Method for calculating deflection rigidity of track pattern block, application and computer program product

Abstract

The invention relates to the technical field of rubber track simulation design, in particular to a method for calculating deflection rigidity of a track pattern block, application and a computer program product. The method comprises the following steps: 1, inputting pitch design related parameter information; 2, according to the information, performing calculation based on a sectional inertia moment equivalent method and Hooke's law; and 3, obtaining the deflection and the vertical rigidity under the conditions of the distributed load, the concentrated load and the inverted triangular distributed load. Through the calculation method and a corresponding software tool, the calculation efficiency can be remarkably improved, the operation complexity is reduced, non-professional users can also quickly and accurately calculate the deflection of the crawler belt under different working conditions, and powerful technical support is provided for design and optimization of agricultural machinery.

Description

Technical Field

[0001] The invention relates to the technical field of rubber crawler track simulation design, and in particular to a method for calculating the deflection stiffness of crawler track pattern blocks, an application and a computer program product. Background Art

[0002] Agricultural track blocks generally adopt inline pattern form, and the use scenarios include paddy field driving, soft soil field driving and hard road transportation driving. In order to improve the traction of the track when operating in paddy fields, the block heightening method is usually adopted, but the heightened block will lead to a decrease in the longitudinal and vertical stiffness of the track block, causing vehicle shaking problems when driving on hard roads. Therefore, it is very necessary to quickly estimate the longitudinal and vertical stiffness of the block when designing the track. However, the track block is a variable cross-section, and it is difficult to calculate the deflection and vertical stiffness of the block. For equal-section components, since the cross-section characteristics are constants, the deflection value at any position of the component can be easily calculated by directly using the integral method. Various practical calculation manuals generally have ready-made deflection calculation formulas for application. However, for variable-section components, since their cross-section characteristics are variables of the cross-section position, it is difficult to calculate the product when using the integral method to calculate their deflection. When the cross-section shape is complex, it may even be impossible to solve. Therefore, for the deflection calculation of variable-section components, approximate methods are often used. Simplified methods for calculating the deflection of variable-section components include the conjugate beam method, superposition method, equivalent stiffness method, magnification coefficient method, initial parameter method, finite difference method, multi-coefficient equivalent inertia moment method, etc. However, many of these methods, such as the conjugate beam method, superposition method, magnification coefficient method, initial parameter method, etc., are difficult to apply to variable-section components with continuously changing cross-sections; and some methods suitable for deflection meters of components with continuously changing cross-sections, such as the finite difference method, equivalent stiffness method, multi-coefficient equivalent inertia moment method, etc., are not convenient for practical application due to the cumbersome calculation process.

[0003] For this reason, traditional methods for calculating track pattern stiffness and deflection are often complex, not intuitive, and have long cycles, making it difficult to quickly adapt to changing market demands. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a method for calculating the deflection stiffness of the track pattern block, which can significantly improve the calculation efficiency and reduce the operation complexity, so that non-professional users can also quickly and accurately calculate the deflection of the track under different working conditions, providing strong technical support for the design and optimization of agricultural machinery.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] A method for calculating the deflection stiffness of a track pattern block, characterized in that the method comprises the following steps:

[0007] 1) Input pitch design related parameter information, including: tread block height, tread block thickness, cross-sectional length, uniform pressure, inverted triangle pressure, concentrated load and elastic modulus;

[0008] 2) The deflection value Δ of the contact point is calculated by the equivalent method of section inertia moment. The variable cross-section pattern block is divided into four sections of equal length. The moment of inertia of each section is I 0 , I 1 , I 2 , I 3 , I 4 , the Simpson numerical integration formula is used to obtain the grounding point deflection value Δ:

[0009]

[0010] H is the height of the pattern, q is the inverted triangle distribution load, and E is the elastic modulus;

[0011] 3) Calculate the four areas A according to b and h in the longitudinal stiffness of the flower block, substitute them according to Hooke's law to obtain K, and then use the series formula to calculate the total stiffness of the flower block. The calculation method is as follows:

[0012] Since the flower block is divided into four equal parts, l = H / 4, A1 = h1*b1, A2 = h2*b2, A3 = h3*b3, A4 = h4*b4, calculate K respectively 1 , K 2 , K 3 , K 4 ; Where h1-h4 is the thickness of the pattern block at different cross-sectional positions, and b1-b4 is the width of the pattern block at different cross-sectional positions;

[0013]

[0014] K is the final vertical stiffness, vertical deformation = F / K, and F is the load.

[0015] Preferably, the section inertia moment equivalent method in step 2) is as follows:

[0016] For a cantilever structure with uniform cross-section, the integral formula for calculating deflection is:

[0017]

[0018] When it is a variable cross-section structure, the above formula becomes:

[0019]

[0020] The cross section of the agricultural track pattern changes linearly, and the bending moment MP(x) at the cross section height X and They are: M p (x) = 0.5qx 2 , Substituting into the above formula:

[0021]

[0022] To find the deflection value of the grounding point, the Simpson numerical integration formula is used to calculate the above formula, assuming f(x) = x 3 / I(x) then:

[0023]

[0024] Preferably, in step 2), for a rod with a uniform cross section, the deflection calculation formula of the distributed load cantilever structure is:

[0025]

[0026] The calculation formula of equivalent section moment of inertia is:

[0027]

[0028] Preferably, the deflection formula of the concentrated load of the regular cross section in step 2) is:

[0029]

[0030] The calculation formula of equivalent section moment of inertia is:

[0031]

[0032] Preferably, the deflection formula of the inverted triangle distributed load of the regular cross section in step 2) is:

[0033]

[0034] The formula for calculating the equivalent moment of inertia of a cross section is:

[0035]

[0036] Preferably, the step 3) is based on Hooke's law as follows:

[0037] According to Hooke's law

[0038]

[0039] but:

[0040]

[0041] According to the spring series formula:

[0042]

[0043] Calculate the four areas A according to b and h in the longitudinal stiffness of the flower block respectively, and substitute them to obtain K.

[0044] Furthermore, the present invention also discloses the application of the method in the simulation design of agricultural track pattern blocks.

[0045] Furthermore, the present invention also discloses a computer device, including a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the method.

[0046] Furthermore, the present invention also discloses a computer-readable storage medium, on which a computer program or instruction is stored, and the method is implemented when the computer program or instruction is executed by a processor.

[0047] Furthermore, the present invention also discloses a computer program product, including a computer program or instructions, which implement the method when executed by a processor.

[0048] The present invention adopts the above-mentioned technical solution, which can significantly improve the calculation efficiency and reduce the operation complexity through the calculation method and corresponding software tools, so that non-professional users can also quickly and accurately calculate the deflection of the crawler under different working conditions, providing strong technical support for the design and optimization of agricultural machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the track block fully embedded in the soil load.

[0050] Figure 2 Schematic diagram of track block transfer load on hard pavement.

[0051] Figure 3 Schematic diagram of the load when the track block is not fully embedded in the soil.

[0052] Figure 4 Schematic diagram of the vertical stiffness of track blocks.

[0053] Figure 5 To verify the finite element calculation results of Scheme 1, A is the lateral deflection value of 9.887mm; B is the vertical compression deformation value of 1.46mm (stiffness = 1000N / 1.46 = 684.9N / mm).

[0054] Figure 6 To verify the finite element calculation results of Scheme 2, A is the lateral deflection value of 16.45 mm; B is the vertical compression deformation value of 1.61 mm (stiffness = 1000 N / 1.61 = 619 N / mm). DETAILED DESCRIPTION

[0055] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0056] A method and program for calculating the deflection stiffness of a track pattern block, comprising the following steps:

[0057] 1. Input the pitch design related parameter information, including: tread block height, tread block thickness, cross-sectional length, uniform pressure, inverted triangle pressure, concentrated load, and elastic modulus;

[0058] 2. Based on the above information, calculations are performed based on the equivalent method of section inertia moment and Hooke's law;

[0059] 3. Obtain the deflection under distributed load, concentrated load, inverted triangle distributed load, and vertical stiffness.

[0060] Furthermore, the calculation method of the section inertia moment equivalent method of the present invention is specifically as follows:

[0061] For a cantilever structure with uniform cross-section, the integral formula for calculating deflection is:

[0062]

[0063] When it is a variable cross-section structure, the above formula becomes:

[0064]

[0065] The cross section of agricultural track pattern changes linearly, such as Figure 1-4 As shown, the bending moment MP(x) at the section height X and They are: M p (x) = 0.5qx 2 , Substituting into the above formula:

[0066]

[0067] In order to find the deflection value of the grounding point, the Simpson numerical integration formula is used to calculate the above formula, such as Figure 1-4 As shown, the variable cross-section pattern block is divided into four sections of equal length, and the moment of inertia of each section is I 0 , I 1 , I 2 , I 3 , I 4 , H is the height of the pattern, q is the inverted triangle distribution load, E is the elastic modulus; let f(x) = x 3 / I(x) then:

[0068]

[0069] For a uniform cross-section member, the deflection calculation formula for a distributed load cantilever structure is:

[0070]

[0071] Assuming that the same load produces the same deflection, different cross sections can be considered to have the same area moment of inertia, then

[0072]

[0073] Similarly, the deflection formula for a concentrated load on a regular section is

[0074]

[0075] The equivalent section moment of inertia is:

[0076]

[0077] The deflection formula for the inverted triangle distributed load of a regular section is:

[0078]

[0079] The equivalent moment of inertia of the cross section is:

[0080]

[0081] Calculation example:

[0082] Assuming the length of the pattern cross section is b, the width of the pattern grounding end section is h = 0, and the width of the pattern root section is h, when the pattern is divided into 4 sections, then

[0083]

[0084] The equivalent moment of inertia is:

[0085]

[0086] The deflection of the pattern grounding point is:

[0087]

[0088] Further, the calculation parameters of agricultural track blocks are input:

[0089] Calculate and input the lateral length b of the tread block, ignoring the root chamfer, divide the tread block vertically into four equal parts, input the thickness h1, h2, h3, h4 of the tread block, the height H of the tread block, and the q of the inverted triangle distributed load is the maximum value q at the end.

[0090] According to Hooke's law

[0091]

[0092] but:

[0093]

[0094] According to the spring series formula

[0095] Calculate the four areas A according to b and h in the longitudinal stiffness of the flower block, substitute them to get K, and then use the series formula to calculate the total stiffness of the flower block. The specific calculation method is as follows:

[0096] Since the flower block is divided into four equal parts, l = H / 4, A1 = h1*b1, A2 = h2*b2, A3 = h3*b3, A4 = h4*b4, calculate K respectively 1 , K 2 , K 3 , K 4 ; Where h1-h4 is the thickness of the pattern block at different cross-sectional positions, and b1-b4 is the width of the pattern block at different cross-sectional positions;

[0097]

[0098] K is the final vertical stiffness, vertical deformation = F / K, and F is the load.

[0099] Furthermore, the present invention has developed a GUI program based on PyQt, which allows users to intuitively input parameters and quickly obtain calculation results. Through the program, users can conveniently input the size parameters and load conditions of the track blocks, and the program automatically calculates and displays the longitudinal stiffness and deflection results.

[0100] Application Examples

[0101] This example designs two schemes (as shown in Table 1 and Table 2), inputs the pitch design related parameter information, including: tread block height, tread block thickness, cross-section length, uniform pressure, inverted triangle pressure, concentrated load, elastic modulus; according to the above information, calculations are performed based on the section inertia equivalent method and Hooke's law; the deflection under distributed load, concentrated load, inverted triangle distributed load, and vertical stiffness are obtained; the results are compared with the simulation method to verify the accuracy. After inspection, this simple method has high accuracy and can well meet the needs of daily design use.

[0102] Table 1

[0103]

[0104] Table 2

[0105]

[0106] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed herein.

Claims

1. A method for calculating the deflection stiffness of a track block, characterized in that: The method comprises the following steps: 1) Input pitch design related parameter information, including: tread block height, tread block thickness, cross-sectional length, uniform pressure, inverted triangle pressure, concentrated load and elastic modulus; 2) The deflection value Δ of the ground contact point is calculated by the equivalent method of section inertia moment. The variable cross-section pattern block is divided into four sections of equal length. The moments of inertia of each section are I0, I1, I2, I3, and I4 respectively. The deflection value Δ of the ground contact point is obtained by using the Simpson numerical integration formula: H is the height of the pattern, q is the inverted triangle distribution load, and E is the elastic modulus; 3) Calculate the four areas A according to b and h in the longitudinal stiffness of the flower block, substitute them according to Hooke's law to obtain K, and then use the series formula to calculate the total stiffness of the flower block. The calculation method is as follows: Since the pattern block is divided into four equal parts, l = H / 4, A1 = h1*b1, A2 = h2*b2, A3 = h3*b3, A4 = h4*b4, calculate K1, K2, K3, K4 respectively; where h1-h4 is the thickness of the pattern block at different cross-sectional positions, and b1-b4 is the width of the pattern block at different cross-sectional positions; K is the final vertical stiffness, vertical deformation = F / K, and F is the load.

2. A method for calculating the flexural stiffness of a crawler tread block according to claim 1, characterized in that: The equivalent method of section inertia moment in step 2) is as follows: For a cantilever structure with uniform cross-section, the integral formula for calculating deflection is: When it is a variable cross-section structure, the above formula becomes: The cross section of the agricultural track pattern changes linearly, and the bending moment MP(x) at the cross section height X and They are: M p (x) = 0.5qx 2 Substituting into the above formula: To find the deflection value of the grounding point, the Simpson numerical integration formula is used to calculate the above formula, assuming f(x) = x 3 / I(x) then:

3. The method for calculating the flexural stiffness of a crawler tread block according to claim 1, characterized in that: In step 2), for a uniform cross-section member, the deflection calculation formula for a distributed load cantilever structure is: The calculation formula of equivalent section moment of inertia is:

4. The method for calculating the flexural stiffness of a crawler tread block according to claim 1, characterized in that: The deflection formula for the concentrated load of the regular section in step 2) is: The calculation formula of equivalent section moment of inertia is:

5. The method for calculating the flexural stiffness of a crawler tread block according to claim 1, characterized in that: The deflection formula of the inverted triangle distributed load of the regular section in step 2) is: The formula for calculating the equivalent moment of inertia of a cross section is:

6. The method for calculating the flexural stiffness of a crawler tread block according to claim 1, characterized in that: In step 3), according to Hooke's law, it is as follows: According to Hooke's law but: According to the spring series formula: Calculate the four areas A according to b and h in the longitudinal stiffness of the flower block respectively, and substitute them to obtain K.

7. Application of the method described in any one of claims 1 to 6 in the simulation design of agricultural track pattern blocks.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, the method described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the method described in any one of claims 1 to 6 is implemented.

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