Method and system for testing the wear resistance of rubber seals

Abstract

The present application relates to the technical field of wear measurement, in particular to a rubber sealing piece wear resistance test method and system, in the present application, the tangential friction torque and normal compression displacement sequence are acquired synchronously, and the corresponding time window data segment is extracted, the weighted cumulative torque and the friction interface temperature gradient are standardized and multiplied to construct the thermal coupling cumulative damage parameter, the torque maximum value and the displacement minimum value are extracted to construct the envelope boundary sequence and perform the discrete cross-correlation operation to establish the torque displacement correlation characteristics, the correlation characteristics of the mechanical dimension and the cumulative damage of the thermal physical dimension are fused to generate the multi-physical quantity coupling correlation characteristic value, the historical evolution difference value of the characteristic value is combined to track the microstructure change strength, the microstructure peeling starting point of the surface material is accurately captured, the limitation of single data measurement is overcome, the qualitative and quantitative evaluation of multi-dimensional physical parameter fusion is realized, and the accuracy of the wear resistance state test conclusion is ensured.

Description

Technical Field

[0001] This invention relates to the field of wear measurement technology, and in particular to a method and system for testing the wear resistance of rubber seals. Background Technology

[0002] The field of loss measurement technology mainly involves the quantitative assessment of the amount of material loss and the degree of physical performance degradation of various materials and devices under working conditions such as stress, friction and scratching. By simulating the actual service environment and applying specific mechanical stress, thermal stress or chemical corrosion conditions, the morphological changes, mass reduction and mechanical index changes of the material surface are observed, thereby establishing a systematic testing system for material loss and environmental parameters.

[0003] Traditional methods for testing the wear resistance of rubber seals typically involve building a monitoring interface using an integrated programming environment, configuring a data acquisition card to simulate the input channel to read the voltage pulse signal output by the friction torque sensor, then writing the mechanical values ​​and corresponding system timestamps into a comma-separated value format table file. When the global variable count reaches the set loop termination condition, a Boolean truth value is triggered to cut off the stepper motor serial port output command. Finally, a specific script reads the coordinate values ​​in the table file line by line and performs trapezoidal surface accumulation and summation to obtain the basic data for wear assessment.

[0004] Traditional methods for testing the wear resistance of rubber seals rely on data acquisition cards to read single frictional torque pulse signals and directly perform simple geometric trapezoidal surface accumulation and summation to obtain basic evaluation data. This operating mode only stays at the shallow dimension of a single mechanical physical quantity, severing the complex thermo-mechanical interaction caused by friction. As a result, the test system cannot reflect the true stress and heat coupling state of the rubber material during the operating cycle. At the same time, the lag processing logic of single-dimensional data is very likely to mask early signs of degradation of the material's microstructure in long-term testing, and cannot accurately capture the critical starting point of micro-peeling of the material's surface. Ultimately, this results in a serious distortion of the overall wear resistance performance assessment conclusion, making it difficult to provide reliable safety guidance for the actual service life evolution of seals. Summary of the Invention

[0005] To address the technical problems existing in the prior art, embodiments of the present invention provide a method for testing the wear resistance of rubber seals, including the following steps:

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for testing the wear resistance of rubber seals, comprising the following steps:

[0007] S1: During the relative friction operation test cycle of the rubber seal on the performance test bench, obtain the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal, and extract the first data segment of torque and the second data segment of displacement from them.

[0008] S2: Perform weighted calculation on the continuous numerical sequence of tangential friction torque to obtain the weighted cumulative torque value, obtain the current friction interface temperature gradient value, and perform standardized mapping with the weighted cumulative torque value to generate a thermal coupling cumulative damage degree value.

[0009] S3: Filter the maximum values ​​in the first data segment of torque to generate the upper envelope value sequence of torque extreme values, and filter the minimum values ​​in the second data segment of displacement to generate the lower envelope value sequence of displacement extreme values.

[0010] S4: Perform cross-correlation operation on the upper envelope value sequence of the torque extreme value and the lower envelope value sequence of the displacement extreme value to generate a cross-correlation matrix, extract the diagonal extreme value of the cross-correlation matrix, and calculate the ratio of the diagonal extreme value to the cumulative damage degree value of the thermo-coupling as the multi-physical quantity coupling correlation feature value;

[0011] S5: Calculate the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determine whether the rubber seal has reached the critical point of micro-peeling of wear, and generate the wear resistance performance status test result of the rubber seal.

[0012] As a further aspect of the present invention, the first torque data segment includes an initial tangential friction torque term, a process tangential friction torque term, and a final tangential friction torque term; the second displacement data segment includes an initial normal displacement term, a process normal displacement term, and a final normal displacement term; the thermo-coupling cumulative damage degree value is specifically a single quantitative value calculated by the standardized mapping relationship between the weighted torque accumulation value and the current friction interface temperature gradient value; the upper envelope value sequence of torque extrema includes an initial maximum torque term, an intermediate maximum torque term, and an end maximum torque term; the lower envelope value sequence of displacement extrema includes an initial minimum displacement term, an intermediate minimum displacement term, and an end minimum displacement term; the multi-physical quantity coupling correlation feature value is specifically a single feature correlation value calculated by the proportional relationship between the diagonal extrema and the thermo-coupling cumulative damage degree value; and the rubber seal wear resistance performance status test result includes a historical deviation record of feature values, a peeling critical point judgment mark, and a seal wear status conclusion.

[0013] As a further aspect of the present invention, step S1 specifically comprises:

[0014] S101: During the relative friction operation test cycle of the rubber seal on the performance test bench, the continuous numerical sequence of tangential friction torque of the rubber seal is obtained by the torque sensor, and the corresponding time window range is defined to generate the tangential friction torque time window.

[0015] S102: Within the same test cycle, the continuous numerical sequence of the normal compression displacement of the rubber seal is synchronously acquired through the displacement sensor, and the corresponding time window range is defined to obtain the normal displacement time window.

[0016] S103: Extract the set of torque values ​​within the defined range corresponding to the tangential friction torque time window to obtain the first torque data segment; extract the set of normal displacement values ​​within the defined range corresponding to the normal displacement time window to obtain the second displacement data segment.

[0017] As a further aspect of the present invention, step S2 specifically comprises:

[0018] S201: Input the continuous numerical sequence of tangential friction torque into the Grunwald-Letnikov discretization algorithm, and perform a weighted operation on each tangential friction torque value in the continuous numerical sequence of tangential friction torque based on a preset attenuation factor to obtain a weighted torque cumulative value.

[0019] S202: Within the same test cycle, the current friction surface temperature value and the current internal measuring point temperature value of the rubber seal are obtained by an infrared temperature probe. Combined with the preset distance between the surface of the rubber seal and the internal measuring point, the current friction interface temperature gradient value is calculated.

[0020] S203: Perform standardization processing on the weighted torque accumulation value and the friction interface temperature gradient value at the current moment, and calculate the product between the standardized weighted torque accumulation value and the friction interface temperature gradient value at the current moment as the cumulative damage degree value of thermal coupling.

[0021] As a further aspect of the present invention, step S3 specifically comprises:

[0022] S301: Determine the relationship between the tangential friction torque value of the current node in the first data segment of torque and the tangential friction torque values ​​of the adjacent time nodes, filter out the nodes with the maximum tangential friction torque values ​​corresponding to the adjacent items and sort them in time sequence to obtain the torque maximum value node sequence.

[0023] S302: Determine the relationship between the normal compression displacement value of the current node in the second displacement data segment and the normal compression displacement value of the adjacent time nodes, filter out nodes with the minimum normal compression displacement value corresponding to the adjacent items and sort them in time sequence to obtain the displacement minimum value node sequence.

[0024] S303: Perform interpolation connection processing on each maximum tangential friction torque in the maximum torque node sequence to obtain the maximum value envelope boundary state; perform interpolation connection processing on each minimum normal compression displacement in the minimum displacement node sequence to obtain the minimum value envelope boundary state; and construct the upper envelope value sequence of maximum torque and the lower envelope value sequence of maximum displacement respectively.

[0025] As a further aspect of the present invention, step S4 specifically comprises:

[0026] S401: Using the upper envelope value sequence of the torque extremum as the first signal source and the lower envelope value sequence of the displacement extremum as the second signal source, perform discrete cross-correlation operation on the corresponding data point items of the first signal source and the second signal source to establish a torque-displacement cross-correlation matrix.

[0027] S402: Select the maximum cross-correlation value inside the main diagonal region of the torque-displacement cross-correlation matrix as the representative feature of torque-displacement correlation, and obtain the diagonal extreme value;

[0028] S403: Calculate the ratio of the diagonal extreme value to the cumulative damage value of the thermal coupling to obtain the multi-physical quantity coupling correlation characteristic value.

[0029] As a further aspect of the present invention, step S5 specifically comprises:

[0030] S501: Read the historical multi-physical quantity coupling correlation feature value recorded in the previous test cycle, calculate the difference between the current multi-physical quantity coupling correlation feature value and the historical multi-physical quantity coupling correlation feature value, and use it as the state change intensity value;

[0031] S502: When the intensity value of the state change exceeds the preset judgment threshold, the rubber seal is determined to have reached the critical state of the micro-detachment starting point of the surface material structure, and the judgment result of the micro-peeling critical point of wear is obtained.

[0032] S503: Summarize and archive the test cycle status of the determination results of the wear micro-stripping critical point, organize the material consumption and structural damage evolution evaluation data of the rubber seal within the current friction operation test cycle, and obtain the wear resistance status test results of the rubber seal.

[0033] A rubber seal wear resistance testing system includes:

[0034] The data acquisition and interception module acquires the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal during the relative friction operation test cycle of the rubber seal on the performance test bench, and extracts the first data segment of torque and the second data segment of displacement from them.

[0035] The thermo-coupling damage calculation module performs weighted calculations on the continuous numerical sequence of tangential friction torque to obtain a weighted cumulative torque value, acquires the current friction interface temperature gradient value, and performs standardized mapping with the weighted cumulative torque value to generate a thermo-coupling cumulative damage degree value.

[0036] The extreme value envelope sequence generation module filters the maximum values ​​in the first data segment of torque to generate an upper envelope value sequence of extreme torque values, and filters the minimum values ​​in the second data segment of displacement to generate a lower envelope value sequence of extreme displacement values.

[0037] The coupling correlation feature calculation module performs cross-correlation operation on the upper envelope value sequence of the torque extreme value and the lower envelope value sequence of the displacement extreme value to generate a cross-correlation matrix, extracts the diagonal extreme value of the cross-correlation matrix, and calculates the ratio of the diagonal extreme value to the cumulative damage degree value of the thermo-coupling as the multi-physical quantity coupling correlation feature value.

[0038] The wear resistance performance status assessment module calculates the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determines whether the rubber seal has reached the critical point of micro-peeling of wear, and generates the wear resistance performance status test result of the rubber seal.

[0039] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0040] In this invention, by synchronously acquiring the tangential friction torque and normal compressive displacement sequences and extracting the corresponding time window data segments, the weighted cumulative torque and the friction interface temperature gradient are standardized and multiplied to construct thermo-mechanically coupled cumulative damage parameters. The maximum torque value and the minimum displacement value are extracted to construct the envelope boundary sequence and discrete cross-correlation operation is performed to establish the torque-displacement correlation characteristics. The correlation characteristics of the mechanical dimension and the cumulative damage of the thermophysical dimension are fused to generate multi-physical quantity coupled correlation characteristic values. The historical evolution difference of the characteristic values ​​is combined to track the intensity of microstructure changes, accurately capture the micro-scraping initiation point of the surface material, overcome the limitations of single data measurement, realize the qualitative and quantitative evaluation of multi-dimensional physical parameter fusion, and ensure the accuracy of the wear resistance performance status test conclusions. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the steps of the present invention;

[0043] Figure 2This is a detailed schematic diagram of S1 of the present invention;

[0044] Figure 3 This is a detailed schematic diagram of S2 of the present invention;

[0045] Figure 4 This is a detailed schematic diagram of S3 of the present invention;

[0046] Figure 5 This is a detailed schematic diagram of S4 of the present invention;

[0047] Figure 6 This is a detailed schematic diagram of S5 of the present invention;

[0048] Figure 7 This is a system module diagram of the present invention. Detailed Implementation

[0049] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0050] Please see Figure 1 This invention provides a method for testing the wear resistance of rubber seals, comprising the following steps:

[0051] S1: During the relative friction operation test cycle of the rubber seal on the performance test bench, obtain the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal, and extract the first data segment of torque and the second data segment of displacement from them.

[0052] S2: Perform weighted calculations on the continuous numerical sequence of tangential friction torque to obtain the weighted cumulative torque value, obtain the current friction interface temperature gradient value, and perform standardized mapping with the weighted cumulative torque value to generate a thermal coupling cumulative damage value.

[0053] S3: Filter the maximum values ​​in the first data segment of torque to generate the upper envelope value sequence of torque extreme values; filter the minimum values ​​in the second data segment of displacement to generate the lower envelope value sequence of displacement extreme values.

[0054] S4: Perform cross-correlation operation on the upper envelope value sequence of torque extrema and the lower envelope value sequence of displacement extrema to generate a cross-correlation matrix. Extract the diagonal extrema of the cross-correlation matrix and calculate the ratio of the diagonal extrema to the cumulative damage degree value of thermal coupling as the characteristic value of multi-physical quantity coupling correlation.

[0055] S5: Calculate the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determine whether the rubber seal has reached the critical point of wear micro-stripping, and generate the wear resistance performance status test results of the rubber seal.

[0056] The first data segment of torque includes the initial tangential friction torque, the intermediate tangential friction torque, and the final tangential friction torque. The second data segment of displacement includes the initial normal displacement, the intermediate normal displacement, and the final normal displacement. The cumulative damage value of thermo-coupling is a single quantitative value calculated by the standardized mapping relationship between the weighted cumulative torque value and the temperature gradient value of the friction interface at the current moment. The upper envelope value sequence of torque extrema includes the initial maximum torque, the intermediate maximum torque, and the final maximum torque. The lower envelope value sequence of displacement extrema includes the initial minimum displacement, the intermediate minimum displacement, and the final minimum displacement. The multi-physical quantity coupling correlation characteristic value is a single characteristic correlation value calculated by the proportional relationship between the diagonal extrema and the cumulative damage value of thermo-coupling. The test results of the wear resistance performance of rubber seals include the historical deviation record of characteristic values, the identification mark of the peeling critical point, and the conclusion of the wear status of the seals.

[0057] Please see Figure 2 Step S1 is as follows:

[0058] S101: During the relative friction operation test cycle of the rubber seal on the performance test bench, the continuous numerical sequence of tangential friction torque of the rubber seal is obtained by the torque sensor, and the corresponding time window range is defined to generate the tangential friction torque time window.

[0059] The control performance test bench starts operating according to the set spindle speed and contact load. A high-precision torque sensor continuously collects the tangential friction torque signal of the rubber seal, obtaining a continuous numerical sequence of tangential friction torque. The sampling frequency of the torque sensor is set by extracting the highest vibration frequency value from historical tangential friction test records. This highest vibration frequency value is multiplied by a predetermined factor to determine the base sampling value, and a redundant frequency is added to the base sampling value to determine the final sampling frequency. For example, if the highest vibration frequency value in the historical tangential friction test records is 50 Hz, multiplying 50 by 2.5 gives 125 Hz, and adding 10 Hz determines the sampling frequency to be 135 Hz. After obtaining the sequence, the corresponding time window range is directly defined. The definition process involves obtaining the target load stabilization trigger time point from the test equipment's operating status parameters as the start node of the time window, and obtaining the load unloading trigger time point as the end node of the time window. The time span between the start and end points is determined, and there are three possible classifications: First, the time span is less than 10 seconds, classified as a short-term test condition; second, the time span is greater than or equal to 10 seconds and less than or equal to 60 seconds, classified as a standard test condition; and third, the time span is greater than 60 seconds, classified as a long-term fatigue condition. For example, if the start point is currently set at 5 seconds and the end point at 25 seconds, the time span is 20 seconds, falling into the second possibility, the standard test condition. This time span between the start and end points is defined as the corresponding time window range. All tangential friction torque values ​​within this range are extracted to generate the tangential friction torque time window.

[0060] S102: Within the same test cycle, the continuous numerical sequence of the normal compression displacement of the rubber seal is synchronously acquired through the displacement sensor, and the corresponding time window range is defined to obtain the normal displacement time window.

[0061] By synchronizing the hardware clocks of a laser displacement sensor and a torque sensor, the normal compression displacement signal of the rubber seal is continuously acquired to obtain a continuous numerical sequence of normal compression displacement. The synchronous acquisition process involves receiving the same hardware trigger pulse signal and recording the normal compression displacement value point-by-point according to the set sampling frequency. After acquiring the continuous numerical sequence of normal compression displacement, a corresponding time window range is defined. This definition process involves extracting the start and end nodes of the tangential friction torque time window and directly mapping and aligning these nodes to the time axis of the continuous numerical sequence of normal compression displacement, thus defining the effective intercept interval of the normal compression displacement. There are three possible classifications for displacement fluctuations within the intercept interval: the difference between the maximum and minimum displacement values ​​within the interval is calculated. A difference less than 0.1 mm is classified as a micro-displacement fluctuation level; a difference greater than or equal to 0.1 mm and less than or equal to 0.5 mm is classified as a normal displacement fluctuation level; and a difference greater than 0.5 mm is classified as a severe displacement fluctuation level. Based on the defined effective intercept interval, extract all normal compressive displacement values ​​within the interval from the continuous numerical sequence of normal compressive displacement, and output the extracted numerical set directly to obtain the normal displacement time window.

[0062] S103: Extract the set of torque values ​​within the defined range corresponding to the tangential friction torque time window to obtain the first torque data segment; extract the set of normal displacement values ​​within the defined range corresponding to the normal displacement time window to obtain the second displacement data segment.

[0063] Data is retrieved from the tangential friction torque time window and the normal displacement time window respectively. All tangential friction torque values ​​within the defined range of the tangential friction torque time window are extracted and arranged in chronological order of their original acquisition time, forming a one-dimensional array. This one-dimensional array is then directly assigned as the first torque data segment. Similarly, all normal compression displacement values ​​within the defined range of the normal displacement time window are extracted and arranged in chronological order of their original acquisition time, forming a one-dimensional array. This one-dimensional array is then directly assigned as the second displacement data segment. A comparison is performed between the total number of values ​​in the first torque data segment and the total number of values ​​in the second displacement data segment. Three data length matching possibilities exist: the first possibility is that the total number of values ​​in the first torque data segment is greater than the total number of values ​​in the second displacement data segment; the second possibility is that the total number of values ​​in both is exactly equal; and the third possibility is that the total number of values ​​in the first torque data segment is less than the total number of values ​​in the second displacement data segment. If the judgment result falls into the first or third possibility, that is, there is a discrepancy in the total number of values ​​contained in the two data segments, then the data segment with the smaller total number of values ​​is used as the benchmark, and the excess node values ​​at the end of the data segment with the larger total number of values ​​are truncated and removed. After the comparison and truncation operation, the first data segment of torque and the second data segment of displacement with the number of nodes are obtained with perfect alignment.

[0064] Please see Figure 3 Step S2 is as follows:

[0065] S201: Input the continuous numerical sequence of tangential friction torque into the Grunwald-Letnikov discretization algorithm. Based on the preset attenuation factor, perform a weighted operation on each tangential friction torque value in the continuous numerical sequence of tangential friction torque to obtain the weighted torque cumulative value.

[0066] The process of setting the preset attenuation factor is as follows:

[0067] Obtain the total number of time nodes in the continuous numerical sequence of tangential friction torque;

[0068] The initial attenuation calibrator value of the Grunwald-Letnikov discretization algorithm is obtained as the preset initial reference value;

[0069] The attenuation factor is obtained by performing a positive correlation mapping process on the preset initial reference value based on the total number of time nodes of the continuous numerical sequence of tangential friction torque;

[0070] Each tangential friction torque value in the continuous numerical sequence is input into the Grunwald-Letnikov discretization algorithm to obtain the total number of time nodes in the continuous numerical sequence. The initial attenuation calibration value of the Grunwald-Letnikov discretization algorithm is used as the preset initial benchmark value. The preset initial benchmark value is set based on the attenuation rate data set of friction tests of the same type of rubber seal from multiple historical batches. The arithmetic mean of all attenuation rate values ​​within this data set is calculated by summing all values ​​and dividing by the sample size of the data set. For example, if the arithmetic mean of the historical attenuation rate is 0.25, then the preset initial benchmark value is set to 0.25. A positive correlation mapping process is performed on the preset initial benchmark value based on the total number of time nodes. The process involves dividing the total number of time nodes by the preset standard number of nodes (set to a fixed value of 1000 nodes) to obtain a ratio. The ratio is then multiplied by the preset initial benchmark value, and the product is the attenuation factor. The attenuation factor is divided into three influence level ranges. The first possibility is a slow attenuation influence level when the attenuation factor is less than 0.8; the second possibility is a normal attenuation influence level when the attenuation factor is greater than or equal to 0.8 and less than or equal to 1.5; and the third possibility is a rapid attenuation influence level when the attenuation factor is greater than 1.5. For example, if the total number of time nodes is 5000, dividing by 1000 gives 5, multiplying by 0.25 gives an attenuation factor of 1.25, falling into the second possibility of the normal attenuation influence level. After obtaining the attenuation factor, a weighted calculation is performed on each tangential friction torque value in the continuous numerical sequence of tangential friction torque. For the current calculation node, all historical nodes before the current calculation node are traced in reverse chronological order, and the time step difference between the historical nodes and the current calculation node is calculated. The attenuation factor is multiplied by a factorial operation of continuously decreasing factors, and the result of the factorial operation of the time step difference is multiplied by the factorial operation of the difference between the attenuation factor and the time step difference, and the result is multiplied by the factorial operation of the difference between the attenuation factor and the time step difference, and the result is used as the denominator. The numerator is divided by the denominator and multiplied by an alternating sign term to calculate the corresponding historical node weight allocation value. The tangential friction torque value corresponding to each historical node is multiplied by the corresponding historical node weight allocation value to obtain a single-point weighted product. Finally, the tangential friction torque value corresponding to the current calculation node is summed with the single-point weighted products of all historical nodes to obtain the weighted torque cumulative value.

[0071] S202: Within the same test cycle, the current friction surface temperature value and the current internal measuring point temperature value of the rubber seal are obtained by an infrared temperature probe. Combined with the preset distance between the surface of the rubber seal and the internal measuring point, the current friction interface temperature gradient value is calculated.

[0072] The distance between the surface of the rubber seal and the internal measuring point is set according to the total thickness of the radial solid section of the rubber seal and the detection depth parameter corresponding to the infrared temperature probe.

[0073] Infrared radiation signals generated by the friction surface are read by a first infrared temperature probe aligned with the contact surface area of ​​the rubber seal, and the radiation signals are converted into the temperature value of the friction surface at the current moment based on the infrared radiation characteristics. Simultaneously, a contact temperature sensor is embedded at a preset position inside the rubber seal to collect the thermal conductivity temperature of the material at that position in real time, obtaining the temperature value of the internal measuring point at the current moment. A preset distance parameter between the surface of the rubber seal and the internal measuring point is extracted. This distance parameter is set based on the total thickness of the radial solid cross-section of the rubber seal and the installation depth parameter of the contact temperature sensor inside the rubber seal. The distance parameter is obtained by subtracting the installation depth parameter from the total thickness of the radial solid cross-section; this linear distance difference characterizes the actual distance between the surface of the rubber seal and the internal measuring point. The temperature difference between the inside and outside of the cross-section at the current moment is obtained by subtracting the temperature value of the internal measuring point at the current moment from the temperature value of the friction surface at the current moment. The temperature difference between the inside and outside of the cross-section at the current moment is divided by the distance parameter to calculate the temperature change rate per unit thickness, and this rate of change is used as the temperature gradient value of the friction interface at the current moment. There are three possible classifications of thermal stress intensity ranges based on temperature gradient values: First, a temperature gradient value less than 2.0 degrees Celsius per millimeter is classified as a low thermal stress intensity range; second, a temperature gradient value greater than or equal to 2.0 and less than or equal to 5.0 degrees Celsius per millimeter is classified as a medium thermal stress intensity range; and third, a temperature gradient value greater than 5.0 degrees Celsius per millimeter is classified as a high thermal stress intensity range. For example, if the friction surface temperature is 85.0 degrees Celsius, the internal measuring point temperature is 55.0 degrees Celsius, the thickness is 15.0 millimeters, and the depth is 5.0 millimeters, then the temperature difference is 30.0 degrees Celsius. With a spacing parameter of 10.0 millimeters, dividing the temperature difference by the spacing parameter yields a temperature gradient value of 3.0 degrees Celsius per millimeter, which falls into the second type, the medium thermal stress intensity range.

[0074] S203: Perform standardization on the weighted cumulative torque value and the current friction interface temperature gradient value, and calculate the product between the standardized weighted cumulative torque value and the current friction interface temperature gradient value as the value of cumulative thermal coupling damage.

[0075] Standardization is performed on both the weighted torque cumulative value and the current friction interface temperature gradient value. The specific process for standardizing the weighted torque cumulative value is as follows: extract all historical weighted torque cumulative values ​​to form a sample set; calculate the arithmetic mean of all values ​​in this sample set as the baseline torque mean; calculate the standard deviation of all values ​​in this sample set as the baseline torque standard deviation. Subtract the baseline torque mean from the currently acquired weighted torque cumulative value to obtain the torque deviation; divide the torque deviation by the baseline torque standard deviation to obtain the standardized weighted torque cumulative value. Similarly, the specific process for standardizing the current friction interface temperature gradient value is as follows: extract all historical friction interface temperature gradient values ​​to form a sample set; calculate the arithmetic mean of this sample set as the baseline gradient mean; calculate the standard deviation of this sample set as the baseline gradient standard deviation. Subtract the baseline gradient mean from the current friction interface temperature gradient value to obtain the gradient deviation; divide the gradient deviation by the baseline gradient standard deviation to obtain the standardized current friction interface temperature gradient value. The standardized weighted cumulative torque value is multiplied by the standardized temperature gradient value of the friction interface at the current moment. The product is directly defined as the cumulative thermal coupling damage value. Based on the magnitude of this product, there are three possible damage assessments: first, a result less than 1.5 indicates slight thermal damage; second, a result greater than or equal to 1.5 and less than or equal to 3.0 indicates moderate thermal damage; and third, a result greater than 3.0 indicates severe thermal damage. For example, if the standardized weighted cumulative torque value is 1.0 and the standardized temperature gradient value is 2.0, multiplying them yields a cumulative thermal coupling damage value of 2.0, falling into the second possibility of moderate thermal damage.

[0076] Please see Figure 4 Step S3 is as follows:

[0077] S301: Determine the relationship between the tangential friction torque value of the current node in the first data segment of torque and the tangential friction torque values ​​of the adjacent time nodes before and after it. Filter out the nodes with maximum tangential friction torque values ​​that are greater than the adjacent items before and after it and sort them in time sequence to obtain the sequence of nodes with maximum torque values.

[0078] The process iterates through all tangential friction torque values ​​within the first data segment of the torque data in chronological order. For the tangential friction torque value of the current node during the traversal, the tangential friction torque values ​​of the preceding and following time nodes immediately adjacent to the current node are extracted from the timeline. A comparison is then performed between the current node's tangential friction torque value and the values ​​of the preceding and following time nodes. The judgment logic is to check whether the current node's tangential friction torque value is simultaneously and strictly greater than both the preceding and following time node's tangential friction torque values. The comparison result has two possibilities: the first possibility is a local bulge state where the current node's tangential friction torque value satisfies the condition of being simultaneously greater than both adjacent nodes; the second possibility is a non-local bulge state that does not satisfy this condition. If the judgment result falls into the first possibility, the current node is determined to be a node with a maximum tangential friction torque value, and the corresponding tangential friction torque value is filtered and recorded in a temporary maximum value storage list. If the result falls into the second possibility, the record is discarded and the process continues to the next time node. After the data segment has been traversed, all tangential friction torque maximum value nodes are extracted from the temporary maximum value storage list, and the original acquisition timestamps corresponding to each node are obtained. A time-series sorting process is performed on all tangential friction torque maximum value nodes. Specifically, the original acquisition timestamp values ​​between nodes are compared, and nodes with smaller timestamp values ​​are placed before nodes with larger timestamp values. This process is repeated until all maximum value nodes completely follow the ascending time order. The sorted sequence is output, yielding the torque maximum value node sequence.

[0079] S302: Determine the relationship between the normal compressive displacement value of the current node in the second displacement data segment and the normal compressive displacement values ​​of the adjacent time nodes before and after it, filter out the nodes with the minimum normal compressive displacement values ​​that are smaller than the adjacent items before and after it, and sort and organize them in time sequence to obtain the displacement minimum value node sequence.

[0080] The system iterates through all normal compression displacement values ​​within the second data segment of the displacement table in chronological order. For the normal compression displacement value of the current node during the traversal, it extracts the normal compression displacement values ​​of the preceding and following time nodes immediately adjacent to the current node. It then compares the current node's normal compression displacement value with both the preceding and following time node values. The judgment logic checks whether the current node's normal compression displacement value is simultaneously and strictly less than both the preceding and following time node values. The comparison result has two possibilities: the first possibility is a local concavity state where the current node's normal compression displacement value satisfies the condition of being simultaneously less than both adjacent nodes; the second possibility is a non-local concavity state that does not satisfy this condition. If the judgment result falls into the first possibility, the current node is determined to be a node with a minimum normal compression displacement value, and the corresponding normal compression displacement value is filtered and recorded in a temporary minimum value storage list. If the result falls into the second possibility, the record is discarded and the process continues to the next time node. After traversal, all normal compressive displacement minimum value nodes are extracted from the temporary minimum value storage list, and the original acquisition timestamps corresponding to each normal compressive displacement minimum value node are obtained. A temporal sorting process is performed on all normal compressive displacement minimum value nodes. Specifically, the original acquisition timestamp values ​​between any two nodes are compared sequentially, and the minimum value node with the earlier timestamp value is moved to the front of the minimum value node with the later timestamp value. This comparison and swapping continues until all nodes in the entire list are arranged in ascending order of time. The sorted sequence is output, yielding the displacement minimum value node sequence.

[0081] S303: Perform interpolation connection processing on each maximum tangential friction torque in the maximum torque node sequence to obtain the maximum value envelope boundary state; perform interpolation connection processing on each minimum normal compressive displacement in the minimum displacement node sequence to obtain the minimum value envelope boundary state; and construct the upper envelope value sequence of maximum torque and the lower envelope value sequence of maximum displacement respectively.

[0082] The sequence of maximum torque nodes and minimum displacement nodes is retrieved. For the maximum torque node sequence, interpolation is performed on each maximum tangential friction torque in the sequence. The interpolation process involves locating two adjacent maximum tangential friction torque nodes in the sequence, obtaining the numerical difference between them and the time interval between their timestamps. The numerical difference is divided by the time interval to calculate the slope of change between them. For the sampling time of the missing data between two adjacent nodes, the maximum value of the previous node is added to the product of the time shift and the slope of change to calculate and derive the estimated maximum fitting point to fill in that time. The original recorded maximum nodes and all the calculated and derived estimated maximum fitting points are concatenated to form a smooth and continuous data trajectory. The morphological characteristics of this trajectory are obtained as the maximum envelope boundary state. All node values ​​constituting this state are stored in chronological order to construct a sequence of maximum torque envelope values. Similarly, for the displacement minimum value node sequence, the difference in displacement values ​​between two adjacent normal compression displacement minimum value nodes in the sequence is located. The slope of change is obtained by dividing the difference in displacement values ​​by the time interval. The minimum value of the previous node is added to the product of the time shift and the slope to derive the estimated minimum value fitting point for the missing intermediate time. The original minimum value nodes are connected with the derived estimated minimum value fitting points to form a continuous trajectory, and the shape of this trajectory is obtained as the minimum value envelope boundary state. All node values ​​constituting the minimum value envelope boundary state are stored in chronological order to construct the envelope value sequence under displacement extrema.

[0083] Please see Figure 5 Step S4 is as follows:

[0084] S401: Take the upper envelope value sequence of torque extrema as the first signal source and the lower envelope value sequence of displacement extrema as the second signal source. Perform discrete cross-correlation operation on the corresponding data point items of the first signal source and the second signal source to establish the torque-displacement cross-correlation matrix.

[0085] The envelope sequence of torque extrema is used as the first signal source, and the envelope sequence of displacement extrema is used as the second signal source. Discrete cross-correlation is performed on the corresponding data points of the first and second signal sources. The process of discrete cross-correlation is as follows: the total number of data length nodes in the first signal source is obtained; this total number of data length nodes is multiplied by a negative unit value to determine the maximum negative lag step; and the total number of data length nodes is subtracted by a unit value to determine the maximum positive lag step, thus defining the range of time lag offset steps. For each lag offset step value within this range, the lag offset step corresponding to the translation of the entire data of the second signal source along the time axis is calculated. The overlapping data point pairs of the first and second signal sources that are aligned on the time axis after translation are extracted. The first and second signal source values ​​in each overlapping data point pair are multiplied to obtain a single-point product value. Then, all single-point product values ​​are summed, and the summation result is the cross-correlation value corresponding to the current lag offset step value. The lag offset step values ​​are cyclically changed, gradually increasing from the negative maximum to the positive maximum, and the cross-correlation values ​​at all step counts are calculated. All calculated cross-correlation values ​​are then arranged in order of lag offset step count to form a one-dimensional cross-correlation result vector. Based on the positive and negative directions of the lag offset step count and the sequence dimension of the first signal source, the one-dimensional cross-correlation result vector is expanded in rows and columns to establish a two-dimensional structure composed of multiple rows and columns of values, resulting in the torque-displacement cross-correlation matrix.

[0086] S402: Select the maximum cross-correlation value inside the main diagonal region of the torque-displacement cross-correlation matrix as the representative feature of the torque-displacement correlation, and obtain the diagonal extreme value;

[0087] Read the torque-displacement cross-correlation matrix and define the main diagonal region within it. The definition logic involves extracting the matrix row and column indices corresponding to each cross-correlation value. Subtract the column index from the row index to obtain the row difference, and then perform an absolute value operation on this difference. A pre-set tolerance threshold for the main diagonal region is established. This threshold is based on historical torque-displacement cross-correlation matrix data samples from similar devices. The arithmetic mean of the absolute values ​​of the row differences for all diagonal nodes representing perfect synchronization is calculated. For example, if the calculated mean is 2.8, rounding it up determines the tolerance threshold for the main diagonal region to 3. For element positions, two possibilities are considered: first, if the absolute value of the row difference is less than or equal to the tolerance threshold, the element is considered valid within the main diagonal region; second, if the absolute value of the row difference is greater than the tolerance threshold, the element is considered invalid at the edge of the region. All elements falling into the first possibility are filtered and aggregated into a set of elements within the main diagonal region. Within this set, a maximum cross-correlation value search is performed. This involves setting an initial minimum value, reading each cross-correlation value in the set one by one, and comparing it to this initial minimum. If the read value is greater than the currently recorded value, it is replaced and updated, until all values ​​in the set have been compared. The final maximum value is selected and defined as the maximum cross-correlation value within the main diagonal region. This maximum cross-correlation value is used as a representative characteristic for measuring the synchronous coordination strength of torque and displacement, and is assigned a value to obtain the diagonal extreme value.

[0088] S403: Calculate the ratio of the diagonal extreme value to the cumulative damage value of thermal coupling to obtain the multi-physical quantity coupling correlation characteristic value;

[0089] The process involves obtaining the cumulative thermal coupling damage value generated in the previous calculations and extracting the diagonal extrema determined in the cross-correlation matrix processing step. A share ratio calculation is then performed, where the diagonal extrema are designated as the dividend and the cumulative thermal coupling damage value as the divisor. A division operation is performed between the dividend and divisor, dividing the diagonal extrema by the cumulative thermal coupling damage value to obtain the initial divisor. This initial divisor is then multiplied by a proportional conversion factor, set to a fixed constant of one hundred to meet the requirement of converting pure decimals to percentage-level data. Finally, multiplying the initial divisor by the proportional conversion factor yields the share ratio of the diagonal extrema relative to the cumulative thermal coupling damage value. Regarding the final value of the share ratio, there are three possible classifications for the evaluation level of the correlation state: The first possibility is a weakly coupled correlation state when the share ratio is less than 200, indicating that the two physical quantities change independently; the second possibility is a moderately coupled correlation state when the share ratio is greater than or equal to 200 and less than or equal to 600, indicating that the two physical quantities mutually restrict each other; the third possibility is a strongly coupled abnormal state when the share ratio is greater than 600, indicating adhesion or severe interlocking. For example, if the diagonal extreme value is 9.5 and the cumulative damage degree of thermal coupling is 2.0, dividing 9.5 by 2.0 gives 4.75, and multiplying 4.75 by 100 yields a share ratio value of 475. 475 falls into the moderately coupled correlation state level of the second possibility. This share ratio value is directly output to obtain the multi-physical quantity coupling correlation characteristic value.

[0090] Please see Figure 6 Step S5 is as follows:

[0091] S501: Read the historical multi-physical quantity coupling correlation characteristic value corresponding to the record of the previous test cycle, calculate the difference between the current multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, and use it as the state change intensity value;

[0092] The system reads the corresponding historical multi-physical quantity coupling correlation feature values ​​from the data archive and simultaneously reads the current multi-physical quantity coupling correlation feature values. A difference comparison operation is performed between the current and historical multi-physical quantity coupling correlation feature values. The operation involves subtracting the historical multi-physical quantity coupling correlation feature value from the current value to calculate the baseline difference. The absolute value of this baseline difference is then used as the state change intensity value to measure the rate of state degradation. Three possible degradation rate categories are determined for this state change intensity value: the first possibility is a stable running-in category when the state change intensity value is less than 10, representing extremely low microscopic wear; the second possibility is an accelerated degradation category when the state change intensity value is greater than or equal to 10 and less than or equal to 20, representing an increasing degree of wear; the third possibility is a rapidly deteriorating category when the state change intensity value is greater than 20, representing imminent surface failure. For example, the current multi-physical quantity coupling correlation feature value is 475, and the historical multi-physical quantity coupling correlation feature value is 460. Subtracting 460 from 475 yields a base difference of 15. Taking the absolute value of 15 gives the state change intensity value of 15. This value of 15 falls into the second possible accelerated degradation category, and is used as the final output state change intensity value.

[0093] S502: When the intensity value of the state change exceeds the preset judgment threshold, the rubber seal is determined to have reached the critical state of the micro-detachment starting point of the surface material structure, and the judgment result of the micro-peeling critical point of wear is obtained.

[0094] After obtaining the intensity value of the state change, a preset judgment threshold is extracted. The preset judgment threshold is set based on a sample group of intensity values ​​of the state change of rubber seals of the same specification in historical destructive fatigue life tests, several test cycles before the critical point of microscopic detachment and blistering. All values ​​in the sample group are summed and divided by the total number of samples to obtain the arithmetic mean. Then, the product of this arithmetic mean and the set safety margin coefficient is the preset judgment threshold. For example, if the statistical arithmetic mean of the sample group is 18 and the safety margin coefficient is set to 90%, 18 is multiplied by 0.9 to calculate and set the preset judgment threshold to 16.2. The calculated intensity value of the state change is compared with the preset judgment threshold. There are two possible conclusions: the first possibility is that the intensity value of the state change is greater than the preset judgment threshold, in which case the alarm logic is triggered to determine that the rubber seal has reached the critical state of the starting point of microscopic detachment of the surface material structure; the second possibility is that the intensity value of the state change is less than or equal to the preset judgment threshold, in which case the rubber seal has not reached the critical state of the starting point of microscopic detachment of the surface material structure. For example, if the intensity of the state change is 15 and the preset judgment threshold is 16.2, and the comparison judgment is that 15 is less than 16.2, falling into the second possibility, then the text conclusion is output that the rubber seal has not reached the critical state of the micro-detachment starting point of the surface material structure, and the judgment result of the micro-detachment critical point of wear is obtained.

[0095] S503: Summarize and archive the test cycle status of the results of the determination of the critical point of micro-stripping of wear, organize the material consumption and structural damage evolution evaluation data of the rubber seal within the current friction operation test cycle, and obtain the test results of the wear resistance status of the rubber seal.

[0096] Obtain the results of the wear micro-stripping critical point determination and the previously generated characteristic values. Perform a summary and archiving operation of the test cycle status. The process involves creating a new structured text data record entry, writing the test environment parameters and operating condition data of the current test cycle into the entry's identifier field, and then sequentially filling the current multi-physical quantity coupling correlation characteristic values, state change intensity values, and wear micro-stripping critical point determination results into the internal storage fields of the data record entry. After completing the field filling, save the structured data record entry to a local disk file. Organize the material consumption and structural damage evolution evaluation data of the rubber seals within this friction operation test cycle. The organization process involves extracting quantitative data of the thermal coupling cumulative damage degree, quantitative data of the diagonal extreme values, and qualitative text of the wear micro-stripping critical point determination results. Concatenate the above quantitative data and qualitative text to generate a comprehensive evaluation text data. The structure of the comprehensive evaluation text data includes a sequential arrangement of the quantitative values ​​of each indicator and the qualitative conclusions of the state. The comprehensive evaluation text data after assembly is used as the final report content reflecting the remaining service life and service status of the rubber seals, and the output is the test results of the wear resistance performance of the rubber seals.

[0097] Please see Figure 7 A rubber seal wear resistance testing system, including:

[0098] The data acquisition and interception module acquires the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal during the relative friction operation test cycle of the rubber seal on the performance test bench, and extracts the first data segment of torque and the second data segment of displacement from them.

[0099] The thermo-coupling damage calculation module performs weighted calculations on the continuous numerical sequence of tangential friction torque to obtain the weighted cumulative torque value, obtains the current friction interface temperature gradient value, and performs standardized mapping with the weighted cumulative torque value to generate a thermo-coupling cumulative damage degree value.

[0100] The extreme value envelope sequence generation module filters the maximum values ​​in the first data segment of torque to generate the upper envelope value sequence of torque extreme values, and filters the minimum values ​​in the second data segment of displacement to generate the lower envelope value sequence of displacement extreme values.

[0101] The coupling correlation feature calculation module performs cross-correlation operation on the upper envelope value sequence of torque extreme values ​​and the lower envelope value sequence of displacement extreme values ​​to generate a cross-correlation matrix. It extracts the diagonal extreme values ​​of the cross-correlation matrix and calculates the ratio of the diagonal extreme values ​​to the cumulative damage degree value of thermal coupling, which is used as the multi-physical quantity coupling correlation feature value.

[0102] The wear resistance performance status assessment module calculates the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determines whether the rubber seal has reached the critical point of micro-peeling of wear, and generates the wear resistance performance status test results of the rubber seal.

[0103] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for testing the wear resistance of rubber seals, characterized in that, Includes the following steps: S1: During the relative friction operation test cycle of the rubber seal on the performance test bench, obtain the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal, and extract the first data segment of torque and the second data segment of displacement from them. S2: Perform weighted calculation on the continuous numerical sequence of tangential friction torque to obtain the weighted cumulative torque value, obtain the friction interface temperature gradient value at the current moment, perform standardization processing on the weighted cumulative torque value and the friction interface temperature gradient value at the current moment, and calculate the product between the standardized weighted cumulative torque value and the friction interface temperature gradient value at the current moment as the cumulative damage degree value of thermal coupling. S3: Filter the maximum values ​​in the first data segment of torque to generate the upper envelope value sequence of torque extreme values, and filter the minimum values ​​in the second data segment of displacement to generate the lower envelope value sequence of displacement extreme values. S4: Perform cross-correlation operation on the upper envelope value sequence of the torque extreme value and the lower envelope value sequence of the displacement extreme value to generate a cross-correlation matrix, extract the diagonal extreme value of the cross-correlation matrix, and calculate the ratio of the diagonal extreme value to the cumulative damage degree value of the thermo-coupling as the multi-physical quantity coupling correlation feature value; S5: Calculate the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determine whether the rubber seal has reached the critical point of micro-peeling of wear, and generate the wear resistance performance status test result of the rubber seal.

2. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, The first data segment of torque includes an initial tangential friction torque term, a process tangential friction torque term, and a final tangential friction torque term. The second data segment of displacement includes an initial normal displacement term, a process normal displacement term, and a final normal displacement term. The cumulative damage degree value of thermo-coupling is specifically a single quantitative value calculated by the standardized mapping relationship between the weighted torque accumulation value and the temperature gradient value of the friction interface at the current moment. The upper envelope value sequence of torque extrema includes an initial maximum torque term, an intermediate maximum torque term, and an end maximum torque term. The lower envelope value sequence of displacement extrema includes an initial minimum displacement term, an intermediate minimum displacement term, and an end minimum displacement term. The multi-physical quantity coupling correlation feature value is specifically a single feature correlation value calculated by the proportional relationship between the diagonal extrema and the cumulative damage degree value of thermo-coupling. The test results of the wear resistance performance of the rubber seal include historical deviation records of feature values, a peeling critical point judgment mark, and a conclusion on the wear state of the seal.

3. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, Step S1 is as follows: S101: During the relative friction operation test cycle of the rubber seal on the performance test bench, the continuous numerical sequence of tangential friction torque of the rubber seal is obtained by the torque sensor, and the corresponding time window range is defined to generate the tangential friction torque time window. S102: Within the same test cycle, the continuous numerical sequence of the normal compression displacement of the rubber seal is synchronously acquired through the displacement sensor, and the corresponding time window range is defined to obtain the normal displacement time window. S103: Extract the set of torque values ​​within the defined range corresponding to the tangential friction torque time window to obtain the first torque data segment; extract the set of normal displacement values ​​within the defined range corresponding to the normal displacement time window to obtain the second displacement data segment.

4. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, Step S2 is as follows: S201: Input the continuous numerical sequence of tangential friction torque into the Grunwald-Letnikov discretization algorithm, and perform a weighted operation on each tangential friction torque value in the continuous numerical sequence of tangential friction torque based on a preset attenuation factor to obtain a weighted torque cumulative value. S202: Within the same test cycle, the current friction surface temperature value of the rubber seal is obtained by an infrared temperature probe, and the current internal measuring point temperature value is obtained by a temperature sensor inside the rubber seal. Combined with the preset distance between the surface of the rubber seal and the internal measuring point, the current friction interface temperature gradient value is calculated. S203: Perform standardization processing on the weighted torque accumulation value and the friction interface temperature gradient value at the current moment, and calculate the product between the standardized weighted torque accumulation value and the friction interface temperature gradient value at the current moment as the cumulative damage degree value of thermal coupling.

5. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, Step S3 is as follows: S301: Determine the relationship between the tangential friction torque value of the current node in the first data segment of torque and the tangential friction torque values ​​of the adjacent time nodes, filter out the maximum value nodes that are greater than the corresponding tangential friction torque values ​​of the adjacent items and sort them in time sequence to obtain the torque maximum value node sequence. S302: Determine the relationship between the normal compression displacement value of the current node in the second displacement data segment and the normal compression displacement values ​​of the adjacent time nodes before and after it, filter out the minimum value nodes that are smaller than the corresponding normal compression displacement values ​​of the adjacent items before and after it, and sort them in time sequence to obtain the displacement minimum value node sequence. S303: Perform interpolation connection processing on each maximum tangential friction torque in the maximum torque node sequence to obtain the maximum value envelope boundary state; perform interpolation connection processing on each minimum normal compression displacement in the minimum displacement node sequence to obtain the minimum value envelope boundary state; and construct the upper envelope value sequence of maximum torque and the lower envelope value sequence of maximum displacement respectively.

6. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, Step S4 is as follows: S401: Using the upper envelope value sequence of the torque extremum as the first signal source and the lower envelope value sequence of the displacement extremum as the second signal source, perform discrete cross-correlation operation on the corresponding data point items of the first signal source and the second signal source to establish a torque-displacement cross-correlation matrix. S402: Select the maximum cross-correlation value inside the main diagonal region of the torque-displacement cross-correlation matrix as the representative feature of torque-displacement correlation, and obtain the diagonal extreme value; S403: Calculate the ratio of the diagonal extreme value to the cumulative damage value of the thermal coupling to obtain the multi-physical quantity coupling correlation characteristic value.

7. The method for testing the wear resistance of rubber seals according to claim 1, characterized in that, Step S5 is as follows: S501: Read the historical multi-physical quantity coupling correlation feature value recorded in the previous test cycle, calculate the difference between the current multi-physical quantity coupling correlation feature value and the historical multi-physical quantity coupling correlation feature value, and use it as the state change intensity value; S502: When the intensity value of the state change exceeds the preset judgment threshold, the rubber seal is determined to have reached the critical state of the micro-detachment starting point of the surface material structure, and the judgment result of the micro-peeling critical point of wear is obtained. S503: Summarize and archive the test cycle status of the determination results of the wear micro-stripping critical point, organize the material consumption and structural damage evolution evaluation data of the rubber seal within the current friction operation test cycle, and obtain the wear resistance status test results of the rubber seal.

8. The method for testing the wear resistance of rubber seals according to claim 4, characterized in that, The process of setting the preset attenuation factor is as follows: Obtain the total number of time nodes in the continuous numerical sequence of tangential friction torque; The initial attenuation calibrator value of the Grunwald-Letnikov discretization algorithm is obtained as the preset initial reference value; The attenuation factor is obtained by performing positive correlation mapping on the preset initial reference value based on the total number of time nodes of the continuous numerical sequence of tangential friction torque.

9. The method for testing the wear resistance of rubber seals according to claim 4, characterized in that, The distance between the surface of the rubber seal and the internal measuring point is set according to the total thickness of the radial solid section of the rubber seal and the installation depth of the temperature sensor inside the rubber seal.

10. A rubber seal wear resistance testing system, characterized in that, The system is used to implement the method for testing the wear resistance of rubber seals according to any one of claims 1-9, and the system comprises: The data acquisition and interception module acquires the continuous numerical sequence of tangential friction torque and the continuous numerical sequence of normal compression displacement of the rubber seal during the relative friction operation test cycle of the rubber seal on the performance test bench, and extracts the first data segment of torque and the second data segment of displacement from them. The thermo-coupling damage calculation module performs weighted calculations on the continuous numerical sequence of tangential friction torque to obtain a weighted cumulative torque value, acquires the friction interface temperature gradient value at the current moment, performs standardization processing on the weighted cumulative torque value and the friction interface temperature gradient value at the current moment, and calculates the product between the standardized weighted cumulative torque value and the friction interface temperature gradient value at the current moment as the thermo-coupling cumulative damage degree value. The extreme value envelope sequence generation module filters the maximum values ​​in the first data segment of torque to generate an upper envelope value sequence of extreme torque values, and filters the minimum values ​​in the second data segment of displacement to generate a lower envelope value sequence of extreme displacement values. The coupling correlation feature calculation module performs cross-correlation operation on the upper envelope value sequence of the torque extreme value and the lower envelope value sequence of the displacement extreme value to generate a cross-correlation matrix, extracts the diagonal extreme value of the cross-correlation matrix, and calculates the ratio of the diagonal extreme value to the cumulative damage degree value of the thermo-coupling as the multi-physical quantity coupling correlation feature value. The wear resistance performance status assessment module calculates the deviation between the multi-physical quantity coupling correlation characteristic value and the historical multi-physical quantity coupling correlation characteristic value, determines whether the rubber seal has reached the critical point of micro-peeling of wear, and generates the wear resistance performance status test result of the rubber seal.

Images