Indentation characterization method and device for irregular polymer film material and electronic equipment

Abstract

The invention relates to the technical field of material physical property measurement, in particular to an indentation characterization method and device for an irregular polymer thin film material and electronic equipment, and the method comprises the following steps: deriving an analytical solution based on dimensional analysis and an elastic-viscoelastic correspondence principle; predicting the relationship between the creep function of the invisible appliance and the time-dependent indentation displacement based on the analytical solution; and under the guidance of preset theoretical analysis, designing an indentation creep experiment under the condition of ensuring that the area of the contact area is basically unchanged, and determining a final creep function of the invisible orthodontic appliance. Therefore, the problems that mechanical testing is difficult to conduct due to the irregular shape of the invisible orthodontic appliance, a quantitative model for the influence of a thermal forming process on the performance is lacked, performance evolution research is insufficient in long-term clinical use, orthodontic scheme estimation deviation is caused, the treatment effect is affected and the like in related technologies are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material physical property measurement, in particular to a method and device for indentation characterization of irregular high polymer film material and electronic equipment. BACKGROUND

[0002] At present, the invisible aligner realizes the concealment treatment of tooth correction by integrating 3D scanning and thermoplastic manufacturing technology, meets the demand of appearance of adult patients and professionals, and is widely accepted due to the advantages of removable wearing, reduction of mucosal irritation and predictability brought by digital workflow. The clinical effect of the invisible aligner depends on the material properties, mainly using thermoplastic polymers such as polyurethane, polyethylene terephthalate, polymethyl methacrylate and polyetherimide. In addition to meeting the requirement of biocompatibility, the mechanical properties of these materials have become the focus of interdisciplinary research.

[0003] In the related art, the elastic modulus, yield strength and fatigue resistance are characterized by tensile, bending and indentation tests. For the original aligner film, the dynamic mechanical analysis equipment is used to periodically load under different temperature and frequency conditions, monitor the change of stress and strain with time during stress relaxation and creep process, establish a viscoelastic model, and deeply explore the performance evolution law of the film under long-term stress or temperature change.

[0004] However, in the related art, due to the irregular shape of the invisible aligner, mechanical tests such as tension and compression are difficult to accurately reproduce the conditions to the overall structure, and cannot accurately reflect the real mechanical behavior of the irregular curved surface of the aligner and the multi-point contact with the teeth. The change of material crystallinity caused by thermoforming process affects the elastic modulus, but there is a lack of quantitative correlation model between process parameters and final performance. In long-term clinical use, the dynamic change of aligner performance is affected by factors such as oral temperature and humidity, microorganisms, and the performance evolution is lack of research, which leads to insufficient estimation of doctors when formulating treatment plan, affecting treatment stability and accuracy, and needs to be improved. SUMMARY

[0005] The present application provides a method and device for indentation characterization of irregular high polymer film material and electronic equipment to solve the problems in the related art that the irregular shape of the invisible aligner makes it difficult to carry out mechanical tests, the influence of the thermoforming process on the performance lacks a quantitative model, and the performance evolution is insufficient in long-term clinical use, which leads to deviation of treatment plan estimation and affects the treatment effect.

[0006] The embodiment of the first aspect of the present application provides a method for characterizing indentation of irregular polymer film material, comprising the following steps: deriving an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle; predicting the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the analytical solution; under the guidance of the preset theoretical analysis, designing an indentation creep experiment while ensuring that the contact area is basically unchanged, and determining the final creep function of the invisible aligner.

[0007] Through the above technical means, the embodiment of the present application can derive an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle to predict the relationship between the reduced creep function and the time-dependent indentation displacement, so as to quickly and efficiently and accurately calculate the deformation degree of the invisible aligner for different users, thereby providing a reliable key basis for developing a suitable invisible aligner.

[0008] Optionally, in an embodiment of the present application, the indentation depth of the invisible aligner is: , wherein, F is the indentation load, E is the elastic modulus of the measured material, v is the Poisson's ratio of the measured material. is the geometric shape parameter of the invisible aligner, a is the radius of the flat-ended indenter.

[0009] Through the above technical means, the embodiment of the present application can derive the indentation depth of the invisible aligner, thereby providing a quantitative basis for indentation testing, which is helpful to accurately evaluate the deformation of the material under simulated oral stress, and further optimize the structural design of the aligner.

[0010] Optionally, in an embodiment of the present application, the method comprises: applying the Buckingham π theorem in dimensional analysis to the indentation depth of the invisible aligner to obtain an improved equation; obtaining a linear relationship between the indentation load and the indentation depth based on the improved equation; and performing Laplace inverse transform based on the linear relationship to obtain the correlation between the indentation experiment response and the system geometry and physical parameters.

[0011] Through the above technical means, the embodiment of the present application can convert the multivariate equation into dimensionless groups by dimensional analysis, thereby reducing the complexity of solving, and converting the result in the transform domain back to the time domain through Laplace inverse transform, so as to more intuitively reflect the actual physical process, and enhance the comprehensiveness and depth of the mechanical performance analysis of the invisible aligner.

[0012] Optionally, in an embodiment of the present application, the linear relationship is: , wherein, a geometry parameter of the invisible aligner, a Laplace transform of the creep function, s a transform variable, a Laplace transform of the indentation load, a Laplace transform of the indentation depth, a dimensionless function.

[0013] Through the technical means, the embodiment of the present application can clearly show the correlation of the key variables in the Laplace transform domain through the linear relationship, provide a mathematical framework for the inversion of the creep function from the indentation displacement, and help to further solve and verify the mechanical performance parameters of the invisible aligner.

[0014] Optionally, in an embodiment of the present application, the expression of the correlation between the creep function and the indenter displacement in the indentation creep experiment is: , wherein, = / , = / , is the instantaneous creep compliance, is the indenter displacement at the starting point of the creep test.

[0015] Through the technical means, the embodiment of the present application can present the quantitative relationship between the indentation experiment response and the system geometry and physical parameters through the correlation expression, and through the operation and analysis of these parameters, the mechanical properties of the invisible aligner in the creep process can be deeply understood, and key data support can be provided for material performance evaluation and aligner design optimization.

[0016] The second aspect embodiment of the present application provides an indentation characterization device for irregular polymer film materials, comprising: a derivation module for deriving an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle; a prediction module for predicting the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the analytical solution; and a characterization module for designing an indentation creep experiment under the guidance of a preset theoretical analysis, determining the final creep function of the invisible aligner under the condition of ensuring that the contact area is basically unchanged.

[0017] Through the technical means, the embodiment of the present application can derive an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle to predict the relationship between the reduced creep function and the time-dependent indentation displacement, so as to quickly and efficiently and accurately calculate the deformation degree of the invisible aligner for different users, and provide a reliable key basis for developing a suitable invisible aligner.

[0018] Optionally, in an embodiment of the present application, the indentation depth of the invisible aligner is: , wherein, F is the indentation load, E is the elastic modulus of the measured material, v is the Poisson's ratio of the measured material. is the geometric shape parameter of the invisible aligner, a is the radius of the flat-ended indenter.

[0019] Through the above technical means, the embodiment of the present application can deduce the indentation depth of the invisible aligner, provide a quantitative basis for indentation testing, help to accurately evaluate the deformation of the material under simulated oral stress, and further optimize the structural design of the aligner.

[0020] Optionally, in an embodiment of the present application, it comprises: an improvement module for applying the Buckingham Pi theorem in dimensional analysis to the indentation depth of the invisible aligner to obtain an improved equation; an acquisition module for acquiring a linear relationship between the indentation load and the indentation depth based on the improved equation; a transformation module for performing inverse Laplace transform based on the linear relationship to obtain the correlation between the indentation experiment response and the system geometry and physical parameters.

[0021] Through the above technical means, the embodiment of the present application can use dimensional analysis to convert the multivariate equation into a dimensionless group, reduce the complexity of solving, convert the result in the transform domain back to the time domain through inverse Laplace transform, thereby more directly reflecting the actual physical process, and enhancing the comprehensiveness and depth of the mechanical property analysis of the invisible aligner.

[0022] Optionally, in an embodiment of the present application, the linear relationship is: , wherein, is the geometric shape parameter of the invisible aligner, is the Laplace transform of the creep function, s is the transform variable, is the Laplace transform of the indentation load, is the Laplace transform of the indentation depth, is a dimensionless function.

[0023] Through the above technical means, the embodiment of the present application can clearly the correlation of each key variable in the Laplace transform domain through the linear relationship, provide a mathematical framework for the inversion of the creep function from the indentation displacement, and help to further solve and verify the mechanical property parameters of the invisible aligner.

[0024] Optionally, in one embodiment of the present application, the expression of the correlation between the creep function and the indenter displacement in the indentation creep experiment is: , wherein, = / , = / , is the instantaneous creep compliance, is the indenter displacement at the starting point of the creep test.

[0025] Through the above technical means, the embodiment of the present application can present the quantitative relationship between the indentation experiment response and the system geometry and physical parameters through the correlation expression, and through the operation and analysis of these parameters, the mechanical properties of the invisible aligner in the creep process can be deeply understood, and key data support can be provided for material performance evaluation and aligner design optimization.

[0026] The third aspect of the present application provides an electronic device, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to realize the indentation characterization method of the irregular polymer film material as described in the above embodiments.

[0027] The fourth aspect of the present application provides a non-volatile computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the indentation characterization method of the irregular polymer film material as described above.

[0028] The fifth aspect of the present application provides a computer program product, which stores a computer program, and the program is executed by a processor to realize the indentation characterization method of the irregular polymer film material as described above.

[0029] The embodiment of the present application can predict the relationship between the reduced creep function and the time-dependent indentation displacement by dimension analysis and the principle of elastic-viscoelastic correspondence to derive an analytical solution, so as to quickly and efficiently and accurately calculate the deformation degree of the invisible aligner for different users, and provide a reliable key basis for developing a suitable invisible aligner. Therefore, the problems in the related art that the irregular shape of the invisible aligner leads to difficulty in mechanical testing, the influence of the thermoforming process on the performance lacks a quantitative model, the performance evolution research in long-term clinical use is insufficient, the treatment scheme estimation deviation is caused, and the treatment effect is affected are solved.

[0030] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the references to the figures, in which: Figure 1 A flow chart of a method for indentation characterization of irregular polymer film material according to an embodiment of the present application; Figure 2 A comparison diagram of creep function according to an embodiment of the present application; Figure 3 A structural diagram of an indentation characterization device for irregular polymer film material according to an embodiment of the present application; Figure 4 A structural diagram of an electronic device according to an embodiment of the present application.

[0032] Reference Signs: 10 - indentation characterization device for irregular polymer film material; 100 - derivation module, 200 - prediction module, 300 - characterization module; 401 - memory, 402 - processor, 403 - communication interface. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below with reference to the attached drawings, which show by way of example, embodiments in which like numerals indicate like elements or elements having the same or similar function. The embodiments described below are examples intended to explain the present application, and are not to be understood as limiting the present application.

[0034] The indentation characterization method, device and electronic device for irregular polymer film material of the embodiments of the present application are described below with reference to the drawings. In view of the problems in the related art mentioned in the background art, such as the irregular shape of the invisible aligner leading to difficulty in replicating the real stress in mechanical testing, the lack of quantitative models for the influence of the thermoforming process on performance, the lack of research on performance evolution in long-term clinical use, leading to deviation in the estimation of the treatment plan and affecting the treatment effect, the present application provides an indentation characterization method for irregular polymer film material. In this method, the relationship between the reduced creep function and the time-dependent indentation displacement can be predicted by dimensional analysis and the elastic-viscoelastic correspondence principle to derive an analytical solution, thereby quickly and efficiently and accurately calculating the deformation degree of the invisible aligner for different users, providing a reliable key basis for developing a suitable invisible aligner. Thus, the problems in the related art, such as the irregular shape of the invisible aligner leading to difficulty in mechanical testing, the lack of quantitative models for the influence of the thermoforming process on performance, the lack of research on performance evolution in long-term clinical use, leading to deviation in the estimation of the treatment plan and affecting the treatment effect, are solved.

[0035] Specifically,Figure 1 A flowchart of a method for indentation characterization of irregular polymer film material provided by an embodiment of the present application.

[0036] As shown in the method for indentation characterization of irregular polymer film material includes the following steps: Figure 1 In step S101, an analytical solution is derived based on dimensional analysis and elastic-viscoelastic correspondence principle.

[0037] It can be understood that the dimensional analysis in the embodiment of the present application can be to convert physical quantities into dimensionless groups, simplify multivariate equations, and indicate the arbitrariness of the physical law independent of the selection of physical quantity units, to derive the relationship between physical quantities involved in a specific phenomenon, to understand and characterize the phenomenon.

[0038] In actual execution process, the embodiment of the present application can convert the load, displacement, material parameters and geometric parameters involved in indentation test into dimensionless combination through dimensional analysis and elastic-viscoelastic correspondence principle, and derive an analytical solution based on the elastic-viscoelastic correspondence principle, and characterize the correlation between experimental response and system geometry and physical parameters based on dimensional analysis. Under the given indenter profile and loading conditions, the analytical solution shows characteristics independent of the geometry of the appliance.

[0039] The embodiment of the present application can break through the dependence of traditional test methods on regular geometry by deriving the analytical solution, so that the analytical solution can be applied to different teeth and different curved surface shapes of the invisible aligner, and provide stable and reliable theoretical basis for material screening and appliance design optimization.

[0040] In step S102, the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement is predicted based on the analytical solution.

[0041] It can be understood that the creep function in the embodiment of the present application can be a function describing the change of strain of the invisible aligner material with time under the action of constant load; and the time-dependent indentation displacement can be the change amount of indentation depth over time after the indenter is pressed into the appliance.

[0042] In actual execution process, the embodiment of the present application can consider the flat head indentation of linear viscoelastic invisible aligner to predict the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the correlation between the experimental response and the system geometry and physical parameters characterized by dimensional analysis.

[0043] ​The embodiment of the present application can establish a model based on a real orthodontic appliance curved surface, establish a quantitative relationship between the creep characteristics and time and indentation displacement of the invisible orthodontic appliance under a complex mechanical environment, provide a theoretical basis for in-depth understanding of the mechanical behavior of the orthodontic appliance, and help to more accurately evaluate the performance change of the orthodontic appliance in the long-term use in the oral environment.

[0044] Optionally, in an embodiment of the present application, the indentation depth of the invisible orthodontic appliance is: , wherein, F is the indentation load, E is the elastic modulus of the measured material, v is the Poisson's ratio of the measured material. is a geometric shape parameter of the invisible orthodontic appliance, and M is a finite integer, a is the radius of the flat-ended indenter.

[0045] It can be understood that the radius of the flat-ended indenter in the embodiment of the present application can be the radius of the contact part of the indenter and the orthodontic appliance, covering the size of the tooth crown contact point.

[0046] In actual execution, the indentation depth of the flat-ended indenter of the linear elastic invisible orthodontic appliance can be a function of the following independent parameters: , wherein, F is the indentation load, E is the elastic modulus of the measured material, v is the Poisson's ratio of the measured material. is a geometric shape parameter of the invisible orthodontic appliance, and M is a finite integer, a is the radius of the flat-ended indenter.

[0047] The embodiment of the present application can derive the indentation depth of the invisible orthodontic appliance, provide a quantitative basis for the indentation test, help to accurately evaluate the deformation of the material under simulated oral stress, and further optimize the structural design of the orthodontic appliance.

[0048] Optionally, in an embodiment of the present application, the following steps are included: applying the Buckingham Pi theorem in dimensional analysis to the indentation depth of the invisible orthodontic appliance to obtain an improved equation; obtaining a linear relationship between the indentation load and the indentation depth based on the improved equation; and performing Laplace inverse transformation based on the linear relationship to obtain the correlation between the indentation test response and the system geometry and physical parameters.

[0049] It can be understood that the Buckingham Pi theorem in the embodiment of the present application can be a theorem for reducing physical variables by constructing dimensionless parameters.

[0050] For example, the embodiment of the present application can apply the Buckingham Pi theorem to combine the indentation depth equation of the invisible aligner into a dimensionless parameter, simplify the original equation to obtain an improved equation, and assume The Buckingham Pi theorem in dimensional analysis is applied to the indentation depth of the invisible aligner to obtain an improved equation; , wherein, and have independent dimensions, ( ) and are real numbers. is a dimensionless function. When the indentation depth is small and the contact area under the flat indentation does not change significantly, there is a linear relationship between the indentation load and the indentation depth. The equation can be further rewritten as: , thereby obtaining a relationship, obtaining a linear relationship between the indentation load and the indentation depth based on the improved equation, and performing Laplace inverse transform based on the linear relationship to obtain the correlation between the indentation experiment response and the system geometry and physical parameters.

[0051] The embodiment of the present application can use dimensional analysis to convert a multivariate equation into a dimensionless group, reduce the complexity of solving, convert the result in the transform domain back to the time domain through Laplace inverse transform, thereby more directly reflecting the actual physical process, and enhancing the comprehensiveness and depth of the mechanical property analysis of the invisible aligner.

[0052] Optionally, in an embodiment of the present application, the linear relationship is: , wherein, is a geometric shape parameter of the invisible aligner, M is a finite integer, is the Laplace transform of the creep function, s is a transform variable, is the Laplace transform of the indentation load, is the Laplace transform of the indentation depth, is a dimensionless function.

[0053] For example, the embodiment of the present application can assume that the Poisson's ratio is independent of time, apply the elastic-viscoelastic correspondence principle, and replace the elastic modulus with to obtain a linear relationship from the equation relationship: , wherein, a geometry parameter of the invisible aligner, a Laplace transform of a creep function, s a transform variable, a Laplace transform of an indentation load, a Laplace transform of an indentation depth, a dimensionless function. a relationship between and = a linear relationship, and a Laplace inverse transform of the linear relationship is: , further rewritten as: , Embodiments of the present application can explicitly correlate the key variables in the Laplace transform domain through a linear relationship, provide a mathematical framework for the inversion of the creep function from the indentation displacement, and help to further solve and verify the mechanical performance parameters of the invisible aligner.

[0054] In step S103, under the guidance of the preset theoretical analysis, the indentation creep experiment is designed to ensure that the contact area is basically unchanged, and the final creep function of the invisible aligner is determined.

[0055] It can be understood that the preset theoretical analysis in the embodiments of the present application can be based on the indentation depth equation of the invisible aligner, wherein the indentation depth can be a function of the following independent parameters: , wherein, F is an indentation load, E is an elastic modulus of the measured material, v is a Poisson's ratio of the measured material. a geometry parameter of the invisible aligner, M is a finite integer, a is a radius of the flat head indenter; the dimensionless parameter is combined by applying the Buckingham Pi theorem to simplify the original equation to obtain an improved equation, assuming has a length dimension, the Buckingham Pi theorem in dimensional analysis is applied to the indentation depth of the invisible aligner to obtain an improved equation; , wherein, and have independent dimensions, ( ) and are real numbers; is a dimensionless function; when the indentation depth is small and the contact area under the flat head indentation changes insignificantly, there is a linear relationship between the indentation load and the indentation depth, and the equation can be further rewritten as: , Thus, the linear relationship between the indentation load and the indentation depth can be obtained based on the improved equation, the linear relationship is obtained from the equation Based on the improved equation, the linear relationship between the indentation load and the indentation depth is obtained, the elastic modulus is replaced by The linear relationship is obtained from the equation The linear relationship is obtained from the equation , Wherein, is a geometric shape parameter of the invisible aligner, is a Laplace transform of a creep function, s is a transform variable, is a Laplace transform of an indentation load, is a Laplace transform of an indentation depth, is a dimensionless function; The relationship between and is = ,The inverse Laplace transform of the linear relationship is obtained: , Further rewritten as: , The correlation between the indentation experiment response and the system geometry and physical parameters is obtained.

[0056] In actual implementation process, the embodiment of the application can design the indentation creep experiment under the guidance of the preset theoretical analysis, in the case of ensuring that the contact area is basically unchanged, in the indentation creep experiment, the load is described by the Heaviside step function: , Wherein, is a creep load. The differential of the Heaviside step function gives the Kronecker delta function, therefore, the load step function is substituted into the linear relationship to obtain: , According to the integral property of the Kronecker delta function, the following can be obtained: , At this time, all geometric parameters are contained in the term , which is independent of time, and the final creep function of the invisible aligner is determined.

[0057] The embodiment of the present application can design the indentation creep experiment under the condition of ensuring that the contact area is basically unchanged, determine the final creep function of the invisible aligner, utilize the characteristic that the geometric parameters are irrelevant to time, and solve the creep function through the change relationship of the indenter displacement with time, thereby simplifying the experimental operation and data processing procedure.

[0058] Optionally, in an embodiment of the present application, the expression of the correlation between the creep function and the indenter displacement in the indentation creep experiment is: , wherein, = / , = / , is the instantaneous creep compliance, is the indenter displacement at the starting point of the creep experiment.

[0059] It can be understood that the indenter displacement at the starting point of the creep experiment in the embodiment of the present application can be the initial displacement of the indenter pressed into the invisible aligner at the starting moment of the creep experiment.

[0060] In the actual execution process, the embodiment of the present application can derive the simple proportional relationship between the reduced creep function and the normalized indenter displacement from the correlation between the system geometry and the physical parameters: , wherein, = / , = / , is the instantaneous creep compliance, represents the indenter displacement at the starting point of the creep experiment. As long as the contact area is basically unchanged, the above derivation is effective for invisible aligners of any geometric shape, the expression of the correlation is independent of the geometric shape of the system, and is very useful in explaining the indentation creep experiment of the invisible aligner with irregular geometric shape.

[0061] The embodiment of the present application can present the quantitative relationship between the indentation experiment response and the system geometry and physical parameters through the correlation expression, and through the operation and analysis of these parameters, the mechanical properties of the invisible aligner in the creep process can be deeply understood, thereby providing key data support for material performance evaluation and aligner design optimization.

[0062] The embodiment of the present application can quantify the creep and relaxation behavior of the invisible aligner, thereby detecting the mechanical properties of the invisible aligner with irregular geometric shape.

[0063] Specifically, the present application can be combined with Figure 2 The working principle of the indentation characterization method of the irregular polymer film material in the embodiment of the present application is described in detail with one specific embodiment.

[0064] As shown in Figure 2 The figure shows the creep function of the appliance without use and the creep function of the appliance in the oral environment respectively, and the influence of the oral environment on the viscoelastic properties of the appliance can be quantitatively analyzed by comparing the two.

[0065] The indentation characterization method of the irregular polymer film material according to the embodiment of the present application can derive an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principles to predict the relationship between the reduced creep function and the time-dependent indentation displacement, so that the deformation degree of the invisible aligner for different users can be quickly and efficiently and accurately calculated, and reliable key basis is provided for the development of suitable invisible aligners. Thus, the problems in the related art that the irregular shape of the invisible aligner leads to difficulty in replicating the real stress in mechanical testing, the influence of the thermoforming process on the performance lacks a quantitative model, and the performance evolution research in long-term clinical use is insufficient, resulting in deviation of the treatment plan estimation and affecting the treatment effect are solved.

[0066] Secondly, the indentation characterization device of the irregular polymer film material according to the embodiment of the present application is described with reference to the accompanying drawings.

[0067] Figure 3 is a structural schematic diagram of the indentation characterization device of the irregular polymer film material according to the embodiment of the present application.

[0068] As shown in Figure 3 The indentation characterization device 10 of the irregular polymer film material includes a derivation module 100, a prediction module 200 and a characterization module 300.

[0069] The derivation module 100 is configured to derive an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principles.

[0070] The prediction module 200 is configured to predict the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the analytical solution.

[0071] The characterization module 300 is configured to design an indentation creep experiment under the guidance of a preset theoretical analysis to determine the final creep function of the invisible aligner while ensuring that the contact area is basically unchanged.

[0072] Optionally, in one embodiment of the present application, the indentation depth of the invisible aligner is: , wherein, F is the indentation load, E is the elastic modulus of the measured material,v is the Poisson's ratio of the material under test. is a geometric parameter of the orthodontic aligner, M is a finite integer, a is the radius of the flat-ended indenter.

[0073] Optionally, in an embodiment of the present application, comprising: an improving module, an obtaining module and a transforming module.

[0074] The improving module is configured to apply the Buckingham Pi theorem in dimensional analysis to the indentation depth of the orthodontic aligner to obtain an improved equation.

[0075] The obtaining module is configured to obtain a linear relationship between the indentation load and the indentation depth based on the improved equation.

[0076] The transforming module is configured to perform an inverse Laplace transform based on the linear relationship to obtain a correlation between the indentation experiment response and the system geometry and physical parameters.

[0077] Optionally, in an embodiment of the present application, the linear relationship is: , wherein, is a geometric parameter of the orthodontic aligner, M is a finite integer, is the Laplace transform of the creep function, s is a transform variable, is the Laplace transform of the indentation load, is the Laplace transform of the indentation depth, is a dimensionless function.

[0078] Optionally, in an embodiment of the present application, wherein the expression of the correlation between the creep function and the indenter displacement in the indentation creep experiment is: , wherein, = / , = / , is the instantaneous creep compliance, is the indenter displacement at the starting point of the creep experiment.

[0079] It should be noted that the foregoing explanation and description of the indentation characterization method embodiment of the irregular polymer film material also applies to the indentation characterization device of the irregular polymer film material of this embodiment, which will not be described here.

[0080] The indentation characterization device of the irregular polymer film material provided by the embodiment of the present application can derive an analytical solution through dimensional analysis and the principle of elastic-viscoelastic correspondence to predict the relationship between the reduced creep function and the time-dependent indentation displacement, so that the deformation degree of the invisible aligner for different users can be quickly and efficiently and accurately calculated, and reliable key basis for developing a suitable invisible aligner is provided. Therefore, the problems in the prior art that the irregular shape of the invisible aligner leads to difficulty in replicating the real stress in the mechanical test, the influence of the thermoforming process on the performance lacks a quantitative model, and the performance evolution in long-term clinical use is insufficient, which leads to deviation of the treatment scheme estimation and affects the treatment effect are solved.

[0081] Figure 4 The structural schematic diagram of the electronic device provided by the embodiment of the present application is provided. The electronic device can include: The memory 401, the processor 402 and the computer program stored in the memory 401 and executable on the processor 402.

[0082] The processor 402 implements the indentation characterization method of the irregular polymer film material provided in the above embodiment when executing the program.

[0083] Further, the electronic device further includes: The communication interface 403 is used for communication between the memory 401 and the processor 402.

[0084] The memory 401 is used to store the computer program executable on the processor 402.

[0085] The memory 401 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0086] If the memory 401, the processor 402 and the communication interface 403 are independently implemented, the communication interface 403, the memory 401 and the processor 402 can be connected to each other through a bus and complete the communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 4 Only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0087] Optionally, in a specific implementation, if the memory 401, the processor 402 and the communication interface 403 are integrated on a chip, the memory 401, the processor 402 and the communication interface 403 can complete the communication among each other through an internal interface.

[0088] The processor 402 can be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement one or more embodiments of the present application.

[0089] The embodiment further provides a non-volatile computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the indentation characterization method of the irregular polymer thin film material.

[0090] The embodiment further provides a computer program product, which stores a computer program, and the computer program is executed by a processor to implement the indentation characterization method of the irregular polymer thin film material.

[0091] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0092] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0093] Any processes or methods described in the flowcharts or otherwise described herein can be understood as representing a module, segment, or portion of code that includes one or N executable instructions for implementing the specified logical function or process, and the various embodiments of the application can include additional or fewer steps, operations, or processes in implementations of this application that can be rearranged, combined, or divided into other ways without deviating from the spirit and scope of the application as expressed in the appended claims.

[0094] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing the logic function, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be a product of the manufacturing and / or processing, and can be a machine-readable storage medium (alternatively, the medium can be a machine-readable signal medium). The computer-readable medium can be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical), and a portable compact disc read-only memory (CDROM). Note that the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the medium is a suitable medium with the program printed on the medium. The computer-readable medium can be a non-transitory computer-readable medium. The term "non-transitory" can also mean "not entirely transitory." Accordingly, the computer-readable medium described herein can be transitory media where the program is propagated on a carrier wave and can be delayed, for example, on a wireless signal.

[0095] It should be understood that aspects of the application can be implemented in hardware, software, firmware, or combinations thereof. In the embodiments described above, the steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. If implemented in hardware, and in another embodiment, the hardware can include any or a combination of the following technologies, which are all well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), and / or the like.

[0096] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by programs instructing related hardware, and the programs can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0097] In addition, each functional unit in each embodiment of the present application can be integrated into one processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The integrated module can be realized in the form of hardware or in the form of a software functional module. When the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0098] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A method of indent characterization of an irregular polymeric film material, characterized by, The method comprises the following steps: deducing an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle; predicting the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the analytical solution; designing an indentation creep experiment under the guidance of preset theoretical analysis, determining the final creep function of the invisible aligner, and ensuring that the area of the contact zone is basically unchanged.

2. The method of claim 1, wherein the irregular polymeric film material is a polyethylene film. The indentation depth of the invisible aligner is: ， wherein, F is the indentation load, E is the elastic modulus of the material being tested, v is the Poisson's ratio of the material being tested, is a geometric shape parameter of the invisible aligner, a is the radius of the flat ended indenter.

3. The method of indentation characterization of an irregular polymeric film material according to claim 2, wherein, The method comprises the following steps: applying the Buckingham π theorem in dimensional analysis to the indentation depth of the invisible aligner to obtain an improved equation; obtaining a linear relationship between the indentation load and the indentation depth based on the improved equation; performing Laplace inverse transformation based on the linear relationship to obtain the correlation between the indentation experiment response and the system geometry and physical parameters.

4. The method of claim 3, wherein the irregular polymeric film material is a polyethylene terephthalate film. The linear relationship is: ， wherein is a geometrical parameter of the orthodontic aligner, is the Laplace transform of the creep function, s is the transform variable, is the Laplace transform of the indentation load, is the Laplace transform of the indentation depth, is a dimensionless function.

5. The method of claim 1, wherein, wherein, The expression of the correlation between the creep function and the indenter displacement in the indentation creep experiment is: ， wherein = 1 / , = 1 / , = 1 = 1 6. An apparatus for indentation characterization of an irregular polymeric film material, comprising: The method comprises the following steps: deducing an analytical solution based on dimensional analysis and elastic-viscoelastic correspondence principle; predicting the relationship between the creep function of the invisible aligner and the time-dependent indentation displacement based on the analytical solution; designing an indentation creep experiment under the guidance of preset theoretical analysis, determining the final creep function of the invisible aligner, and ensuring that the area of the contact zone is basically unchanged.

7. The apparatus for indentation characterization of irregular polymeric thin film materials of claim 6, wherein, The indentation depth of the invisible aligner is: ， wherein, F is the indentation load, E is the elastic modulus of the material being tested, v is the Poisson's ratio of the material being tested, is a geometric shape parameter of the orthodontic aligner, a is the radius of the flat ended indenter.

8. An electronic device, comprising: The method comprises the following steps: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the indentation characterization method of the irregular polymer film material according to any one of claims 1-5.

9. A non-transitory computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the indentation characterization method of the irregular polymer film material according to any one of claims 1-5.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed to implement the indentation characterization method of the irregular polymer film material according to any one of claims 1-5.

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