CN109446704B - Product family finite element model parameterization method based on regular grammar - Google Patents
Product family finite element model parameterization method based on regular grammar Download PDFInfo
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Abstract
The invention relates to a product family finite element model parameterization method based on a regular grammar and oriented to a product family. The method is characterized in that a script is modeled through a regular grammar, and a finite element analysis model is generated according to grammar derivation, and comprises the following steps: 1) Performing semantic splitting on FEA scripts of products in a product family FEA script library to obtain first FEA script fragments and form a first FEA script fragment library; 2) Extracting a composition rule of the first FEA script fragment by using a regular grammar; 3) And deducing a new FEA script according to the extracted composition rule to realize the parameterization of the finite element model of the product family. The method provided by the invention can ensure that the automatic construction of the FEA model can still be completed when the topological structure of the geometric model of the product is changed, the workload of finite element analysis personnel is reduced, and meanwhile, the finite element analysis can be carried out independently, thereby reducing the product design cost for enterprises, saving the manpower and physical resources, effectively improving the product quality and shortening the design period.
Description
Technical Field
The invention relates to the technical fields of parameterization technology of finite element models, regular grammar and the like, in particular to a product family-oriented product family finite element model parameterization method based on the regular grammar.
Background
Finite Element Analysis (FEA) is a process of simulating a real physical system (geometry and load conditions) by using a mathematical approximation method. Finite element analysis is not available in modern product design, and the finite element analysis is an effective technical means for improving the product quality and shortening the design period. With the rapid development of computer technology, finite element analysis has also been widely used in the fields of aerospace, automobiles, machine manufacturing, ships, special equipment, and the like. The finite element analysis process generally includes three steps: preprocessing, loading solving and postprocessing. Common finite element analysis software such as Ansys, abaqus, MSC and the like plays a key role in solving practical problems and can effectively improve the research, development and design capabilities of enterprises.
The main content of the FEA work is to construct an FEA model, the FEA model comprises information such as the shape, the size, the stress condition and the like of the geometric model to be analyzed, and the FEA model can be solved and an analysis result can be obtained after the construction of the FEA model is completed. In the process of finite element analysis, the finite element software automatically records each operation of an analyst to form an FEA script, and each operation has a unique corresponding FEA script segment. Experienced finite element analysis engineers often build FEA models by editing FEA scripts and use FEA script parameterization methods to improve analysis efficiency. Common FEA script parameterization methods are of the following types: the Shanghai university's book (template parameterization finite element analysis and implementation in the Internet environment, china mechanical engineering, 2004) parameterizes and templates the existing finite analysis model, and the parameters are transmitted into the existing template, so that the aim of quickly constructing the FEA model is fulfilled; the hole constitution of the university of Western electronic technology, etc. (Rapid integrated parametric Transformer based on a script template 2015, advanced in software integration) defines variables in FEA scripts as identifiers, and then completes the construction of parameterized FEA scripts through the identification and replacement of input parameters, thereby establishing the FEA model. The method comprises the steps that three scheme libraries of pre-processing, solution calculation and post-processing are constructed in the morning and the like (web-based remote finite element analysis service system, 2004, chinese mechanical engineering) of the university of Sichuan, and a scheme is selected from the three scheme libraries according to the needs of a user, so that the function of reusing an FEA model is achieved; the invention discloses a finite element parametric analysis system based on a database (CN 105Q 38758A), which is used for constructing the finite element parametric analysis system based on the database, converting data input by a user into an FEA script, and constructing different geometric models by changing parameters of the geometric models or increasing and decreasing the data so as to realize the finite element analysis of the different geometric models.
However, the FEA model is closely related to the geometric model, and when the topological structure of the geometric model of the product to be analyzed changes, the FEA script parameterization method is difficult to reuse the existing FEA template or FEA scheme, so that the FEA model cannot be quickly constructed.
Therefore, the invention provides a product family-oriented FEA model automatic generation method according to the regular grammar. According to the method, under the condition that the topological structure of the geometric model of the product is changed, the FEA model can still be automatically constructed by generating the FEA script.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a product family finite element model parameterization method based on a regular grammar.
The product family finite element model parameterization method based on the regular grammar is characterized by modeling a script through the regular grammar and generating a finite element analysis model according to grammar derivation, and comprises the following steps:
1) Performing semantic splitting on FEA scripts of products in a product family FEA script library to obtain first FEA script fragments and form a first FEA script fragment library;
2) Extracting composition rules of the first FEA script fragments in the first FEA script fragment library in the step 1) by using a regular grammar;
3) Deducing a new FEA script according to the composition rule extracted in the step 2) to realize parameterization of the finite element model of the product family.
The product family finite element model parameterization method based on the regular grammar is characterized by comprising the following steps:
1) Establishment of product family FEA script library and semantic splitting of FEA script
1.1 Build a family of products FEA script library
Collecting FEA scripts in a product family, and constructing a product family FEA script library;
1.2 Semantic splitting of FEA scripts
Performing semantic splitting on the FEA script in the product family according to a finite element analysis process to obtain a first FEA script fragment; the finite element analysis comprises the following steps: the method comprises three stages of pretreatment, loading solution and post-treatment, wherein the pretreatment comprises unit types, material parameters, real constants, grid division and the like;
2) Using canonical grammar descriptions to generate rules for new FEA scripts
After the semantic splitting of the FEA script is completed, designing and organizing and extracting composition rules among the first FEA script fragments by using a regular grammar;
2.1 Canonical grammar
The regular grammar G, which is a set of sentences describing a given language, is defined as a quadruple, i.e. G = { V = } n ,V t P, S }, wherein V n Representing a set of non-terminals; v t Representing a set of terminals; p is a set of production equations, including A → alpha, A → alpha indicates that A is replaced by alpha, and A belongs to V n α includes V t Or V n A plurality of elements of (1), V t The elements in (1) are constituent elements of sentences in the language, S is a starting symbol, and derivation of all scripts is carried out from S;
2.2 Description of finite element analysis by canonical grammar, construction of derivation rules
Defining a product family FEA script library as a language L, defining an FEA script as a sentence in the language L, and defining the pre-processing, loading solving and post-processing of the FEA process as a non-terminal character V n The element in (1), the unit type, the material parameter, the real constant and the gridding division in the pretreatment are defined as a terminator V t Each terminator corresponding to a first FEA script fragment in the FEA script library;
3) Algorithmically deriving and generating new FEA scripts
3.1 ) settings of inputs
Four parameters are required to generate a complete FEA script: geometric parameters, FEA labels, load position codes and FEA parameters, wherein the FEA labels are the names of the first FEA script segments obtained by 1.2), the FEA parameters are input numerical values of the FEA labels, the geometric parameters are design parameters of a geometric model, and the load position codes are action positions for marking the FEA labels; in order to generate a complete new FEA script, geometric parameters and load position codes need to be input in the derivation process;
3.2 Acquisition of a load position code
Selecting the same load position of each product in the product family by using a coordinate selection mode in ANSYS software, converting the selected load position into a second FEA script fragment, and finally coding the second FEA script fragment to form a load position code;
3.3 Generate a new FEA script
After the four input parameters are determined, the algorithm reads the four parameters from the input buffer, and then deduces and generates a new FEA script according to the regular grammar given in step 2.1).
The product family finite element model parameterization method based on the regular grammar is characterized in that in the step 3.1), the input is divided into the following types according to the combination mode of four parameters: [ FEA tag ], [ FEA tag, FEA parameter ], [ FEA tag, payload position code, FEA parameter ];
the method for deriving the output for different input types in the derivation process is as follows:
a. directly outputting a first FEA script fragment corresponding to the FEA label;
b. filling FEA parameters into a first FEA script segment corresponding to the FEA label and then outputting the FEA parameters;
c. outputting a second FEA script segment of the load position code, and then inputting a first FEA script segment corresponding to the FEA label;
d. and outputting the second FEA script segment of the load position code, and then filling the first FEA script segment corresponding to the FEA label with FEA parameters and outputting.
The product family finite element model parameterization method based on the regular grammar is characterized in that in the step 3.2), the specific process of forming the load position code is as follows:
3.2.1 Setting a coding object
Setting the same load position of each product in the product family as a coding object;
3.2.2 ) selecting an object to be encoded
Searching for geometric features which have a set relationship with the coded object, wherein the geometric features are common features of all products in a product family; matching the selected geometric features with a coordinate system, determining the positions of the geometric features in the coordinate system, and directly or indirectly selecting a set encoding object; and (3) converting the selection process into a second FEA script segment, extracting the geometric parameters required in the step 3.1) from the converted second FEA script segment, and adding codes to the second FEA script segment to obtain the load position codes.
The product family finite element model parameterization method based on the regular grammar is characterized in that the indirect method is as follows: the method is suitable for the coding objects to be positioned at different positions on the geometric model in the product family and have different numbers.
The product family finite element model parameterization method based on the regular grammar is characterized in that the direct method comprises the following steps: the method is suitable for the coding objects to be positioned at the same position on the geometric model in the product family and have the same number.
The product family finite element model parameterization method based on the regular grammar is characterized in that non-terminal characters and terminal characters in the derivation process are temporarily stored by a stack.
The product family finite element model parameterization method based on the regular grammar is characterized in that the coordinate system of 3.2.2) is a rectangular coordinate system, a spherical coordinate system or a cylindrical coordinate system.
By adopting the technology, the invention has the following beneficial effects: the method for modeling the script by the regular grammar and generating the finite element analysis model by deduction according to the grammar can ensure that the automatic construction of the FEA model can be still completed under the condition that the topological structure of the geometric model of the product is changed, the work load of finite element analysis personnel is reduced, meanwhile, the finite element analysis can be independently performed by the product design personnel, the product design cost is reduced for enterprises, the manpower and the physical resources are saved, the product quality is effectively improved, and the design period is shortened.
Drawings
FIG. 1 is a schematic diagram of the overall system framework of the present invention;
FIG. 2 is a schematic flow chart of the present invention;
FIG. 3 is a schematic diagram of a finite element analysis process;
FIG. 4 is a schematic diagram of the derivation process;
FIG. 5 is a schematic diagram comparing different types of seal head FEA scripts;
FIG. 6 is a diagram of a first FEA script fragment corresponding to all terminators;
FIG. 7 is a schematic view of the common loading positions of different products in the end socket product family;
FIG. 8 is a schematic diagram of the operation steps of the derivation process of coupling analysis of the spherical head;
FIG. 9a is a schematic cross-sectional view of a spherical head;
FIG. 9b is a schematic view of the coupling analysis input to the spherical head;
FIG. 9c is a diagram of the result of the encoding of the load position of the spherical head;
FIG. 10 is a flow chart of an indirect selection method;
FIG. 11 is a new FEA script of a hemispherical head obtained by the grammar of the present invention;
FIG. 12 is a diagram of a set of equations according to an embodiment of the present invention;
fig. 13 is an algorithm flow chart.
In the figure: w1-bottom, W2-side, W3-outer, W4-inner.
Detailed Description
The invention is further described below with reference to the drawings and examples, but the scope of protection of the invention is not limited thereto:
as shown in fig. 1-13, according to the method for parameterizing a product family finite element model based on a canonical grammar, a script is modeled by the canonical grammar, a finite element analysis model is generated by derivation according to the grammar, firstly, FEA scripts of each product in a product family FEA script library are semantically split, a first FEA script fragment is obtained, and a first FEA script fragment library is formed; extracting a composition rule of a first FEA script fragment in a first FEA script fragment library by using a regular grammar; according to the extracted composition rules, a new FEA script is deduced to realize the parameterization of a finite element model of a product family, and the FEA script is generated by taking a pressure container end socket product as an example and specifically comprises the following steps:
1) Establishment of product family FEA script library and semantic splitting of FEA script
1.1 Build a family of products FEA script library
The end socket is an important component of the pressure container and can be divided into a hemispherical end socket, a large-curvature flat cover, a spherical cap end socket, a welding flat cover and the like according to the shape, the stress condition of the end socket takes the hemispherical end socket as the best, the elliptical end socket is arranged next, and the other three types of stress are poor;
collecting FEA analysis scripts of a pressure container end enclosure product family to obtain FEA scripts of a large-curvature flat cover structure, a hemispherical end enclosure structure, a spherical cap type end enclosure, a welding-shaped flat cover and the like shown in figure 5, and forming an end enclosure product family FEA script library;
1.2 Semantic splitting S of FEA scripts
The FEA process of the present invention is represented by the tree structure shown in fig. 3; the FEA software records each finite element analysis process and forms an FEA script file, each FEA operation in the FEA process has a first FEA script segment which is uniquely corresponding to each FEA operation, and each FEA script has unique and definite semantics; the gray square in fig. 3 represents FEA operations, the white square represents FEA stages, each operation has a corresponding first FEA script segment corresponding to it, and the first FEA script segment can be obtained by performing semantic splitting on a complete FEA script, and the invention splits the collected FEA script of the end socket product, specifically: the end socket product family finite element analysis is divided into: the method comprises three FEA stages of pretreatment, loading solution and post-treatment, wherein the pretreatment comprises geometric parameters, unit types, material parameters, real constants and grid division, and the grid division comprises intelligent division, mapping division and sweeping division; the loading solution comprises constraint, load and solution, the constraint is divided into structural analysis and thermal analysis, the structural analysis comprises fixed constraint and symmetrical constraint, and the thermal analysis comprises constant temperature and reference temperature; the load comprises a structural force and a thermal force, wherein the structural force is pressure, and the thermal force is heat convection; the post-processing comprises general post-processing, special post-processing, document storage and thermal field reading, the general post-processing comprises graph display and list display, and the special post-processing is path analysis; obtaining a first FEA script segment such as geometric parameters, element types, material parameters, etc., with the final result shown in fig. 6;
2) Using canonical grammar descriptions to generate rules for new FEA scripts
After the semantic splitting of the FEA script is completed, designing and organizing and extracting composition rules among the first FEA script fragments by using a regular grammar;
2.1 Canonical grammars
The canonical grammar G, which is a set of sentences describing a given language, is defined as a quadruple, i.e., G = { V = n ,V t P, S }, wherein V n Representing a set of non-terminals; v t Representing a set of terminals; p is a set of production equations, including A → alpha production equation, A → alpha indicates that A is replaced by alpha, and A belongs to V n α includes V t Or V n A plurality of elements of (1), V t The elements in (1) are constituent elements of sentences in the language, S is a starting symbol, and derivation of all scripts is carried out from S;
2.2 Description of regular grammar to finite element analysis, construction of derivation rules
Defining a product family FEA script library as a language L, defining an FEA script as a sentence in the language L, and defining the pre-processing, loading solving and post-processing of the FEA process as a non-terminal character V n The element in (1), the unit type, the material parameter, the real constant and the grid division in the pre-processing are defined as a terminal character V t Each terminator corresponding to a first FEA script fragment in the FEA script library;
in the invention, each analysis stage (such as preprocessing, loading and solving, etc.) is set as a non-terminal (marked as capital letter), specific operation (such as unit type, material parameter, etc. in preprocessing) is set as a terminal (marked as lowercase letter), and finally a generation formula set P is formed, wherein S is a starting symbol, as shown in fig. 12;
3) Algorithmically deriving and generating new FEA scripts
3.1 ) settings of inputs
Four parameters are required to generate a complete FEA script: geometric parameters, FEA labels, load position codes and FEA parameters, in order to generate a complete new FEA script, the geometric parameters and the load position codes need to be input in the derivation process, wherein:
1) Geometric parameters are as follows: design parameters of the geometric model, length, width, height and radius;
2) FEA label: representing each FEA operation, there is its corresponding FEA script segment, which in this embodiment is 1.2) the name of the resulting script segment, such as: applying pressure;
3) And (3) load position coding: for marking the location of action of a force or constraint in the FEA, such as the numbering of points, lines, faces;
4) FEA parameters: is input parameter in FEA process, such as pressure value of 10Mpa;
depending on the way in which the parameters are combined, the inputs can be classified into the following types: [ FEA tag ], [ FEA tag, FEA parameter ], [ FEA tag, payload position code, FEA parameter ]; the method for assigning values to different input parameters in the derivation process is as follows:
1) Directly assigning the FEA script segment corresponding to the FEA label;
2) Filling parameters into FEA script segments corresponding to the FEA labels (or geometric parameters) and then assigning values;
3) Firstly, determining script segments of load position codes, and then determining script segments corresponding to FEA labels;
4) Firstly, determining script segments of load position codes, then determining script segments corresponding to FEA labels and filling FEA parameters;
the invention takes the coupling analysis of the spherical end socket as an example, the input geometric parameters are shown in fig. 9a, wherein R1 is the longitudinal height of the geometric model, i.e. R1=1.386m, R2 is the transverse width of the geometric model, i.e. R2=0.546m, and R3 is the outer surface fillet radius of the geometric model, i.e. R3=0.546m, as shown in fig. 9 b:
as shown in fig. 9b, the FEA labels of the geometric parameter mo, the cell type et, etc. will act on the overall geometric model, except that in addition, the constant temperature and pressure will act on the inner surface W4 of the geometric model, the symmetric constraint will act on the two side surfaces W2, the fixed constraint will act on the bottom surface W1, and the thermal convection will act on the outer surface W3;
3.2 Acquisition of the position code of the load
Before the derivation, the script of the payload position code is prepared first. The invention selects the common load position of the product family by using a coordinate selection mode in ANSYS software, converts the selection process into a second FEA script segment, and finally codes the second FEA script segment (namely the load position code), wherein the specific process is as follows:
3.2.1 Setting a coding object
The invention sets the coding object as a common load position of a product family, and different loads can be borne on the same load position due to different analysis requirements, and the coding object comprises the following coding objects:
1) An inner surface W4 for bearing pressure or constant temperature load;
2) The bottom surface W1 of the end socket is fixedly restrained;
3) A side W2, symmetrically constrained;
4) An outer surface W3 for receiving thermal convection load;
establishing a quarter geometric model for a head product family, taking the common load position of the head product family as a coding object, wherein the coding object comprises a head inner surface W4, left and right side surfaces W2, an outer surface W3 and a bottom surface W1, and the specific structure is shown in FIG. 7;
3.2.2 ) selecting an object to be encoded
Taking the ANSYS software as an example, the ANSYS software provides a powerful feature selection function, and although there is a structural difference between product family geometric models, by using the coordinate selection method provided by the ANSYS software, the same feature in different geometric models can be selected by using the same selection strategy (for example, the inner surfaces of all the end sockets can be selected by using the same selection strategy). To ensure that the generated FEA script fragments apply to all products within a product family, the present invention selects the code object as follows: 1) An indirect selection method: searching a group of geometric characteristics which have a set relation with the coded object, wherein the group of geometric characteristics are contained in all products; matching a coordinate system (rectangular coordinate system, spherical coordinate system or cylindrical coordinate system, in the embodiment of the invention, selecting a cylindrical coordinate system and determining the position of the geometric feature in the cylindrical coordinate system, indirectly selecting a coding object, converting the selection process into FEA script segments, extracting parameters and setting variables for the script segments, and finally adding codes such as W1, W2 and the like for the script segments, wherein the working principle of the indirect selection method is shown in FIG. 10, and 2) a direct selection method: if the coding objects are all located at the same position on the geometric model in the product family, the coding objects are directly selected by matching the coordinate system.
The method comprises the following specific steps: 1) An indirect selection method: taking the example of selecting the inner surface W4 as an example, as shown in fig. 7, the inner surface W4 cannot be directly selected because the number of segments of the inner surface W4 varies greatly within the product family, but the number of segments of the outer surface W3 varies little (2 segments are provided on the outer surfaces of the hemispherical head and the spherical cap head, and 3 segments are provided on the outer surfaces of the remaining products), and because the contour line of the outer surface W3 and the contour line of the inner surface W4 are on the same side, and the contour line of the outer surface is on the outer surface W3, the contour line of the outer surface is taken as the set of geometrical characteristics for selecting the inner surface W4. The selection process is as follows: by using the cylindrical coordinate system, all lines on the side surface W2 are selected, the outer surface contour line, the bottom end transverse line and the top end transverse line are excluded, all the surfaces connected with the inner contour line are selected, the side surfaces are excluded, and the rest are the inner surfaces. 2) Direct selection method: for the bottom surface, only one bottom surface is arranged on all the models and is positioned at the bottommost end of the models, and the bottom surface can be directly selected by utilizing a cylindrical coordinate system.
Similarly, the other encoding objects may be selected according to the same method, and the finally obtained second FEA script fragment and encoding result are shown in fig. 9c, where a bold font is the encoding of each encoding object, a parameter R1 is the longitudinal height of the geometric model of the product family, R2 is the transverse width of the geometric model of the product family, and R1 is the outer surface fillet radius of each geometric model of the head product family, which is shown in fig. 9 a;
3.3 Generate a script
After determining the various types of input parameters, the present invention proposes to generate a script according to the flow shown in fig. 4. In order to ensure that the derivation process is not repeated and the whole analysis step of the FEA of the product is not omitted, the invention temporarily stores the non-terminal character and the terminal character in the derivation process by using a data structure-stack.
Take the generation set as an example: s → B | C, B → a | B, C → C | d, and there is an input string ac. During derivation, non-terminal characters and terminal characters in the derivation process are temporarily stored by a stack, a generating type initial character S is firstly pressed into the stack, the stack top is S, S is popped out, the generating type reverse order is put into the stack, the stack top is B non-terminal character, B is popped out of the stack, the stack top a is the terminal character, a is the same as the characters in an input string, a is popped out, the stack top is B, the operation of the step is abandoned, and the steps are the same. Until the stack $ is empty, the derivation is complete and the specific process of the algorithm is as shown in FIG. 13.
The hemispherical head coupling analysis can be divided into two stages of thermal analysis and structural analysis, taking the thermal analysis as an example, the algorithm derivation process is as follows: pressing a start symbol S of the grammar into a stack, wherein S is a terminal symbol, pushing a generated reverse sequence into the stack, popping a PR at the top of the stack, then pushing the PR to generate the generated reverse sequence, wherein the inner mo, the et, the mp and the r are the terminal symbols, sequentially popping the terminal symbols out of the stack and writing a corresponding script fragment, then popping a non-terminal symbol ME at the top of the stack, pushing the generated reverse sequence into the stack, wherein the sm at the top of the stack is the same as the character in the input string, popping the filled parameter of the terminal symbol sm, and popping se, sw and the like; and at the moment, the stack top is LS, the LS is popped out, the LS is put on the stack in a production type reverse order, then non-terminal characters CO and CD are popped out in sequence, terminal characters fi and sy in the stack are popped out, scripts are output, the stack top is HD, symbols under the HD are popped out in sequence, then the stack top is so, so and script fragments are output, then the stack top is PO, PO is popped out, and stack tops sa and re are popped out. Then, the structure analysis stage is entered, and as in the thermal analysis, the symbols of the production formula are sequentially popped up, and finally a new script is formed as shown in fig. 11.
Claims (7)
1. A product family finite element model parameterization method based on a regular grammar models a script is modeled through the regular grammar, and a finite element analysis model is generated according to grammar derivation, and the method comprises the following steps: 1) Semantic splitting is carried out on FEA scripts of products in a FEA script library of a product family to obtain first FEA script fragments and form a first FEA script fragment library;
2) Extracting a composition rule of the first FEA script fragment in the first FEA script fragment library in the step 1) by using a regular grammar; 3) Deducing a new FEA script according to the composition rule extracted in the step 2) to realize the parameterization of a finite element model of a product family,
the method is characterized by comprising the following steps:
1) Establishment of product family FEA script library and semantic splitting of FEA script
1.1 Build a family of products FEA script library
Collecting FEA scripts in a product family, and constructing a product family FEA script library;
1.2 Semantic splitting of FEA scripts
Semantic splitting is carried out on the FEA scripts in the product family according to a finite element analysis process, and a first FEA script fragment is obtained; the finite element analysis component process comprises: the method comprises three stages of pretreatment, loading solution and post-treatment, wherein the pretreatment comprises unit type, material parameters, real constants and grid division;
2) Using canonical grammar descriptions to generate rules for new FEA scripts
After the semantic splitting of the FEA script is completed, designing and organizing and extracting composition rules among the first FEA script fragments by using a regular grammar;
2.1 Canonical grammar
The regular grammar G, which is a set of sentences describing a given language, is defined as a quadruple, i.e. G = { V = } n ,V t P, S }, wherein V n Representing a set of non-terminals; v t Representing a set of terminals; p is a set of production equations, including A → alpha production equation, A → alpha indicates that A is replaced by alpha, and A belongs to V n α includes V t Or V n A plurality of elements of (1), V t The elements in (1) are constituent elements of sentences in the language, S is a starting symbol, and derivation of all scripts is carried out from S;
2.2 Description of finite element analysis by canonical grammar, construction of derivation rules
Defining FEA script library of product family as language L, one FEA script as one sentence in language L, preprocessing FEA process and addingBoth solution and post-processing are defined as non-terminal V n The element in (1), the unit type, the material parameter, the real constant and the grid division in the pre-processing are defined as a terminal character V t Each terminator corresponding to a first FEA script fragment in the FEA script library;
3) Algorithmically deriving and generating new FEA scripts
3.1 ) settings of inputs
Four parameters are required to generate a complete FEA script: the method comprises the following steps of (1) obtaining a geometric parameter, an FEA label, a load position code and an FEA parameter, wherein the FEA label is the name of a first FEA script fragment obtained in 1.2), the FEA parameter is an input numerical value of the FEA label, the geometric parameter is a design parameter of a geometric model, and the load position code is an action position for marking the FEA label; in order to generate a complete new FEA script, geometric parameters and load position codes need to be input in the derivation process;
3.2 Acquisition of a load position code
Selecting the same load position of each product in the product family by using a coordinate selection mode in ANSYS software, converting the selected load position into a second FEA script fragment, and finally coding the second FEA script fragment to form a load position code;
3.3 Generate a new FEA script
After the four input parameters are determined, the algorithm reads the four parameters from the input buffer, and then deduces and generates a new FEA script according to the regular grammar given in step 2.1).
2. The method for parameterizing a finite element model of a product family based on a canonical grammar as in claim 1, wherein in step 3.1), the input is classified into the following types according to the combination mode of four parameters: [ FEA tag ], [ FEA tag, FEA parameter ], [ FEA tag, payload position code, FEA parameter ];
the method of deriving the output for different input types during the derivation process is as follows:
a. directly outputting a first FEA script fragment corresponding to the FEA label;
b. filling FEA parameters into a first FEA script segment corresponding to the FEA label and then outputting the FEA parameters;
c. outputting a second FEA script segment of the load position code, and then inputting a first FEA script segment corresponding to the FEA label;
d. and outputting the second FEA script segment of the load position code, and then filling the first FEA script segment corresponding to the FEA label with FEA parameters and outputting.
3. The canonical grammar-based product family finite element model parameterization method according to claim 1, wherein in step 3.2), the specific process of forming the load position code is as follows:
3.2.1 Setting an encoding object
Setting the same load position of each product in the product family as a coding object;
3.2.2 ) selecting an encoding object
Searching for geometric features which have a set relationship with the coded object, wherein the geometric features are common features of all products in a product family; matching a coordinate system for the selected geometric features, determining the positions of the geometric features in the coordinate system, and directly or indirectly selecting a set coding object; and (3) converting the selection process into a second FEA script fragment, extracting the geometric parameters required in the step 3.1) from the converted second FEA script fragment, and adding codes to the second FEA script fragment to obtain the load position codes.
4. A canonical grammar-based product family finite element model parameterization method according to claim 3, characterized in that the indirectly selected conditions are: the method is suitable for the coding objects to be positioned at different positions on the geometric model in the product family and have different numbers.
5. A canonical grammar-based product family finite element model parameterization method according to claim 3, characterized in that the conditions directly chosen are: the method is suitable for the coding objects to be positioned at the same position on the geometric model in the product family and have the same number.
6. The method of claim 1, wherein non-terminal and terminal characters in the derivation process are buffered by a stack.
7. A method as claimed in claim 3, wherein the 3.2.2) coordinate system is a rectangular coordinate system, a spherical coordinate system or a cylindrical coordinate system.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108197353A (en) * | 2017-12-17 | 2018-06-22 | 内蒙航天动力机械测试所 | A kind of solid propellant rocket Fixture Design method of the APDL language based on ANSYS |
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| CN108197353A (en) * | 2017-12-17 | 2018-06-22 | 内蒙航天动力机械测试所 | A kind of solid propellant rocket Fixture Design method of the APDL language based on ANSYS |
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