阅读说明：本技术 一种基于ANSYS Workbench的多层膜热分析方法 (Multilayer film thermal analysis method based on ANSYS Workbench ) 是由 徐中民 梁柯林 于 2021-08-03 设计创作，主要内容包括：本发明涉及一种基于ANSYS Workbench的多层膜热分析方法,包括以下步骤：S1建立基底和多层膜的模型,并指定基底的材料属性、多层膜周期数以及每一层膜的物理参数和材料属性；S2对基底和多层膜的模型进行网格划分,并使多层膜与基底上表面的网格划分保持一致；S3在多层膜模型上施加热流载荷并设置约束方程；S4求解,得到多层膜模型的温度分布。本发明的方法通过壳单元模拟多层膜解决了高纵横比多层膜网格划分和结构物理属性匹配的问题,不仅可以极大程度减少单元数量,优化操作步骤,而且相较于经典版操作界面更具有交互性好,操作简便,处理效率高的优点,同时使用Workbench计算的方法更容易复现和再利用。(The invention relates to a multilayer film thermal analysis method based on ANSYS Workbench, which comprises the following steps: s1, establishing a model of the substrate and the multilayer film, and specifying the material property of the substrate, the number of cycles of the multilayer film, and the physical parameters and the material property of each layer of film; s2, carrying out mesh division on the models of the substrate and the multilayer film, and keeping the mesh division of the multilayer film and the upper surface of the substrate consistent; s3 applying heat flow load on the multilayer film model and setting a constraint equation; and S4, solving to obtain the temperature distribution of the multilayer film model. The method solves the problems of grid division and structure physical attribute matching of the multilayer film with high aspect ratio through the shell unit simulation multilayer film, not only can greatly reduce the number of units and optimize operation steps, but also has the advantages of good interactivity, simple and convenient operation and high processing efficiency compared with a classic operation interface, and is easier to reproduce and reuse by using a Workbench calculation method.)

1. A multilayer film thermal analysis method based on ANSYS Workbench is characterized by comprising the following steps:

s1: establishing a model of a substrate and a multilayer film in an ANSYS Workbench, and specifying the material attribute of the substrate, the number of cycles of the multilayer film and the physical parameters and the material attribute of each layer of the film;

s2: carrying out meshing on the models of the substrate and the multilayer film, and keeping the meshing of the multilayer film and the upper surface of the substrate consistent;

s3: applying heat flow load on the multilayer film model and setting a constraint equation;

s4: and solving the constraint equation to obtain the temperature distribution of the multilayer film model.

2. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein in step S1, the cell type of the substrate model is a solid cell and the cell type of the multilayer film model is a shell cell.

3. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 2, wherein the cell type of the substrate model is Solid90 cells and the cell type of the multilayer film model is Shell132 cells.

4. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein step S2 comprises:

the upper surface of the base model and the multilayer film model are divided by using quadrilateral meshes, the sizes of corresponding edges are set to be the same, and then the base model is divided by using hexahedral meshes.

5. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 4, wherein the cell order is set to second order at the time of the mesh division.

6. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein step S3 comprises:

newly building a surface effect unit only containing heat flow density, then selecting all nodes of the multilayer film model unit, covering the surface effect unit on the nodes, then copying a layer of surface effect unit upwards, deleting the original surface effect unit, then setting the heat flow density and applying the heat flow density to the copied surface effect unit, and finishing the application of heat flow load.

7. The ANSYS Workbench-based multilayer film thermal analysis method of claim 6, wherein step S3 further comprises:

and setting a constraint equation to connect corresponding nodes in different surfaces, and ensuring that the temperature of the corresponding node of the plane where the surface effect unit is located and the uppermost layer film of the multilayer film model unit is equal to the temperature of the corresponding node of the upper surface of the substrate model and the lowermost layer film of the multilayer film model unit, so that the temperature transfer and transition are continuous.

8. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein the constraint equation in step S3 is: and respectively taking all the nodes of the two adjacent surfaces, and sequentially enabling the temperatures of the corresponding nodes to be equal through circulation.

9. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein said substrate material is Si, and said multilayer film material comprises B₄C and Pd.

10. The ANSYS Workbench-based multilayer film thermal analysis method as recited in claim 1, wherein step S4 further comprises: and storing the node temperature of the multilayer film in an external file in an array form.

Technical Field

The invention relates to the field of multilayer film finite element analysis, in particular to a multilayer film thermal analysis method based on ANSYS Workbench.

Background

Compared with the common monochromator, the multilayer film monochromator has the advantages of large bandwidth, high reflectivity and high luminous efficiency, so that the multilayer film monochromator is widely applied to various synchronous radiation devices at home and abroad, such as BSRF, NSRL and SSRF in China, Spring-8 in Japan, ESRF in France, APS in America and the like.

In order to predict the performance and service life of the multilayer film structure, a finite element method can be adopted for simulation analysis, but because the high aspect ratio of the multilayer film structure, namely the size difference between the thickness (nm) and the length (mm) of the film is huge (10^6), if the grid is divided by the size in the length and width directions, the thickness direction is ignored, and the accuracy of the calculation result is seriously influenced; if the meshes are divided according to the size in the thickness direction, the number of the whole units is an extremely huge number, and the solution cannot be completed according to the calculation level of the conventional common computer, so that great difficulty is brought to finite element meshing and simulation analysis.

In addition, due to the function limitation of finite element software, multilayer film simulation per se has considerable difficulty, a user is often required to program and expand a method by himself, the existing multilayer film simulation is usually realized by writing APDL command streams in an ANSYS classic environment, a large number of codes are required to be written in the processes of modeling, grid division, load application and the like, the simulation is not intuitive enough, man-machine interaction is not friendly to each other, the use is inconvenient, and problems are difficult to be solved if the problems occur.

The ANSYS Workbench is popular among a plurality of users by virtue of the characteristics of intuitive and friendly interface, high front and back treatment efficiency, easy realization and simple and convenient operation. However, the ANSYS Workbench itself does not have a function of directly operating the multilayer film, and due to the difference of platforms, the APDL command stream of the ANSYS classic version cannot be directly transplanted into the Workbench to realize the analysis of the multilayer film, so that the finite element analysis of the multilayer film structure in the Workbench is difficult. Therefore, how to find a multilayer film thermal analysis method based on ANSYS Workbench, which is simple and convenient to operate, is a technical problem to be solved urgently by technical personnel in the field.

Disclosure of Invention

The invention aims to provide a multilayer film thermal analysis method based on ANSYS Workbench, and aims to solve the problem that a multilayer film structure is difficult to carry out finite element analysis in the ANSYS Workbench.

The invention provides a multilayer film thermal analysis method based on ANSYS Workbench, which comprises the following steps:

s1: establishing a model of a substrate and a multilayer film in an ANSYS Workbench, and specifying the material attribute of the substrate, the number of cycles of the multilayer film and the physical parameters and the material attribute of each layer of the film;

s2: carrying out meshing on the models of the substrate and the multilayer film, and keeping the meshing of the multilayer film and the upper surface of the substrate consistent;

s3: applying heat flow load on the multilayer film model and setting a constraint equation;

s4: and solving the constraint equation to obtain the temperature distribution of the multilayer film model.

Further, in step S1, the cell type of the substrate model is a solid cell, and the cell type of the multilayer film model is a shell cell.

Further, the cell type of the substrate model is Solid90 cells, and the cell type of the multilayer film model is Shell132 cells.

Further, step S2 includes:

the upper surface of the base model and the multilayer film model are divided by using quadrilateral meshes, the sizes of corresponding edges are set to be the same, and then the base model is divided by using hexahedral meshes.

Further, the cell order is set to second order at the time of mesh division.

Further, step S3 includes:

newly building a surface effect unit only containing heat flow density, then selecting all nodes of the multilayer film model unit, covering the surface effect unit on the nodes, then copying a layer of surface effect unit upwards, deleting the original surface effect unit, then setting the heat flow density and applying the heat flow density to the copied surface effect unit, and finishing the application of heat flow load.

Further, step S3 further includes:

and setting a constraint equation to connect corresponding nodes in different surfaces, and ensuring that the temperature of the corresponding node of the plane where the surface effect unit is located and the uppermost layer film of the multilayer film model unit is equal to the temperature of the corresponding node of the upper surface of the substrate model and the lowermost layer film of the multilayer film model unit, so that the temperature transfer and transition are continuous.

Further, the constraint equation in step S3 is: and respectively taking all the nodes of the two adjacent surfaces, and sequentially enabling the temperatures of the corresponding nodes to be equal through circulation.

Further, the material of the substrate is Si, and the material of the multilayer film comprises B₄C and Pd.

Further, step S4 further includes: and storing the node temperature of the multilayer film in an external file in an array form.

According to the multilayer film thermal analysis method based on ANSYS Workbench, the problems of grid division and structure physical attribute matching of the high-aspect-ratio multilayer film are solved by simulating the multilayer film through the Shell132 unit; the problem that heat flow cannot be directly and accurately applied in Workbench is solved by establishing and using the SURF152, and meanwhile, the establishment of the SURF not only can apply uniform load, but also allows heat flow density with different distributions to be applied, so that the range of heat load is expanded; the modeling and the grid division are rapidly and intuitively completed by combining the advantages of the Workbench, functions required to be realized are organically integrated into a Workbench architecture by using the Commands command in a proper place, and the problem that the conventional multilayer film analysis which only depends on APDL complex programming processing is transplanted into the Workbench to be simply and intuitively realized is solved, so that the problems of poor interactivity and difficulty in reproduction of a finite element classical version are solved, the operation efficiency is improved, and the whole operation process is intuitive and easy to understand.

Drawings

Fig. 1 is a flowchart of a multilayer film thermal analysis method based on ANSYS Workbench according to an embodiment of the present invention;

FIG. 2 is a temperature profile of an ANSYS Workbench based multilayer film model provided by an embodiment of the present invention;

fig. 3A and 3B are temperature distributions of (0, 0, 10) and (0, 0, 80) points, respectively, in a 10-layer film on a Shell cell provided by an embodiment of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, an embodiment of the present invention provides a multilayer film thermal analysis method of an ANSYS Workbench, including the following steps:

s1: models of the substrate and multilayer film were built in ANSYS Workbench and specified material properties of the substrate, number of cycles of multilayer film, and physical parameters and material properties of each layer of film.

Wherein, S1 specifically includes:

s11: and selecting a Steady-state Thermal module to perform Steady-state Thermal analysis by entering an ANSYS Workbench interface, and creating the required material and setting the attribute of the material in Engineering Data.

Specifically, a Workbench software is opened to select a Steady-state Thermal module to perform Steady-state Thermal analysis on the Multilayer film, and a file is named as Multilayer FE; newly building materials of a substrate and a multilayer film in Engineering Data and editing the properties of the materials, wherein the substrate material is Si, and the multilayer film material comprises B₄C (boron carbide) and Pd (palladium), the properties and parameters of each material are shown in table 1.

Table 1 material Properties and parameters

S12: establishing a substrate and a multilayer film model by using a Design Modeler tool in Geometry, wherein the substrate is Solid, the multilayer film is Surface Body, and the cell type setting substrate is Solid90 entity cells; the multilayer film is a Shell132 unit with a middle node; each Shell cell comprises a plurality of sub-layers with physical significance, the problem of high aspect ratio is solved by simulating the multilayer film by the Shell cells, modeling is visual and rapid, and operation of using a large number of codes for modeling is avoided. In this example, an 1/4 model was created, the size of the base cell was 50 × 30 × 60mm, and the size of the multi-layer cell was 50 × 30mm, and a total of 8 Shell cells were used, each Shell cell containing 10 layers of films, and a total of 80 layers of films.

S13: in order to specify the number of cycles of the multilayer film and the physical parameters and material properties of each film, a command code is inserted under the multilayer film model in Geometry in the tree classification menu for defining the multilayer film unit and the Shell structure, and finally the property specification of the base material is still conventional operation.

Specifically, in this embodiment, the material of the substrate Solid is first specified as Si by a conventional method in the model tree geometry, and then the Commands are edited under Surface Body, and the data of the multilayer film, including the single Pd layer with a thickness of 10, is first defined^-6mm, single layer B₄The thickness of the C layer is 10^-6mm, and the number of cycles of the multilayer film is 5, each cycle comprising 2 layers of film, i.e. B₄C layer and Pd layer, then defining multilayer film unit and Shell structure, firstly defining B₄Material numbers for C and Pd, cell number for Shell132, cross-sectional type number, and film properties including thickness and material for each layer.

S2: and meshing the models of the substrate and the multilayer film, and keeping the meshing of the multilayer film and the upper surface of the substrate consistent.

In order to calculate the result accurately, the grid division of the multilayer film is required to be kept consistent with the upper surface of the substrate, in APDL, the upper surface of the substrate with the grid divided is copied to the multilayer film, and the method cannot be realized in Workbench. Therefore, in Workbench, the multilayer film and the upper surface of the substrate are divided by quadrilateral grids by Face masking, then the sizes of corresponding edges are controlled to be the same by Edge Sizing, and finally the substrate is divided by hexahedral grids by multitone. The grid division also needs to make the order of the cell be second order to ensure that the membrane cell is the Shell132 containing the intermediate node, so as to ensure the accuracy of the calculation result. In this embodiment, the short side mesh size is 0.5mm, and the long side mesh size is 1 mm.

S3: heat flow loads are applied to the multilayer film model and constraint equations are set.

Because the heat flow density can not be directly added on the multilayer film in the ANSYS classic environment, when the heat flow density is directly applied on the surface of the unit in the Workbench, the heat flow density acts on the TBOT layer and acts on the TTOP layer in accordance with the actual situation, so that in order to finish the accurate application of the heat flow density, a surface effect unit is introduced, the newly-built surface effect unit can not generate any influence on the analysis of the original multilayer film, and the limitation of uniform heat flow density can be removed while the problem of heat flow density application is solved after the introduction, thereby allowing the application of heat flows with different distribution densities. The specific implementation method is that a command is inserted under Steady-State Thermal, a SURF152 only containing heat flux density is defined, then all nodes of the Shell cell on the uppermost layer are selected, a SURF152 layer is covered on the nodes, a surface effect plane is copied upwards, the original surface effect plane is deleted, the plane where the Shell cell is located and the plane where the surface effect cell is located can be distinguished in the selected plane, then the heat flux density is set to be applied to the copied surface effect plane, and the heat load application is completed.

And then, setting a constraint equation for connecting corresponding nodes in different planes, ensuring that the temperature of the corresponding node of the plane where the surface effect unit is located and the corresponding node of the uppermost layer film of the Shell unit is equal to the temperature of the corresponding node of the uppermost layer film of the Shell unit and the temperature of the corresponding node of the upper surface and the lowermost layer film of the Shell unit, so that the temperature transmission and transition are continuous, if the number of layers of the multilayer film exceeds 31 layers, realizing by using a plurality of sets of Shell units, and similarly, ensuring the connection of each set of Shell units by the constraint equation, namely, ensuring that the temperature of the node of the lowermost layer film in the previous plane is equal to the temperature of the corresponding node of the uppermost layer film in the next plane. Specifically, the Convection was selected and applied to the right side of the substrate to set the Convection coefficient at 0.005W/mm²The temperature of the environment is 293K, and then the specified areas of the surface effect unit in X direction 0 to 1 and Y direction 0 to 38.2 are loaded through the Commands Commands, and the heat flow density is 5235W/mm²Then, the surface effect units are summed up by constraint equationThe upper layer film, the substrate, the lowest layer film and different film layers are connected, the temperature of a corresponding node of a plane where the surface effect unit is located and the uppermost layer film of the Shell unit is ensured, and the temperature of the corresponding node of the upper surface of the substrate and the lowermost layer film of the Shell unit is equal to the temperature of the corresponding node of the lowermost layer film of the last Shell unit and the uppermost layer film of the next Shell unit.

Specifically, the constraint equation is to take all the nodes of two adjacent faces respectively, and sequentially equalize the temperatures of the corresponding nodes through a loop, and the final equation is actually a code (the code is ansys programming language), CE, NEXT,0, ncoin1, TTOP,1, ncoin2, TEMP, -1(ncoin1 is a node in the NEXT plane, TTOP is the temperature of the uppermost film of the NEXT set of Shell cells, and for the NEXT layer being the base, TTOP here should be changed to TEMP, which is essentially the temperature of that face, ncoin2 is a node in the previous plane, and TEMP is the temperature of the previous face), two adjacent faces should be made 10 faces for each set of Shell cells (because each set of Shell cells in this embodiment contains 10 films), so that if each set of Shell cells contains more layers than 31 layers, the constraint equation also ensures the connection of each set of Shell cells, that is, the node temperature of the topmost film in the previous plane is equal to the corresponding node temperature of the topmost film in the next plane.

S4: and solving to obtain the temperature distribution of the multilayer film model.

For convenience of post-processing, Commands Commands can be inserted under Solution, the temperature distribution of each film layer in the multilayer film can be checked, and the node temperature of the multilayer film can be saved in an external file in an array form for subsequent structural analysis.

If the heat carrier is directly heated without introducing the surface effect unit, the temperature between the 10 films will be the same, and the calculation result is greatly different from the actual one, so that the temperature between the films must be distinguished. Fig. 2 shows a temperature profile of the multilayer film model of this example. In order to verify that the temperature distributions of the 10-layer films defined in the Shell cell are different, the temperature distributions (unit:. degree. C.) of the (0, 0, 10) point and the (0, 0, 80) point in the 10-layer films on the Shell cell were selected, and the results are shown in FIGS. 3A and 3B, respectively, from which it can be seen that the temperature distributions of the respective films are different.

Further, in order to verify the feasibility of the method, the finite element thermal analysis result is compared with the thermal analysis result under the classical ANSYS interface, the maximum temperature of the finite element thermal analysis result and the maximum temperature of the finite element thermal analysis result are 410.97596K, the temperature difference of 411.034K is 0.058K, and the error is one ten thousandth, so that the comparison result shows that the multilayer film thermal analysis method based on the ANSYS Workbench is basically consistent with the calculation result of the classical ANSYS. The method of the invention not only can greatly reduce the number of units and optimize the operation steps, but also has the advantages of good interactivity, simple and convenient operation and high processing efficiency compared with an ANSYSAPDL operation interface, and simultaneously, the method using Workbench calculation is easier to reproduce and recycle.

According to the multilayer film thermal analysis method based on ANSYS Workbench, provided by the embodiment of the invention, the problems of grid division and structure physical attribute matching of the high-aspect-ratio multilayer film are solved by simulating the multilayer film through the Shell132 unit; the problem that heat flow cannot be directly and accurately applied in Workbench is solved by establishing and using the SURF152, and meanwhile, the establishment of the SURF not only can apply uniform load, but also allows heat flow density with different distributions to be applied, so that the range of heat load is expanded; the modeling and the grid division are rapidly and intuitively completed by combining the advantages of the Workbench, functions required to be realized are organically integrated into a Workbench architecture by using the Commands command in a proper place, and the problem that the conventional multilayer film analysis which only depends on APDL complex programming processing is transplanted into the Workbench to be simply and intuitively realized is solved, so that the problems of poor interactivity and difficulty in reproduction of a finite element classical version are solved, the operation efficiency is improved, and the whole operation process is intuitive and easy to understand.

The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.