-time pressure withstand capability of the optical fiber sample is obtained based on the correlation between pressure and time. After the optical fiber sample is measured in a preset environment, the elastic deformation range, permanent deformation rate, and recovery rate of the measured optical fiber sample are evaluated.

[0174] The optical fiber compressive strength testing device provided in this embodiment of the invention includes a tensile testing module 10 (including an image acquisition unit 11), an optical fiber attenuation testing module 20, and a control module 30. The optical fiber attenuation testing module 20 is connected to the optical fiber sample, and the control module 30 is electrically connected to both the tensile testing module 10 and the optical fiber attenuation testing module 20. The image acquisition unit 11 measures the initial damage state of the coating layer of the optical fiber sample under a preset test environment, and the optical fiber attenuation testing module 20 measures the initial signal attenuation value of the optical fiber sample under the same preset test environment. The control module 30 acquires the data from the tensile testing module 10 and the optical fiber attenuation testing module 20, performs cyclic testing of the optical fiber sample's compressive strength under the preset test environment, evaluates the compressive strength of the optical fiber sample, and assesses the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after the test under the preset test environment. By adopting the above technical solution, cyclic testing of the optical fiber compressive strength under a preset environment is achieved, improving the accuracy of the optical fiber compressive strength test and realizing a comprehensive evaluation of the optical fiber compressive strength. It solves the problems of not being able to simultaneously test the mechanical properties and transmission performance of optical fibers, as well as the problems of single and poor repeatability of optical fiber performance testing.

[0175] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for testing the compressive strength of optical fibers, characterized in that, include: Provide fiber optic samples; The initial state parameters of the optical fiber sample are obtained under a preset test environment. The initial state parameters include the initial signal attenuation value of the optical fiber sample and the initial damage state of the coating layer of the optical fiber sample. The initial damage state includes the initial damage degree and the initial damage type. The optical fiber sample was subjected to a cyclic test of its compressive strength under the preset test environment to evaluate its compressive strength. The elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment are evaluated.

2. The optical fiber compressive strength test method according to claim 1, characterized in that, The step of performing a cyclic test on the compressive strength of the optical fiber sample under the preset test environment to evaluate the compressive strength of the optical fiber sample includes: Set the pressure range and number of test cycles; Based on the cyclic test pressure range and the number of cyclic tests, the fiber optic sample is subjected to a compressive strength test under the preset test environment.

3. The optical fiber compressive strength test method according to claim 2, characterized in that, The step of testing the compressive strength of the optical fiber sample under the preset test environment based on the cyclic test pressure range and the number of cyclic tests includes: The optical fiber sample is placed on the tensile testing module, and the pressure is applied step by step according to the preset pressure loading step value and preset pressure holding time. The signal attenuation value of the optical fiber sample, the real-time attenuation state of the coating layer of the optical fiber sample, the pressure value on the optical fiber sample, and the strain state of the optical fiber sample are monitored after the preset pressure is maintained for a preset time. The correspondence between the signal attenuation value and time, the image sequence of coating layer damage evolution, and the correspondence between pressure and time are obtained. The sensitivity of the optical fiber sample to pressure is evaluated based on the correspondence between the signal attenuation value and time; the compressive strength of the optical fiber sample is evaluated based on the coating damage evolution image sequence; and the real-time pressure that the optical fiber sample can withstand is obtained based on the correspondence between pressure and time.

4. The optical fiber compressive strength test method according to claim 3, characterized in that, The step of evaluating the sensitivity of the optical fiber sample to pressure based on the correspondence between the signal attenuation value and time includes: Calculate the average signal attenuation value of the optical fiber sample under various pressure levels; Data whose signal attenuation value deviation from the optical fiber sample is greater than a preset deviation value are filtered out. The signal attenuation change rate of the optical fiber sample is calculated based on the average attenuation value of the signal attenuation value of the optical fiber sample under the filtered multi-level pressure, and the sensitivity of the optical fiber sample to pressure is evaluated based on the attenuation change rate. The compressive strength of the optical fiber sample was evaluated based on the coating damage evolution image sequence, including: By comparing the image sequence of the coating damage evolution of the optical fiber sample with the initial damage state of the coating of the optical fiber sample, the real-time damage degree of the coating of the optical fiber sample is determined, and the compressive strength of the optical fiber sample is evaluated based on the real-time damage degree of the coating of the optical fiber sample.

5. The optical fiber compressive strength test method according to claim 3, characterized in that, The optical fiber compressive strength test method further includes: measuring the ultimate pressure that the optical fiber sample can withstand, and evaluating the additional loss of the optical fiber sample.

6. The optical fiber compressive strength test method according to claim 5, characterized in that, The measurement of the ultimate stress that the optical fiber sample can withstand and the evaluation of the additional loss of the optical fiber sample include: The first pressure value is measured when the coating of the optical fiber sample has a crack or peel exceeding a preset length, the second pressure value is measured when the rate of change of the signal attenuation value of the optical fiber sample exceeds a preset rate of change, or the third pressure value is measured when the optical fiber sample breaks, and the first pressure value, the second pressure value, or the third pressure value is determined to be the ultimate pressure that the optical fiber sample can withstand. The signal attenuation increment of the optical fiber sample under the ultimate withstand pressure is measured, and the additional loss of the optical fiber sample is evaluated based on the signal attenuation increment under the ultimate withstand pressure.

7. The optical fiber compressive strength test method according to claim 1, characterized in that, The evaluation of the elastic deformation range, permanent deformation rate, and recovery rate of the optical fiber sample after testing under the preset test environment includes: After the optical fiber sample is tested under the preset test environment, the elastic deformation range of the optical fiber sample is evaluated based on the deformation range of the coating layer of the optical fiber sample that is fully recovered; the permanent deformation rate of the optical fiber sample is evaluated based on the ratio of the retained deformation amount of the coating layer of the optical fiber sample to the initial length; and the recovery rate of the optical fiber sample is evaluated based on the percentage of signal attenuation that recovers to the initial value.

8. The method for testing the compressive strength of optical fibers according to claim 1, characterized in that, The process of obtaining the initial state parameters of the optical fiber sample under a preset test environment includes: The optical fiber sample is placed in the tensile testing module and the optical fiber sample is in a straight state. Connect the optical fiber sample to the optical fiber attenuation test module; The initial attenuation value of the optical fiber sample was measured and recorded, and the initial damage state of the coating layer of the optical fiber sample was monitored and recorded.

9. The method for testing the compressive strength of optical fibers according to claim 1, characterized in that, The step of testing the initial state parameters of the optical fiber sample under a preset test environment further includes: The initial state parameters of the optical fiber sample are tested under a temperature test environment, and / or the initial state parameters of the optical fiber sample are tested under a humidity test environment.

10. An optical fiber compressive strength testing device, applied to the optical fiber compressive strength testing method according to any one of claims 1-9, characterized in that, include: Tensile testing module, fiber optic attenuation testing module, and control module; The tensile testing module includes an image acquisition unit, which is used to measure the initial damage state of the coating layer of the optical fiber sample under a preset test environment. The initial damage state includes the initial damage degree and the initial damage type. The fiber optic attenuation test module is connected to the fiber optic sample and is used to measure the initial signal attenuation value of the fiber optic sample under a preset test environment. The control module is electrically connected to the tensile testing module and the fiber attenuation testing module, respectively, and is used to perform cyclic testing of the compressive strength of the fiber sample under the preset testing environment, evaluate the compressive strength of the fiber sample, and evaluate the elastic deformation range, permanent deformation rate and recovery rate of the fiber sample after the test is completed under the preset testing environment.

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