A method, tool, device and storage medium for calculating yield torque of a shaft
By replacing the static torque experiment with the finite element calculation method, the yield torque of the transmission shaft is calculated, which solves the problems of long experimental period and high cost, and achieves fast and accurate yield torque evaluation and improves design efficiency.
Patent Information
- Application Number
- CN202111606066.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-25
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2041-12-25
AI Technical Summary
In the prior art, the yield torque experiment of the transmission shaft requires physical verification, with a long period and high cost, so it is impossible to timely determine whether the strength of the design structure of the shaft-type parts meets the actual requirements.
Using a method based on finite element calculation, the initial torsional stiffness value and torsional stiffness value of each point are calculated by calculating the angle-torque relationship curve, determining the stiffness fit confidence and initial stiffness retention rate, and finally calculating the torsional stiffness of the yield torque point of the shaft Values and torque values are replaced by static torque experiments.
Quickly calculate the yield torque of shaft parts, shortens the calculation cycle, saves costs, improves calculation efficiency, and has high accuracy, allowing intuitive judgment of whether the design meets the requirements.
Smart Images
Figure CN114398729B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of strength calculation of transmission shafts, and relates to a method, tool, device and storage medium for calculating the yield torque of the shaft, and in particular to a method, tool, device and storage medium for calculating the yield torque of the shaft based on finite element calculation results. Background Art
[0002] In the strength calculation of the transmission shaft, it is necessary to obtain the yield torque of the shaft according to the design structure, and then judge whether the structure meets the requirements of the use conditions. Usually, the yield torque of shaft parts is selected through the results of static torsion tests, but static torsion tests require physical objects, the experimental verification cycle is long, the experimental cost is high, and it is impossible to timely judge whether the strength of the design structure of shaft parts meets the actual requirements. Therefore, designing a method that can replace the static torque test to judge the yield torque of shaft parts in order to overcome the shortcomings of static torque tests that require physical objects, long verification cycles, and high experimental costs is an urgent problem to be solved in the current strength calculation of shafts. Summary of the invention
[0003] The purpose of the present invention is to solve the problems in the prior art and to provide a method, tool, equipment and storage medium for calculating the yield torque of a shaft based on finite element calculation results, so as to replace the static torque test to obtain the yield torque of shaft parts, and then judge whether the strength of the design structure of the shaft parts meets the actual requirements.
[0004] In order to achieve the above object, the present invention adopts the following technical solutions:
[0005] The present invention provides a method for calculating the yield torque of a shaft, comprising the following steps:
[0006] Calculate the angle-torque relationship of the shaft and draw the angle-torque relationship curve;
[0007] Determine the stiffness fitting confidence and initial stiffness retention rate;
[0008] Calculate the initial torsional stiffness value based on the stiffness fitting confidence and the angle-torque relationship curve;
[0009] According to the rotation angle-torque relationship curve, the torsional stiffness value of each point in the rotation angle-torque relationship curve is calculated;
[0010] According to the initial torsional stiffness value and the torsional stiffness value of each point in the angle-torque relationship curve, the stiffness retention rate of each point in the angle-torque relationship curve is calculated;
[0011] According to the initial stiffness retention rate, the stiffness retention rate of each point in the angle-torque relationship curve and the torsional stiffness value of each point in the angle-torque relationship curve, the torsional stiffness value of the shaft at the yield torque point is calculated;
[0012] The torque value at the yield torque point of the shaft is calculated based on the torsional stiffness value at the yield torque point of the shaft.
[0013] Furthermore, the stiffness fitting confidence level is 0.999.
[0014] Furthermore, the initial stiffness retention rate is 0.2.
[0015] Furthermore, the calculation method of the initial torsional stiffness value is: in the angle-torque relationship curve, starting from the smallest point, that is, the first point, a linear fit is performed to obtain the initial torsional stiffness value curve, and when the confidence level of the fitted torsional stiffness value reaches the stiffness fitting confidence level, the initial torsional stiffness value is obtained.
[0016] Furthermore, the method for calculating the torsional stiffness value of each point in the angle-torque relationship curve is: in the angle-torque relationship curve, take the smallest point as the starting point, start from the second point, select points in sequence, and make a linear fit between the previous point value of the selected point, the selected point value, and the next point value of the selected point, and the obtained torsional stiffness value is the torsional stiffness value of the selected point.
[0017] Furthermore, the method for calculating the stiffness retention rate of each point in the angle-torque relationship curve is: dividing the torsional stiffness value of each point in the angle-torque relationship curve by the initial torsional stiffness value one by one to obtain the stiffness retention rate of each point.
[0018] Furthermore, the calculation method of the torsional stiffness value at the yield torque point of the shaft is: arrange the stiffness retention rates of each point in the calculated angle-torque relationship curve in descending order, select the first point whose stiffness retention rate is lower than the determined initial stiffness retention rate, and perform linear interpolation between this point and the previous point of this point, so that the stiffness retention rate of the interpolation point is exactly the determined initial stiffness retention rate, and the torsional stiffness value of the interpolation point obtained is the torsional stiffness value of the yield torque point of the shaft.
[0019] A calculation tool using the above shaft yield torque calculation method, comprising:
[0020] A data import module, which imports the angle-torque relationship data calculated by the finite element analysis software into the yield torque calculation tool and draws an angle-torque relationship curve diagram;
[0021] Numerical setting module, used to determine the stiffness fitting confidence and initial stiffness retention rate;
[0022] An initial torsional stiffness calculation module is used to calculate the initial torsional stiffness value according to the initial stiffness fitting confidence and the angle-torque relationship curve;
[0023] A module for calculating the torsional stiffness value of each point, used to calculate the torsional stiffness value of each point in the angle-torque relationship curve;
[0024] The module for calculating the stiffness retention rate of each point is used to calculate the stiffness retention rate of each point in the angle-torque relationship curve;
[0025] A module for calculating the torsional stiffness value at the yield torque point of the shaft, used for calculating the torsional stiffness value at the yield torque point of the shaft;
[0026] A torque value calculation module of the yield torque point of the shaft, used to calculate the torque value of the yield torque point of the shaft;
[0027] The data result output module is used to draw and display the torsional stiffness change curve of the yield torque point of the shaft, and output the yield torque value result of the shaft.
[0028] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the above method steps are implemented when the computer program is executed.
[0029] A computer-readable storage medium is used to store a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.
[0030] Compared with the prior art, the present invention has the following beneficial effects:
[0031] This method can quickly calculate the yield torque of shaft parts without the need to conduct experiments on physical shaft parts, which greatly shortens the calculation cycle of the yield torque of shaft parts, saves calculation costs, and improves calculation efficiency.
[0032] Secondly, the shaft yield torque calculated according to this method has high precision, accurate calculation results, simple and scientific design principles, and the shaft yield torque selection tool designed according to this method is easy to operate and can quickly obtain the shaft yield torque value. It can also more intuitively determine whether the yield strength design of shaft parts meets the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0034] Figure 1 This is a flow chart of the method for calculating the yield torque of a shaft according to the present invention.
[0035] Figure 2 It is a finite element analysis diagram of the shaft in the embodiment of the present invention.
[0036] Figure 3 It is a curve diagram of the calculation results of the yield torque of the shaft in the embodiment of the present invention. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0040] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0041] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0042] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0043] The present invention is further described in detail below in conjunction with the accompanying drawings:
[0044] See also Figure 1 to Figure 2 First, use the finite element analysis software to perform finite element modeling on the shaft that needs to analyze the yield torque. Couple the meshing spline to the tangent point A where the spline meshes with the shaft and the point B corresponding to A. The degree of freedom of point A is fully constrained. Apply an axial torque M = 25000Nm at point B, and set the maximum incremental step to 0.05. Then submit the model for calculation to obtain the finite element analysis results, extract the torque value of point A with the incremental step, extract the angular value of point B with the incremental step, and convert the unit of the angular value of point B from "radians" to "degrees";
[0045] By matching the rotation angle values with the torque values one by one, we can get the rotation angle-torque relationship table of the shaft, as shown in the following table:
[0046] The relationship between the rotation angle and torque obtained by finite element calculation
[0047]
[0048]
[0049] See also Figure 3 , draw the angle-torque relationship curve.
[0050] Set the stiffness fitting confidence level R 2 The minimum value is 0.999, and the initial stiffness retention rate is set to 0.2. This value is obtained by processing a large amount of test data. When the stiffness retention rate is designed to be 0.2, the yield torque value of the shaft can be predicted more accurately.
[0051] In the angle-torque relationship curve, starting from the smallest point, i.e. the first point, a linear fit is made to the torsional stiffness value of the point to obtain the initial torsional stiffness value curve. When the confidence level of the fitted torsional stiffness value reaches the confidence level R 2 When it is 0.999, the initial torsional stiffness value and the number of points of the initial torsional stiffness value are obtained. This operation can make the initial torsional stiffness value calculated with higher accuracy.
[0052] In the angle-torque relationship curve, take the smallest point as the starting point, start from the second point, select points in sequence, and make a linear fit between the torsional stiffness values of the previous point of the selected point, the selected point value, and the next point value of the selected point. The obtained torsional stiffness value is the torsional stiffness value of the selected point. This method is used to calculate the torsional stiffness value of each point in the angle-torque relationship curve.
[0053] The torsional stiffness value of each point in the angle-torque relationship curve is divided by the initial torsional stiffness value to obtain the stiffness retention rate of each point in the angle-torque relationship curve. The stiffness retention rate is a direct standard for judging the yield torque of the shaft structure.
[0054] Arrange the stiffness retention rates of each point in the angle-torque relationship curve in descending order, find the first point whose stiffness retention rate is lower than the set initial stiffness retention rate of 0.2, and perform linear interpolation between this point and the previous point of this point, so that the stiffness retention rate of the interpolation point is exactly the set value of 0.2. The torsional stiffness value of the interpolation point obtained is the torsional stiffness value of the yield torque point of the shaft. Finally, based on the torsional stiffness value of the yield torque point of the shaft, the torque value of the yield torque point of the shaft can be calculated.
[0055] The shaft yield torque calculation tool designed according to this shaft yield torque calculation method includes:
[0056] A data import module, which imports the angle-torque relationship data calculated by the finite element analysis software into the yield torque calculation tool, and draws a curve diagram of the angle-torque relationship;
[0057] Numerical setting module, used to determine the stiffness fitting confidence R 2 is 0.999 and the initial stiffness retention rate is 0.2;
[0058] An initial torsional stiffness calculation module is used to calculate the initial torsional stiffness value according to the initial stiffness fitting confidence and the angle-torque relationship curve;
[0059] The torsional stiffness value calculation module of each point is used to calculate the torsional stiffness value of each point in the angle-torque relationship curve according to the angle-torque relationship curve;
[0060] A module for calculating the stiffness retention rate of each point, used to calculate the stiffness retention rate of each point in the angle-torque relationship curve according to the initial torsional stiffness value and the torsional stiffness value of each point in the angle-torque relationship curve;
[0061] The torsional stiffness value calculation module of the yield torque point of the shaft is used to calculate the torsional stiffness value of the yield torque point of the shaft according to the initial stiffness retention rate of 0.2, the stiffness retention rate of each point in the rotation angle-torque relationship curve and the torsional stiffness value of each point in the rotation angle-torque relationship curve;
[0062] A torque value calculation module of the yield torque point of the shaft, used to calculate the torque value of the yield torque point of the shaft according to the torsional stiffness value of the yield torque point of the shaft;
[0063] The data result output module is used to draw and display the torsional stiffness change curve of the yield torque point of the shaft, and output the result of the yield torque value of the shaft.
[0064] When using it, you can enter the setting of the stiffness fitting confidence level of 0.999 and the initial stiffness retention rate of 0.2 in the setting interface of the yield torque calculation tool, click Select Data, import the angle-torque relationship table obtained by the finite element analysis software into the yield torque selection tool, click Calculate Analysis, and complete the corresponding calculation through each module. Finally, the final result is output and displayed in the data result output module.
[0065] The present invention provides a terminal device including: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.
[0066] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.
[0067] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.
[0068] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
[0069] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.
[0070] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.
[0071] Based on the finite element calculation results, the present invention extracts the angle-torque relationship and sets the stiffness fitting confidence R 2 and initial stiffness retention rate, calculate the initial torsional stiffness value of each point, calculate the torsional stiffness value of each point in the angle-torque relationship curve and the stiffness retention rate of each point, and finally calculate the torsional stiffness value and torque value of the yield torque point of the shaft. The method of the present invention successfully replaces the yield torque calculation method of the shaft similar to the static torsion test, solves the problem of long static torsion physical verification cycle and high verification cost, and can timely, effectively and quickly calculate the yield torque point value of the shaft, reduce the number of changes in the design of shaft parts, and improve the design efficiency of shaft parts.
[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for calculating the yield torque of a shaft, It is characterized in that The following steps are involved: Calculate the angle-torque relationship of the shaft and draw the angle-torque relationship curve; Determine the stiffness fitting confidence and initial stiffness retention rate; Calculate the initial torsional stiffness value based on the stiffness fitting confidence and the angle-torque relationship curve; According to the rotation angle-torque relationship curve, the torsional stiffness value of each point in the rotation angle-torque relationship curve is calculated; According to the initial torsional stiffness value and the torsional stiffness value of each point in the angle-torque relationship curve, the stiffness retention rate of each point in the angle-torque relationship curve is calculated; According to the initial stiffness retention rate, the stiffness retention rate of each point in the angle-torque relationship curve and the torsional stiffness value of each point in the angle-torque relationship curve, the torsional stiffness value of the yield torque point of the shaft is calculated; the torsional stiffness value of the yield torque point of the shaft is calculated as follows: the stiffness retention rates of each point in the angle-torque relationship curve are arranged in descending order, the first point whose stiffness retention rate is lower than the determined initial stiffness retention rate is selected, and linear interpolation is performed between the point and the previous point of the point, so that the stiffness retention rate of the interpolation point is exactly the determined initial stiffness retention rate, and the torsional stiffness value of the interpolation point is the torsional stiffness value of the yield torque point of the shaft; The torque value at the yield torque point of the shaft is calculated based on the torsional stiffness value at the yield torque point of the shaft.
2. A method for calculating the yield torque of a shaft according to claim 1, It is characterized in that The stiffness fit confidence level is 0.
999.
3. A method for calculating the yield torque of a shaft according to claim 1, It is characterized in that The initial stiffness retention rate is 0.
2.
4. A method for calculating the yield torque of a shaft according to claim 1, It is characterized in that The calculation method of the initial torsional stiffness value is as follows: in the angle-torque relationship curve, starting from the smallest point, that is, the first point, a linear fit is performed to obtain the initial torsional stiffness value curve. When the confidence level of the fitted torsional stiffness value reaches the stiffness fitting confidence level, the initial torsional stiffness value is obtained.
5. A method for calculating the yield torque of a shaft according to claim 1, It is characterized in that The method for calculating the torsional stiffness value of each point in the angle-torque relationship curve is as follows: in the angle-torque relationship curve, take the smallest point as the starting point, start from the second point, select points in sequence, and make a linear fit between the previous point value of the selected point, the selected point value, and the next point value of the selected point. The torsional stiffness value obtained is the torsional stiffness value of the selected point.
6. A method for calculating the yield torque of a shaft according to claim 1, It is characterized in that The method for calculating the stiffness retention rate of each point in the angle-torque relationship curve is: divide the torsional stiffness value of each point in the angle-torque relationship curve by the initial torsional stiffness value one by one to obtain the stiffness retention rate of each point.
7. A shaft yield torque calculation tool for implementing the method of claim 1, It is characterized in that include: A data import module, which imports the angle-torque relationship data calculated by the finite element analysis software into the yield torque calculation tool and draws an angle-torque relationship curve diagram; Numerical setting module, used to determine the stiffness fitting confidence and initial stiffness retention rate; An initial torsional stiffness calculation module is used to calculate the initial torsional stiffness value according to the initial stiffness fitting confidence and the angle-torque relationship curve; A module for calculating the torsional stiffness value of each point, used to calculate the torsional stiffness value of each point in the angle-torque relationship curve; The module for calculating the stiffness retention rate of each point is used to calculate the stiffness retention rate of each point in the angle-torque relationship curve; A module for calculating the torsional stiffness value at the yield torque point of the shaft, used for calculating the torsional stiffness value at the yield torque point of the shaft; A torque value calculation module of the yield torque point of the shaft, used to calculate the torque value of the yield torque point of the shaft; The data result output module is used to draw and display the torsional stiffness change curve of the yield torque point of the shaft, and output the yield torque value result of the shaft.
8. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.
9. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.