A method for efficiently calculating a structural safety factor

Abstract

The application belongs to the technical field of strength durability and high efficiency, and relates to a high-efficiency calculation method for structural safety factor, comprising the following steps: manually preparing a control arm grid model, including structural hard points and structural attributes; manually establishing a unit set, which contains component material names in the set name; manually establishing a total set with a fixed name; judging the hard point coordinate tolerance and load case name, and applying corresponding load cases to the structural hard points; after identifying the load case name, set material name and total set name, modifying the FEMFAL script file template; FEMFAL calling the script file, completing safety factor calculation of all load cases, and outputting safety factor result files of all load cases; all components of the same material are established into a unit set, all component sets to be calculated for safety factor are established into a total set Zsetall, the FEMFAT script file template is automatically modified, FEMFAT is called to complete high-efficiency calculation of safety factors of all load cases, and work efficiency is greatly improved, and human resources are liberated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of strength durability and high efficiency, and relates to a high-efficiency calculation method of structural safety factor. BACKGROUND

[0002] In a traditional automobile strength durability development process, the safety factor of a bearing structure under the action of typical working conditions and limit working conditions must meet the evaluation indexes stipulated by an enterprise. However, when the structural safety factor is calculated, model import, component material assignment, output setting, and the calculation and output of a safety factor file need to be completed for each working condition. Moreover, when the software calculates the safety factor of one working condition, an engineer needs to wait until the calculation is completed before calculating the safety factor of the next working condition. If there are 20 or more typical working conditions and limit working conditions, the calculation efficiency will be seriously affected.

[0003] Patent document 1 (CN104992027A) determines the involute profile, root transition curve, and node coordinates of a single-tooth end face of a double helical gear according to the conjugate theory of tooth surfaces, realizes automatic modeling of the gear through programming, and reduces the workload of analysts.

[0004] Patent document 2 (CN107103119A) performs grid division and quality inspection on a tire section according to the structural features and material distribution of the tire, is used for finite element analysis, and shortens the product development cycle.

[0005] Patent document 3 (CN109657376A) completes grid division and quality inspection according to a whole vehicle CAD model and a corresponding structural BOM file, and improves work efficiency.

[0006] The above are some automatic modeling methods for CAE simulation, and no method for automatic calculation of a structural static load safety factor is found. SUMMARY

[0007] The application aims to solve the following technical problems and objects:

[0008] In the traditional automobile strength endurance development process, the safety factor of the bearing structure under the action of typical working conditions and extreme working conditions must meet the evaluation index specified by the enterprise. Generally speaking, the number of automobile typical working conditions and extreme working conditions is in the range of 9-30, which may be slightly different for different enterprises. The general steps of manually completing the structure safety factor calculation are as follows: ① grid division of the structure and attribute assignment; ② loading of each structure typical working condition and extreme working condition; ③ calling FEMFAT software, considering the structure stress gradient, calculating the static load safety factor of all typical working conditions and extreme working conditions; when calculating the structure safety factor, each working condition needs to complete model import, component material assignment, output setting, safety factor file calculation output, and when the software calculates the safety factor of one working condition, the engineer needs to wait for its completion before calculating the safety factor of the next working condition. If there are 20 typical working conditions and extreme working conditions, it will seriously affect the work efficiency.

[0009] In order to solve the above problems, the application provides a structure safety factor efficient calculation method. Based on TCL script language, through the method of solidifying typical working condition and extreme working condition name, solidifying material name in material database, and modifying FEMFAT script file template, the automatic calculation of structure safety factor is realized, and the work efficiency is greatly improved.

[0010] To solve the above technical problems, the application is implemented by using the following technical solutions, which are described in combination with the drawings as follows:

[0011] It should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0012] A structure safety factor efficient calculation method, comprising:

[0013] Manually preparing a control arm grid model, including structure hard points and structure attributes;

[0014] Manually establishing a unit set, and the set name contains the component material name;

[0015] Manually establishing a total set with fixed name;

[0016] Judging the hard point coordinate tolerance and load working condition name, and applying the corresponding working condition load at the structure hard point;

[0017] After identifying the working condition name, the set material name and the total set name, the FEMFAL script file template is modified;

[0018] The FEMFAL calls the script file to complete the safety factor calculation of all load working conditions and outputs the safety factor result file of all load working conditions.

[0019] Further, after judging the hard point coordinate tolerance and the load working condition name, the corresponding working condition load is applied at the structure hard point, and the calculation file *.inp file is outputted;

[0020] The program reads the *.inp file and identifies the keyword *LOAD CASE, NAME = VERTICAL_BUMP in the *.inp file, and stores the load working condition name VERTICAL_BUMP in the array;

[0021] The program reads the *.inp file and identifies the keyword *ELSET, ELSET = Zset_QT450 in the *.inp file, and stores the contained set and material name Zset_QT450 in the array;

[0022] The program reads the *.inp file and identifies the keyword *ELSET, ELSET = Zsetall in the *.inp file.

[0023] Preferably, the script file template of the FEMFAT software is a *.ffj file.

[0024] Preferably, the safety factor result file is a *.dma file or a *.res file.

[0025] Further, the manual establishment unit set contains the component material name in the set name, and the specific content is as follows:

[0026] The model contains three components, two of which are made of QT450, and the other is made of QT800. A unit set named Zset_QT450 is established in the grid model to contain the two components made of QT450, and a unit set named Zset_QT800 is established to contain the component made of QT800. Finally, a total unit set with a fixed name is established, named Zsetall, which contains all the units contained in the two sets Zset_QT450 and Zset_QT800.

[0027] Further, when the FEMFAL calls the script file to complete the safety factor calculation of all load working conditions, the material needs to be identified according to the set name and then automatically assigned.

[0028] Further, after applying the corresponding working condition load at the structural hard point, the output calculation file *.inp file is also included:

[0029] Taking ABAQUS software as the solving calculation software, the solving calculation is completed, and the *.odb file is output.

[0030] Further, the solving calculation is that the *.inp file after loading is manually submitted to the ABAQUS software for calculation, and after the calculation is completed, the ABAQUS software outputs the *.ODB file.

[0031] Preferably, the number of load working conditions is the same as the number of keywords *LOAD CASE in the *.inp file.

[0032] Preferably, the number of material names is the same as the number of keywords *ELSET in the *.inp file.

[0033] Compared with the prior art, the beneficial effects of the present application are:

[0034] The present application adopts TCL script language, establishes a unit set collection of all components of the same material and a total set Zsetall of all components set collections to be calculated for safety factor before finite element analysis preprocessing, automatically modifies the FEMFAT script file template (*.ffj file) by solidifying the names of typical working conditions and limit working conditions, and calls FEMFAT to complete efficient calculation of safety factors of all working conditions, thereby greatly improving work efficiency and liberating human resources. BRIEF DESCRIPTION OF DRAWINGS

[0035] The present application will be further described below in combination with the drawings:

[0036] Figure 1a It is a control arm model diagram;

[0037] Figure 1b It is a Set collection name schematic diagram;

[0038] Figure 2 It is an automatic identification *.inp file *LOAD CASE keyword and record load working condition information schematic diagram;

[0039] Figure 3 It is an automatic identification *.inp file *ELSET keyword and record material information schematic diagram;

[0040] Figure 4 It is a flow chart of the structure safety factor efficient calculation method according to the present application. DETAILED DESCRIPTION

[0041] For the purpose, technical solutions and advantages of the implementation of the present application, the technical solutions in the embodiments of the present application will be described in more detail below in combination with the drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, not all embodiments. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0043] The present application will be described in detail below in combination with the drawings:

[0044] The technical problem to be solved by the present application is to provide a structural safety coefficient automatic calculation method, and the specific content is as follows:

[0045] Manually prepare control arm structure grid and attribute model;

[0046] Manually establish a unit Set collection;

[0047] The program automatically completes the hard point loading and outputs the calculation file *.inp file according to the recognition hard point coordinate tolerance.

[0048] The hard point coordinates are manually inputted according to the vehicle calculation parameter table when the model is manually established in the first step. The so-called hard point, taking the present application as an example, has two hard points of the control arm, representing the positions of the control arm structure connected with other structures.

[0049] The program here is some conditional judgment statements written based on TCL script language.

[0050] When manually establishing a structure model, there are hard point coordinates. Through load decomposition of ADAMS software, the load of each working condition of all structure hard points is decomposed out. At this time, through the program written, it is judged whether the hard point coordinates in the model match the hard point coordinates decomposed out in the ADAMS software. If the distance between the hard point coordinates is less than the set tolerance 0.05mm, and the name of the load working condition matches, for example: NAME = VERTICAL_BUMP represents the vertical impact working condition, the load of the vertical impact working condition decomposed out in the ADAMS software is loaded into the manually established model.

[0051] The program reads the *.inp file and identifies the keyword *LOAD CASE, NAME = VERTICAL_BUMP in the *.inp file, and stores the load working condition name VERTICAL_BUMP in the array;

[0052] *LOAD CASE is a keyword, which means a load working condition, and NAME = VERTICAL_BUMP is a further explanation of the keyword, which explains that the name of this keyword is the vertical impact working condition. There are many working conditions in the calculation of the strength and durability of the automobile chassis, and there is also NAME = CORNERING, which is the cornering working condition, after *LOAD CASE.

[0053] *ELSET is a keyword, and ELSET = Zset_QT450 represents the set name.

[0054] The program reads the *.inp file and identifies the keyword *ELSET, ELSET = Zset_QT450 in the *.inp file, and stores the contained set and material name Zset_QT450 in the array;

[0055] The program reads the *.inp file and identifies the keyword *ELSET, ELSET = Zsetall in the *.inp file;

[0056] The program automatically modifies the script file template of the FEMFAT software according to the identified load working condition and set material keyword.

[0057] The program automatically calls the FEMFAT software to complete the automatic calculation of the safety factor of all load working conditions of the structure, and outputs the safety factor result file of all load working conditions.

[0058] The script file template of the FEMFAT software is *.ffj file.

[0059] The safety factor result file is *.dma file or *.res file.

[0060] The manual establishment unit Set collection, the specific content is as follows:

[0061] The model contains three components, two of which are made of QT450, and the other is made of QT800. In the grid model, a unit collection named Zset_QT450 is established to contain the two components made of QT450, and a unit collection named Zset_QT800 is established to contain the component made of QT800. Finally, a total unit collection with a fixed name, named Zsetall, is established, which contains all the units contained in the two collections Zset_QT450 and Zset_QT800.

[0062] When the FEMFAT software is automatically called for subsequent safety factor calculation, the material needs to be identified according to the name of the collection, and then automatically assigned.

[0063] The FEMFAT script file, i.e. *.ffj file, records all the operation processes in the FEMFAT software. Before performing structural safety factor calculation, the safety factor of all working conditions of the structure is calculated once manually in the software, and the script file, i.e. *.ffj file, is retained. Next time when calculating the safety factor of other structures, only the keywords representing the structure in the file need to be modified, which mainly include the stress results of each working condition required for this calculation, the material and property characteristics of each collection of the structure, etc. After replacement, it can be directly imported into FEMFAT for safety factor calculation.

[0064] After completing the hard point loading, the calculation file *.inp file is output, which also includes:

[0065] Taking ABAQUS software as the solving and calculating software, the solving and calculating is completed, and the *.odb file is output.

[0066] The solving and calculating here is the prior art, which manually submits the calculation file after loading, generally *.inp file, to ABAQUS software for calculation. After calculation, ABAQUS software outputs *.ODB file.

[0067] The number of load cases is the same as the number of keywords *LOAD CASE in the *.inp file.

[0068] The number of material names is the same as the number of keywords *ELSET in the *.inp file.

[0069] The present application will be further described in detail in combination with the drawings and specific embodiments.

[0070] Referring to Figure 1a , Figure 1b , it is a schematic diagram of a control arm model of a certain vehicle type and a Set collection name schematic diagram.

[0071] Here to a control arm as an example, detailed introduction of control arm structure safety factor efficient calculation method steps, see Figure 4 .

[0072] The first step, manual preparation of control arm structure grid and attribute model.

[0073] The second step, control arm grid model only has one component, such as Figure 1a , Figure 1b As shown, and the material of this component is QT450. Need to manually establish a unit set named Zset_QT450 in the grid model, including the components with material QT450, and establish a unit set with fixed name, named Zsetall, this set contains all the units contained in Set_QT450 set. (When calling FEMFAT software to calculate safety factor automatically later, you need to identify the material according to the name of the set, and automatically assign the material. Note that the material naming needs to be the same as the material naming in FEMFAT material library)

[0074] The third step, the program automatically completes the hard point loading according to the recognition of hard point coordinate tolerance, outputs the calculation file (*.inp file, here ABAQUS software is used as the solving calculation software, Nastran and other software are the same), and completes the solving calculation, outputs *.odb file.

[0075] The fourth step, the program reads the *.inp file, and identifies the keyword *LOAD CASE, NAME=VERTICAL_BUMP in the *.inp file, and stores the black font after the equal sign (load case name) in the array. There are several keywords *LOAD CASE in the *.inp file, and several load cases are stored.

[0076] The fifth step, the program reads the *.inp file, and identifies the keyword *ELSET, ELSET=Zset_QT450 in the *.inp file, and stores the font after the keyword (material name) in the array. There are several keywords *LOADCASE in the *.inp file, and several material names are stored.

[0077] The sixth step, the program reads the *.inp file, and identifies the keyword *ELSET, ELSET=Zsetall in the *.inp file, and any *.inp file needs to have this constant keyword.

[0078] Step 7, the program automatically modifies the script file template (*.ffj file) of the FEMFAT software according to the load conditions and the set material keywords identified in steps 4, 5 and 6.

[0079] Step 8, the program automatically calls the FEMFAT software to complete the automatic calculation of the safety factors of the structure under all load conditions, and outputs the safety factor result files (*.dma files or *.res files) of all load conditions, without human intervention, greatly improving the calculation efficiency.

[0080] The application realizes the automatic calculation of the safety factors of the structure based on the secondary development of the TCL script language.

[0081] Referring to Figure 2 , all load condition information is recorded by identifying the *LOAD CASE keyword in the *.inp calculation file.

[0082] Referring to Figure 3 , the material information of all components is recorded by identifying the *ELSET, ELSET=Zset_ keyword in the *.inp calculation file.

[0083] Figure 2 The leftmost column of numbers in the table represents the hard point numbers 249053, 249054, the middle column of numbers 1, 2, 3, 4, 5, 6 represents the freedom direction of the joint, and the rightmost column of numbers represents the load value in a certain direction.

[0084] Figure 3 The numbers in the table represent all the element numbers contained in the element set.

[0085] The automatic load loading is realized by hard point coordinate tolerance identification.

[0086] The application prepares the FEMFAT standard script file (*.ffj file) for calculating the safety factors of the structure in advance.

[0087] The load conditions and component material information identified by the program are automatically modified to the script file (*.ffj file) for FEMFAT safety factor calculation.

[0088] The application automatically calls the FEMFAT software to automatically calculate the safety factors of the structure by using the modified safety factor script file (*.ffj file), and outputs the safety factor result files (*.dma files or *.res files) of all conditions.

[0089] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement within the technical range disclosed by the present application and within the spirit and principle of the present application should be covered within the protection scope of the present application. Meanwhile, the contents not described in detail in the present specification are all the prior art known by the skilled in the art.

Claims

1. A method for efficiently calculating structural safety factors, characterized in that, include: The first step is to manually prepare the control arm structure mesh and attribute model; The second step is to create a unit set in the model and name it Zsetall (the total unit set); subsequent steps... When automatically calling FEMFAT software to calculate the safety factor, the material is identified according to the name of the set and automatically assigned to the material. The material name is the same as the material name in the FEMFAT material library. The third step is that the program automatically loads the hard points and outputs a calculation file (*.inp) based on the hard point coordinate tolerance. The loaded *.inp file is then manually submitted to the ABAQUS software for calculation. After the calculation is completed, the ABAQUS software will output a *.odb file. The fourth step is for the program to read the *.inp file and identify the keyword *LOAD within it. CASE, NAME = VERTICAL_BUMP, and store the load case name after the keyword equals sign in the array; Step 5: The program reads the *.inp file and identifies the keyword *ELSET within the *.inp file. And store the material name following the keyword in an array; Step 6: The program reads the *.inp file and identifies the keyword *ELSET in the *.inp file. ELSET = Zsetall. This constant keyword is required in every *.inp file. Step 7: The program automatically modifies the FEMFAT software script file template based on the load conditions and aggregate material keywords identified in steps 4, 5, and 6. Step 8: The program automatically calls the FEMFAT software to automatically calculate the safety factor for all load conditions of the structure and outputs the safety factor result file for all load conditions.

2. The efficient method for calculating structural safety factor according to claim 1, characterized in that: The script file template for the FEMFAT software is a *.ffj file.

3. The efficient method for calculating structural safety factor according to claim 1, characterized in that: The safety factor result file is either a *.dma file or a *.res file.

4. The efficient method for calculating structural safety factor according to claim 1, characterized in that: The second step model contains three components. Two of the components are made of QT450 material, and the third component is made of QT800 material. In the mesh model, a set of elements named Zset_QT450 is created to contain the two components made of QT450 material. Then, a set of elements named Zset_QT800 is created to contain the component made of QT800 material. Finally, a set of elements with a fixed name, Zsetall, is created, which contains all the elements contained in the two sets Zset_QT450 and Zset_QT800.

5. The efficient method for calculating structural safety factor according to claim 3, characterized in that: When FEMFAL calls the script file to complete the safety factor calculation for all load conditions, it needs to identify the materials based on the name of the set and then automatically assign the materials.

6. The efficient method for calculating structural safety factor according to claim 1, characterized in that: The number of load cases is the same as the number of *LOAD CASE keywords in the *.inp file.

7. The efficient method for calculating structural safety factor according to claim 1, characterized in that: The number of material names is the same as the number of *ELSET keywords in the *.inp file.

Images