Pore-gradient-discretely-embedded composite bone tissue modeling method

Abstract

The application discloses a pore gradient discrete embedded composite bone tissue modeling method, which comprises the following steps: establishing a three-phase composite bone tissue geometric model of "cortical bone, cancellous bone and cortical bone" with discrete random pores; establishing a material constitutive model of a cortical bone model and a cancellous bone model in the three-phase composite bone tissue geometric model; and performing grid division on the three-phase composite bone tissue geometric model to obtain a composite bone tissue model. The pore gradient discrete embedded composite bone tissue modeling method can effectively simulate the composite structure of the bone tissue from the cortical bone to the cancellous bone, improves the accuracy of bone model simulation, and solves the problem of homogeneous distortion of the material constitutive of the existing bone tissue cutting simulation.

Description

Technical Field

[0001] The present invention relates to the technical field of bone tissue modeling, and in particular to a pore gradient discrete embedded composite bone tissue modeling method. Background Art

[0002] Studying the biomechanical properties of bone tissue can provide a theoretical basis for orthopedic surgery and is the key to further optimizing surgical operations and improving surgical quality. However, with the development and deepening of related research, the limitations of bone tissue as an experimental material have gradually emerged. It is very difficult to obtain bone tissue materials, and the quantity is difficult to meet the requirements. The emergence of the finite element model of bone tissue not only effectively avoids the above problems, but also can intuitively display the real-time change information of various physical quantities such as stress, strain, and temperature. At the same time, it also has certain advantages in experimental costs. Therefore, the finite element model of bone tissue has gradually become an important research tool.

[0003] Research on the anatomical structure of human bone tissue shows that bone tissue is primarily composed of cortical bone on both sides and cancellous bone in the middle. Cortical bone is dense, while cancellous bone is porous and spongy, playing an overwhelmingly dominant role in bone tissue. However, existing bone tissue models often compare bone to engineering materials such as wood and steel, ignoring the influence of its anatomical structure and material constitutive model on its mechanical properties. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing bone tissue model cannot take into account the refined composite bone tissue anatomical structure and the realization of finite element simulation, and to provide a pore gradient discrete embedded composite bone tissue modeling method based on the structural characteristics of the pore gradient change of the composite bone tissue. It can effectively simulate the composite structure of bone tissue transitioning from cortical bone to cancellous bone, improve the accuracy of bone model simulation, and solve the problem of constitutive homogeneity distortion of existing bone tissue cutting simulation materials.

[0005] In order to achieve the above object, the present invention provides a pore gradient discrete embedded composite bone tissue modeling method, comprising the steps of:

[0006] S1. Establish a three-phase composite bone tissue geometric model of "cortical bone, cancellous bone, and cortical bone" with discretized random pores;

[0007] S2. Establishing the material constitutive model of the cortical bone model and the cancellous bone model in the three-phase composite bone tissue geometric model;

[0008] S3. Mesh the three-phase composite bone tissue geometric model to obtain a composite bone tissue model.

[0009] The three-phase composite bone tissue geometric model of "cortical bone, cancellous bone and cortical bone" was established by secondary development of Abaqus software using Python language, including:

[0010] Based on Abaqus / Python software, a .rpy script file was developed to create a cancellous bone tissue model based on discretized random pores.

[0011] An Abaqus plug-in was compiled to visualize the code language of the .rpy script file to obtain a cancellous bone model;

[0012] The cancellous bone model generated by secondary development in Abaqus software and the rectangular cortical bone model directly generated in the part plate were imported into Auto-CAD software and combined to form a three-phase composite bone tissue geometric model with a gradient random pore structure.

[0013] The secondary development based on Abaqus / Python software can create an .rpy script file that can create cancellous bone tissue modeling based on discretized random pores, including:

[0014] Call the random function CircleByCenterPerimeter to randomly generate a set of circular holes (R i ,x i ,y i ), R i ,x i ,y i Respectively represent the radius and coordinate value of the circular pore;

[0015] The generated circular pores (R i ,x i ,y i ) and the existing matrix center[(R q ,x q ,y q )] to determine the intersection of each circle. If the circular pore (R i ,x i ,y i ) and any circle (R q ,x q ,y q ) is smaller than the set optimal gap G, then return to the previous line of command to regenerate a new set of circular pores (R i ,x i ,y i ) and perform intersection determination again until a circular hole (R i ,x i ,yi ), and then the circular aperture (R i ,x i ,y i ) is stored in the existing matrix center[] to obtain the .rpy script file that can create cancellous bone tissue modeling based on discretized random pores.

[0016] The process of compiling an Abaqus plug-in to visualize the code language of the .rpy script file to obtain a cancellous bone model includes:

[0017] Use UltraEdit to open the generated .rpy script file in the Part module working directory in Abaqus / CAE. Filter the script file based on the function name and parameter value to obtain the script functions and expressions for drawing rectangles and circles. Then, perform a trial run to check if there are any problems with the rewritten script file.

[0018] Use RSG to build plug-ins and create different GUI interfaces under the RSG Dialog Builder section of the Plug-ins menu;

[0019] The .rpy script file is bound to the GUI interface to realize the visual processing of the code language of the .rpy script file and obtain the cancellous bone model.

[0020] The combination of the cortical bone model and the cancellous bone model to form a composite bone tissue geometric model with a gradient random pore structure includes:

[0021] The cancellous bone model with discretized random pores and the rectangular cortical bone models on both sides were imported into AutoCAD software and modified and combined to form a composite bone tissue geometric model with discretized random pores.

[0022] Among them, the established composite bone tissue geometric model is rectangular, and its size parameters are set as: horizontal total length 10mm, height 4mm, and stretched width 3mm. The width of the cortical bone model is 1.25mm, and the total length of the cancellous bone model is 7.5mm. The width of the two outer regions of the cancellous bone model is 1mm, the pore radius ranges from 0.1-0.2mm, and the minimum pore interval is 0.1mm; the width of the inner region of the cancellous bone model is 5.5mm, the pore radius ranges from 0.3-0.5mm, and the minimum pore interval is 0.1mm.

[0023] In step S2, the material constitutive models of the cortical bone model and the cancellous bone model are established in Abaqus / Explicit, including:

[0024] The Brittle-Cracking constitutive model, in which brittle behavior is dominant, was selected as the material constitutive model for the cortical bone model and the cancellous bone model.

[0025] The material parameters of the material constitutive models of the cortical bone model and the cancellous bone model are set to obtain the material constitutive models of the cortical bone and the cancellous bone.

[0026] The cortical bone material parameters of the material constitutive model of the cortical bone model are set as follows: density 1.8×10 - 9 t / mm 3 , Young's modulus 2.2×10 -4 MPa, Poisson's ratio 0.4, fracture energy 1.374 N / mm, crack strain 0.2%, failure stress 219 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), import coefficient 0.56mJ / (s·℃);

[0027] The cancellous bone material parameters of the cancellous bone model are set as follows: density 5.5×10 - 10 t / mm 3 , Young's modulus 1.1×10 -4 MPa, Poisson's ratio 0.3, fracture energy 2.912 N / mm, crack strain 0.2%, failure stress 110 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), introduction coefficient 0.18mJ / (s·℃).

[0028] In step S3, the meshing of the three-phase composite bone tissue geometric model is completed in Abaqus / CAE, including:

[0029] The three-phase composite bone tissue geometric model adopts a global unilateral seeding method as a whole. The hexahedral mesh is selected as the mesh unit shape of the three-phase composite bone tissue geometric model. The mesh unit type is the C3D8RT unit with reduced integration, explicit, linear, and temperature-displacement coupling. The style grid size is set. The cortical bone model is divided into networks using the standard structural meshing method, and the cancellous bone model is divided into meshes using the swept meshing method.

[0030] Wherein, in the meshing step of the three-phase composite bone tissue geometric model, the mesh size is set to 0.2.

[0031] The present invention divides bone tissue into cortical bone and cancellous bone according to its physiological anatomical structure, function and respective biomechanical properties, establishes finite element models of cortical bone and cancellous bone respectively, and selects a more accurate material constitutive model based on the material properties. Finally, a pore gradient discretized embedded composite bone tissue is established, which can be used to accurately realize finite element simulation of bone tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of the pore gradient discrete embedded composite bone tissue modeling method of the present invention;

[0033] Figure 2 This is a flow chart for generating and verifying the discretized random pore characteristic parameters of the present invention;

[0034] Figure 3 Schematic diagram of generating random pores by the Abaqus random pore plug-in of the present invention;

[0035] Figure 4 A schematic diagram of a composite bone tissue geometric model with gradient discretized random pores constructed according to an embodiment of the present invention;

[0036] Figure 5 Flowchart for calculation of parameter setting for the Brittle-Cracking constitutive model of the present invention;

[0037] Figure 6 This is a schematic diagram of the discretized random pore composite bone tissue geometric model constructed in an embodiment of the present invention after meshing. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the examples described are only some embodiments of the invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making innovative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1 As shown, the pore gradient discrete embedded composite bone tissue modeling method according to an embodiment of the present invention includes the following steps:

[0040] S1. Establish a three-phase composite bone tissue geometric model of "cortical bone, cancellous bone, and cortical bone" with discretized random pores;

[0041] S2. Establishing the material constitutive model of the cortical bone model and the cancellous bone model in the three-phase composite bone tissue geometric model;

[0042] S3. Mesh the three-phase composite bone tissue geometric model to obtain a composite bone tissue model.

[0043] In the embodiment of the present application, the three-phase composite bone tissue geometric model of "cortical bone, cancellous bone and cortical bone" is established by secondary development of Abaqus software using Python language, including:

[0044] Based on Abaqus / Python software, a .rpy script file was developed to create a cancellous bone tissue model based on discretized random pores.

[0045] An Abaqus plug-in was compiled to visualize the code language of the .rpy script file to obtain a cancellous bone model;

[0046] The cancellous bone model generated by secondary development in Abaqus software and the rectangular cortical bone model directly generated in the part plate were imported into Auto-CAD software and combined to form a three-phase composite bone tissue geometric model with a gradient random pore structure.

[0047] In the embodiment of the present application, the secondary development based on Abaqus / Python software can create an .rpy script file that can create cancellous bone tissue modeling based on discretized random pores, including:

[0048] Call the random function CircleByCenterPerimeter to randomly generate a set of circular holes (R i ,x i ,y i ), R i ,x i ,y i Represent the radius and coordinate value of the circular pore respectively, such as Figure 3 As shown, the given range is a rectangular area Xmax, Ymin, Figure 3 On the interface shown, you can select the maximum radius Rmax, minimum radius Rmin, optimal distance G, and maximum number of circular pores N1, all in mm.

[0049] like Figure 2 As shown, interference judgment is performed on the generated circular pores:

[0050] The generated circular pores (R i ,x i ,y i ) and the existing matrix center[(R q ,x q ,y q )] to determine the intersection of each circle. If the circular pore (R i,x i ,y i ) and any circle (R q ,x q ,y q ) is smaller than the set optimal gap G, then return to the previous line of command to regenerate a new set of circular pores (R i ,x i ,y i ) and perform intersection determination again until a circular hole (R i ,x i ,y i ), and then the circular aperture (R i ,x i ,y i ) is stored in the existing matrix center[] to obtain the .rpy script file that can create cancellous bone tissue modeling based on discretized random pores.

[0051] Specifically, such as Figure 2 As shown, enter X max ,Y min 、R max 、R min , G, N1, generate random circular pores (R i ,x i ,y i ), R i ∈[R min ,R max ,],x i ∈[R i +G,X max -R i -G],y i ∈[R i +G,Y max -R i -G], i represents the circular pore number; then enter the steps:

[0052] Determine whether i is equal to 0. If so, proceed to the next step and add a circular hole (R i ,x i ,y i ) to the existing matrix center[(R q ,x q ,y q )], then after adding 1 to i, determine whether i is greater than or equal to N1. When i ≥ N1, output the circular aperture R that meets the minimum or optimal gap. q ,x q ,y q , when i≥N1 is not true, return to generate a random circular hole (Ri ,x i ,y i ) steps;

[0053] If i is not equal to 0, then judge (x i -x q ) 2 +(y i -y q ) 2 ≥(R i +R q +G) 2 Is it true? If so, add a circular hole (R i ,x i ,y i ) to the existing matrix center[(R q ,x q ,y q )], otherwise, after adding 1 to i, determine whether i is greater than or equal to N1. When i ≥ N1, output the circular aperture (R q ,x q ,y q) , when i≥N1 is not true, return to generate a random circular hole (R i ,x i ,y i ) steps.

[0054] In the embodiment of the present application, the Abaqus plug-in is compiled to visualize the code language of the .rpy script file to obtain a cancellous bone model, including:

[0055] Use UltraEdit to open the generated .rpy script file in the Part module working directory in Abaqus / CAE. Filter the script file based on the function name and parameter value to obtain the script functions and expressions for drawing rectangles and circles. Then, perform a trial run to check if there are any problems with the rewritten script file.

[0056] Use RSG to build plug-ins and create different GUI interfaces under the RSG Dialog Builder section of the Plug-ins menu;

[0057] The .rpy script file is bound to the GUI interface to realize the visual processing of the code language of the .rpy script file and obtain the cancellous bone model.

[0058] It should be noted that in the above steps, if the rewritten script file is checked for problems through trial operation, then return to the above script file steps and re-modify the script function. If there are no problems, then proceed to the following steps of creating a different GUI interface.

[0059] In the embodiment of the present application, the cortical bone model and the cancellous bone model are combined to form a composite bone tissue geometric model with a gradient random pore structure, including:

[0060] The cancellous bone model with discretized random pores and the rectangular cortical bone models on both sides were imported into AutoCAD software and modified and combined, as shown in Figure 2. Figure 4 The lower figure shown in the figure shows a cancellous bone model in the middle and cortical bone models on both sides. Figure 4 The upper middle diagram corresponds to the actual bone tissue structure.

[0061] In the embodiment of the present application, the established composite bone tissue geometric model is rectangular, and its size parameters are set as: horizontal total length 10 mm, height 4 mm, stretched width 3 mm, wherein the width of the cortical bone model is 1.25 mm, the total length of the cancellous bone model is 7.5 mm, wherein the width of the two outer regions of the cancellous bone model is 1 mm, the pore radius range is 0.1–0.2 mm, and the minimum pore spacing is 0.1 mm; the width of the inner region of the cancellous bone model is 5.5 mm, the pore radius range is 0.3–0.5 mm, and the minimum pore spacing is 0.1 mm.

[0062] In the embodiment of the present application, in step S2, the material constitutive models of the cortical bone model and the cancellous bone model are established in Abaqus / Explicit, including:

[0063] The Brittle-Cracking constitutive model, in which brittle behavior is dominant, was selected as the material constitutive model for the cortical bone model and the cancellous bone model.

[0064] The material parameters of the material constitutive models of the cortical bone model and the cancellous bone model are set to obtain the material constitutive models of the cortical bone and the cancellous bone.

[0065] In the embodiment of the present application, the Brittle-Cracking constitutive model is composed of three parts: Brittle Cracking, Brittle Shear and Brittle Failure, which correspond to the crack damage initiation, crack damage evolution and unit failure deletion of the material respectively. At the same time, the linear elastic process of the material is represented by Young's modulus and Poisson's ratio. The calculation process of the Brittle-Cracking constitutive model is as follows: Figure 5 As shown, where E is the Young's modulus of the material, σ t is the ultimate stress of the material, σ i Calculate stresses for materials, is the material cracking strain, is the maximum cracking strain of the material. The calculation process includes the following steps:

[0066] First, the relevant material parameters are input, and then a certain material calculation point is compressed under external influences. The compression process is differentiated into n finite compression processes, where the time seconds corresponding to a single compression process is a time increment step. Before compression, the time increment counter is initialized to 0, and then compression processing is performed by adding 1 to multiple time increments. After the compression of n finite compression processes is completed, that is, after the compression of n time increments is completed, the calculation results are output to obtain the corresponding material parameters.

[0067] Among them, in the i-th time increment, the theoretical compression of the material calculation point is e i In the compression process, when the compression is not completed, it is determined whether the calculation point is damaged, or whether the calculation point is invalid. When the calculation point is determined to be invalid, the material calculation point is deleted and the calculation result is output.

[0068] If the calculation is judged to be without damage, σi=E×ei is calculated according to the elastic compression process; if the calculation point is not invalid, the calculation is performed according to the damage degree.

[0069] Among them, whether the calculation point is invalid is determined according to the formula Judge, if If it holds, the calculation point is considered to be valid, otherwise it is considered to be invalid.

[0070] Among them, judging whether the calculation point is damaged is based on the formula E×e i ≥σ t Judge, if E×e i ≥σ t If it holds, the calculation point is considered damaged, otherwise it is considered that there is no damage.

[0071] By setting the material parameters in the above manner, the material parameters of the material constitutive models of the cortical bone model and the cancellous bone model are obtained.

[0072] In the embodiment of the present application, the cortical bone material parameters of the material constitutive model of the cortical bone model are set as follows: density 1.8×10 -9 t / mm 3 , Young's modulus 2.2×10 -4 MPa, Poisson's ratio 0.4, fracture energy 1.374 N / mm, crack strain 0.2%, failure stress 219 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), import coefficient 0.56mJ / (s·℃);

[0073] The cancellous bone material parameters of the cancellous bone model are set as follows: density 5.5×10 - 10t / mm 3 , Young's modulus 1.1×10 -4 MPa, Poisson's ratio 0.3, fracture energy 2.912 N / mm, crack strain 0.2%, failure stress 110 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), introduction coefficient 0.18mJ / (s·℃).

[0074] In the embodiment of the present application, in step S3, the meshing of the three-phase composite bone tissue geometric model is completed in Abaqus / CAE, including:

[0075] The three-phase composite bone tissue geometric model adopts a global unilateral seeding method as a whole, and a hexahedral mesh is selected as the mesh unit shape of the three-phase composite bone tissue geometric model. The mesh unit type is a C3D8RT unit with reduced integration, explicit, linear, and temperature-displacement coupling. The style grid size is set, and the cortical bone model is meshed using the standard structural meshing method. The cancellous bone model is meshed using the sweeping meshing method. After the network division, Figure 6 As shown, in the meshing step of the three-phase composite bone tissue geometric model, the mesh size is set to 0.2.

[0076] The present invention divides bone tissue into cortical bone and cancellous bone according to its physiological anatomical structure, function and respective biomechanical properties, establishes finite element models of cortical bone and cancellous bone respectively, and selects a more accurate material constitutive model based on the material properties. Finally, a pore gradient discretized embedded composite bone tissue is established, which can be used to accurately realize finite element simulation of bone tissue.

[0077] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0078] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A composite bone tissue modeling method with pore gradient discrete embedded, characterized in that: Including steps: S1. Establish a three-phase composite bone tissue geometric model of "cortical bone, cancellous bone, and cortical bone" with discretized random pores; S2. Establishing the material constitutive model of the cortical bone model and the cancellous bone model in the three-phase composite bone tissue geometric model; S3. Meshing the three-phase composite bone tissue geometric model to obtain a composite bone tissue model; The three-phase composite bone tissue geometric model of "cortical bone, cancellous bone and cortical bone" was established by secondary development of Abaqus software using Python language, including: Based on Abaqus / Python software, a .rpy script file was developed to create a cancellous bone tissue model based on discretized random pores. An Abaqus plug-in was compiled to visualize the code language of the .rpy script file to obtain a cancellous bone model; The cancellous bone model generated by secondary development in Abaqus software and the rectangular cortical bone model generated directly in the part plate were imported into Auto-CAD software and combined to form a three-phase composite bone tissue geometric model with a gradient random pore structure. The secondary development based on Abaqus / Python software can create an .rpy script file that can create cancellous bone tissue modeling based on discretized random pores, including: Call the random function CircleByCenterPerimeter to randomly generate a set of circular holes (R i ,x i ,y i ), R i ,x i ,y i Respectively represent the radius and coordinate value of the circular pore; The generated circular pores (R i ,x i ,y i ) and the existing matrix center[(R q ,x q ,y q )] in each circle (R q ,x q ,y q ) to make an intersection judgment, if the circular pore (R i ,x i ,y i ) and any circle in the existing matrix center[] is less than the set optimal gap G, then return to the previous line command to regenerate a new set of circular pores (R i ,x i ,y i ) and perform intersection determination again until a circular hole (R i ,x i ,y i ), and then the circular aperture (R i ,x i ,y i ) is stored in the existing matrix center[] to obtain the .rpy script file that can create cancellous bone tissue modeling based on discretized random pores.

2. The pore gradient discrete embedded composite bone tissue modeling method according to claim 1, characterized in that: The Abaqus plug-in is compiled to perform visual processing on the code language of the .rpy script file to obtain a cancellous bone model, including: Use UltraEdit to open the generated .rpy script file in the Part module working directory of Abaqus / CAE. Filter the script file based on the function name and parameter value to obtain the script functions and expressions for drawing rectangles and circles. Then, perform a trial run to check whether there are any problems with the rewritten script file. Use RSG to build plug-ins and create different GUI interfaces under the RSG Dialog Builder section of the Plug-ins menu; The .rpy script file is bound to the GUI interface to realize the visual processing of the code language of the .rpy script file and obtain the cancellous bone model.

3. The pore gradient discrete embedded composite bone tissue modeling method according to claim 1, characterized in that: The cortical bone model and the cancellous bone model are combined to form a composite bone tissue geometry model with a gradient random pore structure, including: The cancellous bone model with discretized random pores and the rectangular cortical bone models on both sides were imported into AutoCAD software and modified and combined to form a composite bone tissue geometric model with discretized random pores. Among them, the established composite bone tissue geometric model is rectangular, and its size parameters are set as: horizontal total length 10mm, height 4mm, and stretched width 3mm. The width of the cortical bone model is 1.25mm, and the total length of the cancellous bone model is 7.5mm. The width of the two outer regions of the cancellous bone model is 1mm, the pore radius ranges from 0.1-0.2mm, and the minimum pore interval is 0.1mm; the width of the inner region of the cancellous bone model is 5.5mm, the pore radius ranges from 0.3-0.5mm, and the minimum pore interval is 0.1mm.

4. The pore gradient discrete embedded composite bone tissue modeling method according to claim 1, characterized in that: In step S2, the material constitutive models of the cortical bone model and the cancellous bone model are established in Abaqus / Explicit, including: The Brittle-Cracking constitutive model, in which brittle behavior is dominant, was selected as the material constitutive model for the cortical bone model and the cancellous bone model. The material parameters of the material constitutive models of the cortical bone model and the cancellous bone model are set to obtain the material constitutive models of the cortical bone and the cancellous bone.

5. The pore gradient discrete embedded composite bone tissue modeling method according to claim 4, characterized in that: The cortical bone material parameters of the material constitutive model of the cortical bone model are set as follows: density 1.8×10 -9 t / mm 3 , Young's modulus 2.2×10 -4 MPa, Poisson's ratio 0.4, fracture energy 1.374 N / mm, crack strain 0.2%, failure stress 219 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), introduction coefficient 0.56mJ / (s·℃).

6. The pore gradient discrete embedded composite bone tissue modeling method according to claim 4, characterized in that: The cancellous bone material parameters of the cancellous bone model are set as follows: density 5.5×10 -10 t / mm 3 , Young's modulus 1.1×10 -4 MPa, Poisson's ratio 0.3, fracture energy 2.912 N / mm, crack strain 0.2%, failure stress 110 MPa, shear retention factor 2, failure displacement 0.001 mm, specific heat capacity 1.26×10 9 mJ / (t·℃), introduction coefficient 0.18mJ / (s·℃).

7. The pore gradient discrete embedded composite bone tissue modeling method according to claim 1, characterized in that: In step S3, the meshing of the three-phase composite bone tissue geometric model is completed in Abaqus / CAE, including: The three-phase composite bone tissue geometric model adopts a global unilateral seeding method as a whole. The hexahedral mesh is selected as the mesh unit shape of the three-phase composite bone tissue geometric model. The mesh unit type is the C3D8RT unit with reduced integration, explicit, linear, and temperature-displacement coupling. The style grid size is set. The standard structural meshing method is used for network division of the cortical bone model, and the swept meshing method is used for the cancellous bone model.

8. The pore gradient discrete embedded composite bone tissue modeling method according to claim 7, characterized in that: In the meshing step of the three-phase composite bone tissue geometric model, the mesh size is set to 0.2.

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