Material aging state evaluation method and device, terminal equipment and storage medium

Abstract

The invention discloses a material aging state evaluation method and device, terminal equipment and a storage medium. The method comprises the following steps: obtaining a performance index of a to-be-evaluated material in each sub-time period in a preset time period; performing pairwise comparison according to each index in the performance indexes, and determining an initial weight matrix of the performance indexes; a matrix consistency ratio is calculated according to the current weight matrix, and a final target weight matrix is obtained until the matrix consistency ratio is smaller than a preset matrix ratio threshold value; updating the current weight matrix according to the matrix consistency ratio; performing principal component analysis according to the performance indexes and the target weight matrix to obtain a principal component relational expression; according to the principal component relational expression and the final target weight matrix, calculating to obtain a comprehensive evaluation score of the to-be-evaluated material; and performing aging state evaluation on the to-be-evaluated material according to the comprehensive evaluation score to obtain an aging state evaluation result of the to-be-evaluated material. By implementing the invention, the accuracy of evaluating the aging state of the material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material aging assessment in high voltage and insulation technology, and in particular to a material aging status assessment method, device, terminal equipment and storage medium. Background Art

[0002] PE (polyethylene) materials are widely used in many fields due to their excellent performance. In the fields of urban water supply and natural gas transportation, PE pipes have become an ideal pipe material choice due to their comprehensive advantages such as safety, hygiene and convenient construction. In addition, PE materials are also widely used in the plastics, rubber, fiber and other industries to produce various containers, pipes, films and other products.

[0003] At present, the aging behavior of PE materials may show nonlinear and complex characteristics. For example, long-term exposure of PE materials to ultraviolet radiation and high temperature environments can easily lead to material aging; the influence of mechanical stress can cause the PE material to deform and accelerate aging; contact with chemical substances can also cause the PE material to degrade and accelerate aging. At present, the interaction of multiple factors makes it impossible for a single model to accurately evaluate the performance of PE materials under multiple aging conditions. Existing PE material aging status assessment methods are also mostly concentrated on a single physical field assessment model. For example, independent studies on thermal aging, light aging or mechanical aging fail to fully reflect the comprehensive aging status of PE materials, resulting in low accuracy in PE material aging status assessment. Summary of the invention

[0004] The embodiments of the present invention provide a material aging status assessment method, device, terminal device and storage medium, which can effectively solve the problem that the prior art fails to fully reflect the comprehensive aging status of PE materials, resulting in low accuracy in PE material aging status assessment.

[0005] An embodiment of the present invention provides a material aging state assessment method, comprising:

[0006] Obtain the performance indicators of each sub-period within the preset period of the material to be evaluated;

[0007] Performing pairwise comparisons on each of the performance indicators to determine an initial weight matrix of the performance indicators;

[0008] Calculating a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, obtaining a final target weight matrix; and updating the current weight matrix according to the matrix consistency ratio;

[0009] Performing principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula;

[0010] According to the principal component relationship formula and the final target weight matrix, a comprehensive evaluation score of the material to be evaluated is calculated;

[0011] Performing an aging status assessment on the material to be assessed according to the comprehensive assessment score to obtain an aging status assessment result of the material to be assessed;

[0012] The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

[0013] Furthermore, comparing each of the performance indicators in pairs to determine the initial weight matrix of the performance indicators includes:

[0014] According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs;

[0015] According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators;

[0016] According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

[0017] Further, a matrix consistency ratio is calculated according to the current weight matrix, and when the matrix consistency ratio is less than a preset matrix ratio threshold, a final target weight matrix is ​​obtained, including:

[0018] According to the current weight matrix, the current characteristic root maximum value of the current weight matrix and the order of the weight matrix are calculated;

[0019] Determine the average random consistency index of the current weight matrix according to the weight matrix order and a preset consistency index table;

[0020] The current matrix consistency ratio is calculated based on the ratio of the current eigenvalue maximum value and the average random consistency index;

[0021] The current matrix consistency ratio is compared with the preset matrix ratio threshold until the current matrix consistency ratio is less than the preset matrix ratio threshold, and the current weight matrix corresponding to the current matrix consistency ratio is used as the final target weight matrix.

[0022] Furthermore, principal component analysis is performed based on the performance indicators and the final target weight matrix to obtain a principal component relationship, including:

[0023] According to the final target weight matrix, the first eigenvector of the target weight matrix is ​​calculated;

[0024] Performing multiplication calculation based on the first eigenvector and the performance index to obtain a weighted performance index;

[0025] Determining the data volume of each indicator according to the performance indicator;

[0026] According to the data volume of each indicator and the weighted performance indicator, a correlation coefficient matrix of the performance indicator is calculated;

[0027] According to the correlation coefficient matrix, a first eigenvalue and a second eigenvector of the correlation coefficient matrix are calculated;

[0028] According to the first eigenvalue, a cumulative variance contribution rate is calculated; until the change rate of the cumulative variance contribution rate is less than a preset change rate threshold, a corresponding performance indicator is extracted as a principal component factor;

[0029] A principal component relationship equation is constructed according to the principal component factors and the second eigenvector.

[0030] Furthermore, according to the principal component relationship and the final target weight matrix, the comprehensive evaluation score of the material to be evaluated is calculated, including:

[0031] According to the final target weight matrix and the second eigenvector of the corresponding correlation coefficient matrix, the eigenvector of the principal component factor is determined;

[0032] According to the eigenvector of the principal component factor and the principal component relationship formula, a comprehensive evaluation score of the material to be evaluated is calculated.

[0033] Furthermore, before performing pairwise comparisons on each of the performance indicators, the method further includes:

[0034] The impact strength, the thermal decomposition starting temperature and the melting peak value temperature in the performance indicators are respectively converted into inverse indicators to obtain the final impact strength, the final thermal decomposition starting temperature and the final melting peak value temperature;

[0035] According to the carbonyl index and the hydroxyl index in the performance index, respectively determine the corresponding optimal carbonyl index and the optimal hydroxyl index;

[0036] According to the carbonyl index and the corresponding optimal carbonyl index, a suitable index conversion is performed to obtain the final carbonyl index;

[0037] Performing appropriate index conversion according to the hydroxyl index and the corresponding optimal hydroxyl index to obtain the final hydroxyl index;

[0038] The final performance indicators are obtained according to the final impact strength, the final thermal decomposition starting temperature, the final melting peak temperature, the final carbonyl index, the final hydroxyl index, the tensile strength and the flexural strength.

[0039] As an improvement of the above solution, another embodiment of the present invention provides a material aging state assessment device, including:

[0040] An indicator acquisition module is used to obtain the performance indicators of each sub-period within a preset period of the material to be evaluated;

[0041] An initial weight matrix determination module, used to determine the initial weight matrix of the performance indicators by comparing each of the performance indicators in pairs;

[0042] A target weight matrix determination module is used to calculate a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, to obtain a final target weight matrix; and to update the current weight matrix according to the matrix consistency ratio;

[0043] A principal component analysis module, used to perform principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula;

[0044] A comprehensive evaluation score determination module is used to calculate the comprehensive evaluation score of the material to be evaluated based on the principal component relationship formula and the final target weight matrix;

[0045] A material aging assessment module, used to assess the aging status of the material to be assessed according to the comprehensive assessment score, and obtain an aging status assessment result of the material to be assessed;

[0046] The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

[0047] Furthermore, the initial weight matrix determination module is used to determine the initial weight matrix of the performance indicators by comparing each of the performance indicators in pairs;

[0048] According to each of the performance indicators, pairwise comparison is performed to determine the initial weight matrix of the performance indicators, including:

[0049] According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs;

[0050] According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators;

[0051] According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

[0052] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, a material aging status assessment method as described in the above embodiment is implemented.

[0053] Another embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute a material aging status assessment method described in the above embodiment.

[0054] By implementing the present invention, at least the following beneficial effects are achieved:

[0055] The present invention provides a material aging status assessment method, device, terminal equipment and storage medium, the method can obtain the performance index of each sub-period within a preset time period of the material to be assessed; perform pairwise comparison according to each index in the performance index to determine the initial weight matrix of the performance index; calculate the matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than the preset matrix ratio threshold, obtain the final target weight matrix; and update the current weight matrix according to the matrix consistency ratio; perform principal component analysis according to the performance index and the target weight matrix to obtain the principal component relationship formula; calculate the comprehensive assessment score of the material to be assessed according to the principal component relationship formula and the final target weight matrix; perform aging status assessment on the material to be assessed according to the comprehensive assessment score to obtain the aging status assessment result of the material to be assessed; wherein the performance indexes include: tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak peak temperature; the current weight matrix when the matrix consistency ratio is calculated for the first time is the initial weight matrix. Through the performance indicators of the material to be evaluated in each sub-period within the preset time period, we can fully understand the performance changes of the material in different time periods. The tensile strength, flexural strength and impact strength reflect the influence of mechanical aging, the carbonyl index and hydroxyl index reflect the influence of light aging and thermal aging, the thermal decomposition starting temperature and the melting peak temperature reflect the influence of thermal aging. In addition, these performance indicators also reflect the influence of multiple factors on the material to be evaluated; the comprehensive evaluation score is obtained by combining multiple performance indicators and the final target weight matrix, which realizes the comprehensive quantitative evaluation of the aging status of the material to be evaluated, and improves the accuracy of the aging status evaluation of the material to be evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a flow chart of a material aging state assessment method provided by one embodiment of the present invention;

[0057] Figure 2 is another schematic flow chart of a material aging state assessment method provided by another embodiment of the present invention;

[0058] Figure 3 It is a schematic diagram of a principal component analysis process of a material aging state assessment method provided by an embodiment of the present invention;

[0059] Figure 4 It is a structural schematic diagram of a material aging state assessment device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] See also Figure 1 , is a flow chart of a material aging state assessment method provided by an embodiment of the present invention, comprising:

[0062] S1. Obtain the performance index of each sub-period within the preset period of the material to be evaluated;

[0063] S2. Performing pairwise comparisons on each of the performance indicators to determine an initial weight matrix of the performance indicators;

[0064] S3, calculating a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, obtaining a final target weight matrix; and updating the current weight matrix according to the matrix consistency ratio;

[0065] S4, performing principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula;

[0066] S5. Calculate the comprehensive evaluation score of the material to be evaluated based on the principal component relationship formula and the final target weight matrix;

[0067] S6. Evaluate the aging state of the material to be evaluated according to the comprehensive evaluation score to obtain an aging state evaluation result of the material to be evaluated;

[0068] The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

[0069] Specifically, an aging simulation experiment is conducted on the material to be evaluated. The aging state in multi-physical scenarios is simulated. Multi-physical fields include electric fields, thermal fields, mechanical fields, magnetic fields, optical fields, etc., and can be the superposition of any two or more of these physical fields; the performance indicators of the material to be evaluated in each sub-period within the preset time period are obtained in real time, and the change data of multiple indicators in multiple sub-periods are obtained; the initial weight matrix represents the initial representation weight of each indicator in the performance indicator; the final target weight matrix represents the weight matrix with reasonable weight distribution after the initial weight matrix is ​​tested for consistency; the principal component relationship represents the relationship between the main components that affect the aging of the material to be evaluated determined in the performance indicator. The tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition onset temperature and melting peak peak temperature are taken as variables that change with aging time in the material to be evaluated. Tensile strength measures the material's resistance to stretching by external forces; flexural strength reflects the dynamic changes in the material's curvature, which is an important parameter for evaluating the material's integrity under bending stress; impact strength reveals the material's toughness when subjected to sudden impact; changes in the carbonyl index and hydroxyl index are of great significance for understanding the breaking and formation of chemical bonds during material aging. An increase in the carbonyl index may mean a deepening of the material's oxidation degree, while changes in the hydroxyl index may reflect changes in the material's internal moisture content or reactions with other substances; changes in the thermal decomposition onset temperature and the melting peak temperature, these two parameters are used to evaluate the material's thermal stability and processing performance. An increase in the thermal decomposition onset temperature means that the material can only decompose at a higher temperature, thereby improving its thermal stability; changes in the melting peak temperature may affect the material's processing temperature range and melting behavior.

[0070] In a preferred embodiment of the present invention, the performance indicators of each sub-period within a preset time period of the material to be evaluated are first obtained, and the performance indicators include: tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak peak temperature; then, each indicator in the performance indicators is compared pairwise to determine the initial weight matrix of the performance indicators; then, the matrix consistency ratio is calculated according to the current weight matrix, until the matrix consistency ratio is less than the preset matrix ratio threshold, the final target weight matrix is ​​obtained; and the current weight matrix is ​​updated according to the matrix consistency ratio; wherein, the current weight matrix when the matrix consistency ratio is calculated for the first time is the initial weight matrix; then, principal component analysis is performed according to the performance indicators and the target weight matrix to obtain the principal component relationship formula; then, according to the principal component relationship formula and the final target weight matrix, the comprehensive evaluation score of the material to be evaluated is calculated, that is, Figure 2 The comprehensive evaluation index is calculated; finally, the aging state of the material to be evaluated is evaluated according to the comprehensive evaluation score to obtain the aging state evaluation result of the material to be evaluated.

[0071] Specifically, comparing each of the performance indicators in pairs to determine the initial weight matrix of the performance indicators includes:

[0072] According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs;

[0073] According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators;

[0074] According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

[0075] In a preferred embodiment of the present invention, the preset hierarchy table records the hierarchy to which each indicator belongs; the preset scale table quantifies and scales the hierarchy to which each indicator belongs, indicating the influence relationship between two indicators. The scale table is shown in Table 1 below:

[0076] Table 1

[0077]

[0078] For example, the tensile strength is two levels higher than the thermal decomposition starting temperature. When the tensile strength and the thermal decomposition starting temperature are compared in levels, the tensile strength has a stronger influence than the thermal decomposition starting temperature. According to the table above, the correlation scale is 5; the tensile strength and the bending strength belong to the same level, and the tensile strength and the bending strength have the same influence on the material to be evaluated, so the correlation scale between the two is 1. Similarly, each indicator is compared in pairs, and the correlation scale C of each two indicators is finally obtained. ij, and then determine the initial weight matrix C of the performance index = (C ij ) n×n ,

[0079] Preferably, a matrix consistency ratio is calculated according to the current weight matrix, and when the matrix consistency ratio is less than a preset matrix ratio threshold, a final target weight matrix is ​​obtained, including:

[0080] According to the current weight matrix, the current characteristic root maximum value of the current weight matrix and the weight matrix order are calculated;

[0081] Determine the average random consistency index of the current weight matrix according to the weight matrix order and a preset consistency index table;

[0082] The current matrix consistency ratio is calculated based on the ratio of the current eigenvalue maximum value and the average random consistency index;

[0083] The current matrix consistency ratio is compared with the preset matrix ratio threshold until the current matrix consistency ratio is less than the preset matrix ratio threshold, and the current weight matrix corresponding to the current matrix consistency ratio is used as the final target weight matrix.

[0084] In a preferred embodiment of the present invention, the preset consistency index table represents the average random consistency index corresponding to each weight matrix order; the preset matrix ratio threshold represents the threshold compared with the current matrix consistency ratio, which is set to 0.1 in this embodiment. The consistency index table is shown in Table 2, where n represents the weight matrix order, I R Represents the average random consistency index:

[0085] Table 2

[0086]

[0087] First, according to the current weight matrix, calculate the current characteristic root maximum value λ of the current weight matrix max And the weight matrix order n; then according to the weight matrix order and the preset consistency index table, determine the average random consistency index I of the current weight matrix R ; Then, according to the ratio of the current maximum value of the characteristic root and the average random consistency index, the current matrix consistency ratio R is calculated C , R C =I C / I R , where I C =(λ max -n) / (n-1) and then compare the current matrix consistency ratio with the preset matrix ratio threshold, that is, according to Figure 2 The consistency ratio is less than 0.1 until the current matrix consistency ratio is less than the preset matrix ratio threshold, that is, R c When <0.1, the current weight matrix allocation is reasonable and has satisfactory consistency. The current weight matrix corresponding to the current matrix consistency ratio is used as the final target weight matrix. In this embodiment, the final target weight matrix can be expressed as:

[0088] If the condition is not met (greater than or equal to the matrix ratio threshold), the elements in the current weight matrix need to be appropriately adjusted to achieve satisfactory consistency.

[0089] Preferably, a principal component analysis is performed based on the performance index and the final target weight matrix to obtain a principal component relationship, including:

[0090] According to the final target weight matrix, the first eigenvector of the target weight matrix is ​​calculated;

[0091] Performing multiplication calculation based on the first eigenvector and the performance index to obtain a weighted performance index;

[0092] Determining the data volume of each indicator according to the performance indicator;

[0093] According to the data volume of each indicator and the weighted performance indicator, a correlation coefficient matrix of the performance indicator is calculated;

[0094] According to the correlation coefficient matrix, a first eigenvalue and a second eigenvector of the correlation coefficient matrix are calculated;

[0095] According to the first eigenvalue, a cumulative variance contribution rate is calculated; until the change rate of the cumulative variance contribution rate is less than a preset change rate threshold, a corresponding performance indicator is extracted as a principal component factor;

[0096] A principal component relationship equation is constructed according to the principal component factors and the second eigenvector.

[0097] Specifically, the first eigenvector represents the eigenvector of the final target weight matrix; the first eigenvalue represents the eigenvalue of the correlation coefficient matrix; the second eigenvector represents the eigenvector of the correlation coefficient matrix. First, according to the final target weight matrix, the first eigenvector W of the target weight matrix is ​​calculated. j , then according to the first eigenvector W j And the performance index X ij ′ is multiplied to obtain the weighted performance index W ij ,W ij =W j ×Xij '; Determine the data volume k of each indicator according to the performance indicator, and then calculate the correlation coefficient matrix R of the performance indicator according to the data volume k of each indicator and the weighted performance indicator, Where W ti , W tj After the correlation coefficient matrix is ​​obtained, the first eigenvalue λ1λ2…λ of the correlation coefficient matrix can be calculated by the Jacobi method according to the correlation coefficient matrix. p and the second eigenvector a i =(a i1 ,a i1 ,…,a ip ), then according to the first eigenvalue, the cumulative variance contribution rate Y is calculated m , first calculate the variance contribution rate using the following formula: Then calculate the cumulative variance contribution rate Y m (Cumulative variance contribution of the first m principal components): After the variance contribution rate is calculated, the cumulative variance contribution rate after taking out m principal component factors is less than the preset change rate threshold (or remains constant), and the corresponding performance index is extracted as the principal component factor. Then, according to the principal component factor and the second eigenvector, the principal component relationship is constructed as shown below:

[0098]

[0099] P1,...,P n It represents the extracted principal component factors. In this embodiment, there are at most 7 principal component factors.

[0100] In a preferred embodiment of the present invention, the square root method can be used to calculate the eigenvector of the target weight matrix. For example, first determine the product M of each row element of the matrix. i : Then calculate M i The nth root W i : Finally, the eigenvector W i To normalize:

[0101] Schematically, according to the principal component relationship and the final target weight matrix, the comprehensive evaluation score of the material to be evaluated is calculated, including:

[0102] According to the final target weight matrix and the second eigenvector of the corresponding correlation coefficient matrix, the eigenvector of the principal component factor is determined;

[0103] According to the eigenvector of the principal component factor and the principal component relationship formula, a comprehensive evaluation score of the material to be evaluated is calculated.

[0104] In a preferred embodiment of the present invention, Figure 3 As shown in the figure, after extracting the principal component factors, the comprehensive evaluation score Z is calculated by the following formula:

[0105]

[0106] Preferably, before performing pairwise comparisons on each of the performance indicators, the method further includes:

[0107] The impact strength, the thermal decomposition starting temperature and the melting peak value temperature in the performance indicators are respectively converted into inverse indicators to obtain the final impact strength, the final thermal decomposition starting temperature and the final melting peak value temperature;

[0108] According to the carbonyl index and the hydroxyl index in the performance index, respectively determine the corresponding optimal carbonyl index and the optimal hydroxyl index;

[0109] According to the carbonyl index and the corresponding optimal carbonyl index, a moderate index conversion is performed to obtain the final carbonyl index;

[0110] Performing appropriate index conversion according to the hydroxyl index and the corresponding optimal hydroxyl index to obtain the final hydroxyl index;

[0111] The final performance indicators are obtained according to the final impact strength, the final thermal decomposition starting temperature, the final melting peak temperature, the final carbonyl index, the final hydroxyl index, the tensile strength and the flexural strength.

[0112] In a preferred embodiment of the present invention, the tensile strength measures the resistance of the material to external tension and is a positive indicator; the bending strength reflects the dynamic change of the material's bending degree, which is an important parameter for evaluating the integrity of the material under bending stress and is a positive indicator; the impact strength reveals the toughness of the material when it is subjected to a sudden impact and is an inverse indicator; the changes in the carbonyl index and the hydroxyl index are of great significance for understanding the breaking and formation of chemical bonds during the aging process of the material and are moderate indicators. The increase in the carbonyl index may mean the deepening of the oxidation degree of the material, while the change in the hydroxyl index may reflect the change in the moisture content inside the material or the reaction with other substances and is a moderate indicator; the change in the thermal decomposition starting temperature and the melting peak temperature, these two parameters are used to evaluate the thermal stability and processing performance of the material. The increase in the thermal decomposition starting temperature means that the material can only undergo a decomposition reaction at a higher temperature, thereby improving its thermal stability and is an inverse indicator; the change in the melting peak temperature may affect the processing temperature range and melting behavior of the material and is an inverse indicator. These indicator changes are processed to make the indicators homogeneous and standardized. Index synchronisation refers to converting the inverse index and the appropriate index into a positive index, and performing inverse index conversion on the impact strength, the thermal decomposition onset temperature and the melting peak temperature, respectively, to obtain the final impact strength, the final thermal decomposition onset temperature and the final melting peak temperature: Among them, X ij is the value before the inverse index conversion, indicating the value of the i-th index at the j-th time point; X' ij It is the value after the inverse index conversion. The carbonyl index and the hydroxyl index are appropriately converted: Y′ ij Indicates the value after the fitness index is converted, Y ij It represents the value before the appropriate index conversion, and α represents the corresponding optimal index, such as the optimal carbonyl index and the optimal hydroxyl index.

[0113] In a preferred embodiment of the present invention, taking photo-oxidation aging as an example, during the simulation experiment, the results of the variables changing over time are recorded. These variables include the tensile strength, impact toughness, heat deformation temperature, light transmittance, etc. of the material, which reflect the performance of the material under different environmental conditions, and obtain the results of the variables X1, X2, X3, X4, X5, X6, and X7 changing over time under the influence of multiple physical fields, which are summarized as performance indicators of aging index parameters, laying the foundation for subsequent analysis. Next, the properties of each indicator in the performance index are judged. This process includes isotropic processing of the indicators, also known as positive conversion. Specifically, the inverse index and the appropriateness index are converted into positive indicators to facilitate subsequent analysis, ensuring the comparability between different indicators, making the subsequent weighted and comprehensive evaluation more accurate.

[0114] After completing the data preprocessing, the tomographic analysis method was used to determine the initial weight matrix of the polyethylene material aging performance indicators. First, the importance of each indicator was evaluated, and the specific values ​​in the initial weight matrix were determined through a nine-level scale. As a polymer material, the mechanical properties of polyethylene under different use environments are the main reference and are obviously the most important. Among them, tensile strength and flexural strength are particularly critical because they directly affect the material's bearing capacity and toughness. Impact strength is slightly less important than the above two parameters, so C 11 =C 12 =C 22 =C 33 =C 44 =C 55 =C 66 =C 77 =1, C 13 =C 23 = 2. The chemical structure often undergoes significant changes during the aging process, so the carbonyl index and hydroxyl index should be ranked second, so C 45 =1, C 14 =C 15 =C 24 =C 25 =3, C 34 =C 35 =C 24 =C 25 =3, these indicators reflect the degree of chemical degradation of the material. In contrast, the changes in thermal properties and melting properties are not significant during aging, indicating that they have less impact on polyethylene, so they are ranked third, so C 67 =1, C 16 =C 17 =C 26 =C 27 =5, C 36 =C 37 =4, C 46 =C 47 =C 56 =C 57 =3. Through the above analysis, we can get the upper triangular matrix of the judgment matrix, and through the symmetry, we can get the initial weight matrix C.

[0115] Then, the square root method is used to calculate the eigenvector of the initial weight matrix, and the necessary consistency ratio test is performed to ensure that the weight vector is reasonable and effective. After passing the consistency test, a reliable weight vector is obtained. The weight vector is multiplied by the aging index (performance index) to form the target weight matrix and the weighted performance index. This matrix reflects the comprehensive influence of each index on the aging characteristics of polyethylene materials, and provides a basis for the subsequent principal component analysis.

[0116] The correlation coefficient matrix of the performance index is calculated through the target weight matrix, and its variance and contribution rate are calculated to obtain the variance contribution rate of the principal component score. As shown in Table 3, taking three principal component factors, the principal component variance contribution rate has basically remained above 98% unchanged (the cumulative variance contribution rate change rate is less than the preset change rate threshold), Component (performance index), Characteristic value (principal component rate), Var iance (variance contribution rate), Accumu lated variance (cumulative variance contribution rate):

[0117] Table 3

[0118]

[0119] Therefore, this embodiment extracts three principal component factors. After determining the number of principal component factors, the eigenvalues ​​and eigenvectors of the performance indicators are calculated to obtain a comprehensive evaluation score under the light-oxidation aging condition:

[0120]

[0121] The comprehensive evaluation score of polyethylene materials was obtained, and the results obtained by the improved principal component analysis method and the traditional principal component analysis method were compared. The results showed that the aging process of LDPE can be divided into several stages: the aging effect is strong in the early stage (0-8 days), and the Z value drops sharply; the aging effect slows down in the middle stage (8-24 days), and the Z value changes slowly; the aging effect is strengthened again in the late stage (24-64 days), and the Z value drops rapidly. Compared with the traditional PCA method, the improved method can more accurately reveal the three-stage change characteristics of LDPE in light-oxidation aging. In the early stage of aging, the LDPE surface undergoes strong oxidation, resulting in significant changes in mechanical properties and chemical structure; the oxidation slows down in the middle stage, and the aging tends to be stable; in the late stage, due to the damage of the surface morphology, the aging is accelerated again. The improved PCA method provides a more reasonable and systematic method for evaluating the aging process of polyethylene materials, which has broad application prospects. The comprehensive evaluation score provides a detailed method support for the performance evaluation of materials. Through in-depth research on the aging characteristics of polyethylene materials, its performance in practical applications can be better predicted, thereby improving the reliability and service life of products.

[0122] By implementing this embodiment, the performance indicators of each sub-period within a preset time period of the material to be evaluated are obtained; each indicator in the performance indicators is compared pairwise to determine the initial weight matrix of the performance indicators; the matrix consistency ratio is calculated according to the current weight matrix, until the matrix consistency ratio is less than the preset matrix ratio threshold, the final target weight matrix is ​​obtained; and the current weight matrix is ​​updated according to the matrix consistency ratio; principal component analysis is performed according to the performance indicators and the target weight matrix to obtain the principal component relationship; the comprehensive evaluation score of the material to be evaluated is calculated according to the principal component relationship and the final target weight matrix; the aging status of the material to be evaluated is evaluated according to the comprehensive evaluation score to obtain the aging status evaluation result of the material to be evaluated; wherein, the performance indicators include: tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition onset temperature and melting peak peak temperature; the current weight matrix when the matrix consistency ratio is calculated for the first time is the initial weight matrix. Through the performance indicators of the material to be evaluated in each sub-period within the preset time period, we can fully understand the performance changes of the material in different time periods. The tensile strength, flexural strength and impact strength reflect the influence of mechanical aging, the carbonyl index and hydroxyl index reflect the influence of light aging and thermal aging, the thermal decomposition starting temperature and the melting peak temperature reflect the influence of thermal aging. In addition, these performance indicators also reflect the influence of multiple factors on the material to be evaluated; the comprehensive evaluation score is obtained by combining multiple performance indicators and the final target weight matrix, which realizes the comprehensive quantitative evaluation of the aging status of the material to be evaluated, and improves the accuracy of the aging status evaluation of the material to be evaluated.

[0123] See also Figure 4 , is a schematic diagram of the structure of a material aging state assessment device provided by an embodiment of the present invention, comprising:

[0124] An indicator acquisition module is used to obtain the performance indicators of each sub-period within a preset period of the material to be evaluated;

[0125] An initial weight matrix determination module, used to determine the initial weight matrix of the performance indicators by comparing each of the performance indicators in pairs;

[0126] A target weight matrix determination module is used to calculate a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, to obtain a final target weight matrix; and to update the current weight matrix according to the matrix consistency ratio;

[0127] A principal component analysis module, used to perform principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula;

[0128] A comprehensive evaluation score determination module is used to calculate the comprehensive evaluation score of the material to be evaluated based on the principal component relationship formula and the final target weight matrix;

[0129] A material aging assessment module, used to assess the aging status of the material to be assessed according to the comprehensive assessment score, and obtain an aging status assessment result of the material to be assessed;

[0130] The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

[0131] Preferably, the initial weight matrix determination module is used to determine the initial weight matrix of the performance indicators by performing pairwise comparison on each of the performance indicators;

[0132] According to each of the performance indicators, pairwise comparison is performed to determine the initial weight matrix of the performance indicators, including:

[0133] According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs;

[0134] According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators;

[0135] According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

[0136] The present invention provides a material aging state evaluation device, which obtains the performance index of each sub-period within a preset time period of the material to be evaluated according to an index acquisition module; in an initial weight matrix determination module, performs pairwise comparison according to each index in the performance index to determine the initial weight matrix of the performance index; in a target weight matrix determination module, calculates a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, obtains the final target weight matrix; and updates the current weight matrix according to the matrix consistency ratio; in a principal component analysis module, performs principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship; in a comprehensive evaluation score determination module, calculates a comprehensive evaluation score of the material to be evaluated according to the principal component relationship and the final target weight matrix; finally, in a material aging evaluation module, performs aging state evaluation on the material to be evaluated according to the comprehensive evaluation score to obtain an aging state evaluation result of the material to be evaluated; wherein the performance indexes include: tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak peak temperature; the current weight matrix when the matrix consistency ratio is calculated for the first time is the initial weight matrix. Through the performance indicators of the material to be evaluated in each sub-period within the preset time period, we can fully understand the performance changes of the material in different time periods. The tensile strength, flexural strength and impact strength reflect the influence of mechanical aging, the carbonyl index and hydroxyl index reflect the influence of light aging and thermal aging, the thermal decomposition starting temperature and the melting peak temperature reflect the influence of thermal aging. In addition, these performance indicators also reflect the influence of multiple factors on the material to be evaluated; the comprehensive evaluation score is obtained by combining multiple performance indicators and the final target weight matrix, which realizes the comprehensive quantitative evaluation of the aging status of the material to be evaluated, and improves the accuracy of the aging status evaluation of the material to be evaluated.

[0137] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0138] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0139] Another embodiment of the present invention further provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements a material aging state assessment method as described in the above embodiment when executing the computer program. The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory.

[0140] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0141] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device or other volatile solid-state storage device.

[0142] Another embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute a material aging status assessment method described in the above embodiment.

[0143] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0144] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A material aging state assessment method, characterized in that: include: Obtain the performance indicators of each sub-period within the preset period of the material to be evaluated; Performing pairwise comparisons on each of the performance indicators to determine an initial weight matrix of the performance indicators; Calculating a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, obtaining a final target weight matrix; and updating the current weight matrix according to the matrix consistency ratio; Performing principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula; According to the principal component relationship formula and the final target weight matrix, a comprehensive evaluation score of the material to be evaluated is calculated; Performing an aging status assessment on the material to be assessed according to the comprehensive assessment score to obtain an aging status assessment result of the material to be assessed; The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

2. A material aging state assessment method according to claim 1, characterized in that: According to each of the performance indicators, pairwise comparison is performed to determine the initial weight matrix of the performance indicators, including: According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs; According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators; According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

3. A material aging state assessment method according to claim 1, characterized in that: The matrix consistency ratio is calculated according to the current weight matrix, and when the matrix consistency ratio is less than a preset matrix ratio threshold, the final target weight matrix is ​​obtained, including: According to the current weight matrix, the current characteristic root maximum value of the current weight matrix and the weight matrix order are calculated; Determine the average random consistency index of the current weight matrix according to the weight matrix order and a preset consistency index table; The current matrix consistency ratio is calculated based on the ratio of the current eigenvalue maximum value and the average random consistency index; The current matrix consistency ratio is compared with the preset matrix ratio threshold until the current matrix consistency ratio is less than the preset matrix ratio threshold, and the current weight matrix corresponding to the current matrix consistency ratio is used as the final target weight matrix.

4. A material aging state assessment method according to claim 1, characterized in that: According to the performance index and the final target weight matrix, a principal component analysis is performed to obtain a principal component relationship, including: According to the final target weight matrix, the first eigenvector of the target weight matrix is ​​calculated; Performing multiplication calculation based on the first eigenvector and the performance index to obtain a weighted performance index; Determining the data volume of each indicator according to the performance indicator; According to the data volume of each indicator and the weighted performance indicator, a correlation coefficient matrix of the performance indicator is calculated; According to the correlation coefficient matrix, a first eigenvalue and a second eigenvector of the correlation coefficient matrix are calculated; According to the first eigenvalue, a cumulative variance contribution rate is calculated; until the change rate of the cumulative variance contribution rate is less than a preset change rate threshold, a corresponding performance indicator is extracted as a principal component factor; A principal component relationship equation is constructed according to the principal component factors and the second eigenvector.

5. A material aging state assessment method as claimed in claim 4, characterized in that: According to the principal component relationship and the final target weight matrix, the comprehensive evaluation score of the material to be evaluated is calculated, including: According to the final target weight matrix and the second eigenvector of the corresponding correlation coefficient matrix, the eigenvector of the principal component factor is determined; According to the eigenvector of the principal component factor and the principal component relationship formula, a comprehensive evaluation score of the material to be evaluated is calculated.

6. A material aging state assessment method according to claim 1, characterized in that: Before performing pairwise comparisons on each of the performance indicators, the method further includes: The impact strength, the thermal decomposition starting temperature and the melting peak value temperature in the performance indicators are respectively converted into inverse indicators to obtain the final impact strength, the final thermal decomposition starting temperature and the final melting peak value temperature; According to the carbonyl index and the hydroxyl index in the performance index, respectively determine the corresponding optimal carbonyl index and the optimal hydroxyl index; According to the carbonyl index and the corresponding optimal carbonyl index, a moderate index conversion is performed to obtain the final carbonyl index; Performing appropriate index conversion according to the hydroxyl index and the corresponding optimal hydroxyl index to obtain the final hydroxyl index; The final performance indicators are obtained according to the final impact strength, the final thermal decomposition starting temperature, the final melting peak temperature, the final carbonyl index, the final hydroxyl index, the tensile strength and the flexural strength.

7. A material aging status assessment device, characterized in that: include: An indicator acquisition module is used to obtain the performance indicators of each sub-period within a preset period of the material to be evaluated; An initial weight matrix determination module, used to determine the initial weight matrix of the performance indicators by comparing each of the performance indicators in pairs; A target weight matrix determination module is used to calculate a matrix consistency ratio according to the current weight matrix, until the matrix consistency ratio is less than a preset matrix ratio threshold, to obtain a final target weight matrix; and to update the current weight matrix according to the matrix consistency ratio; A principal component analysis module, used to perform principal component analysis according to the performance index and the target weight matrix to obtain a principal component relationship formula; A comprehensive evaluation score determination module is used to calculate the comprehensive evaluation score of the material to be evaluated based on the principal component relationship formula and the final target weight matrix; A material aging assessment module, used to assess the aging status of the material to be assessed according to the comprehensive assessment score, and obtain an aging status assessment result of the material to be assessed; The performance indicators include tensile strength, flexural strength, impact strength, carbonyl index, hydroxyl index, thermal decomposition starting temperature and melting peak temperature; the current weight matrix when calculating the matrix consistency ratio for the first time is the initial weight matrix.

8. A material aging state assessment device as claimed in claim 7, characterized in that: The initial weight matrix determination module is used to determine the initial weight matrix of the performance indicators by comparing each of the performance indicators in pairs; According to each of the performance indicators, pairwise comparison is performed to determine the initial weight matrix of the performance indicators, including: According to the performance indicators and a preset hierarchy table, determining the hierarchy to which each indicator in the performance indicators belongs; According to the level of each indicator and the preset scale table, the level of each two indicators is compared to obtain the relevant scale of each two indicators; According to the correlation scale of every two indicators, the initial weight matrix of the performance indicators is determined.

9. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a material aging state assessment method as claimed in any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute a material aging state assessment method as described in any one of claims 1 to 6.

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