Crack analysis method

Abstract

The disclosure provides a crack analysis method, which can be applied to the technical fields of additive manufacturing and fracture mechanics. The crack analysis method comprises: determining a three-dimensional digital model of a biomimetic anti-fracture structure containing a designable hard fiber phase and a soft matrix phase feature; importing the three-dimensional digital model into the geometry preprocessing software of a material printing device for assembly to obtain a three-dimensional assembly model with the soft and hard phases adhered together; performing two-dimensional processing on the three-dimensional assembly digital model to obtain two-dimensional slice data containing the geometry of the soft and hard phases; importing the two-dimensional slice data into the material printing device for operation processing to obtain the optimal running track of the nozzle of the printing device and the type of material sprayed; layer by layer spraying and solidifying according to the optimal running track and the type of material sprayed to obtain a biomimetic anti-fracture structure sample containing a hard fiber and a soft matrix; performing a fracture test on the biomimetic anti-fracture structure sample, observing and analyzing the crack surface morphology and the fracture mode, and obtaining the observation results.

Description

Technical Field

[0001] This disclosure relates to the fields of additive manufacturing and fracture mechanics, and more specifically, to a crack analysis method. Background Technology

[0002] Naturally occurring bio-Bouligand structural materials are composed of soft and hard multiphase components such as minerals, proteins, and chitin fibers. Among them, chitin fibers are stacked at a certain helical angle to form a Bouligand structure with the characteristics of a torsional fiber laminate. This structure is widely found in crustacean exoskeletons, mammalian skeletons, fish scales, etc., and has fracture toughness hundreds or thousands of times greater than that of its components. This is closely related to its complex internal crack propagation path.

[0003] However, due to the heterogeneous structural characteristics of biological Bouligand structures, such as multi-component and multi-scale structures, the relationship between the internal crack propagation path and the structural characteristics of Bouligand is still unclear, resulting in the fracture toughness of artificial biomimetic Bouligand structural materials falling far short of the performance level of biological materials.

[0004] In related technologies, the analytical methods for biomimetic fracture-resistant structures mainly include experimental methods and numerical simulation methods. Among them, experimental methods cannot reproduce the crack propagation morphology of biological Bouligand structures or are difficult to accurately control the mechanical properties of structural parameters and components; numerical simulation methods are mostly limited to two-dimensional crack morphology or single fracture modes, and cannot predict the three-dimensional irregular crack surface morphology formed by the coupling of multiple fracture modes such as crack torsion and fiber fracture within biological Bouligand structures. Summary of the Invention

[0005] In view of this, this disclosure provides a crack analysis method.

[0006] One aspect of this disclosure provides a crack analysis method, comprising: determining a three-dimensional digital model of a biomimetic fracture-resistant structure containing designable hard fiber phase and soft matrix phase characteristics; importing the three-dimensional digital model into the geometric preprocessing software of a material printing device for assembly to obtain a three-dimensional assembly model of the two phases; performing two-dimensional processing on the three-dimensional assembly digital model to obtain two-dimensional slice data containing the geometry of the hard and soft phases; importing the two-dimensional slice data into the material printing device for computational processing to obtain the optimal operating trajectory of the nozzle of the printing device and the type of ejected material; spraying and curing layer by layer according to the optimal operating trajectory and the ejected material type to obtain a biomimetic fracture-resistant structure sample containing hard fibers and soft matrix; and performing fracture testing on the biomimetic fracture-resistant structure sample, observing and analyzing the crack surface morphology and fracture mode to obtain observation results.

[0007] This disclosure also provides a crack analysis device, comprising: a determination module for determining a three-dimensional digital model of a biomimetic fracture-resistant structure containing designable hard fiber phase and soft matrix phase characteristics; an assembly module for importing the three-dimensional digital model into the geometric preprocessing software of a material printing device for assembly, obtaining a three-dimensional assembly model of the two phases; a first processing module for performing two-dimensional processing on the three-dimensional assembly digital model to obtain two-dimensional slice data containing the geometry of the hard and soft phases; a second processing module for importing the two-dimensional slice data into the material printing device for calculation and processing, obtaining the optimal running trajectory of the nozzle of the printing device and the type of ejected material; a curing module for layer-by-layer spray curing according to the optimal running trajectory and the type of ejected material, obtaining a biomimetic fracture-resistant structure sample containing hard fibers and soft matrix; and an analysis module for performing fracture tests on the biomimetic fracture-resistant structure sample, observing and analyzing the crack surface morphology and fracture mode, and obtaining observation results.

[0008] Another aspect of this disclosure provides an electronic device comprising: one or more processors; and a memory for storing one or more programs, wherein, when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to perform the method as described above.

[0009] Another aspect of this disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed, are used to implement the method described above.

[0010] Another aspect of this disclosure provides a computer program product including computer-executable instructions that, when executed, are used to implement the method described above.

[0011] According to embodiments of this disclosure, a three-dimensional digital model of a biomimetic fracture-resistant structure incorporating designable hard fiber and soft matrix phases is established. This model is then imported into geometric preprocessing software for assembly, resulting in a three-dimensional assembly model with both hard and soft phases bonded together. The three-dimensional assembly model is then subjected to two-dimensional processing and computation to obtain the optimal trajectory of the printing nozzle and the type of ejected material. Finally, based on the optimal trajectory and material type, layer-by-layer spraying and curing are performed to obtain a biomimetic fracture-resistant structure sample containing hard fibers and a soft matrix. This achieves micron-level precise control of the structural parameters and component properties of the biomimetic Bouligand fracture-resistant structure containing hard fiber and soft matrix phases. Through parametric modeling and high-precision printing, the biomimetic fracture-resistant structure is accurately reproduced, providing guidance for the precise manufacturing and crack analysis of biomimetic fracture-resistant structures with multi-component, multi-scale characteristics. Furthermore, by conducting fracture tests on the biomimetic fracture-resistant structure sample, the crack surface morphology and fracture mode are observed and analyzed to obtain observation results, thus enabling crack analysis of the biomimetic fracture-resistant structure. Attached Figure Description

[0012] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0013] Figure 1 An exemplary system architecture for crack analysis methods and apparatus that can be applied according to this disclosure is illustrated schematically;

[0014] Figure 2 A flowchart illustrating a crack analysis method according to an embodiment of the present disclosure is shown schematically.

[0015] Figure 3 A flowchart illustrating a crack analysis method according to another embodiment of the present disclosure is shown schematically;

[0016] Figure 4 A three-dimensional digital model of a biomimetic fracture-resistant structure according to an embodiment of the present disclosure is illustrated schematically.

[0017] Figure 5 A crack analysis method for a single-layer fiberboard according to an embodiment of the present disclosure is illustrated schematically.

[0018] Figure 6 This illustration schematically demonstrates a crack analysis method for a biomimetic Bouligand fracture-resistant structure according to an embodiment of the present disclosure;

[0019] Figure 7 A block diagram of a crack analysis apparatus according to an embodiment of the present disclosure is schematically shown; and

[0020] Figure 8 A block diagram of an electronic device suitable for implementing a crack analysis method according to an embodiment of the present disclosure is shown schematically. Detailed Implementation

[0021] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0023] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0024] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0025] In the embodiments disclosed herein, the collection, updating, analysis, processing, use, transmission, provision, disclosure, and storage of data (e.g., including but not limited to user personal information) comply with relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures have been taken to prevent unauthorized access to user personal information data and to safeguard user personal information security and network security.

[0026] The fracture resistance of a material is closely related to the crack propagation path influenced by its internal structure. By guiding the crack propagation path through biomimetic heterogeneous structure design, the fracture toughness of the material can be controlled.

[0027] Naturally occurring bio-Bouligand structural materials are composed of soft and hard multiphase components such as minerals, proteins, and chitin fibers. Among them, chitin fibers are stacked at a certain helical angle to form a Bouligand structure with the characteristics of a torsional fiber laminate. This structure is widely found in crustacean exoskeletons, mammalian skeletons, fish scales, etc., and has fracture toughness hundreds or thousands of times greater than that of its components. This is closely related to its complex internal crack propagation path.

[0028] However, due to the heterogeneous structural characteristics of biological Bouligand structures, such as multi-component and multi-scale structures, the relationship between the internal crack propagation path and the structural characteristics of Bouligand is still unclear, resulting in the fracture toughness of artificial biomimetic Bouligand structural materials falling far short of the performance level of biological materials.

[0029] In related technologies, the analysis methods for biomimetic fracture-resistant structures mainly include experimental methods and numerical simulation methods.

[0030] In experimental methods, the rapid development of additive manufacturing technologies, represented by 3D printing, has provided conditions for the precise and efficient fabrication of various complex biomimetic structures. However, biomimetic Bouligand structures fabricated by 3D printing are often composed of a single material, lacking multi-material 3D printing methods for fabricating high-precision biomimetic Bouligand structures containing both soft and hard phase components, and thus unable to reproduce the crack propagation morphology of biological Bouligand structures. Furthermore, traditional synthesis methods struggle to precisely control structural parameters and the mechanical properties of components, resulting in the fracture toughness of artificial biomimetic Bouligand structure materials falling far short of the performance levels of biological materials.

[0031] Numerical simulation methods, including element deletion, interface element method, and extended finite element method, require explicit tracking of crack paths. Cracks can only propagate at mesh boundaries, making it difficult to accurately predict complex spatial crack paths. Crack propagation paths within the bio-Bouligand structure exhibit multiple fracture modes, such as crack torsion, tilting, and fiber fracture, resulting in a three-dimensional serrated crack surface morphology. Numerical simulation methods are mostly limited to two-dimensional crack morphology or single fracture modes, failing to predict the three-dimensional irregular crack surface morphology formed by the coupling of multiple fracture modes such as crack torsion and fiber fracture within the bio-Bouligand structure.

[0032] This disclosure provides a crack analysis method, comprising: determining a three-dimensional digital model of a biomimetic fracture-resistant structure containing designable hard fiber phase and soft matrix phase characteristics; importing the three-dimensional digital model into the geometric preprocessing software of a material printing device for assembly to obtain a three-dimensional assembly model of the two phases; performing two-dimensional processing on the three-dimensional assembly digital model to obtain two-dimensional slice data containing the geometry of the hard and soft phases; importing the two-dimensional slice data into the material printing device for calculation and processing to obtain the optimal running trajectory of the printing device nozzle and the ejected material type; spraying and curing layer by layer according to the optimal running trajectory and ejected material type to obtain a biomimetic fracture-resistant structure sample containing hard fiber and soft matrix; and performing fracture testing on the biomimetic fracture-resistant structure sample, observing and analyzing the crack surface morphology and fracture mode to obtain observation results.

[0033] Figure 1 An exemplary system architecture 100, in accordance with embodiments of the present disclosure, is illustrated. It should be noted that... Figure 1 The examples shown are merely examples of system architectures that can be applied to the embodiments of this disclosure, in order to help those skilled in the art understand the technical content of this disclosure, but do not mean that the embodiments of this disclosure cannot be used in other devices, systems, environments or scenarios.

[0034] like Figure 1As shown, the system architecture 100 according to this embodiment may include a first terminal device 101, a second terminal device 102, a third terminal device 103, a network 104, and a server 105. The network 104 serves as a medium for providing communication links between the first terminal device 101, the second terminal device 102, the third terminal device 103, and the server 105. The network 104 may include various connection types, such as wired and / or wireless communication links, etc.

[0035] Users can use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the server 105 via the network 104 to receive or send messages, etc. Various communication client applications can be installed on the first terminal device 101, the second terminal device 102, and the third terminal device 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, and / or social media platform software, etc. (for example only).

[0036] The first terminal device 101, the second terminal device 102, and the third terminal device 103 can be various electronic devices with displays and support web browsing, including but not limited to smartphones, tablets, laptops, and desktop computers.

[0037] Server 105 can be a server that provides various services, such as a backend management server that supports websites browsed by users using the first terminal device 101, the second terminal device 102, and the third terminal device 103 (this is just an example). The backend management server can analyze and process data such as received user requests, and feed back the processing results (such as web pages, information, or data obtained or generated according to user requests) to the terminal devices.

[0038] It should be noted that the crack analysis method provided in this embodiment can generally be executed by server 105. Correspondingly, the crack analysis system provided in this embodiment can generally be located in server 105. The crack analysis method provided in this embodiment can also be executed by a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Correspondingly, the crack analysis system provided in this embodiment can also be located in a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Alternatively, the crack analysis method provided in this embodiment can also be executed by the first terminal device 101, the second terminal device 102, or the third terminal device 103, or by other terminal devices different from the first terminal device 101, the second terminal device 102, or the third terminal device 103. Accordingly, the crack analysis system provided in this embodiment may also be installed in the first terminal device 101, the second terminal device 102 or the third terminal device 103, or in other terminal devices different from the first terminal device 101, the second terminal device 102 or the third terminal device 103.

[0039] For example, the three-dimensional digital model can be originally stored in any one of the first terminal device 101, the second terminal device 102, or the third terminal device 103 (e.g., the first terminal device 101, but not limited thereto), or it can be stored on an external storage device and imported into the first terminal device 101. Then, the first terminal device 101 can execute the crack analysis method provided in the embodiments of this disclosure locally, or send the three-dimensional digital model to other terminal devices, servers, or server clusters, and have the other terminal devices, servers, or server clusters that receive the three-dimensional digital model execute the crack analysis method provided in the embodiments of this disclosure.

[0040] It should be understood that Figure 1 The number of terminal devices, networks, and servers shown is merely illustrative. Depending on implementation needs, any number of terminal devices, networks, and servers can be included.

[0041] Figure 2 A flowchart illustrating a crack analysis method according to an embodiment of the present disclosure is shown schematically.

[0042] like Figure 2 As shown, the method includes operations S210~S260.

[0043] In operation S210, a three-dimensional digital model of a biomimetic fracture-resistant structure containing designable hard fiber phase and soft matrix phase features is determined.

[0044] In operation S222, the three-dimensional digital model is imported into the geometric preprocessing software of the material printing equipment for assembly, resulting in a three-dimensional assembly model with both soft and hard phases bonded together.

[0045] In operation S230, the three-dimensional assembly digital model is processed into two dimensions to obtain two-dimensional slice data containing soft and hard phase geometry.

[0046] In operation S240, the two-dimensional slice data is imported into the material printing equipment for calculation and processing to obtain the optimal running trajectory of the printing equipment nozzle and the type of ejected material.

[0047] By operating the S250, layer-by-layer spraying and curing were performed according to the optimal operating trajectory and the type of ejected material to obtain a biomimetic fracture-resistant structural sample containing hard fibers and a soft matrix.

[0048] Using the S260, fracture tests were conducted on the biomimetic fracture-resistant structural sample. The crack surface morphology and fracture mode were observed and analyzed to obtain the observation results.

[0049] According to embodiments of this disclosure, optional hard fiber features in the three-dimensional digital model may include dimensions (diameter, length), helix angle (angle between two adjacent fiber layers), material properties (modulus, strength), etc.; optional soft matrix features may include dimensions (matrix thickness between adjacent fibers within a layer and matrix thickness between layers), material properties (modulus, strength), etc.; optional geometry of the biomimetic fracture-resistant structure conforming to the fracture test standard (ASTM-E1820) may include length, width, height, initial notch size, etc.

[0050] According to embodiments of this disclosure, the three-dimensional digital models of the hard fiber phase and the soft matrix phase in the biomimetic fracture-resistant structure can be exported as stereolithography (STL) files, and then imported into the geometric preprocessing software of a multi-material printing device for assembly to obtain a three-dimensional assembly model in which the hard and soft phases are perfectly bonded.

[0051] According to embodiments of this disclosure, 3D printing additive manufacturing technology can be used to fabricate biomimetic fracture-resistant structural samples.

[0052] According to embodiments of this disclosure, a three-dimensional digital model of a biomimetic fracture-resistant structure incorporating designable hard fiber and soft matrix phases is established. This model is then imported into geometric preprocessing software for assembly, resulting in a three-dimensional assembly model with both hard and soft phases bonded together. The three-dimensional assembly model is then subjected to two-dimensional processing and computation to obtain the optimal trajectory of the printing nozzle and the type of ejected material. Finally, based on the optimal trajectory and material type, layer-by-layer spraying and curing are performed to obtain a biomimetic fracture-resistant structure sample containing hard fibers and a soft matrix. This achieves micron-level precise control of the structural parameters and component properties of the biomimetic Bouligand fracture-resistant structure containing hard fiber and soft matrix phases. Through parametric modeling and high-precision printing, the biomimetic fracture-resistant structure is accurately reproduced, providing guidance for the precise manufacturing and crack analysis of biomimetic fracture-resistant structures with multi-component, multi-scale characteristics. Furthermore, by conducting fracture tests on the biomimetic fracture-resistant structure sample, the crack surface morphology and fracture mode are observed and analyzed to obtain the observation results, thus enabling crack analysis of the biomimetic fracture-resistant structure.

[0053] According to embodiments of this disclosure, the above crack analysis method further includes: establishing a fracture phase field model for predicting crack paths based on a three-dimensional digital model and the characteristics of a biomimetic fracture-resistant structural sample; calculating the predicted crack path based on the fracture phase field model for predicting crack paths; and comparing the predicted crack path with the observation results to obtain a comparison result.

[0054] According to embodiments of this disclosure, the above crack analysis method further includes: adjusting the fracture phase field model based on the comparison results.

[0055] According to embodiments of this disclosure, by establishing a fracture phase field model to predict crack paths and calculating the predicted crack paths accordingly, the crack paths predicted by numerical simulation can be compared with those observed by experimental methods, allowing for further analysis of the crack paths and verification and adjustment of the fracture phase field model.

[0056] According to embodiments of this disclosure, based on the characteristics of the three-dimensional digital model and the biomimetic fracture-resistant structural sample, establishing a fracture phase-field model for predicting crack paths includes: establishing an anisotropic phase-field fracture theory that considers fiber orientation and the properties of both soft and hard phases; and establishing a fracture phase-field model for predicting crack paths based on the anisotropic phase-field fracture theory and the material properties, geometric dimensions, and boundary conditions of the three-dimensional printed sample.

[0057] According to embodiments of this disclosure, the material properties, geometric dimensions, and boundary conditions of the biomimetic fracture-resistant structural sample can first be obtained using standard mechanical tests. A finite element geometric model and computational mesh of the biomimetic fracture-resistant structure can then be established based on the ABAQUS platform. User-defined elements can be written for phase-field element solving. Actual loads can be applied to predict crack morphology and fracture modes.

[0058] According to embodiments of this disclosure, in related technologies, numerical simulation methods are mostly limited to two-dimensional crack morphology or a single fracture mode, and cannot predict the three-dimensional irregular crack surface morphology formed by the coupling of multiple fracture modes such as crack torsion and fiber fracture within biological structures. This disclosure establishes an anisotropic phase-field fracture theory by considering fiber orientation and the properties of both soft and hard phases, and establishes a fracture phase-field model for predicting crack paths based on the anisotropic phase-field fracture theory and the material properties, geometric dimensions, and boundary conditions of the 3D printed sample, which can more accurately predict complex in-plane fracture morphologies.

[0059] According to embodiments of this disclosure, a multi-material printing and crack prediction method for biomimetic fracture-resistant structures is established to achieve high-precision and high-efficiency fabrication of biomimetic fracture-resistant structures containing both soft and hard phase components. A combined crack propagation simulation method is used to accurately predict mixed fracture modes such as crack torsion and fiber fracture, as well as irregular crack morphology, within the biomimetic fracture-resistant structure, based on consideration of internal fiber orientation and the properties of soft and hard components.

[0060] According to embodiments of this disclosure, the traditional fracture phase field method often only considers the elastic strain energy of homogeneous solids. Biomimetic fracture-resistant structural samples have two phases, a hard fiber phase and a soft matrix phase, and are often subjected to tensile-shear mixed loading. In order to more accurately predict various fracture modes such as crack torsion and fiber fracture of biomimetic fracture-resistant structural samples under tensile-shear mixed loading, in embodiments of this disclosure, the elastic energy of material properties in the fracture phase field model can include the tensile elastic energy of the fiber phase, the tensile elastic energy of the matrix phase, and the shear elastic energy of the matrix phase.

[0061] According to embodiments of this disclosure, the tensile elastic properties of a fiber phase can be determined based on the fiber tensile elasticity density, fiber fracture toughness, and fiber anisotropy coefficient.

[0062] According to embodiments of this disclosure, the tensile elastic properties of the matrix phase can be determined based on the matrix tensile elastic energy density and the matrix tensile fracture toughness.

[0063] According to embodiments of this disclosure, the shear elastic energy of the matrix phase can be determined based on the matrix shear elastic energy density and the matrix shear fracture toughness.

[0064] According to embodiments of this disclosure, the elastic energy of material properties in the fracture phase-field model The expression is formula (1):

[0065] (1)

[0066] In the formula, The energy release rate at the crack boundary. For fiber fracture toughness, and These represent matrix type I and type II fracture toughness, respectively. Here are the anisotropy coefficients. , and These represent the elastic energy densities under fiber stretching, matrix stretching, and matrix shearing, respectively.

[0067] According to embodiments of this disclosure, the fiber tensile elastic energy density can be determined based on the stress component and strain component acting on a plane perpendicular to the first direction and along the first direction.

[0068] According to embodiments of this disclosure, the tensile elastic energy density of the matrix can be determined based on the stress and strain components acting on a plane perpendicular to the second direction and along the second direction, and the stress and strain components acting on a plane perpendicular to the third direction and along the third direction.

[0069] According to embodiments of this disclosure, the matrix shear elastic energy density can be determined based on the stress and strain components acting on a plane perpendicular to the first direction and along the second direction, the stress and strain components acting on a plane perpendicular to the second direction and along the third direction, and the stress and strain components acting on a plane perpendicular to the first direction and along the third direction.

[0070] According to an embodiment of this disclosure, the first direction is the fiber direction.

[0071] According to embodiments of this disclosure, the calculation expressions for the elastic energy density during fiber stretching, matrix stretching, and matrix shearing are given by formula (2):

[0072] (2)

[0073] In the formula, , and These are stress and strain components, respectively. , 1 represents the fiber direction, and 2 and 3 represent directions perpendicular to the fiber direction.

[0074] According to embodiments of this disclosure, the above crack analysis method further includes: based on the standard fracture phase field method, combining fracture energy, elastic energy, and external force work, determining the total potential energy expression of the system to which the biomimetic fracture-resistant structure belongs as formula (3):

[0075] (3)

[0076] In the formula, Crack surface density, For phase field variables ( (Indicates a crack) Represents the phase field gradient. For block regions, As the boundary, It is a degenerate function. For elastic properties, For displacement field, and For physical strength and surface strength.

[0077] According to embodiments of this disclosure, considering the in-plane anisotropy of the biomimetic fracture-resistant structure, a crack surface density function expression for fiber orientation anisotropy in composite materials can be adopted. For formula (4):

[0078] (4)

[0079] In the formula, For phase field variables ( (Indicates a crack) Represents the phase field gradient. For dispersion length parameter, Let N be the structural tensor and N be the fiber orientation vector. The anisotropy coefficient is denoted as .

[0080] According to embodiments of this disclosure, the evolutionary governing equations can be obtained by variationally solving the total potential energy equation with respect to the displacement field and the phase field. The evolutionary governing equations include a first equation related to the displacement field and a second equation related to the phase field.

[0081] According to embodiments of this disclosure, the above crack analysis method further includes: using the standard fracture phase field method, solving the total potential energy variationally with respect to the displacement field and phase field to obtain the corresponding evolution control equation and boundary conditions as formula (5):

[0082] (5)

[0083] In the formula, For stress tensor, A vector perpendicular to the boundary. H is the derivative of the degenerate function. + For the historical field variables of strain energy driving force of biomimetic fracture-resistant structures, For dispersion length parameter, It is a structure tensor.

[0084] According to embodiments of this disclosure, a multi-field coupling problem can be decomposed into displacement field and phase field minimization using an interleaved solution format, and then iteratively solved using a custom element user subroutine on the ABAQUS platform and the Newton iteration algorithm.

[0085] According to embodiments of this disclosure, the historical field variables of the strain energy driving force of the biomimetic fracture-resistant structure are as follows: (6)

[0086] (6).

[0087] According to embodiments of this disclosure, the form H = max() is to ensure that the crack does not heal again after cracking, and the crack driving force is taken as the maximum value within the evolution time.

[0088] According to embodiments of this disclosure, the traditional standard fracture phase field method only considers the fracture driving force of homogeneous solids under tensile load, while biomimetic fracture-resistant structures are often subjected to tensile-shear mixed loading. In order to more accurately predict various fracture modes such as crack torsion and fiber fracture of biomimetic fracture-resistant structures, the strain energy driving force of the second equation can be determined based on the tensile elastic energy of the fiber phase, the tensile elastic energy of the matrix phase, and the shear elastic energy of the matrix phase.

[0089] According to embodiments of this disclosure, by introducing anisotropic fracture toughness and crack driving force, the three-dimensional irregular crack surface morphology formed by the coupling of multiple fracture modes such as crack torsion and fiber fracture within the biomimetic fracture-resistant structure can be predicted.

[0090] The elastic energy strain decomposition and crack driving force forms of the embodiments of this disclosure can characterize various fracture modes such as fiber fracture and crack torsion, providing a simulation means for crack prediction and fracture resistance design of biomimetic heterogeneous materials. The fracture phase field model provided in the embodiments of this disclosure can also be used for cross-sectional prediction of other similar composite structural materials.

[0091] According to embodiments of this disclosure, before obtaining a biomimetic fracture-resistant structure sample containing hard fibers and a soft matrix by layer-by-layer spraying and curing according to the optimal running trajectory and the type of ejected material, the method further includes: selecting a photosensitive resin that is liquid at room temperature as the printing material; adjusting the mechanical properties of the printing material using a liquid photosensitive resin mixing formula; determining that the modulus range of the optional hard fiber material is 0.5~1.0 GPa and the strength range is 30~50 MPa; and determining that the modulus range of the optional soft matrix material is 0.2~4.0 MPa and the strength range is 0.3~3 MPa.

[0092] According to embodiments of this disclosure, obtaining a biomimetic fracture-resistant structure sample containing hard fibers and a soft matrix by layer-by-layer spraying and curing according to the optimal operating trajectory and the type of ejected material includes: extracting printing material from the ink cartridge and spraying it layer by layer onto the tray according to the optimal operating trajectory; controlling the ultraviolet lamp to follow the movement of the printhead and instantaneously curing the ejected printing material to achieve adhesion between different materials; obtaining a biomimetic fracture-resistant structure sample containing hard fibers and a soft matrix by layer-by-layer spraying and curing; and removing the surface support material of the sample by soaking in a target mixed solution.

[0093] According to embodiments of this disclosure, each layer has a thickness of 14 to 18 micrometers.

[0094] According to embodiments of this disclosure, specifically, the three-dimensional assembly digital model can be processed into two dimensions to obtain two-dimensional slice data containing soft and hard phase geometry; the two-dimensional slice data is imported into a material printing device for calculation and processing to obtain the optimal running trajectory of the printer nozzle and the corresponding ejected material type; the multi-material printer device is started, which is equipped with eight nozzles, and can extract the corresponding photosensitive resin material (including soft and hard phase materials and support materials) from the ink cartridge and spray it layer by layer onto the tray according to the trajectory, with each layer being 16 micrometers thick. At the same time, the ultraviolet lamp follows the movement of the nozzle and instantly cures the ejected photosensitive resin material, achieving perfect adhesion between different materials. Layer-by-layer spraying and curing yields a biomimetic Bouligand fracture-resistant structure sample containing hard fibers and a soft matrix; the surface support material of the sample is removed by soaking in a mixed solution of sodium hydroxide and sodium metasilicate; finally, the 3D printed biomimetic Bouligand structure sample is subjected to fracture testing to observe and analyze the crack surface morphology and fracture mode.

[0095] According to embodiments of this disclosure, various biomimetic fracture-resistant structural samples can be precisely and efficiently prepared using printing technology. Utilizing multi-material jet photopolymerization technology, a multi-material 3D printing method with an in-plane resolution of 100 micrometers can be developed, enabling precise control of the structural parameters and composition of biomimetic fracture-resistant structures containing both soft and hard phase components.

[0096] According to embodiments of this disclosure, a photosensitive resin that is liquid at room temperature can be selected as the printing material. The curing area of ​​the material can be controlled by utilizing the high precision and concentrated energy of photocuring technology, so that the in-plane resolution reaches 100 micrometers and the out-of-plane resolution reaches 16 micrometers, thereby achieving precise control of structural parameters.

[0097] According to embodiments of this disclosure, a multi-material printing and crack prediction method for biomimetic fracture-resistant structures is established. Through an integrated process of parametric modeling, high-precision printing and crack prediction, the additive manufacturing accuracy and efficiency of biomimetic fracture-resistant structures with multiple components and orientations are improved, and the mixed fracture modes such as crack torsion and fiber fracture and irregular crack morphology within the biomimetic fracture-resistant structure are accurately predicted.

[0098] Figure 3 A crack analysis method according to another embodiment of the present disclosure is illustrated schematically.

[0099] like Figure 3 As shown, the crack analysis method proposed in this embodiment includes operations S310 to S360.

[0100] In operating S310, three-dimensional geometric digital models of the fiber phase and matrix phase were established based on the geometric dimensions and material properties of the biomimetic Bouligand fracture-resistant structure. Figure 4The schematic diagram illustrates the three-dimensional geometric digital model corresponding to the hard fiber and the soft matrix.

[0101] In the S320, the digital models of the fiber phase and matrix phase are assembled in the geometric preprocessing software of the 3D printer, and the fiber and matrix materials are specified respectively. The slice data is obtained through two-dimensional processing and input into the multi-material printer to obtain the nozzle movement trajectory and the type of ejected material. The printer adopts layer-by-layer spraying and photopolymerization to obtain the biomimetic Bouligand fracture-resistant 3D printed sample.

[0102] In operating the S330, based on the fracture phase field theory, a simulation geometric model of the biomimetic Bouligand fracture-resistant structure is established. According to the experimental test of 3D printed samples, the fiber and matrix material parameters are input, boundary conditions are set, etc., and the crack morphology is predicted by solving the finite element algorithm based on the ABAQUS platform.

[0103] During the operation of the S340, standard fracture test experiments were conducted, and crack morphology and different fracture modes were observed using a camera and X-ray CT technology.

[0104] By operating the S350, the three-dimensional crack morphology and different fracture modes are analyzed based on the solved phase field parameter distribution.

[0105] Using the S360, we performed multi-material 3D printing and crack prediction of biomimetic Bouligand fracture-resistant structures.

[0106] According to embodiments of this disclosure, the three-dimensional crack morphology and fracture mode can be compared and analyzed by combining 3D printed sample fracture experiments and phase field simulation models to verify the accuracy of 3D printing and crack prediction.

[0107] Figure 5 A crack analysis method for a single-layer fiberboard according to an embodiment of the present disclosure is illustrated schematically.

[0108] according to Figure 5 The crack analysis method for single-layer fiberboard proposed in this disclosure includes the following specific steps:

[0109] Step 1: In SOLIDWORKS software, establish a geometric model of the hard fibers and soft matrix of a single-layer fiber composite board with a single-sided notch. The fiber diameter is 0.5 mm, the inter-fiber matrix thickness is 0.2 mm, the model length L = 85 mm, the height H = 16.8 mm, and the initial crack length a0 = 3.6 mm; optionally, the fiber orientation angle... It can be set arbitrarily; here we select... and For example, we constructed digital models of the fiber and matrix with perfectly matched geometric positions.

[0110] Step Two: Export the 3D digital models of the hard fiber and soft matrix from Step One as STL files, and then import them into the geometric preprocessing software of the multi-material printing equipment for assembly to obtain a 3D assembled model with perfect bonding of the hard and soft phases; different materials are assigned to the hard fiber and soft matrix respectively, with the hard fiber material being VeroWhitePlus (photocurable rigid polymer material, modulus 1 GPa, fracture toughness 1 kJ / m). 2 The soft matrix material selected is TangoblackPlus (a photocurable flexible polymer material with a modulus of 0.2 MPa and a fracture toughness of 0.3 kJ / m). 2 The three-dimensional assembly digital model is processed into two dimensions to obtain two-dimensional slice data containing the geometry of the hard and soft phases. The two-dimensional slice data is imported into a multi-material printing device for calculation and processing to obtain the optimal running trajectory of the printer nozzle and the corresponding ejected material type. The multi-material printer device is started, which is equipped with eight nozzles. According to the trajectory, the corresponding photosensitive resin material is extracted from the ink cartridge and sprayed layer by layer onto the tray, with each layer being 16μm thick. At the same time, the ultraviolet lamp follows the movement of the nozzle and instantly cures the ejected photosensitive resin material, achieving perfect adhesion between different materials. Layer-by-layer spraying and curing yields a 3D printed sample of a single-layer fiber composite board containing hard fibers and a soft matrix. The surface support material of the sample is removed by soaking in a mixed solution of sodium hydroxide and sodium metasilicate. Finally, the single-layer fiber composite board with a single-sided notch is subjected to a tensile test, and the crack propagation path is recorded using a camera.

[0111] Step 3: Based on the digital model and fracture phase-field theory from Step 1, construct a simulation geometric model for crack prediction on the ABAQUS platform, and write user-defined elements to solve the phase field; based on the geometry and material of the 3D printed sample from Step 2, set the model's geometric dimensions to be consistent with the 3D printed sample; set the fiber orientation vector in the model. The fiber orientation angle can be set to or To account for both soft and hard phase properties, the fiber fracture toughness G is input separately. f = 1 kJ / m 2 Modulus E f = 1 GPa, matrix type I and type II fracture toughness G mI = G mII = 0.3 kJ / m 2 Modulus E m = 0.3MPa; Apply tensile load, use finite element algorithm to solve the fracture phase field control equation, and predict crack propagation path.

[0112] Step four, as Figure 5As shown, a comparative analysis of the crack morphology in steps two and three revealed that the crack morphology of the 3D printed sample was consistent with the prediction by the fracture phase field method. The cracks all propagated along the soft matrix phase deflection, and the crack deflection angle was consistent with the fiber orientation. This demonstrates the accuracy of the crack analysis method provided in this disclosure.

[0113] Figure 6 The crack analysis method of the biomimetic Bouligand fracture-resistant structure is illustrated schematically.

[0114] according to Figure 6 The crack analysis method proposed in this disclosure includes the following specific steps:

[0115] Step 1: As Figure 4 and Figure 6 As shown in (a), geometric models of hard fibers and soft matrix were established in SOLIDWORKS software. The fiber diameter was 0.5 mm, and the matrix thickness between fibers was 0.2 mm. The fiber orientation was set according to the structural characteristics of bio-Bouligand. In this embodiment, there were 25 layers of fiberboard. The orientation angle between adjacent fiber layers was set to 15°, and the fibers in the middle layer were parallel to the crack propagation direction. The relative angles between the orientations of the 25 stacked fiber layers and the Y-axis were distributed as follows: -180°, -165°, ..., -30°, -15°, 0°, 15°, 30°, ..., 165°, 180°. A single-sided notch biomimetic Bouligand fracture-resistant digital model that meets the fracture test standard was further obtained using a cutting tool. The model length L = 85 mm, height H = 16.8 mm, thickness B = 16.8 mm, and initial crack length a0 = 3.6 mm. Digital models of fibers and matrix with perfect geometric fit were constructed respectively.

[0116] Step 2: Export the 3D digital models of the hard fiber and soft matrix from Step 1 as STL files, then import them into the geometry preprocessing software of the multi-material printing equipment for assembly, obtaining a 3D assembled model with perfectly bonded hard and soft phases; assign different materials to the hard fiber and soft matrix respectively, using VeroWhitePlus for the hard fiber and TangoblackPlus for the soft matrix; perform 2D processing on the 3D assembled digital model to obtain 2D slice data containing the geometry of the hard and soft phases; obtain a 3D printed sample with a biomimetic Bouligand fracture-resistant structure containing hard fiber and soft matrix through layer-by-layer spray curing, such as... Figure 6 As shown in (b), the 3D printed sample was subjected to a three-point bending fracture test on a universal testing machine. The crack surface morphology of the sample after the test was observed and reconstructed in three dimensions using a camera and X-ray CT equipment.

[0117] Step 3, as follows Figure 6As shown in (c), based on the digital models and 3D printed samples from steps one and two, a crack prediction simulation model of the biomimetic Bouligand fracture-resistant structure with the same geometric dimensions was constructed in the ABAQUS platform. User-defined elements were written for phase field solving; fiber orientation vectors in the model were set. The fiber orientation angle of the 25 stacked layers is consistent with that of the 3D printed sample; to account for the soft and hard phase properties, the fiber fracture toughness G is input separately. f = 1 kJ / m 2 Modulus E f =1 GPa, matrix type I and type II fracture toughness G mI = G mII = 0.3 kJ / m 2 Modulus E m = 0.3 MPa; Apply a three-point bending load, use the finite element method to solve the fracture phase field control equation, and predict the crack propagation path.

[0118] Step four, compare and analyze the crack morphology of steps two and three, such as... Figure 6 As shown in (d), the cross-section of the 3D-printed biomimetic Bouligand structure exhibits a serrated crack surface morphology, with a helical configuration at the crack front, including a crack torsion zone and a fiber fracture zone, consistent with the crack surface morphology of the biological Bouligand structure; Figure 6 As shown in (e), the crack surface predicted by the fracture phase field method exhibits a serrated morphology, with the crack front showing a helical configuration, including a crack torsion zone and a fiber fracture zone, which is consistent with... Figure 6 (f) shows that the morphology of the 3D printed crack surface and the fracture mode obtained by X-ray CT reconstruction are consistent, which proves the accuracy of the crack prediction method of the biomimetic Bouligand fracture-resistant structure provided by the present invention.

[0119] Figure 7 A block diagram of a crack analysis apparatus according to an embodiment of the present disclosure is shown schematically.

[0120] like Figure 7 As shown, the crack analysis device 700 includes a determination module 710, an assembly module 720, a first processing module 730, a second processing module 740, a curing module 750, and an analysis module 760.

[0121] The determination module 710 is used to determine a three-dimensional digital model of a biomimetic fracture-resistant structure that includes features of a designable hard fiber phase and a soft matrix phase.

[0122] Assembly module 720 is used to import the three-dimensional digital model into the geometric preprocessing software of the material printing equipment for assembly, so as to obtain a three-dimensional assembly model with soft and hard phases bonded together.

[0123] The first processing module 730 is used to perform two-dimensional processing on the three-dimensional assembly digital model to obtain two-dimensional slice data containing soft and hard phase geometry.

[0124] The second processing module 740 is used to import the two-dimensional slice data into the material printing device for calculation and processing to obtain the optimal running trajectory of the printing device nozzle and the type of ejected material.

[0125] The curing module 750 is used to spray and cure layer by layer according to the optimal running trajectory and the type of sprayed material to obtain a biomimetic fracture-resistant structural sample containing hard fibers and soft matrix.

[0126] Analysis module 760 is used to perform fracture tests on biomimetic fracture-resistant structural samples, observe and analyze crack surface morphology and fracture mode, and obtain observation results.

[0127] Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure, or at least part of the functions of any one or more of them, can be implemented in one module. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure can be implemented by dividing them into multiple modules. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure can be at least partially implemented as hardware circuitry, such as a Field-Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a System-on-Chip, a System-on-a-Substrate, a System-on-Package, an Application-Specific Integrated Circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure can be at least partially implemented as computer program modules, which, when run, can perform corresponding functions.

[0128] For example, any multiple of the determination module 710, assembly module 720, first processing module 730, second processing module 740, solidification module 750, and analysis module 760 can be combined into one module / unit / subunit, or any one of these modules / units / subunits can be split into multiple modules / units / subunits. Alternatively, at least some of the functions of one or more of these modules / units / subunits can be combined with at least some of the functions of other modules / units / subunits and implemented in one module / unit / subunit. According to embodiments of this disclosure, at least one of the determining module 710, assembly module 720, first processing module 730, second processing module 740, solidification module 750, and analysis module 760 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or any other reasonable means of integrating or packaging circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the determining module 710, assembly module 720, first processing module 730, second processing module 740, solidification module 750, and analysis module 760 can be at least partially implemented as a computer program module, which, when run, can perform corresponding functions.

[0129] It should be noted that the data processing system part in the embodiments of this disclosure corresponds to the data processing method part in the embodiments of this disclosure. The specific description of the data processing system part is referred to in the data processing method part, and will not be repeated here.

[0130] Figure 8 A block diagram of an electronic device suitable for implementing the methods described above, according to embodiments of the present disclosure, is illustrated schematically. Figure 8 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0131] like Figure 8As shown, an electronic device 800 according to an embodiment of this disclosure includes a processor 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage portion 808 into a random access memory (RAM) 803. The processor 801 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 801 may also include onboard memory for caching purposes. The processor 801 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this disclosure.

[0132] RAM 803 stores various programs and data required for the operation of electronic device 800. Processor 801, ROM 802, and RAM 803 are interconnected via bus 804. Processor 801 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 802 and / or RAM 803. It should be noted that the programs may also be stored in one or more memories other than ROM 802 and RAM 803. Processor 801 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.

[0133] According to embodiments of this disclosure, the electronic device 800 may further include an input / output (I / O) interface 805, which is also connected to a bus 804. The electronic device 800 may also include one or more of the following components connected to the input / output (I / O) interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the input / output (I / O) interface 805 as needed. A removable medium 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 810 as needed so that computer programs read from it can be installed into the storage section 808 as needed.

[0134] According to embodiments of this disclosure, the method flow according to embodiments of this disclosure can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by processor 801, it performs the functions defined in the system of embodiments of this disclosure. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0135] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0136] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. Examples include, but are not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0137] For example, according to embodiments of this disclosure, a computer-readable storage medium may include the ROM 802 and / or RAM 803 described above and / or one or more memories other than ROM 802 and RAM 803.

[0138] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods provided in the embodiments of this disclosure. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the crack analysis method provided in the embodiments of this disclosure.

[0139] When the computer program is executed by the processor 801, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0140] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 809, and / or installed from a removable medium 811. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0141] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on a user's computing device, partially on a user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0142] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions. Those skilled in the art will understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments of this disclosure may be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0143] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A crack analysis method, characterized in that, include: A three-dimensional digital model of a biomimetic fracture-resistant structure incorporating features of both designable hard fiber phases and soft matrix phases was determined. The three-dimensional digital model is imported into the geometric preprocessing software of the material printing equipment for assembly, resulting in a three-dimensional assembly model with both soft and hard phases bonded together. The three-dimensional assembly model is processed into two dimensions to obtain two-dimensional slice data containing soft and hard phase geometry; The two-dimensional slice data is imported into the material printing device for processing to obtain the optimal running trajectory of the printing device nozzle and the type of ejected material; According to the optimal operating trajectory, the printing material is extracted from the ink cartridge and sprayed layer by layer onto the tray; The ultraviolet lamp is controlled to follow the movement of the printhead and instantly cure the ejected printing material to achieve adhesion between different materials; Layer-by-layer spray curing yielded a biomimetic fracture-resistant structural sample containing hard fibers and a soft matrix; The surface support material of the sample is removed by immersion in a target mixed solution. as well as Fracture tests were conducted on the biomimetic fracture-resistant structure sample to observe and analyze the crack surface morphology and fracture mode, and the observation results were obtained.

2. The method according to claim 1, further comprising: Based on the three-dimensional digital model and the characteristics of the biomimetic fracture-resistant structural sample, a fracture phase field model for predicting crack paths is established. The predicted crack path is calculated based on the fracture phase field model of the crack path. The predicted crack path is compared with the observed results to obtain the comparison results.

3. The method according to claim 2, wherein, The step of establishing a fracture phase-field model for predicting crack paths based on the three-dimensional digital model and the characteristics of the biomimetic fracture-resistant structural sample includes: Establish an anisotropic phase field fracture theory that considers fiber orientation and the properties of both soft and hard phases; Based on the anisotropic phase-field fracture theory and the material properties, geometric dimensions, and boundary conditions of the 3D printed sample, a fracture phase-field model for predicting crack paths is established.

4. The method according to claim 2 or 3, wherein, The elastic energy of material properties in the fracture phase field model The expression is: In the formula, The energy release rate at the crack boundary. For fiber fracture toughness, and These represent matrix type I and type II fracture toughness, respectively. Here is the anisotropy coefficient. , and The elastic energy densities under fiber stretching, matrix stretching, and matrix shearing are respectively given by the following calculation expressions: In the formula, , and These are stress and strain components, respectively. , 1 represents the fiber direction, and 2 and 3 represent directions perpendicular to the fiber direction.

5. The method according to claim 4, further comprising: Based on the standard fracture phase-field method, by combining fracture energy, elastic energy, and external force work, the total potential energy expression of the system to which the biomimetic fracture-resistant structure belongs is determined: In the formula, Crack surface density, For phase field variables, Indicates a crack. Represents the phase field gradient. For block regions, As the boundary, It is a degenerate function. For elastic properties, For displacement field, and For physical strength and surface strength.

6. The method according to claim 5, further comprising: According to the standard fracture phase field method, the total potential energy is solved variationally with respect to the displacement field and phase field to obtain the corresponding evolution control equation and boundary conditions as follows: In the formula, For stress tensor, A vector perpendicular to the boundary. H is the derivative of the degenerate function. + The historical field variables of the strain energy driving force of the biomimetic fracture-resistant structure are... For dispersion length parameter, It is a structure tensor.

7. The method according to claim 6, wherein, The historical field variables of the strain energy driving force of the biomimetic fracture-resistant structure are as follows: 。 8. The method according to claim 1, wherein, Before obtaining a biomimetic fracture-resistant structural sample containing hard fibers and a soft matrix by layer-by-layer spraying and curing according to the optimal operating trajectory and the type of ejected material, the method further includes: Photosensitive resin, which is liquid at room temperature, was selected as the printing material. The mechanical properties of the printing material are adjusted using a liquid photosensitive resin mixing formulation; The modulus range of the hard fiber materials was determined to be 0.5~1.0 GPa, and the strength range was 30~50 MPa. The modulus range of the soft matrix materials was determined to be 0.2~4.0 MPa, and the strength range was 0.3~3 MPa.

9. The method according to claim 1, wherein, Each layer is 14-18 micrometers thick.

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