Design method of finite element analysis unit library data structure and interactive function architecture

Abstract

The invention provides a method for designing a finite element analysis unit library data structure and an interactive function architecture. The method comprises the following steps of: constructing an interactive function data class diagram comprising a unit type setting dialog box class and a unit library abstraction class; constructing a unit library data structure; the unit library data structure comprises a unit library abstraction class, a unit family abstraction class and a topology type, and the unit library abstraction class realizes a set of finite element calculation units with different orders and different shapes; constructing a development template of unit functions; the development template comprises a finite element unit basic class and a general abstract interface; constructing a data structure of the unit family abstract class; the data structure is a combination relationship between a unit family abstract class and a finite element unit class, a unit setting component class and a unit setting information class. According to the method, a grid type setting interaction function with good operation experience is provided on the user level, a standardized unit development template is provided on the development level, and a framework foundation is provided for interaction operation through data structure design of a unit family.

Description

Technical Field

[0001] The present invention relates to the technical field of finite element simulation, and in particular to a design method for a finite element analysis unit library data structure and an interactive functional architecture. Background Art

[0002] As a mainstream CAE technology, Finite Element Analysis (FEA) is widely favored for its powerful analytical capabilities for complex structures and material behaviors. The unit library is one of the core components of finite element software. It carries general functions and advanced algorithms, which is crucial to ensure the accuracy, reliability and efficiency of calculation results. However, in the development process of domestic finite element software, there are still a series of problems that need to be solved: Compatibility of meshing strategy and unit type settings: Although meshing strategy and unit type settings should remain independent from a configuration perspective, they are inherently linked at the data level. Due to the lack of an effective association mechanism, they often lead to incompatibility between the two, which in turn affects the accuracy and computational efficiency of simulation results.

[0003] Lack of standardized unit development and integration guidance: The current unit development lacks systematic standardized guidance, which not only hinders interface reuse, but also causes duplicate development problems and increases maintenance difficulties. In addition, there is no unified data structure and architecture design standard, which further reduces the efficiency of unit integration and may lead to compatibility issues between different modules of the developed unit.

[0004] In view of the above problems, there is an urgent need for a design method for the data structure and interactive functional architecture of the finite element analysis unit library, which aims to solve the problems of incompatibility between the meshing strategy and the unit type setting in the existing unit development process, as well as the irregular integration of various developments and imperfect architecture design. By providing an interface component design with good interactive logic, it is beneficial for developers to design the data structure for standardized unit development and the setting functional architecture design that connects the two, so as to realize the standardized development and efficient integration of computing units, and at the same time improve the user's interactive experience in setting unit types, and improve the efficiency and accuracy of related setting operations. Summary of the invention

[0005] In view of this, it is necessary to provide a design method for the data structure and interactive functional architecture of a finite element analysis unit library to solve the technical problems existing in the prior art, such as the incompatibility between the existing meshing strategy and the unit type setting, the non-standardization of various development integrations, and the imperfect architecture design.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a design method for a finite element analysis unit library data structure and an interactive functional architecture, comprising: Construct an interactive function data class diagram based on the finite state machine design pattern; the interactive function data class diagram includes a unit type setting dialog class and a unit library abstract class that has a composition relationship with the unit type setting dialog class; Construct a unit library data structure; the unit library data structure includes the unit library abstract class, a unit family abstract class that has a composition relationship with the unit library abstract class, a topology type that has an association relationship with the unit library abstract class, a specific topology type unit library class inherited from the unit library abstract class, and a specific unit family class inherited from the unit library abstract class, and the specific unit family class has a composition relationship with the specific topology type unit library class; the unit library abstract class is used to implement a set of finite element calculation units of different orders and different shapes; Construct a development template for unit functions; the development template includes a finite element unit base class and a general abstract interface that has a composition relationship with the finite element base class; Construct a data structure for the unit family abstract class; the data structure is that the unit family abstract class has a composition relationship with the finite element unit class, the unit setting component class, and the unit setting information class.

[0007] In a possible implementation, the unit type setting dialog class designs a unit family list column, and the unit library abstract class includes an available unit family list corresponding to geometric objects of a determined topology type. Based on the init_widget_via_element_lib() method in the unit type setting dialog class and the get_element_families() method in the unit library abstract class, unit family objects in the available unit family list are added to the unit family list column.

[0008] In a possible implementation, the interactive function data class diagram further includes a unit setting component class and a unit setting information class, and the unit type setting dialog class depends on the unit type setting dialog class of the unit setting component class and the unit setting information class. Then, the method further includes: Based on the init_stacked_widget() method and generate_tab_widget() in the unit type setting dialog class, a component object is generated, and after different unit family abstract classes are selected in the unit type setting dialog class, the unit setting components in the unit setting component class are updated in real time.

[0009] In a possible implementation, the interaction function data class diagram further includes a unit type basic state abstract class designed based on the finite state machine design pattern, a unit type control class in a composition relationship with the unit type basic state abstract class, a unit type setting class inherited from the unit type basic state abstract class, a unit type area selection state class, and a geometric unit type class in an association relationship with the unit setting component class. The unit type setting dialog class and the unit type setting state class are in a composition relationship, and the unit setting information class and the geometric unit type class are in an association relationship.

[0010] In a possible implementation, the specific topology type unit library class includes a three-dimensional solid topology type unit library class, a two-dimensional shell topology type unit library class, and a three-dimensional shell topology type unit library class. The specific unit family class includes a plane stress unit family class and a plane strain unit family class.

[0011] In a possible implementation, the unit library data structure further includes a unit library factory class, and the unit library factory class and the unit library abstract class are in a composition relationship.

[0012] In a possible implementation, the general abstract interface includes a Jacobi abstract interface, a shape function abstract interface, a numerical integration abstract class, and a topological shape behavior abstract class.

[0013] In a possible implementation, the development template further includes a finite element basic abstract class, a finite element node class inherited from the finite element basic abstract class, a unit geometric feature type in an association relationship with the finite element unit basic class, a unit setting information class in an aggregation relationship with the finite element unit class, a topological shape behavior abstract class in a composition relationship with the finite element unit class, and the finite element unit basic class is inherited from the finite element basic abstract class.

[0014] In a possible implementation, when the unit type is a plane stress unit, the data class diagram of the plane stress unit includes a plane unit abstract class inherited from the finite element unit class, a two-dimensional shell behavior class inherited from the topological behavior abstract class, a three-node plane unit class, a four-node plane unit class, a six-node plane unit class, and an eight-node plane unit class inherited from the plane unit abstract class, and a three-node plane stress unit class inherited from the three-node plane unit class, a four-node plane stress unit class inherited from the four-node plane unit class, a six-node plane stress unit class inherited from the six-node plane unit class, and an eight-node plane stress unit class inherited from the eight-node plane unit class. The three-node plane stress unit class, the four-node plane stress unit class, the six-node plane stress unit class, and the eight-node plane stress unit class are in a composition relationship with the plane stress behavior class.

[0015] In a possible implementation, when the element type is a plane stress element, the element family is the plane stress element family, and the data structure further includes a plane stress element family class inherited from the abstract class of the element family. The element setting component class includes a three-node plane stress element setting component class, a four-node plane stress element setting component class, a six-node plane stress element setting component class, and an eight-node plane stress element setting component class that have a composition relationship with the plane stress element family class. The element setting information class includes a three-node plane stress element setting information class, a four-node plane stress element setting information class, a six-node plane stress element setting information class, and an eight-node plane stress element setting information class that have a composition relationship with the plane stress element family class.

[0016] The beneficial effects of the present invention are as follows: The design method of the finite element analysis element library data structure and the interaction function architecture proposed by the present invention effectively strengthens the operation logic involved by the user by constructing an interaction function data class diagram based on the finite state machine design pattern. Moreover, by setting the interaction function data class diagram to include an element type setting dialog class, an interaction dialog can be constructed through the element type setting dialog class, improving the interaction performance.

[0017] Furthermore, by setting an abstract class of the element family and setting a composition relationship between the abstract class of the element family and the abstract class of the element library, the present invention can provide a way of setting with the element family rather than a specific element in the prior art as the basic setting unit during the interaction function process, avoiding the setting dependence on a single specific element, and thus overcoming the problem of incompatibility between the mesh generation strategy and the element type setting.

[0018] Even further, by constructing a development template for the element function, at the development level, a standardized element development template is provided. Through a modular architecture and a standardized interface, discrete element functions are encapsulated into pluggable algorithm components, supporting the efficient integration of multi-physical field coupling, complex assembly analysis, and new elements, effectively improving the development efficiency of the element and the integration efficiency of the element library; on this basis, through the data structure design of the abstract class of the element family, an element type interaction setting function architecture design with good scalability and maintainability is realized, providing an architecture basis for the interaction operation. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1Schematic flowchart of an embodiment of the design of the data structure and interaction function architecture of the finite element analysis unit library provided by the present invention; Figure 2 Schematic diagram of an embodiment of the interaction function data class diagram provided by the present invention; Figure 3 Schematic diagram of an embodiment of the data structure of the unit library provided by the present invention; Figure 4 Schematic diagram of a specific design embodiment of the unit function architecture provided by the present invention; Figure 5 Schematic diagram of an embodiment of the plane stress unit designed based on the development template provided by the present invention; Figure 6 Schematic diagram of the specific implementation structure of the plane stress unit of the data structure based on the abstract class of the unit family provided by the present invention. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0022] It should be understood that the schematic drawings are not drawn to actual scale. The flowcharts used in the present invention illustrate the operations implemented according to some embodiments of the present invention. It should be understood that the operations in the flowchart may not be implemented in sequence, and the steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present invention. Some of the block diagrams shown in the drawings are functional entities, and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor systems and / or microcontroller systems.

[0023] Referring to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0024] The present invention provides a design method for the data structure and interaction function architecture of a finite element analysis unit library, which will be described separately below.

[0025] Based on the finite element theory, it is necessary to convert the geometric mesh into an analysis model containing computational unit objects: replace the original geometric data with mesh data, and bind a finite element computational unit to each cell, and finally construct a numerical calculation system that satisfies the discretization of the control equation.

[0026] Therefore, the purpose of the design method for the data structure and interaction function architecture of the finite element analysis unit library proposed in the embodiments of the present invention is: by setting the data structure of the unit library and the interaction function architecture, the purpose of assigning computational units to geometric units is achieved, and then the purpose of the final mesh generation is achieved. In other words, the embodiments of the present invention are part of the design method of the mesh generation module in the finite element simulation software construction system.

[0027] It should be understood that: the units in the unit library in the embodiments of the present invention refer to computational units, and the purpose of the computational units is to endow the geometric mesh with finite element unit objects to realize the construction of the relevant matrices of the control equation for analyzing problems.

[0028] Figure 1 FIG. is a schematic flowchart of an embodiment of the design method for the data structure and interaction function architecture of the finite element analysis unit library provided by the present invention. Figure 2 FIG. is a schematic diagram of an embodiment of the interaction function data class diagram provided by the present invention. Figure 3 FIG. is a schematic diagram of an embodiment of the data structure of the unit library provided by the present invention. As Figures 1 - 3 shown, the design method for the data structure and interaction function architecture of the finite element analysis unit library includes: S101. Construct an interaction function data class diagram based on the finite state machine design pattern; the interaction function data class diagram includes a unit type setting dialog class and a unit library abstract class that has a composition relationship with the unit type setting dialog class.

[0029] Among them, a specific unit library can be designed based on the unit library abstract class, and the unit library includes multiple unit families.

[0030] S102. Construct the data structure of the unit library; the data structure of the unit library includes a unit library abstract class, a unit family abstract class that has a composition relationship with the unit library abstract class, a topological type that has an association relationship with the unit library abstract class, a specific topological type unit library class that inherits from the unit library abstract class, and a specific unit family class that inherits from the unit library abstract class. The specific unit family class has a composition relationship with the specific topological type unit library class; the unit library abstract class is used to implement the set of finite element computational units of different orders and different shapes.

[0031] The finite element calculation unit can be adaptively set according to different analysis objectives. For example, for plane stress problems, the finite element calculation unit can be set to include plane stress elements; for plane strain problems, the finite element calculation unit can be set to include plane strain elements; for three-dimensional problems, solid elements can be set; for plate and shell problems, shell elements can be set. Moreover, in addition to the above solid mechanics field, different finite element calculation units can also be correspondingly set according to thermotics, electromagnetics, fluid mechanics, etc.

[0032] For example: Based on the abstract class of the element library, a specific family of plane stress elements can be designed. The family of plane stress elements includes triangular plane stress elements and quadrilateral plane stress elements, etc. Then, when the user selects a calculation unit, instead of selecting to use triangular plane stress elements and quadrilateral plane stress elements, the corresponding family of plane stress elements is selected, which contains plane stress elements of different orders and shapes, reducing the possibility of misoperation and improving the accuracy and calculation efficiency of the simulation results.

[0033] S103. Construct a development template for the unit function; the development template includes the finite element unit base class and a general abstract interface that has a composition relationship with the finite element base class; S104. Construct the data structure of the element family abstract class; the data structure includes a composition relationship between the element family abstract class, the finite element unit class, the unit setting component class, and the unit setting information class.

[0034] Among them, the main functions of the element family abstract class include two aspects: one is to manage the various elements included under it, and the other is to provide the mapping between the element family and the interactive interface settings. To achieve the former, a composition relationship between the element family abstract class and the finite element unit class is designed to clarify the list of finite element units belonging to the element family. To achieve the latter, on the one hand, it is necessary to introduce components related to the interactive interface settings, and on the other hand, it is necessary to consider the user setting information and construct its association with specific elements. Therefore, the element family abstract class is designed to have a composition relationship with the unit setting component class and the unit setting information class respectively. The above composition relationships are all realized in the form of a key-value pair data structure, and the relevant composition information is managed through different attributes. By setting the composition relationship between the element family abstract class, the finite element unit class, the unit setting component class, and the unit setting information class, when different unit groups are switched in the element family abstract class, the components and information items in the corresponding unit setting component class and unit setting information class can be switched in response, improving the interactive experience of the user setting the unit type and the efficiency and accuracy of relevant setting operations.

[0035] It should be understood that: The architecture design method for the load and boundary condition conversion function in the embodiments of the present invention can be implemented in electronic devices such as desktop computers, notebooks, tablet computers, laptop computers, etc. Any of the above-mentioned electronic devices stores a program prepared by the design method of the finite element analysis unit library data structure and the interaction function architecture. When any of the above-mentioned electronic devices is started, the program is called, and then the architecture design method for the load and boundary condition conversion function is implemented.

[0036] Compared with the prior art, the design method of the finite element analysis unit library data structure and the interaction function architecture proposed in the embodiments of the present invention effectively strengthens the operation logic involved by the user by constructing an interaction function data class diagram based on the finite state machine design pattern. And, by setting that the interaction function data class diagram includes a unit type setting dialog class, an interaction dialog box can be constructed through the unit type setting dialog class, improving the interaction performance.

[0037] Furthermore, by setting a unit family abstract class in the embodiments of the present invention and setting the relationship between the unit family abstract class and the unit library abstract class as a composition relationship, it is possible to provide a way with the unit family rather than a specific unit in the prior art as the basic setting unit during the interaction function process, avoiding the setting dependence on a single specific unit, and thus overcoming the problem of incompatibility between the mesh generation strategy and the unit type setting.

[0038] Even further, by constructing a development template for the unit function in the embodiments of the present invention, at the development level, a standardized unit development template is provided. Through a modular architecture and a standardized interface, discrete unit functions are encapsulated into pluggable algorithm components, supporting the efficient integration of multi-physics field coupling, complex assembly analysis, and new units, effectively improving the unit development efficiency and the integration efficiency of the unit library; on this basis, through the data structure design of the unit family abstract class, an interaction setting function architecture design with good scalability and maintainability is realized, providing an architecture basis for interaction operations.

[0039] In some embodiments of the present invention, the design principle of the interaction function data class diagram is: To construct the interaction function data class diagram, two key settings in the mesh generation module need to be clarified, namely the selection of the mesh generation strategy and the unit type setting. Although from the perspective of the configuration logic, the mesh generation strategy and the unit type allocator need to be independent, there is an implicit coupling between them through the mesh topology data. Therefore, it is necessary to clarify the relationship between the two and avoid the influence of user operations on the mesh generation and unit settings by optimizing the interaction operation logic, and design a general operation strategy.

[0040] Among them, the mesh generation module provides users with a choice of meshing strategies, namely, meshing with tetrahedral elements or with hexahedral elements. Since hexahedral elements have regular shapes and can better simulate the changes in stress, strain, and other field variables in physical phenomena, under the same number of nodes, they can usually provide more accurate results than tetrahedral element meshing, the solution process is more stable, and it is not easy to have problems such as numerical oscillation or divergence. Tetrahedral element meshing is suitable for any complex geometric shape, especially those irregular or highly distorted regions that are difficult to mesh with hexahedral elements. At the same time, the grid generation algorithms related to automated tetrahedral element meshing are relatively mature, and complex models can be meshed in a relatively short time.

[0041] However, sometimes due to various reasons such as complex geometric shapes and functional limitations of the mesh generator, it is impossible to perform the meshing strategy planned by the user for the area to be analyzed. The system needs to be designed for this problem, which requires not only the design of the data structure but also the design of the functional architecture.

[0042] In terms of data structure, the relevant content of geometric shapes is managed in the way of Part, PartFeature, and IShape, so that the meshing operation can be carried out for different geometric shape objects. The advantage of doing this is that for a complex geometric shape, without any operation, it may only be possible to mesh with tetrahedral elements. However, based on such a data structure design, geometric operations such as splitting the Part can be performed using the Boolean operation function provided by the geometric modeling related module.

[0043] A complex geometric shape IShape object is decomposed into multiple geometric shape IShape objects that can be operated independently of each other but have data correlations. Before the process of setting the meshing strategy by the user begins, the finite element simulation system first traverses the IShape list object in the Part object to be set. On the one hand, it detects its topological structure to judge what kind of meshing strategy can be set according to the complexity of the geometric shape. For example, simple shapes can be meshed with structured hexahedral elements, while complex shapes can only be meshed with tetrahedral elements or a mixed mesh of different shaped elements. On the other hand, in the processing order from advanced algorithms to basic stable algorithms, the mesh generator is called to perform mesh generation preprocessing on each IShape object in the background of the system to confirm the available mesh generation operations.

[0044] Based on the above two aspects of judgment, after the user selects the object for setting the meshing strategy, a dialog box with the corresponding strategy setting activated can be popped up for the user to select and set the meshing strategy.

[0045] As can be seen from the above design, the available meshing strategies for geometric shape objects depend on the complexity of the geometric shape itself, as well as the built-in functions and algorithms of the connected mesh generator. Therefore, providing the above-mentioned functional support to users can assist them in reasonably and effectively setting the meshing strategy during the meshing process.

[0046] After determining the meshing strategy, there are two results for the meshed grid: 1. There is only one type of element in the grid. For example, in two-dimensional plane problems, there is only a triangular element grid, and in three-dimensional space problems, there is only a hexahedral element grid. 2. There are elements with multiple geometric forms in the grid, presenting a mixed form. For example, in a complex three-dimensional problem, structured meshing is achieved by hexahedral elements in most areas, while tetrahedral elements are used for meshing in areas with significant geometric shape changes.

[0047] Regardless of which meshing result is obtained, the resulting geometric mesh will face a problem, that is, how to set the element type in the meshing result. At this time, although the geometric shape is divided into a grid composed of elements, it only has a geometric segmentation meaning and does not yet have a discrete form in mathematics. Therefore, under the guidance of the finite element theory, computational elements need to be introduced to construct an analysis model that can be used for numerical simulation calculations. Compared with the interactive model constructed during the modeling process, the analysis model replaces the geometric shape data with grid data as the model basis and assigns finite element computational element objects to each element of the grid to realize the construction of the matrices related to the control equations of the problem to be analyzed.

[0048] In this process, a problem is involved, that is, how to assign the computational element object to the corresponding element in the grid. The connection between the two is that they have the same basic geometric properties of the element, including nodes, element shapes, etc. In actual operation, two problems need to be solved: what type of element the user intends to use, and how to ensure that the computational element set by the user matches the element in the meshing result. Among them, the former is confirmed by the user through interactive settings, while the corresponding relationship of the latter is not automatically satisfied and needs to be realized through the design of the data structure and functional architecture. For example, the user intends to use hexahedral elements for meshing, but due to the complexity of the geometric shape, the meshing strategy can only use tetrahedral elements for meshing. At this time, the computational element set by the user does not match the geometric element obtained by meshing, so the finite element computational element cannot be assigned to the geometric mesh. Another example is that the user wants to use eight-node quadrilateral elements, but the meshing result is a four-node quadrilateral element grid. At this time, although they are both elements of the same shape, the different number of element nodes reflects different orders of the elements, and the computational element attributes still cannot be assigned to the geometric element.

[0049] Therefore, it is necessary to design a setting operation mechanism so that for different mesh division strategies, the matching of computational units and geometric mesh units can be achieved in a stable manner. To this end, an abstract unit library class in a composite relationship with the unit type setting dialog class is designed, and the unit families in the unit library rather than specific units are used as the basic setting unit. On this basis, the user is provided with the setting of unit types and related attribute parameters, thus avoiding the setting dependence on a single specific unit. For example, in this way, the user no longer needs to select whether to use triangular plane stress units or quadrilateral plane stress units, but to select the plane stress unit family, which contains plane stress units of different orders and shapes.

[0050] Based on the above setting operation mechanism, two further aspects need to be considered: From the user's perspective, different unit families have different parameters and characteristics. How to ensure that after the user selects a unit family, the relevant settings for specific units can be conveniently and accurately made; From the developer's perspective, when developing unit families and specific units therein, what method should be used to provide interactive settings for users while ensuring the extensibility and maintainability of relevant functional modules.

[0051] Therefore, an architecture design for the interface of the relevant functions of interactive settings is carried out. On the one hand, the functional architecture of unit type setting is designed based on the finite state machine design pattern, effectively strengthening the operation logic of user design; on the other hand, in the unit type setting dialog class QmyEditElementTypeDialog, a unit family list bar is designed to display all unit families in the unit library, and updated unit family setting components and unit basic option components are designed. After the user selects different unit families, the real-time update of each setting component is realized for the user to set the relevant parameters of the required unit type. The specific interactive function data class diagram is as Figure 2 shown.

[0052] The functional architecture of unit type setting is designed based on the finite state machine design pattern. The whole process is dominated by the unit type control class ElemTypeControl, which forms a composite relationship with the abstract unit type base state class ElemTypeBaseState. In unit type setting, two specific steps are involved, which are realized by the unit type region selection state class ElemTypeRegionSelectionState and the unit type edit state class ElemTypeEditState that inherit from ElemTypeBaseState. The former is responsible for collecting the geometric shape object selected by the user for unit type setting as the setting region, and the latter provides the unit type setting function for the user based on the setting region.

[0053] In the ElemTypeEditState, it is necessary to pop up a dialog box to provide the function of interactive unit type setting for the user, that is, the unit type setting dialog box class QmyEditElementTypeDialog. Two main settings need to be carried out in this state: firstly, the selection of the specific unit family to be used in the analysis; secondly, the specific unit parameter setting for the selected unit family. To achieve the former, a unit family list bar is designed in QmyEditElementTypeDialog, which is bound to the unit library abstract class ElementLib, and the two form a composite relationship. Under the design of the unit development template, all unit families in the unit library are displayed in the unit family list bar. To achieve the latter, corresponding parameter setting widgets need to be designed in QmyEditElementTypeDialog.

[0054] To implement the binding between the unit setting widget and the selected unit family, and at the same time enhance the flexibility and extensibility of QmyEditElementTypeDialog, updateable unit family setting widget class QmyElementSettingWidget and unit basic option widgets are designed in it. The mapping association between the unit family options in the unit family list bar and the updateable widgets in the dialog box is established, so that when the user selects different unit families, the relevant widgets are updated to the widgets related to the current unit family, for the user to set the required unit type related parameters, so that the user can realize the switching of different unit family setting widgets through the interaction operation with the unit family list bar.

[0055] The unit family setting widget is related to the specific unit setting in the unit family. According to the different selected unit families, the available options for setting are different, and the specific setting content is determined by the specific unit selected by the user in the unit family list bar. Therefore, during the unit development process, developers need to determine the setting parameters required for this unit, including but not limited to the integration method, hourglass control and unit form of the unit, and add them to the unit family setting widget class QmyElementSettingWidget. In addition, there will be a description bar for the unit in the updateable unit family setting widget, which simply describes the name, attributes and key status of the unit according to the user's options and settings.

[0056] The unit setting component class QmyElementSettingWidget has an associated relationship with the geometric unit type class GeoElementType of the specific unit, supporting developers to pre-define parameter configuration items such as integration methods, hourglass control, and shape function orders in the unit development template. This component encapsulates the user input parameters through the ElementSettingInfo object, providing data support for the subsequent creation of calculation unit objects. During the interaction process, the dialog box also includes a dynamically updated unit description bar, which displays metadata such as the name of the current unit family, topological type, and key attributes in real time. And QmyEditElementTypeDialog creates the corresponding unit setting information object ElementSettingInfo by obtaining user input, which is used for the creation of the final specific calculation unit and the setting of related attributes. That is: QmyEditElementTypeDialog depends on QmyElementSettingWidget and ElementSettingInfo.

[0057] In the above design, the object for managing the unit family list is the unit library, which forms a composition relationship with QmyEditElementTypeDialog. The specific unit library can provide a clear list of available unit families for geometric objects with determined topological types. To implement the user's interactive setting operation, it is necessary to bind this list of unit families to the unit family list bar in the unit type setting dialog box. For this reason, the initialization function method init_widget_via_element_lib() of the unit family list bar is designed in QmyEditElementTypeDialog. It takes the specific unit library object inherited from ElemetLib as the input parameter, and calls the get_element_families() method of ElemetLib in it to obtain the list of available unit families contained in this specific unit library object, and adds the unit family objects in this list of unit families into the unit family list bar in QmyEditElementTypeDialog. Thus, the association between the unit library and QmyEditElementTypeDialog is constructed, and the interactive setting function is provided for the user.

[0058] In addition, design the init_stacked_widget() method in QmyEditElementTypeDialog. Its input parameter is a specific element family object that inherits from the abstract element family class ElementFamily. In this method, various methods and properties in ElementFamily will be called to obtain information related to element settings, and its own generate_tab_widget() will be called to generate a widget object, realizing the real-time update of the element setting widget after selecting different ElementFamily objects in QmyEditElementTypeDialog. Specifically, when the user selects different element families, the interface update is triggered through the init_stacked_sidget() method. This method receives a specific element family object that inherits from ElementFamily, calls generate_tab_widget() to generate the corresponding parameter setting widget, and realizes the dynamic switching of updatable widgets such as QmyElementSettingWidget.

[0059] Thus, not only does it provide users with a grid type setting interaction function with a better operation experience, improving the efficiency and accuracy of grid type setting, but also it provides developers with an element type interaction setting function architecture with good scalability and maintainability, effectively improving the development efficiency and integration efficiency of element families.

[0060] In a specific embodiment of the present invention, as Figure 3 shown, the specific topology type element library classes include three-dimensional solid topology type element library classes, two-dimensional shell topology type element library classes, and three-dimensional shell topology type element library classes. The specific element family classes include plane stress element family classes and plane strain element family classes.

[0061] It should be noted that: the specific topology type element library classes may also include other element library classes other than the above three categories. Similarly, the specific element family classes may also include entity families, shell families, etc. other than the plane stress family and plane strain family, which will not be elaborated here one by one.

[0062] Furthermore, to achieve the decoupling of the design and use of computational elements, in a specific embodiment of the present invention, as Figure 3 shown, the element library data structure also includes an element library factory class ElementLibFactory. The element library factory class and the element library abstract class are in a composition relationship. This design encapsulates the instantiation process of the element library object inside the factory class, so that when the system expands a new topology type element library, only a new specific element library class needs to be added and registered to the factory, without modifying the existing call logic, significantly enhancing the maintainability of the architecture.

[0063] Specifically, for geometric objects of different topological types, there are differences in the available element families. For example, the plane stress element family and the plane strain element family can only be used for geometric objects of the Shell topological type and cannot be used for geometric objects of the Solid topological type. Therefore, ElementLib is associated with the topological type TopoType. In addition, for geometric objects of a certain topological type, multiple element families can be used, and the user needs to select a specific element family according to the type of analysis and other factors. Therefore, an attribute element family list attribute elem_families is designed in ElementLib, which forms a composite relationship with the element family abstract class ElementFamily, and provides method interfaces such as get_element_families() to provide the element families in this element library.

[0064] For geometric objects of different topological types, specific topological type element library classes are developed that inherit from ElementLib, and it is specified in them which element families are included in their element family list attributes, and abstract method interfaces such as get_default_element_family() are implemented, such as the three-dimensional solid topological type element library class Solid3dElementLib, the two-dimensional shell topological type element library class Shell2dElementLib, and the three-dimensional shell topological type element library class Shell3dElementLib, etc. Taking Shell2dElementLib as an example, plane stress elements can be provided in this element library for two-dimensional shell objects to analyze plane stress problems. Therefore, Shell2dElementLib forms a composite relationship with the plane stress element family class PlaneStressElements. Among them, PlaneStressElements, as a specific element family class, inherits from the element family abstract class ElementFamily.

[0065] In some embodiments of the present invention, for the development template design of element functions, the finite element stiffness matrix calculation based on the virtual work principle generally requires two calculation processes: one is to calculate the element stiffness matrix within the element, that is, to construct and perform integral operations on the geometric matrix through the element behavior object; the other is to complete the assembly of the element stiffness matrix into the global stiffness matrix. The latter is the process of the system using an assembler for element assembly, which involves processing techniques such as the numbering confirmation of the node degrees of freedom of different elements and is not the content concerned by the embodiments of the present invention. The embodiments of the present invention tend to focus on the former, which is directly related to the content related to the element function architecture design.

[0066] In the calculation of the element stiffness matrix, it includes the geometric matrix and the elastic matrix , the geometric matrix It is the product of the strain-related partial differential operator and the shape function matrix, which is determined by the geometric equation. The geometric equation depends on the spatial dimension of the analysis problem and is independent of the specific element type. Therefore, it can be designed as a dimension-related unit behavior object, forming a composite relationship with the finite element calculation unit base class object, namely the TopoShapeBehavior class. This class forms a composite relationship with the finite element calculation unit base class, and provides a unified geometric matrix calculation interface for different dimensional problems by defining the spatial dimension attribute and the implementation method of the geometric equation.

[0067] It should be clear that the elastic matrix is determined by the material. There is a relevant interface design provided in the material setting module, and the elastic matrix corresponding to the material properties determined by the material behavior class MaterialBehavior and the cross-section class Section is constructed .

[0068] Taking the linear elastic material as an example, the base class ElasticBehavior provides the generate_d_mat() method for generating the matrix . For the specific linear elastic material behavior, inherit the base class ElasticBehavior to design the corresponding specific linear elastic behavior class, and further improve the generate_d_mat() method in it to implement the calculation of the specific elements in the elastic matrix . For example, for isotropic materials, design the IsotropicElasticBehavior class and generate the elastic matrix based on generate_d_mat() . For orthotropic materials, design the OrthotropicElalsticBehavior class and generate the elastic matrix based on generate_d_mat() .

[0069] In the calculation unit, by calling the self-designed process_d_mat() method and calling the generate_d_mat() method of the cross-section Section object in it, the calculation result of the above matrix can be obtained.

[0070] If considering in a general CAE system, the geometric shapes processed are often more complex. Therefore, it is necessary to introduce parametric elements to expand the universal range of the spatial shape of the elements, and convert the irregular elements in the overall spatial coordinate system into regular elements in the local natural coordinate system. For this purpose, three aspects of coordinate transformation work are also required: the transformation between the overall spatial coordinate and the local natural coordinate , the partial derivative operator of the overall spatial coordinate Conversion with respect to the partial derivative operator of local natural coordinates , coordinate transformation of the integration domain. The conversion functions in these three aspects need to be incorporated into the design of relevant functions in the specific element development. That is: required function abstraction interfaces, Jacobian interfaces, etc.

[0071] Based on this, the specific design of the unit functional architecture is as Figure 4 shown. The base class is the finite element basic abstract class FEMBase, which provides the basic attributes required by nodes and elements, such as local numbers, global numbers, etc. On this basis, the finite element node class FEMNode and the finite element element basic class FEMElementBase can be inherited. Among them, FEMNode has finite element node information and related call methods, such as coordinate values, degree of freedom labels, etc.; FEMElementBase, as the basic class of finite element elements, not only has a list of FEMNode objects of the nodes that make up the element, but also covers the general attributes and methods in the finite element modeling and analysis process, as well as the abstract interfaces including: The shape function abstract interface ShapeFuncInterface provides abstract method interfaces related to shape functions required in the process of constructing a finite element analysis model, such as the generate_shape_function() method interface for generating a shape function matrix, the generate_dn_lcoord() method interface for obtaining the partial derivative value matrix of the shape function with respect to local natural coordinates, the get_order() method interface for providing the order of the shape function, etc.

[0072] The Jacobian abstract interface JacobianInterface provides abstract method interfaces related to coordinate transformation required in the process of constructing a finite element analysis model, such as the generate_jacobian() method interface for generating a Jacobian matrix, the generate_dn_gcoord() method interface for obtaining the partial derivative matrix of the shape function with respect to the overall space coordinates, etc.

[0073] The numerical integration abstract class Quadrature provides the integration point information required for relevant numerical integration in the process of constructing a finite element analysis model.

[0074] Based on the above main interface objects, general methods required in the process of constructing a finite element analysis model, such as the get_gcoord_via_lcoord() method for converting local natural coordinates and overall space coordinates, are designed in FEMElementBase. In addition, attributes related to the element geometric feature type ElementGeoFeatureType are designed in FEMElementBase for the conversion process with the visualization model mesh in the post-processing.

[0075] Based on FEMElementBase, further refine the responsibilities and design the finite element unit class FEMElement. As mentioned before, in the structural static simulation analysis, it is necessary to consider some behaviors determined according to the topological shape. Therefore, design the composite relationship between the topological shape behavior abstract class TopoShapeBehavior and FEMElement, and realize the flexible combination and extension of the relevant attributes of the element geometric equation through the composite pattern. In addition, by introducing the element setting information class ElementSettingInfo through the aggregation relationship in FEMElement, the direct association between the user setting information and the element attributes is realized, and the parameter settings during the key method calls in the use process of the finite element unit are clarified.

[0076] In addition, if additional calculation-related functions need to be considered, the unit interface can be further enriched. For example, for the analysis of large deformation problems, geometric nonlinearity can be considered based on the updated Lagrangian format. In the iterative calculation, the update of the configuration (i.e., the coordinate update on the mesh nodes), the calculation of the Cauchy stress under the current configuration, the calculation of the internal force-related terms brought by the displacement increment, etc. need to be considered. Therefore, additional abstract method interfaces need to be added to meet the calculation call requirements in the construction process of the FEMModel for large deformation problems. For example, the coordinate update method interface, the Cauchy stress calculation and vector generation method interface, the internal force term calculation method interface, etc.

[0077] Through the design of the modular interface in the embodiment of the present invention, when adding a new unit type, only need to inherit the base class and implement the specific interface, then it can be seamlessly integrated into the existing calculation framework, improving the scalability and maintainability of the framework.

[0078] It should be noted that for different problems, when constructing a finite element analysis model, units with different characteristics will be developed based on theoretical analysis to achieve the purposes of reducing the degrees of freedom of calculation, improving the calculation efficiency, or enhancing the calculation accuracy.

[0079] For example, when the length of an object is much larger than its cross-sectional dimensions, and the object is constrained in the length direction and not allowed to freely expand or contract. In this case, the problem can be simplified to a plane strain problem, and to solve this type of problem, a two-dimensional model can be constructed and discretized and calculated using plane strain elements, effectively improving the calculation efficiency.

[0080] Another example is for a thin plate whose thickness is much smaller than the other two dimensions, and the load acts on the plate surface, resulting in the stress mainly existing in the plane of the plate surface and not passing through the thickness direction. Under this condition, the problem can be simplified to a plane stress problem, and to solve this type of problem, a two-dimensional model can be constructed and discretized and calculated using plane stress elements, effectively improving the calculation efficiency.

[0081] It can be seen from this that the units corresponding to these two types of problems need to be designed specifically. In the embodiments of the present invention, they are respectively named the Plane Stress Element Family PlaneStressElements and the Plane Strain Element Family PlaneStrainElements. Since there are a large number of common characteristics between the two, a class with common attributes and methods can be designed as the base class, and specific subclasses of plane stress elements and plane strain elements can be developed based on this to implement additional unit behaviors.

[0082] Under the guidance of the unit development template, the development of specific units can be carried out. Here, taking the plane stress element as an example, the structural design of the specific unit subclass is described in detail, as Figure 5 shown: For specific analysis problems, the corresponding subclass inherited from the finite element unit class FEMElement is designed. Since different-shaped plane elements with different numbers of nodes may be involved in the analysis of plane stress problems, and there are common attributes and methods between these elements, an abstract plane element class CPElement inherited from FEMElement is designed as the base class for individual plane elements, which forms a composite relationship with the two-dimensional shell behavior class Shell2dBehavior inherited from the topological shape behavior abstract class TopoShapeBehavior. In CPElement, the general attributes are defined, such as the element dimension, the number of degrees of freedom of the element nodes, and the element degree of freedom identifier. At the same time, the abstract method interfaces are implemented, such as the generate_n_mat() method for calculating the shape matrix, which calls the generate_shape_function() method of its own shape function attribute object ShapeFuncInterface and performs further processing of two-dimensional elements to obtain the shape function matrix; another example is the process_d_mat() method for processing the constitutive-related elastic matrix in which not only the cross-section Section object is used as the input parameter to call its generate_d_mat() to generate the matrix corresponding to the material, but also the matrix processing method of the plane stress behavior PlaneStressBehavior or the plane strain behavior PlaneStrainBehavior object corresponding to the plane_bhv attribute added in CPElement is additionally called to implement the constitutive relationship processing simplified based on the plane problem theory.

[0083] ​Based on CPElement, first consider the influence of the number of nodes, and design subclasses of inheritance, namely the three-node plane element class CP3, the four-node plane element class CP4, the six-node plane element class CP6, and the eight-node plane element class CP8 respectively. In each specific subclass, not only are their respective key combined attributes clarified, including the Jacobian interface attribute JacobianInterface object, the shape function interface attribute ShapeFuncInterface object, and the numerical integration attribute Quadrature object, but also the abstract method interfaces in FEMElement are implemented. For example, for the four-node plane element class CP4, in the configure() method, its Jacobian interface attribute is the JacobianRectangle2d related to the two-dimensional rectangle, its shape function interface attribute is the ShapeFuncLagrange2d4Nodes object of the two-dimensional Lagrange four-node shape function, and its numerical integration attribute is the GaussQuadrature2d of the two-dimensional Gaussian integration; and methods such as generate_tkel_on_gp() and generate_tkenl_on_gp() are implemented to calculate specific matrix elements such as the element stiffness matrix at the Gaussian integration points.

[0084] Subsequently, based on the specific plane element, the PlaneStressBehavior is additionally added to obtain the plane stress element class inherited from the plane element class, including the three-node plane stress element class CPS3, the four-node plane stress element class CPS4, the six-node plane stress element class CPS6, and the eight-node plane stress element class CPS8.

[0085] In some embodiments of the present invention, when the element type is a plane stress element, such as Figure 6As shown in the figure, the specific implementation structure of the data structure based on the unit family abstract class is as follows: First, inherit from ElementFamily to obtain the PlaneStressElements of the plane stress element family. Among them, the specific key-value pair data of each attribute in the above combination relationship need to be specified in the constructor. For the key-value pairs related to FEMElement, through two enumeration class objects, GeoElementType and ElementOrder, as variables, a one-to-one mapping between different geometric shapes and different order combinations and CPS3, CPS4, CPS6, and CPS8 is realized. Using a similar mapping method, the key-value pairs related to QmyElementSettingWidget and ElementSettingInfo are constructed, realizing the mapping of the specific unit setting widgets QmyCPS3Widge, QmyCPS4Widget, QmyCPS6Widget, and QmyCPS8Widget, and the mapping of the specific unit setting information CPS3SettingInfo, CPS4SettingInfo, CPS6SettingInfo, and CPS8SettingInfo respectively.

[0086] Based on the above design, after the user selects the corresponding unit setting in the unit type setting dialog QmyEditElementTypeDialog, the preliminary selection of the calculation unit can be completed. For example, for plane stress elements, if the user selects to use first-order elements, the unit setting widgets presented in QmyEditElementTypeDialog are QmyCPS3Widget and QmyCPS4Widget, and the user can switch between the two on the interface and input relevant parameter settings. Based on the user's settings, CPS3SettingInfo and CPS4SettingInfo objects can be generated for constructing CPS3 and CPS4 units. Subsequently, based on the above selection and the mesh division result, the system automatically assigns CPS3 or CPS4 to the corresponding specific geometric units in the mesh, thus finally realizing the purpose of converting the geometric units in the mesh into plane stress CPS3 and CPS4 units, providing key data model support for constructing a finite element analysis model.

[0087] In summary, the design method of the finite element analysis unit library data structure and interaction function architecture proposed in the embodiments of the present invention effectively coordinates the collaborative definition of geometric topology and element attributes by decoupling the mesh generation strategy and the element type allocator, and constructing a dynamic strategy pre-screening and parameter constraint mechanism. Based on the factory pattern and abstract interface design, the unit library realizes the elastic expansion of multiple topology types (solid / shell), and combines the parametric unit calculation framework (shape function, Jacobian matrix, integration rule standardization) and the hierarchical material model to support efficient numerical modeling of complex geometric mapping and multi-material scenarios.

[0088] Those skilled in the art can understand that all or part of the processes of implementing the above embodiment methods can be completed by instructing relevant hardware (such as processors, controllers, etc.) through computer programs, and the computer programs can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a disk, an optical disc, a read-only memory or a random access memory, etc.

[0089] The above has introduced in detail a design method for the data structure and interaction function architecture of a finite element analysis unit library provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for designing a finite element analysis unit library data structure and interactive functional architecture, characterized in that: include: Constructing an interactive function data class diagram based on a finite state machine design pattern; the interactive function data class diagram includes a unit type setting dialog class and a unit library abstract class that is in a combination relationship with the unit type setting dialog class; Constructing a cell library data structure; the cell library data structure includes the cell library abstract class, a cell family abstract class in a combination relationship with the cell library abstract class, a topology type in an association relationship with the cell library abstract class, a specific topology type cell library class inherited from the cell library abstract class, and a specific cell family class inherited from the cell library abstract class, wherein the specific cell family class is in a combination relationship with the specific topology type cell library class; the cell library abstract class is used to realize a collection of finite element calculation units of different orders and shapes; A development template for constructing unit functions; the development template includes a finite element unit base class and a general abstract interface that is in a combination relationship with the finite element base class; Constructing the data structure of the unit family abstract class; the data structure is a combination relationship between the unit family abstract class and the finite element unit class, the unit setting component class and the unit setting information class.

2. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The unit type setting dialog class designs a unit family list column, and the unit library abstract class includes an available unit family list corresponding to geometric objects of a determined topological type. Based on the init_widget_via_element_lib() method in the unit type setting dialog class and the get_element_families() method in the unit library abstract class, the unit family objects in the available unit family list are added to the unit family list column.

3. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The interactive function data class diagram also includes a unit setting component class and a unit setting information class, and the unit type setting dialog class depends on the unit type setting dialog class of the unit setting component class and the unit setting information class, and the method further includes: A component object is generated based on the init_stacked_widget() method and generate_tab_widget() in the unit type setting dialog class, so that after different unit family abstract classes are selected in the unit type setting dialog class, the unit setting components in the unit setting component class are updated in real time.

4. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 3, characterized in that: The interactive function data class diagram also includes a unit type basic state abstract class designed based on the finite state machine design pattern, a unit type control class that is in a combination relationship with the unit type basic state abstract class, a unit type setting class that inherits from the unit type basic state abstract class, a unit type area selection state class, and a geometric unit type class that is in an associated relationship with the unit setting component class, the unit type setting dialog class is in a combination relationship with the unit type setting state class, and the unit setting information class is in an associated relationship with the geometric unit type class.

5. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The specific topology type unit library class includes a three-dimensional solid topology type unit library class, a two-dimensional shell topology type unit library class and a three-dimensional shell topology type unit library class, and the specific unit family class includes a plane stress unit family class and a plane strain unit family class.

6. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The cell library data structure also includes a cell library factory class, and the cell library factory class is in a combination relationship with the cell library abstract class.

7. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The general abstract interface includes a Jacobi abstract interface, a shape function abstract interface, a numerical integration abstract class and a topological shape behavior abstract class.

8. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 1, characterized in that: The development template also includes a finite element basic abstract class, a finite element node class inherited from the finite element basic abstract class, a unit geometry feature type associated with the finite element unit basic class, a unit setting information class aggregated with the finite element unit class, and a topological shape behavior abstract class combined with the finite element unit class. The finite element unit basic class inherits from the finite element basic abstract class.

9. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 8, characterized in that: When the unit type is a plane stress unit, the data class diagram of the plane stress unit includes a plane unit abstract class inherited from the finite element unit class, a two-dimensional shell behavior class inherited from the topological behavior abstract class, a three-node plane unit class, a four-node plane unit class, a six-node plane unit class and an eight-node plane unit class inherited from the plane unit abstract class, and a three-node plane stress unit class inherited from the three-node plane unit class, a four-node plane stress unit class inherited from the four-node plane unit class, a six-node plane stress unit class inherited from the six-node plane unit class and an eight-node plane stress unit class inherited from the eight-node plane unit class, and the three-node plane stress unit class, the four-node plane stress unit class, the six-node plane stress unit class and the eight-node plane stress unit class are in a combination relationship with the plane stress behavior class.

10. The method for designing a finite element analysis unit library data structure and an interactive functional architecture according to claim 9, characterized in that: When the unit type is a plane stress unit, and the unit family is a plane stress unit family, the data structure also includes a plane stress unit family class inherited from the unit family abstract class, the unit setting component class includes a three-node plane stress unit setting component class, a four-node plane stress unit setting component class, a six-node plane stress unit setting component class, and an eight-node plane stress unit setting component class that are in a combination relationship with the plane stress unit family class, and the unit setting information class includes a three-node plane stress unit setting information class, a four-node plane stress unit setting information class, a six-node plane stress unit setting information class, and an eight-node plane stress unit setting information class that are in a combination relationship with the plane stress unit family class.

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