A method for calculating the wear thickness of a sliding shoe in static-dynamic coupling analysis

Abstract

The application discloses a kind of static and dynamic mechanical coupling analysis's sliding shoe wear thickness calculation method, based on Archard formula derivation sliding shoe wear thickness calculation formula, through sliding shoe wear pin, slide rail wear disc carries out pin disc experiment, determines the wear coefficient of sliding shoe-rail friction pair, based on the statics analysis result calculation sliding shoe static wear thickness, finally based on dynamic response analysis result calculation sliding shoe dynamic wear thickness.The application can be carried out accurate calculation of test whole wear thickness for different sliding shoes in different rocket sled tests, accurately assesses the clearance between rocket sled sliding shoe and track, so as to provide accurate boundary conditions for the on-orbit dynamic response analysis of rocket sled, provide data reference for the accurate design of rocket sled test, improve test design efficiency, ensure test success rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of target test, and particularly relates to a calculation method of sliding shoe wear thickness in static-dynamic mechanical coupling analysis. BACKGROUND

[0002] The sliding shoe is a link between the rocket sled sled body and the track, and cooperates with the slide rail through the flange of the slide rail to support the forward movement of the sled body. In order to avoid the sliding shoe from being stuck, a certain gap should be provided between the sliding shoe and the track. However, with the friction interaction between the sliding shoe and the track, the sliding shoe is continuously worn, and the gap between the sliding shoe and the track gradually increases. The size of the gap between the sliding shoe and the track has different influences on the on-orbit running state of the rocket sled sled body. Only the wear thickness of the sliding shoe of the sled body can be accurately calculated, the size of the gap between the sliding shoe and the track can be accurately estimated, and the dynamic response of the rocket sled can be accurately evaluated. Therefore, the calculation of the wear thickness of the sliding shoe in the test process has very important significance in the test design of the rocket sled.

[0003] The wear of the sliding shoe is affected by many factors, such as the contact sliding distance of the sliding shoe and the track, the pressure between the sliding shoe and the track, etc. The accurate calculation of the wear thickness of the sliding shoe needs to determine the running state of the rocket sled, and the contact sliding distance of the sliding shoe on the track and the impact force of the sliding shoe on the track are calculated by the dynamic response calculation method of the rocket sled-track coupling system. However, the gap between the sliding shoe and the track is one of the boundary conditions when the dynamic response of the rocket sled-track coupling system is analyzed. Therefore, the calculation of the wear thickness of the sliding shoe is coupled with the dynamic response calculation of the rocket sled-track coupling system, which makes the problem complicated and difficult to develop. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the application provides a calculation method of sliding shoe wear thickness in static-dynamic mechanical coupling analysis. The calculation formula of the wear thickness of the sliding shoe is derived based on the Archard formula. The wear coefficient of the sliding shoe-track friction pair is determined by the pin-disc experiment of the sliding shoe and the slide rail. The static wear thickness of the sliding shoe is calculated based on the static analysis result. Finally, the dynamic wear thickness of the sliding shoe is calculated based on the dynamic response analysis result. The application can accurately calculate the wear thickness of the sliding shoe in the whole test process of different rocket sled tests, accurately evaluate the gap between the sliding shoe and the track, and provide accurate boundary conditions for the on-orbit dynamic response analysis of the rocket sled, provide data reference for the accurate design of the rocket sled test, improve the test design efficiency, and ensure the success rate of the test.

[0005] The technical scheme adopted by the application to solve the technical problems is as follows:

[0006] Step 1: Derivation of the calculation formula of the wear thickness h of the sliding shoe;

[0007] Step 1-1: Archard formula is:

[0008]

[0009] The wear volume generated by unit displacement is derived based on the Archard formula:

[0010]

[0011] In the formula, k is the wear coefficient of the shoe-rail friction pair, W is the load of the contact surface between the shoe and the rail, H is the hardness of the softer material in the shoe-rail friction pair, and V is the wear volume of the shoe;

[0012] Step 1-2: The contact time of the shoe and the rail is calculated by the duty cycle δ, and then the relative sliding distance l between the shoe and the rail is calculated:

[0013] l = δL (3)

[0014] In the formula, L is the trajectory length;

[0015] Step 1-3: The wear volume of the shoe during the entire running of the rocket sled is calculated according to formulas (2) and (3):

[0016]

[0017] Step 1-4: Assuming that the shoe wears uniformly, the calculation formula of the wear thickness h of the shoe is:

[0018]

[0019] In the formula, S is the area of the wear surface of the shoe;

[0020] Taking the speed as the calculation variable, formula (5) is further derived as:

[0021]

[0022] In the formula, v is the running speed of the rocket sled;

[0023] Step 2: Determination of the wear coefficient k of the shoe-rail friction pair;

[0024] The shoe material is processed into a wear pin, and the rail material is processed into a wear disc. The pin-disc experiment is carried out under different pressure loads p and different speeds v, and the wear coefficient is calculated;

[0025] Before the experiment, the wear pin is cleaned, and after drying, its mass is weighed and recorded as m1. The wear distance, pressure load and speed of the pin-disc experiment are set, and the experiment is started. After the machine stops, the wear debris is collected, and the wear pin is cleaned again. After drying, it is weighed and recorded as m2. The wear mass of the wear pin m = m1-m2;

[0026] The wear amount and the product of the pressure load p and the speed v are related, and the wear coefficient k is obtained by fitting;

[0027] Step 3: Calculate the static wear thickness of the sliding shoe based on the static analysis results;

[0028] Taking the rocket sled as the calculation object, the aerodynamic force is applied, and the ANSYS Mechanical software is used for static strength simulation analysis to obtain the bearing capacity W of the sliding shoe j ; Given the bearing capacity W of the sliding shoe j and the total length of the trajectory L, the static wear volume of the sliding shoe is calculated according to formula (1), and the static wear thickness h of the sliding shoe is obtained by dividing the contact surface area S of the sliding shoe j ;

[0029] Step 4: Calculate the dynamic wear thickness of the sliding shoe based on the dynamic response analysis results;

[0030] Select n speed points for dynamic response calculation, and the shoe-rail gap at each speed point is determined by interpolation according to the static wear thickness; Assume that the sled accelerates to v i , i = 1, 2…n, the corresponding running trajectory length is l i , then v i speed point corresponds to the static wear amount v i speed point corresponds to the static wear amount h i and the initial gap d0 between the sliding shoe and the rail is added, which is v i speed point corresponds to the shoe-rail gap d i = d0+h i ;

[0031] After the shoe-rail gap is known, dynamic response calculation is carried out, the shoe-rail impact force and the duty cycle in the calculation results are extracted, and the actual wear thickness h of the sliding shoe is calculated using formula (6).

[0032] Preferably, the sliding shoe is made of 30CrMnSiNi2A steel.

[0033] Preferably, the sliding rail is made of U71Mn steel.

[0034] A computer program, which causes a computer to execute the sliding shoe wear thickness calculation method described above.

[0035] An electronic device, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to make the electronic device execute the sliding shoe wear thickness calculation method described above.

[0036] A computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, implements the sliding shoe wear thickness calculation method.

[0037] A chip, comprising: a processor configured to call and run a computer program from a memory, so that a device installed with the chip executes the sliding shoe wear thickness calculation method.

[0038] A computer program product, comprising a computer storage medium, the computer storage medium storing a computer program, the computer program comprising instructions executable by at least one processor, when the instructions are executed by the at least one processor, the sliding shoe wear thickness calculation method is implemented.

[0039] The beneficial effects of the present application are as follows:

[0040] The present application can accurately calculate the wear thickness of the whole test for different sliding shoes in different rocket sled tests, accurately evaluate the gap between the rocket sled sliding shoe and the track, thereby providing accurate boundary conditions for the on-orbit dynamic response analysis of the rocket sled, providing data reference for the accurate design of the rocket sled test, improving the test design efficiency, and ensuring the success rate of the test. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a schematic diagram of the structure and size of a single-track rocket sled.

[0042] Figure 2 is a schematic diagram of a pin disc experiment.

[0043] Figure 3 is a wear coefficient fitting curve. DETAILED DESCRIPTION

[0044] The present application will be further described below in conjunction with the drawings and examples.

[0045] The purpose of the present application is to solve the problem of calculating the wear thickness of the sliding shoe during the rocket sled test.

[0046] The present application is realized by the following technical solutions, specifically including the following four steps:

[0047] 1) Derivation of the calculation formula of the wear thickness h of the sliding shoe:

[0048] The Archard formula is

[0049]

[0050] Based on the Archard formula, the wear volume generated by unit displacement is derived

[0051]

[0052] where k is the wear coefficient of the shoe-rail friction pair, W is the load of the contact surface between the shoe and the rail, and H is the hardness of the softer material in the shoe-rail friction pair.

[0053] The shoe and the rail are not in contact at all times, and the contact time of the shoe and the rail needs to be calculated by the duty cycle δ, and then the relative sliding distance l between the shoe and the rail is obtained.

[0054] l = δL (3)

[0055] where L is the length of the trajectory.

[0056] The wear volume of the shoe during the entire running of the rocket sled is calculated according to formulas (2) and (3)

[0057]

[0058] After the wear volume of the shoe is obtained, the shoe-rail gap cannot be calculated, and the wear thickness h of the shoe needs to be further obtained. Assuming that the shoe wears uniformly, the calculation formula of the wear thickness h of the shoe is

[0059]

[0060] where S is the area of the wear surface of the shoe.

[0061] When performing dynamic response analysis on the rocket sled, the speed is taken as the calculation variable, and therefore formula (5) is further derived to obtain

[0062]

[0063] where v is the running speed of the rocket sled.

[0064] 2) Determination of the wear coefficient k of the shoe-rail friction pair:

[0065] The shoe material is processed into a grinding pin, and the rail material is processed into a grinding disc. The pin-disc experiment is carried out under different pressure loads p and different speeds v, and the wear coefficient is calculated.

[0066] Before the experiment, the grinding pin is cleaned, and the mass of the dry grinding pin is weighed and recorded as m1. The grinding distance, pressure load, and speed of the pin-disc experiment are set, and the experiment is started. After the machine stops, the grinding dust is collected, and the grinding pin is cleaned again. After drying, the mass is weighed and recorded as m2. The wear mass of the grinding pin m = m1-m2.

[0067] The grinding distance is unchanged, and the pressure load p and the speed v are adjusted respectively to carry out multiple pin-disc experiments. The relationship between the wear amount and the product of the pressure load p and the speed v is established, and the wear coefficient k is obtained by fitting.

[0068] 3) Calculate the static wear thickness of the sliding shoe based on the static analysis results:

[0069] Take the rocket sled as the calculation object, apply the aerodynamic force, and use ANSYS Mechanical software to perform static strength simulation analysis to obtain the bearing capacity W of the sliding shoe j . Given the bearing capacity W of the sliding shoe j and the ballistic full length L, the static wear volume of the sliding shoe is calculated according to formula (1), and the static wear volume is divided by the contact surface area S of the sliding shoe to obtain the static wear thickness h of the sliding shoe j .

[0070] 4) Calculate the dynamic wear thickness of the sliding shoe based on the dynamic response analysis results:

[0071] Select n speed points for dynamic response calculation. The shoe-rail clearance at each speed point is determined by interpolation according to the static wear thickness. Assume that the sled accelerates to v i (i = 1, 2…n) corresponding to the running trajectory length l i , then v i The static wear amount corresponding to the speed point is v i The static wear amount corresponding to the speed point h i is added to the initial clearance d0 between the sliding shoe and the rail, which is v i The shoe-rail clearance d i corresponding to the speed point is d0 + h i .

[0072] After the shoe-rail clearance is known, dynamic response calculation is carried out, and the shoe-rail impact force and duty cycle in the calculation results are extracted. The actual wear thickness h of the sliding shoe is calculated using formula (6).

[0073] Embodiment:

[0074] Take a 3Ma monorail rocket sled test as an example, as shown in Figure 1 , the main steps of the sliding shoe wear calculation implementation based on static and dynamic coupling analysis are carried out:

[0075] Step 1: Process the sliding shoe 30CrMnSiNi2A steel into a wear pin, and the sliding rail U71Mn steel into a wear disc, and carry out a pin-disc experiment, as shown in Figure 2 . The wear distance of the pin-disc experiment is uniformly set to 9km, the load is set to 100N, 150N, 200N, 250N and 300N, and the speed is set to 30m / s, 40m / s, 50m / s, 60m / s and 70m / s. Use linear regression analysis to fit the relationship between the wear coefficient and the load, speed product, as shown in Figure 3 ;

[0076] Step 2: According to the aerodynamic force suffered by the sled during the movement process, the ANSYS Mechanical software is used to carry out static stiffness and strength simulation analysis of the sled 3Ma speed point, and the bearing capacity of the front and rear shoes is obtained, as shown in Table 1. The wear volume of the front and rear shoes is calculated by formula (1), and the static wear thickness of the front and rear shoes is obtained by dividing the shoe contact surface area S, respectively j ;

[0077] Table 1: Shoe support reaction force

[0078]

[0079] Step 3: Select 10 speed points for dynamic response calculation, and the shoe rail clearance of each speed point is determined according to the static wear thickness. Assuming that the corresponding running trajectory length of the sled is l i (i=10) when the sled accelerates to v i (i=10), then the static wear thickness of the v i (i=10) speed point corresponds to d v i speed point corresponds to d i = d0+h i (i=10).

[0080] Step 4: Based on the shoe rail clearance d i = d0+h i (i=10), dynamic response calculation of 10 speed points is carried out, and the shoe rail collision force and duty ratio of the rocket sled at different speed points are obtained. The actual wear thickness h of the shoe is calculated by formula (6), as shown in Table 2.

[0081] Table 2: Calculated value of shoe wear thickness

[0082]

Claims

1. A method for calculating the wear thickness of a sliding shoe based on static and dynamic mechanical coupling analysis, characterized in that: The steps include: Step 1: Derivation of the calculation formula for the wear thickness h of the sliding shoe; Step 1-1: Archard formula is: The wear volume per unit displacement is derived based on Archard's formula: Where k is the wear coefficient of the slider-rail friction pair, W is the load on the contact surface between the slider and the rail, H is the hardness of the softer material in the slider-rail friction pair, and V is the wear volume of the slider; Step 1-2: Calculate the contact time between the slider and the track using the duty cycle δ, and then find the relative sliding distance l between the slider and the track: l=δL (3) Where L is the ballistic length; Step 1-3: Calculate the wear volume of the skid during the entire operation of the rocket sled according to equations (2) and (3): Step 1-4: Assuming the sliding shoe is evenly worn, the calculation formula for the sliding shoe wear thickness h is: Where S is the area of ​​the sliding shoe wear surface; Taking speed as the calculation variable, further deriving formula (5) yields: Where, v is the speed of the rocket sled; Step 2: Determine the wear coefficient k of the shoe-rail friction pair; The shoe material was processed into a grinding pin, and the rail material was processed into a grinding disc. Pin-on-disc experiments were carried out under different pressure loads p and different speeds v to calculate the wear coefficient. Before the experiment, the wear pin was cleaned and dried, and its mass was weighed, recorded as m1. The wear range, pressure load, and speed of the pin-on-disk experiment were set, and the experiment was started. After the machine stopped, the wear debris was collected, and the wear pin was cleaned again, dried, and weighed, recorded as m2. The wear mass of the wear pin, m, = m1 - m2. Keeping the wear distance constant, the pressure load p and speed v were adjusted and multiple pin-on-disk experiments were conducted. The relationship between the wear mass and the product of the pressure load p and speed v was established and fitted to obtain the wear coefficient k. Step 3: Calculate the static wear thickness of the sliding shoe based on the static analysis results; Taking the rocket sled as the calculation object, applying aerodynamic force, and using ANSYS Mechanical software to perform static stiffness simulation analysis, the bearing capacity W of the sliding shoe is obtained. j ; Known shoe bearing capacity W j The static wear volume of the sliding shoe is calculated according to formula (1) with the total length of the trajectory L. The static wear volume is divided by the contact surface area S of the sliding shoe to obtain the static wear thickness h of the sliding shoe. j ; Step 4: Calculate the dynamic wear thickness of the sliding shoe based on the dynamic response analysis results; Select n speed points for dynamic response calculation, and the shoe rail clearance at each speed point is determined by interpolation of static wear thickness; assuming that the skid accelerates to v i , when i=1, 2...n, the corresponding trajectory length is l i , then v i The static wear amount corresponding to the speed point is v i Static wear amount h corresponding to the speed point i Added to the initial gap d0 between the sliding shoe track, it is v i Shoe rail gap d corresponding to the speed point i =d0+h i ; After the shoe-rail gap is known, the dynamic response calculation is carried out, the shoe-rail collision force and duty cycle in the calculation results are extracted, and the actual wear thickness h of the shoe is calculated using formula (6).

2. The method for calculating the wear thickness of a sliding shoe by static and dynamic mechanical coupling analysis according to claim 1, characterized in that: The sliding shoe is made of 30CrMnSiNi2A steel.

3. The method for calculating the wear thickness of a sliding shoe by static and dynamic mechanical coupling analysis according to claim 1, characterized in that: The rails are made of U71Mn steel.

4. An electronic device, characterized in that: include: processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device performs the method according to any one of claims 1 to 3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.

6. A chip, characterized in that: include: A processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes the method according to any one of claims 1 to 3.

7. A computer program product, characterized in that The computer program product comprises a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the method according to any one of claims 1 to 3 is implemented.

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