Methods, equipment, and media for evaluating the mechanical properties of cellulose bulk-doped insulating paper

Abstract

This application discloses a method, equipment, and medium for evaluating the mechanical properties of cellulose bulk-doped insulating paper. The method includes: determining a three-phase model for evaluating the mechanical properties of the insulating paper; obtaining a pre-defined standard mechanical model corresponding to the insulating paper matrix; modifying the standard mechanical model based on the three-phase model to obtain a modified first mechanical model and a second mechanical model; determining the interface layer thickness of the insulating paper at different filler mass fractions using the first and second mechanical models; constructing a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper based on the first and second mechanical models; predicting the target Young's modulus of the insulating paper at different filler mass fractions based on the comprehensive mechanical model and the interface layer thickness; and fitting the corresponding mechanical property curve of the insulating paper using the target Young's modulus to evaluate the mechanical properties of the insulating paper.

Description

Technical Field

[0001] This application relates to the field of insulating paper technology, specifically to a method, equipment, and medium for evaluating the mechanical properties of cellulose bulk-doped insulating paper. Background Technology

[0002] Cellulose-doped insulating paper is widely used in power transformers due to its excellent thermal and insulation properties. However, during transformer operation, the insulating paper is subjected to long-term thermal, electrical, and mechanical stresses, leading to deterioration of its mechanical properties and ultimately electrical faults in the transformer. Therefore, it is necessary to predict and evaluate the mechanical properties of insulating paper to ensure the safe operation of electrical equipment.

[0003] Currently, many classical mechanical models are widely used to determine the mechanical properties of polymer composites, such as the Halpin–Tsai equation, the Ouali model, and mixture models. However, for cellulose bulk-doped insulating paper, its mechanical properties change due to the influence effects between cellulose molecules. Existing classical models cannot fully predict the changes in the mechanical properties of insulating paper with the mass fraction of cellulose filler; they can only predict the nonlinear or linear components, resulting in significant errors. Summary of the Invention

[0004] To address the aforementioned problems, this application proposes a method for evaluating the mechanical properties of cellulose bulk-doped insulating paper, comprising:

[0005] A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase;

[0006] A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper.

[0007] The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model.

[0008] Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted.

[0009] The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper.

[0010] In one implementation of this application, based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model, specifically including:

[0011] The agglomeration coefficient of the insulating paper under the action of the filler phase and the agglomerating phase is determined, and the shape factor of the insulating paper is determined according to the agglomeration coefficient; wherein the agglomeration coefficient is positively correlated with the degree of agglomeration of cellulose doped in the bulk phase of the insulating paper;

[0012] Based on the shape factor, the standard mechanical model is modified to obtain the modified first mechanical model;

[0013] The tensile strength of the insulating paper under the action of the interfacial phase is determined, and the standard mechanical model is corrected based on the tensile strength of the material to obtain a second mechanical model.

[0014] In one implementation of this application, the standard mechanical model is modified based on the tensile strength of the material to obtain a second mechanical model, specifically including:

[0015] The second mechanical model is obtained using the following formula:

[0016]

[0017] η=(gE f / E m -1) / (gE f / E m +ξ)

[0018] ξ=2α

[0019] Among them, E c E represents the Young's modulus of cellulose bulk-doped insulating paper. m E represents the Young's modulus of the insulating paper matrix. f The Young's modulus of the cellulose filler. ξ is the volume fraction of cellulose filler, α is the aspect ratio, τ is the interfacial shear strength, R is the radius of cellulose filler, g is the first orientation factor, and η0 is the second orientation factor.

[0020] In one implementation of this application, a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper is constructed based on the first mechanical model and the second mechanical model, specifically including:

[0021]

[0022] η=(gE f / E m -1) / (gE f / E m +ξ)

[0023]

[0024] Where t is the thickness of the interface layer, and a and b represent the aggregation coefficients.

[0025] In one implementation of this application, the interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model, specifically including:

[0026] Using the first mechanical model, the predicted Young's modulus of the insulating paper under different filler mass fractions is predicted, and the actual Young's modulus of the insulating paper under the filler mass fraction is obtained, so as to determine the difference in Young's modulus between the predicted Young's modulus and the actual Young's modulus.

[0027] The difference in Young's modulus is used as the Young's modulus of the insulating paper and substituted into the second mechanical model to obtain the interface layer thickness of the insulating paper under different filler mass fractions.

[0028] In one implementation of this application, the cellulose doped in the insulating paper includes at least microcellulose, nanocellulose whiskers, and nanocellulose fibers.

[0029] In one implementation of this application, the mechanical properties of the insulating paper are evaluated, specifically including:

[0030] Based on the standard Young's modulus of the insulating paper matrix at different filler mass fractions, the standard mechanical property curves corresponding to the insulating paper matrix are fitted to obtain the curves.

[0031] For insulating papers doped with different types of cellulose, the mechanical property curves corresponding to the insulating paper are compared with the standard mechanical property curves to determine the Young's modulus increment of the insulating paper.

[0032] The mechanical properties of insulating papers doped with different types of cellulose are evaluated based on the Young's modulus increment.

[0033] In one implementation of this application, before modifying the standard mechanical model based on the tensile strength of the material to obtain the second mechanical model, the method further includes:

[0034] Determine the stress parameters corresponding to the cellulose doped in the insulating paper; wherein, the stress parameters include ultimate fiber strength, fiber diameter, and critical fiber length;

[0035] The ratio between the fiber diameter and the fiber critical length is determined, and the interfacial shear strength corresponding to the insulating paper is obtained based on the ratio and the limiting fiber strength.

[0036] This application provides a device for evaluating the mechanical properties of cellulose bulk-doped insulating paper, the device comprising:

[0037] At least one processor; and,

[0038] A memory communicatively connected to the at least one processor; wherein,

[0039] The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to:

[0040] A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase;

[0041] A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper.

[0042] The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model.

[0043] Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted.

[0044] The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper.

[0045] This application provides a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured as follows:

[0046] A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase;

[0047] A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper.

[0048] The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model.

[0049] Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted.

[0050] The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper.

[0051] The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper proposed in this application can bring the following benefits:

[0052] Considering the influence of the interfacial phase and agglomerated phase on the mechanical properties of insulating paper, the standard mechanical model was modified, and the reinforcing effect of the interfacial phase was quantified by the thickness of the interfacial layer. In this way, the target Young's modulus of insulating paper under different filler mass fractions was determined, and the Young's modulus of insulating paper under different doping concentrations was accurately predicted. Attached Figure Description

[0053] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0054] Figure 1 A flowchart illustrating a method for evaluating the mechanical properties of cellulose bulk-doped insulating paper provided in this application embodiment;

[0055] Figure 2 A schematic diagram of a three-phase model provided in an embodiment of this application;

[0056] Figures 3a-3cA schematic diagram illustrating the modification mechanism and performance of insulating paper doped with CNW, CNF, and MFC respectively, provided for embodiments of this application;

[0057] Figure 4 This is a schematic diagram of a device for evaluating the mechanical properties of cellulose bulk-doped insulating paper, provided as an embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0060] like Figure 1 As shown in the embodiments of this application, a method for evaluating the mechanical properties of cellulose bulk-doped insulating paper includes:

[0061] S101: Determine the three-phase model for evaluating the mechanical properties of insulating paper; wherein the three-phase model includes the Young's modulus of the cellulose bulk phase-doped insulating paper under the action of the filler phase, agglomerate phase and interface phase.

[0062] Micro / nano modification technology is widely used in various fields, with nano-SiC, nano-TiO2, and nano-SiO2 materials commonly used for insulation modification. Compared to inorganic nanoparticles, micro / nanocellulose has abundant hydroxyl groups, is natural, environmentally friendly, and has good compatibility, exhibiting superior mechanical properties. Micro / nanocellulose is derived from natural cellulose sources such as wood, cotton, and flax. It is more compatible with the fibers in insulating paper and does not require surface grafting. Micro / nanocellulose possesses excellent chemical and physical properties such as high mechanical strength, large specific surface area, and abundant active groups, making it a promising additive for modifying insulating paper. This application's embodiments involve doping different types of cellulose into insulating paper, thereby preparing modified insulating paper to improve the mechanical properties of the polymer through bulk doping of micro / nanocellulose. The types of cellulose doped in the insulating paper include at least microcellulose (MFC), nanocellulose whiskers (CNW), and nanocellulose fibers (CNF).

[0063] Young's modulus is a physical quantity characterizing the tensile or compressive strength of a material within its elastic limit. Within the elastic limit, the ratio of stress to strain is called Young's modulus. The magnitude of Young's modulus indicates the rigidity of a material; the larger the Young's modulus, the less easily the material deforms. Therefore, this application uses Young's modulus as an indicator to evaluate the mechanical properties of insulating paper. However, Young's modulus changes with the mass fraction of cellulose filler. At low concentrations, nanocellulose has high strength and abundant surface hydroxyl groups, making it easier to increase the contact area between insulating paper fibers, forming interfacial regions and thus improving the mechanical properties of the modified paper. At high concentrations, nanocellulose and microcellulose, due to their abundant hydroxyl groups, are prone to aggregation. Aggregation weakens the interfacial effect, essentially introducing impurities, damaging the structure of the insulating paper fiber bundles, and causing a decrease in the mechanical properties of the insulating paper.

[0064] This application considers the effects of interface and agglomeration on modified insulating paper and determines a three-phase model for evaluating the mechanical properties of the insulating paper. The three-phase model includes the Young's modulus of the cellulose bulk-doped insulating paper under the influence of the filler phase, agglomerate phase, and interface phase. The mechanical properties of the insulating paper are affected by the filler phase, agglomerate phase, and interface phase, and the Young's modulus E of the insulating paper can be used to determine its mechanical properties. c It is believed that the reinforcement E of cellulose to the insulating paper matrix is ​​due to... h The decrease in Young's modulus E caused by aggregation a The increase in Young's modulus E caused by the interface effect affected by dispersion i Composition, namely E c =E h +E a +E i .

[0065] like Figure 2 A schematic diagram of a three-phase model is provided, E h E increases with increasing cellulose doping concentration. a The value decreases as the cellulose doping concentration increases. At low concentrations, E... i It will increase due to the formation of the interface region, but as the concentration continues to increase, E i It will gradually decrease due to the aggregation phase effect.

[0066] S102: Obtain the standard mechanical model corresponding to the preset insulating paper matrix. Based on the three-phase model, modify the standard mechanical model to obtain the modified first mechanical model and second mechanical model. The first mechanical model is used to characterize the influence of filler phase and agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of interface on the insulating paper.

[0067] Since traditional standard mechanical models cannot take into account the modifying effects of interface and agglomeration on insulating paper, this application requires obtaining a standard mechanical model corresponding to a preset insulating paper matrix. Based on the three-phase model, the standard mechanical model is modified to obtain the modified first mechanical model and second mechanical model.

[0068] A standard mechanical model can be represented as:

[0069]

[0070] η=(gE f / E m -1) / (gE f / E m +ξ)

[0071] ξ=2α

[0072] Among them, E c E represents the Young's modulus of cellulose bulk-doped insulating paper. m E represents the Young's modulus of the insulating paper matrix. f The Young's modulus of the cellulose filler. ξ is the volume fraction of cellulose filler, α is the shape factor, g is the aspect ratio, and g is the first orientation factor.

[0073] The first mechanical model is used to characterize the effects of filler phase and agglomeration on insulating paper. When modifying the standard mechanical model, the influence of agglomeration on the mechanical properties of insulating paper at high concentrations must first be considered. The agglomeration coefficient of the insulating paper under the influence of the filler phase and the agglomerated phase needs to be determined, and the shape factor of the insulating paper is determined based on the agglomeration coefficient. The agglomeration coefficient is positively correlated with the degree of agglomeration of cellulose in the bulk phase of the insulating paper. Then, based on the shape factor, the standard mechanical model is modified to obtain the modified first mechanical model. The modified first mechanical model can be expressed as:

[0074]

[0075] η=(gE f / E m -1) / (gE f / E m +ξ)

[0076]

[0077] Where a and b represent aggregation coefficients.

[0078] The second mechanical model is used to characterize the effect of the interface on the insulating paper. When the cellulose doping concentration is low, the insulating paper will exhibit a strong interface effect due to the weak cellulose agglomeration phenomenon. At this time, the tensile strength of the insulating paper under the action of the interface phase can be determined. The standard mechanical model is corrected according to the tensile strength of the material to obtain the second mechanical model.

[0079] The tensile strength model of polymer composite materials (such as insulating paper) can be expressed as:

[0080]

[0081] Where τ is the interfacial shear strength, t is the interfacial layer thickness, R is the radius of the cellulose filler, and η0 is the second orientation factor. If the fiber size is greater than the sample thickness, the fiber is considered to be randomly oriented in the two-dimensional plane, g = 1 / 3, η0 = 1 / 3; if the fiber size is less than the sample thickness, the fiber is considered to be randomly oriented in the three-dimensional plane, g = 1 / 6, η0 = 1 / 3.

[0082] Before modifying the standard mechanical model to obtain the second mechanical model, the interfacial shear strength of the insulating paper needs to be determined based on the force balance equation of the fractured part. First, the force parameters corresponding to the cellulose doped in the insulating paper need to be determined. These force parameters include the limiting fiber strength, fiber diameter, and critical fiber length. Then, the ratio between the fiber diameter and the critical fiber length is determined. Based on this ratio and the limiting fiber strength, the interfacial shear strength of the insulating paper is obtained. The interfacial shear strength can be expressed by the following formula:

[0083]

[0084] Among them, E l The limiting fiber strength of cellulose at the critical length, where d is the fiber diameter and l is the limiting fiber strength. c This represents the critical length of the fiber.

[0085] Since the tensile strength of the insulating paper matrix is ​​much smaller than the interfacial shear strength, when t>0, the reinforcing effect of the interfacial phase is approximately equal to... Therefore, after taking into account the influence of the interface phase, the modified second mechanical model can be expressed as:

[0086]

[0087] η=(gE f / E m -1) / (gE f / E m +ξ)

[0088] ξ=2α

[0089] The second mechanical model can evaluate the effects of cellulose under the action of the interfacial phase, so that the mechanical properties of the modified insulating paper can be predicted more accurately even when the cellulose doping concentration is low.

[0090] S103: Using the first mechanical model and the second mechanical model, determine the interface layer thickness of the insulating paper at different filler mass fractions.

[0091] When evaluating the mechanical properties of cellulose bulk-doped insulating paper, the influence of the degree of cellulose filler aggregation must first be considered. After pre-setting the aggregation coefficient, the predicted Young's modulus of the insulating paper at different filler mass fractions can be predicted using a first mechanical model. Then, the actual Young's modulus of the insulating paper at the above filler mass fractions is obtained experimentally, and the difference between the predicted and actual Young's modulus is determined.

[0092] After adjusting the mechanical model to account for agglomerates, the model predictions for CNW and CNF insulating papers at high concentrations are very close to the experimental values. However, at low concentrations, the first mechanical model still struggles to accurately predict the Young's modulus of the insulating paper. In contrast, the first mechanical model considering the agglomerate phase can predict the Young's modulus of MFC insulating paper as a function of filler mass fraction. This is because MFC is micron-sized, resulting in weak interfacial effects, while CNW and CNF are nanometer-sized, leading to significant interfacial effects between the filler and matrix when uniformly dispersed. The presence of these interfacial effects enhances the interaction forces between fibers, thereby improving the mechanical properties of the insulating paper. Therefore, considering only the agglomerate phase is insufficient to predict the Young's modulus of nanocellulose insulating paper.

[0093] At this point, the difference in Young's modulus can be approximated as the increase in Young's modulus due to the interface effect. This difference can then be substituted into the second mechanical model as the Young's modulus of the insulating paper to obtain the interface layer thickness corresponding to different filler mass fractions. As the filler mass fraction increases, large agglomerates appear between the cellulose fibers, severely affecting the interface effect. Therefore, the interface layer thickness will first increase and then decrease.

[0094] S104: Based on the first mechanical model and the second mechanical model, construct a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper, and predict the target Young's modulus of the insulating paper under different filler mass fractions based on the comprehensive mechanical model and the interface layer thickness.

[0095] Combining the first and second mechanical models, a comprehensive mechanical model for evaluating the mechanical properties of insulating paper can be obtained. The comprehensive mechanical model can be expressed by the following formula:

[0096]

[0097] η=(gE f / E m -1) / (gE f / E m +ξ)

[0098]

[0099] Substituting the previously calculated interface layer thickness into the integrated mechanical model, we can obtain the target Young's modulus E corresponding to different filler mass fractions. c .

[0100] S105: By fitting the target Young's modulus, the mechanical property curves corresponding to the insulating paper are obtained, so as to evaluate the mechanical properties of the insulating paper.

[0101] After predicting the target Young's modulus of the insulating paper under different filler mass fractions, the corresponding mechanical property curve can be fitted, and then the mechanical properties of the insulating paper can be evaluated through the mechanical property curve.

[0102] Specifically, based on the standard Young's modulus corresponding to different filler mass fractions of the insulating paper matrix, a standard mechanical property curve corresponding to the insulating paper matrix is ​​fitted to obtain the curve. Here, the insulating paper matrix refers to insulating paper without cellulose doping. After obtaining the standard mechanical property curve, since this application embodiment is for the mechanical property evaluation of insulating paper doped with multiple types of cellulose, it is necessary to compare the mechanical property curve corresponding to the insulating paper doped with different types of cellulose with the standard mechanical property curve to determine the Young's modulus increment of the insulating paper. Thus, based on the Young's modulus increment, the mechanical properties of insulating paper doped with different types of cellulose can be evaluated, thereby determining the mechanical property enhancement effect of different types of modified insulating paper at different filler mass fractions. CNW modified paper with a 10% doping concentration exhibits the highest Young's modulus, with an increase of 11.99%. As the doping concentration increases, the Young's modulus of CNF modified paper shows a trend of first increasing and then decreasing, with fewer and smaller internal aggregates. The Young's modulus of MFC modified paper shows a smaller increase compared to the other two modified papers.

[0103] Furthermore, based on a three-phase model, this application also analyzes the modification mechanism of insulating paper doped with different cellulose molecules. Figures 3a-3c The diagram illustrates the modification mechanism and performance of insulating paper doped with CNW, CNF, and MFC. (See attached diagram.) Figures 3a-3cIt is evident that, compared to CNW-modified paper, CNF-modified paper exhibits a stronger interfacial effect and weaker agglomeration. This is because CNF has a smaller diameter than CNW, resulting in a stronger interfacial effect on the radial scale. As a soft, elongated nanocellulose, it can form a denser nanocellulose permeation network. Compared to the two types of nanocellulose, MFC-modified paper suffers the most severe reduction in mechanical properties due to agglomeration.

[0104] Therefore, CNW exhibits the strongest mechanical property enhancement due to its high strength and strong interfacial interactions. CNF, with its more flexible and slender morphology, shows the weakest aggregation effect. Meanwhile, MFC, due to its relatively low strength, weak interfacial interactions, and severe aggregation, shows an unsatisfactory modification effect.

[0105] The above are embodiments of the methods proposed in this application. Based on the same idea, some embodiments of this application also provide devices and non-volatile computer storage media corresponding to the above methods.

[0106] Figure 4 This is a schematic diagram of a device for evaluating the mechanical properties of cellulose bulk-doped insulating paper, provided as an embodiment of this application. Figure 4 As shown, it includes:

[0107] At least one processor; and,

[0108] At least one processor-communication-connected memory; wherein,

[0109] The memory stores instructions that can be executed by at least one processor, and the instructions, when executed by at least one processor, enable at least one processor to:

[0110] A three-phase model for evaluating the mechanical properties of insulating paper was determined; wherein, the three-phase model includes the Young's modulus of the cellulose bulk phase-doped insulating paper under the action of the filler phase, agglomerate phase and interface phase;

[0111] Obtain a standard mechanical model corresponding to the preset insulating paper matrix. Based on the three-phase model, modify the standard mechanical model to obtain the modified first mechanical model and second mechanical model. The first mechanical model is used to characterize the influence of filler phase and agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of interface on the insulating paper.

[0112] The interface layer thickness of the insulating paper under different filler mass fractions was determined using the first and second mechanical models.

[0113] Based on the first and second mechanical models, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted.

[0114] By using the target Young's modulus, the mechanical property curves corresponding to the insulating paper are obtained through fitting, so as to evaluate the mechanical properties of the insulating paper.

[0115] This application provides a non-volatile computer storage medium storing computer-executable instructions, which are configured as follows:

[0116] A three-phase model for evaluating the mechanical properties of insulating paper was determined; wherein, the three-phase model includes the Young's modulus of the cellulose bulk phase-doped insulating paper under the action of the filler phase, agglomerate phase and interface phase;

[0117] Obtain a standard mechanical model corresponding to the preset insulating paper matrix. Based on the three-phase model, modify the standard mechanical model to obtain the modified first mechanical model and second mechanical model. The first mechanical model is used to characterize the influence of filler phase and agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of interface on the insulating paper.

[0118] The interface layer thickness of the insulating paper under different filler mass fractions was determined using the first and second mechanical models.

[0119] Based on the first and second mechanical models, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted.

[0120] By using the target Young's modulus, the mechanical property curves corresponding to the insulating paper are obtained through fitting, so as to evaluate the mechanical properties of the insulating paper.

[0121] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and medium embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the description of the method embodiments.

[0122] The devices and media provided in this application are one-to-one with the methods. Therefore, the devices and media also have similar beneficial technical effects as their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0123] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0124] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0125] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0126] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0127] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0128] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0129] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0130] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for evaluating the mechanical properties of cellulose bulk-doped insulating paper, characterized in that, The method includes: A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase; A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper. The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model. Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted. The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper. The revised first mechanical model is represented as follows: Determine the tensile strength of the insulating paper under the action of the interfacial phase, and modify the standard mechanical model based on the tensile strength to obtain a second mechanical model, specifically including: The second mechanical model is obtained using the following formula: in, The Young's modulus of the cellulose bulk-doped insulating paper. The Young's modulus of the insulating paper matrix. The Young's modulus of the cellulose filler. This represents the volume fraction of the cellulose filler. For shape factor, The aspect ratio is... Where R is the interfacial shear strength, and R is the radius of the cellulose filler. As the first orientation factor, It is the second orientation factor; Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper is constructed, specifically including: in, The thickness of the interface layer. This represents the aggregation coefficient.

2. The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper according to claim 1, characterized in that, Based on the three-phase model, the standard mechanical model is modified to obtain the modified first mechanical model and second mechanical model, specifically including: The agglomeration coefficient of the insulating paper under the action of the filler phase and the agglomerating phase is determined, and the shape factor of the insulating paper is determined according to the agglomeration coefficient; wherein the agglomeration coefficient is positively correlated with the degree of agglomeration of cellulose doped in the bulk phase of the insulating paper; Based on the shape factor, the standard mechanical model is modified to obtain the modified first mechanical model; The standard mechanical model is modified based on the tensile strength of the material to obtain a second mechanical model.

3. The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper according to claim 1, characterized in that, Using the first mechanical model and the second mechanical model, the interface layer thickness of the insulating paper at different filler mass fractions is determined, specifically including: Using the first mechanical model, the predicted Young's modulus of the insulating paper under different filler mass fractions is predicted, and the actual Young's modulus of the insulating paper under the filler mass fraction is obtained, so as to determine the difference in Young's modulus between the predicted Young's modulus and the actual Young's modulus. The difference in Young's modulus is used as the Young's modulus of the insulating paper and substituted into the second mechanical model to obtain the interface layer thickness of the insulating paper under different filler mass fractions.

4. The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper according to claim 1, characterized in that, The types of cellulose doped in the insulating paper include at least microcellulose, nanocellulose whiskers, and nanocellulose fibers.

5. The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper according to claim 4, characterized in that, The mechanical properties of the insulating paper are evaluated, specifically including: Based on the standard Young's modulus of the insulating paper matrix at different filler mass fractions, the standard mechanical property curves corresponding to the insulating paper matrix are fitted to obtain the curves. For insulating papers doped with different types of cellulose, the mechanical property curves corresponding to the insulating paper are compared with the standard mechanical property curves to determine the Young's modulus increment of the insulating paper. The mechanical properties of insulating papers doped with different types of cellulose are evaluated based on the Young's modulus increment.

6. The method for evaluating the mechanical properties of cellulose bulk-doped insulating paper according to claim 1, characterized in that, Before correcting the standard mechanical model based on the tensile strength of the material to obtain the second mechanical model, the method further includes: Determine the stress parameters corresponding to the cellulose doped in the insulating paper; wherein, the stress parameters include ultimate fiber strength, fiber diameter, and critical fiber length; The ratio between the fiber diameter and the fiber critical length is determined, and the interfacial shear strength corresponding to the insulating paper is obtained based on the ratio and the limiting fiber strength.

7. A device for evaluating the mechanical properties of cellulose bulk-doped insulating paper, characterized in that, The device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to: A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase; A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper. The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model. Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted. The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper. The revised first mechanical model is represented as follows: Determine the tensile strength of the insulating paper under the action of the interfacial phase, and modify the standard mechanical model based on the tensile strength to obtain a second mechanical model, specifically including: The second mechanical model is obtained using the following formula: in, The Young's modulus of the cellulose bulk-doped insulating paper. The Young's modulus of the insulating paper matrix. The Young's modulus of the cellulose filler. This represents the volume fraction of the cellulose filler. For shape factor, The aspect ratio is... Where R is the interfacial shear strength, and R is the radius of the cellulose filler. As the first orientation factor, It is the second orientation factor; Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper is constructed, specifically including: in, The thickness of the interface layer. This represents the aggregation coefficient.

8. A non-volatile computer storage medium storing computer-executable instructions, characterized in that, The computer-executable instructions are set as follows: A three-phase model for evaluating the mechanical properties of insulating paper is determined; wherein, the three-phase model includes the Young's modulus of cellulose bulk-doped insulating paper under the action of filler phase, agglomerate phase and interface phase; A standard mechanical model corresponding to a preset insulating paper matrix is ​​obtained. Based on the three-phase model, the standard mechanical model is modified to obtain a modified first mechanical model and a second mechanical model. The first mechanical model is used to characterize the influence of the filler phase and the agglomeration on the insulating paper, and the second mechanical model is used to characterize the influence of the interface on the insulating paper. The interface layer thickness of the insulating paper at different filler mass fractions is determined using the first mechanical model and the second mechanical model. Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model is constructed to evaluate the mechanical properties of the insulating paper. Based on the comprehensive mechanical model and the interface layer thickness, the target Young's modulus of the insulating paper at different filler mass fractions is predicted. The mechanical property curve of the insulating paper is obtained by fitting the target Young's modulus to evaluate the mechanical properties of the insulating paper. The revised first mechanical model is represented as follows: Determine the tensile strength of the insulating paper under the action of the interfacial phase, and modify the standard mechanical model based on the tensile strength to obtain a second mechanical model, specifically including: The second mechanical model is obtained using the following formula: in, The Young's modulus of the cellulose bulk-doped insulating paper. The Young's modulus of the insulating paper matrix. The Young's modulus of the cellulose filler. This represents the volume fraction of the cellulose filler. For shape factor, The aspect ratio is... Where R is the interfacial shear strength, and R is the radius of the cellulose filler. As the first orientation factor, It is the second orientation factor; Based on the first mechanical model and the second mechanical model, a comprehensive mechanical model for evaluating the mechanical properties of the insulating paper is constructed, specifically including: in, The thickness of the interface layer. This represents the aggregation coefficient.

Images