Structure and algorithm for increasing sliding auxiliary pressure

Abstract

The present invention discloses a structure for increasing the dynamic pressure of a sliding pair and an algorithm thereof, which relates to the technical field of mechanical equipment with fluid dynamic pressure lubrication. Each rectangular texture on the surface of a friction pair is used as an independent individual for parameterized design. For different friction pair working conditions, a spatial coordinate system is constructed for each texture, and each texture is given three degrees of freedom of adjustability, wherein the length of the texture is l x , the arc length corresponding to the x-axis is α k , the width of the texture is l y , the arc corresponding to the width of the y-axis is β k , the height of the texture is h k , α k The radian range is ‑5000~5000μrad, β k The radian range is ‑5000~5000μrad, h k The length range is ‑5~5μm. This invention aims at the fluid inlet, outlet, center area and boundary area of ​​the lubricating film. By constructing various forms of textures and combining the synergistic effect between the textures, the dynamic pressure of the liquid film can be better gathered and superimposed, so that the sliding pair can obtain better lubrication performance.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical equipment with fluid dynamic pressure lubrication, in particular to a structure for increasing the dynamic pressure of a sliding pair and an algorithm thereof. Background Art

[0002] In industrial production, friction and wear are generally considered to be a harmful process. Reducing friction, improving wear resistance and new lubricating media have always been the focus of research in the field of friction reduction and anti-wear, which is in line with the trend of green and sustainable development. In order to reduce friction, the coupled motion friction pairs of traditional mechanical structures generally adopt the method of adding lubricating media. Although adding lubricating media is convenient and efficient, the lubricating media cannot be used in certain special working conditions, and it affects the service life of the mechanical structure and has great harm to the environment, which is obviously not conducive to the current social development trend.

[0003] Appropriately processing a surface texture with a certain size and arrangement on the surface of a moving friction pair can reduce friction and wear and improve tribological performance. At present, there are many studies and applications on the use of surface texture to improve the lubrication performance of friction pairs. Some scholars have proposed that the application of asymmetric texture has a greater impact on the lubrication performance of friction pairs. However, current research mainly focuses on the distribution form and morphology of the same type or single texture. Research on the use of various forms of texture combinations on the same friction pair surface and applied to the surface of the friction pair is not mature. Summary of the invention

[0004] The technical problem to be solved by the present invention is to start from the study of the same friction pair, use texture to improve the performance of the liquid film, thereby increasing the dynamic pressure of the lubricating film and the lubrication performance of the friction pair, and provide a structure and algorithm for increasing the dynamic pressure of the sliding pair.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a structure for increasing the dynamic pressure of a sliding pair, comprising two friction bodies moving relative to each other, a liquid film is formed between the friction bodies, and a plurality of rectangular textures are arranged at opposite ends of the friction bodies, wherein a point on the opposite surface of the friction bodies is the origin of the texture, and the length of the texture is l x , the arc length corresponding to the x-axis is α k , the width of the texture is l y , the arc corresponding to the width of the y-axis is β k , the height of the texture is h k , the α k The radian range is -5000~5000μrad, the β k The radian range is -5000~5000μrad, and the h k The length range is -5 to 5 μm.

[0006] Furthermore, when the αk , β k and h k When the value of is positive, the texture is pit-like; when the α k , β k and h k When the value of is negative, the texture is a convex platform type; the texture near the liquid film inlet area is a pit type, and the texture near the liquid film outlet is a convex platform type.

[0007] Furthermore, the distribution range of the pit-like texture is inverted U-shape, and the highest point of the boss-like texture is generally biased towards the central area of ​​the liquid film.

[0008] An algorithm for increasing the sliding auxiliary dynamic pressure structure includes the following steps:

[0009] A. Constructing a mathematical model

[0010] The friction body is simplified into two parallel plates, the length and width of the parallel plates are L and B respectively, the thickness of the liquid film between the two parallel plates is h0, and a parameter-independent rectangular texture is set on the lower parallel plate;

[0011] The gaps between textures on the x-axis and y-axis are equal to the length of a single texture on the x-axis and y-axis, respectively, and the distances of the remaining areas on the boundary of the computational domain in the x-axis and y-axis directions are equal to half of the corresponding length of a single texture;

[0012] The lower friction body is taken as the reference, and the upper friction body moves in the positive direction of the x-axis at a speed U;

[0013] B. Calculate film thickness

[0014] h tex =h k +x k tan(α k )+y k tan(β k ) (k=1,2,...,N)

[0015] Among them, h tex is the total film thickness of each texture, and the spatial coordinate system parameter of each texture is x k ,y k , α k , β k and h k (k=1,2,...,N), k is the total number of textures, h k is the depth of the kth texture at the origin of the coordinate system, α k is the kth texture length and x k The arc between the axes, β k is the kth texture width and y k The arc between the axes;

[0016] h=h0+h tex

[0017] Where h is the film thickness of the entire area of ​​the friction pair surface;

[0018] C. Derivation and transformation

[0019] C1. Based on the force balance analysis of the microelement and the continuity condition of the fluid, the general form of the Reynolds equation is derived, as shown in formula (3):

[0020]

[0021] Where η is the dynamic viscosity of the liquid;

[0022] C2. Assuming that the influence of uniform temperature distribution of fluid is negative, the film viscosity is limited in the calculation area, and the change of liquid viscosity with time and position is ignored, the above formula is simplified as formula (4):

[0023]

[0024] C3. Use dimensionless expression of the Reynolds equation, as shown in equation (5):

[0025]

[0026] in, p0 is standard atmospheric pressure;

[0027] C4. When the liquid flows to the edge of the calculation area, the liquid film begins to break. Assuming that the pressure generated by the liquid is zero at this time, we get formula (6):

[0028] p| x＝0 =p| x＝L =p| y＝0 =p| y＝B =0

[0029] C5. Calculate the bearing capacity W generated by the liquid, as shown in formula (7):

[0030] W = ∫∫pdxdy

[0031] Furthermore, after step C5, the method further includes:

[0032] D. Adaptive genetic algorithm for optimization

[0033] D1. Parameter coding

[0034] Mapping the parameters of the texture to multiple physical quantities and interspersing binary data for encoding, constructing chromosomes, and balancing the parameters of the texture in the genetic process;

[0035] D2. Adaptive selection strategy

[0036] Using the carrying capacity Fitness as the fitness value, as shown in formula (8), before the selection process of each generation, the survival of the fittest is carried out;

[0037] Fitness=W=∫∫pdxdy

[0038] D3. Adaptive mutation strategy

[0039] The mutation probability p m Set as the relationship with the population algebra, as shown in formula (9):

[0040]

[0041] Among them, p m is the adaptive mutation probability, G e is the generation of the population, ε is the defined adaptive adjustment coefficient;

[0042] Return to step C3 and recalculate to C5.

[0043] Furthermore, in step B, N is the number of textures after being halved.

[0044] The beneficial effects of the present invention are:

[0045] By constructing various forms of textures and combining the synergistic effect between the textures, the dynamic pressure of the liquid film can be better gathered and superimposed at the fluid inlet, outlet, center area and boundary area of ​​the lubricating film, so that the sliding pair can obtain better lubrication performance. Taking the rectangular texture as the research object, the bottom depth of each texture and the angle between the bottom surface and the horizontal and vertical axes are used as parameters to describe the rectangular microstructure of each part of the sliding surface, and a general mathematical model of the texture is established.

[0046] Adaptive genetic algorithm optimization method was used to calculate the structure of surface texture population with higher liquid film dynamic pressure. The mapping relationship between texture posture parameters and chromosomes was established, and then the fitness of the population was calculated using the classical Reynolds equation, with the increase of liquid film dynamic water pressure as the optimization object. Through the optimization of population chromosomes, adaptive adjustment of each texture was achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0048] Figure 1 It is the model diagram of the sliding pair surface texture;

[0049] Figure 2 It is a parametric model diagram of the texture;

[0050] Figure 3It is the interpolation and encoding map of multi-parameter chromosomes;

[0051] Figure 4 It is the computational flow chart of the adaptive genetic algorithm;

[0052] Figure 5 is the relationship between the average fitness and the maximum fitness and the population generations;

[0053] Figure 6 It is the optimal liquid film thickness and pressure distribution cloud map during the evolution process;

[0054] Figure 7 It is the distribution law diagram of the biased texture;

[0055] Figure 8 It is a convex platform texture morphology image;

[0056] Fig. 9 yes Figure 8 Pressure distribution diagram of the boss-type texture shown;

[0057] Fig.10 It is the pressure distribution and texture morphology diagram at 0.45 along the normalized y-axis direction. DETAILED DESCRIPTION

[0058] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments:

[0059] The concept of this application is to propose applying textures of different deformation forms to the friction pair surface, combining with an adaptive genetic algorithm, introducing three parameters in each texture, encoding multiple variables as chromosomes, and establishing an adaptive optimization model for each texture.

[0060] A structure for increasing the sliding auxiliary pressure, such as Figures 1 to 3 As shown, it includes two friction bodies moving relative to each other, a liquid film is formed between the friction bodies, and several rectangular textures are set at the opposite ends of the friction bodies, wherein a point on the opposite surface of the friction body is the origin of the texture, and the length of the texture is l x , the arc length corresponding to the x-axis is α k , the width of the texture is l y , the arc corresponding to the width of the y-axis is β k , the height of the texture is h k , α k The radian range is -5000~5000μrad, β k The radian range is -5000~5000μrad, h kThe length range is -5 to 5 μm. A rectangular texture means that when the texture is viewed from above, its shape is a rectangle, that is, the texture is projected into a rectangle on the XOY plane.

[0061] In order to improve the accumulation and superposition of liquid film dynamic pressure and make the sliding pair obtain better lubrication performance, the shape of the texture is optimized. For this purpose, the pit type and the boss type are defined. Specifically, when α k , β k and h k When the value of is positive, the texture is pit-like; when α k , β k and h k When the value of is negative, the texture is convex; the texture near the inlet of the liquid film is concave, and the texture near the outlet of the liquid film is convex. Better, the distribution range of the concave texture is inverted U shape, and the highest point of the convex texture is generally biased towards the center of the liquid film.

[0062] An algorithm for increasing the sliding auxiliary dynamic pressure structure includes the following steps:

[0063] A. Constructing a mathematical model

[0064] The friction body is simplified into two parallel plates, the length and width of the parallel plates are L and B respectively, the thickness of the liquid film between the two parallel plates is h0, and a parameter-independent rectangular texture is set on the lower parallel plate. The parameter-independent rectangular texture means that the shape of each texture is not related, and the shape of each texture has its own size.

[0065] The gap between the textures on the x-axis and y-axis is equal to the length of a single texture on the x-axis and y-axis respectively, and the distance of the remaining area on the boundary of the computational domain in the x-axis and y-axis directions is equal to half of the corresponding length of a single texture. The texture is projected as a rectangle on the XOY plane. The gap between the textures on the x-axis represents the distance between the two rectangles in the x-axis direction, and the gap between the textures on the y-axis represents the distance between the two rectangles in the y-axis direction. The remaining area on the boundary of the computational domain refers to the free area outside the rectangle.

[0066] The lower friction body is taken as a reference, and the upper friction body moves in the positive direction of the x-axis at a speed U. The speed U is the relative motion speed between the upper friction body and the lower friction body.

[0067] B. Calculate film thickness

[0068] h tex =h k +x k tan(α k )+y k tan(β k ) (k=1,2,...,N) (1)

[0070] Among them, h tex is the total film thickness of each texture, and the spatial coordinate system parameter of each texture is x k ,y k , α k , β k and h k (k=1,2,...,N), k is the total number of textures, h k is the depth of the kth texture at the origin of the coordinate system, α k is the kth texture length and x k The arc between the axes, β k is the kth texture width and y k The arc between the axes;

[0071] h=h0+h tex (2)

[0073] Where h is the film thickness of the entire friction pair surface area.

[0074] Preferably, in order to reduce the amount of calculation, the parameters of the texture in the calculation domain are distributed symmetrically, and the texture parameter N can be halved.

[0075] C. Derivation and transformation

[0076] C1. Based on the force balance analysis of the microelement and the continuity condition of the fluid, the general form of the Reynolds equation is derived, as shown in formula (3):

[0077]

[0078] Where η is the dynamic viscosity of the liquid;

[0079] C2. Since the lower surface of the friction pair is stationary, the film thickness of the liquid does not change with time, and the cutting speed of the friction pair is selected at a lower value. Assuming that the influence of uniform temperature distribution of the fluid is negative, the film viscosity is limited within the calculation area, and the change of liquid viscosity with time and position is ignored, the above formula is simplified as follows:

[0080]

[0081] C3. Use dimensionless expression of the Reynolds equation, as shown in equation (5):

[0082]

[0083] in, p0 is standard atmospheric pressure;

[0084] C4. If cavitation exists in some areas of the calculation region, the pressure in this area is set to the saturated vapor pressure of the liquid. When the liquid flows to the edge of the calculation region, the liquid film begins to break. Assuming that the pressure generated by the liquid is zero at this time, equation (6) is obtained:

[0085] p| x＝0 =p| x＝L =p| y＝0 =p| y＝B =0 (6)

[0087] C5. Calculate the bearing capacity W generated by the liquid, as shown in formula (7):

[0088] W = ∫∫pdxdy (7)

[0090] Preferably, after step C5, the method further comprises:

[0091] D. Adaptive genetic algorithm for optimization

[0092] D1. Parameter coding

[0093] The parameters of the texture are mapped to multiple physical quantities and interspersed with binary data for encoding to construct chromosomes and balance the parameters of the texture during the genetic process.

[0094] Binary coding is the most commonly used coding method in genetic algorithms. It is simple and easy to implement, meets the minimum character set coding principle, and is easy to analyze using the pattern theorem. The parameters of each texture defined above are mapped to multiple physical quantities, and binary data is interspersed for encoding to construct chromosomes, so that the parameters of the texture can be better balanced during the genetic process.

[0095] D2. Adaptive selection strategy

[0096] In order to find the maximum value of the oil film bearing capacity, the bearing capacity Fitness is used as the fitness value, as shown in formula (8). In order to ensure the stability of the optimization model calculation, before each generation of selection process, the survival of the fittest is carried out;

[0097] Fitness=W=∫∫pdxdy (8)

[0099] D3. Adaptive mutation strategy

[0100] The mutation probability p m Set as the relationship with the population algebra, as shown in formula (9):

[0101]

[0102] Among them, p m is the adaptive mutation probability, Ge is the generation of the population, ε is the defined adaptive adjustment coefficient;

[0103] Return to step C3 and recalculate to C5.

[0104] Adaptive mutation probability is used for initial expansion search to maintain population diversity, and careful search is performed at the end of the search to prevent the optimal solution from being destroyed. In addition, during the optimization process, its operation is performed multiple times from extensive search to detailed search. This process enables the algorithm to not only ensure the comprehensiveness and accuracy of the search, but also to quickly jump out of local optimization, so the search time is shorter and the convergence is better.

[0105] Specific examples:

[0106] The model was discretized by five-point difference method and the program was written in Matlab software. Firstly, the original population was randomly generated, and the distribution of liquid film thickness was solved by combining the chromosome coding of each generation of population.

[0107] The super-relaxation iteration method (SOR) is used to solve the fitness of the population. The simulation and optimization parameters are as follows:

[0108] l x =200μm; l y =200 μm; h0 = 2 μm; U = 1 m / s; η = 0.04 Pa·s; number of grids N: 120×120. In this application, the depth at each texture coordinate origin is set to 8 possible values, which are selected at equal intervals between 0 and 1.4 μm. k Axis, y k The angle between the axes is set to 8 possible values, which are equidistant from -3500 to 3500 rad, such as Figure 3 As shown. Considering the symmetry of the computational domain, the number of textures is halved to 18. Each texture introduces 3 variables, and each variable has 8 possible values. These 8 values ​​are mapped using a linear equation and a three-bit binary code, so the binary code after interpolation and fusion has a total of 162 bits.

[0109] The initial population and crossover probability of the adaptive genetic algorithm are selected as 60 and 0.6 respectively, and the coefficient is also selected as 1.01. Since the results of a single population do not affect each other, the parallel computing method is used to calculate the fitness of each individual in the population, which can greatly improve the calculation speed. According to the termination criterion, the difference in the average value of the fitness function of each generation is used to measure the convergence characteristics of the adaptive genetic algorithm. By observing and analyzing the maximum fitness and average fitness of the population with the population generation G e When the change trend is close to this level, it means that the optimization parameters are close to the optimal value. Here, through preliminary test analysis, it is found that when the error is selected as 10 -5Therefore, the termination operation is determined as follows:

[0110] f(G e +1)-f(G e )<10 -5

[0111] The calculation flow chart of adaptive genetic algorithm is as follows: Figure 4 As shown in the figure. First, a batch of 60 binary-coded chromosome-like data is randomly generated, and then the assumptions about the thickness distribution of the liquid film are given. The Reynolds equation is solved by parallel computing to obtain the fitness value of each individual. Combined with the individual fitness values ​​obtained from the contemporary population, the next generation population is obtained through adaptive selection, crossover, and adaptive mutation, and the search process is repeated until the stop condition is met.

[0112] The average fitness and maximum fitness of individuals in the population are respectively related to the population generation G e The relationship diagram is as follows Figure 5 As shown in Figure 2, it can be found that for the constructed long coding chromosome, both the average fitness and the maximum fitness value can grow very steadily with the increase of generations, and the adaptive genetic algorithm can effectively execute the objective function. In the first 200 generations of population evolution, because the mutation probability p m Still at a large value, it can quickly find a better solution. The average health and maximum health of this variation interval can increase rapidly, indicating that the carrying capacity of the liquid membrane increases rapidly. As the number of generations increases, the population tends to be optimal and the probability of mutation gradually decreases. Figure 5 It can be seen that after 400 generations, the average fitness of the population and the increase in the maximum fitness have not changed. When the search process reaches the 1290th generation, the change in the average carrying capacity of the population meets the convergence condition, and the search process is terminated.

[0113] Figure 6 (a) to (c) are the optimal liquid film thickness and pressure distribution cloud maps during the evolution process. By analyzing the pressure distribution cloud map, we can better summarize the main factors that directly affect the load-bearing capacity, and provide a certain reference for the research and improvement of other liquid film lubrication parameters in the future. It can be found that in the first generation, the micro-texture posture is relatively random, and the maximum liquid film pressure formed is dispersed. From the 10th generation to the 200th generation, the distribution morphology of the texture begins to adjust rapidly.

[0114] from Figure 6As can be seen from (a) to (b), the morphology of the microtexture shows two-stage differentiation. Overall, the liquid film thickness of the microtexture in the fluid inlet area is greater than the liquid film thickness of the microtexture in the outlet area. The liquid film thickness of the microtexture near the liquid outlet is less than the liquid film thickness near the outside of the microtexture, indicating that the microtexture at this location is a convex platform. When the concave area and the convex area gradually separate, the liquid film pressure gradually increases. In particular, the central area is where the pressure is the highest. Figure 6 (c) is the evolution of film thickness and hydraulic pressure from the 500th to the 1290th generation. It can be seen that the division area between the pit type and the boss type is relatively clear. The results show that the microtexture of the two pits in the fourth row in the middle gradually changes to the boss type. The high pressure of the liquid film is transferred from the 5th row of the microtexture to the 4th row, which is closer to the center of the calculation domain.

[0115] By analyzing the distribution law of the rotation axis of the biased texture, such as Figure 7 As shown in the figure, it can be found that the center line of the rotation axis of the pit-type texture is distributed in a ring shape, and at the same time, the area of ​​the pit-type texture is also ring-shaped. It is precisely because of this factor that the fluctuation of the film thickness along the radial direction of the ring provides the prerequisite for the pressure accumulation in the central area of ​​the calculation area. Since the pit-type textures in the first row on both sides are close to the boundary of the calculation domain, the fine-tuning of the rotation angle deviation has little effect on the overall pressure, and the deflection of the texture in this area has little effect on the optimization results. Therefore, considering the timeliness of the calculation, the convergence error of the optimization calculation is defined as 10 -5 , meeting actual requirements.

[0116] Figure 8 The figure shows the morphology of the boss texture. It can be found that the deflection of the boss has a very obvious regularity. All bosses are deflected from the central symmetry axis of the calculation domain. Due to this phenomenon, it is more conducive to the accumulation of high pressure in the central area of ​​the calculation domain. Since the central area of ​​the calculation domain is far away from the liquid film boundary, it is easier to obtain a larger bearing capacity by increasing the pressure in the central area.

[0117] Here, if we Figure 8 The boss type in the figure is distributed in the entire calculation area, and its pressure distribution is as follows: Fig. 9 As shown in the figure, the pressure distribution after optimization is compared with that after optimization. It can be found that when the boss is distributed in the entire area, there is no obvious aggregation effect in the pressure distribution, and the high-pressure area is mainly dispersed independently at the highest point of the boss texture. Its bearing capacity is only 8.32N, which is 27% smaller than the optimization result. The pressure distribution and micro-texture morphology at 0.45 along the normalized y-axis direction are shown in the figure below. Fig.10 As shown, it can be found that when the parallel plate surfaces are uniformly used Figure 8When the bosses in the calculation domain are calculated, although a certain pressure peak can be generated in the convergence zone of each boss, the following divergence zone causes the pressure to decrease rapidly, making it difficult for the pressure to be significantly superimposed and accumulated. By analyzing the relationship between the texture morphology and pressure shown by the best results, it can be found that the depth of the texture is from deep to shallow as a whole, from the fluid inlet to the center of the calculation area. Especially in the central area of ​​the calculation domain, the texture form directly changes from the pit type to the boss type, further reducing the thickness of the membrane. This convergence effect causes the pressure to further accumulate and superimpose. It is precisely because of the diversity of this texture that the liquid film in each texture area has obvious pressure accumulation, which gradually increases from the inlet and reaches the maximum value when it reaches the center.

[0118] The simulation was performed with the maximization of the liquid film bearing capacity as the optimization goal. The optimization results show that the liquid film bearing capacity obtained by this method is 27% higher than that of the uniform use of boss-type micro-textures. By comparing and analyzing the morphology and pressure distribution of the optimized textures, it is found that the optimized textures with different depths and biases are mainly used to effectively superimpose and accumulate the liquid film pressure in each area, and push the high-pressure area to the center of the liquid film. Since the edge area is restricted by the atmospheric pressure boundary due to the rupture of the liquid film, this method can more easily obtain a higher liquid film bearing capacity overall.

[0119] The present invention is described above with reference to the preferred embodiments, but the protection scope of the present invention is not limited thereto. Various improvements can be made to the embodiments and parts thereof can be replaced with equivalents without departing from the scope of the present invention. As long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way, and any figure mark in the claims should not be regarded as limiting the claims involved. No matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. Therefore, all technical solutions falling within the scope of the claims are within the protection scope of the present invention.

Claims

1. An algorithm for increasing the sliding auxiliary pressure structure, characterized in that: The invention also includes a sliding pair dynamic pressure structure, wherein the sliding pair dynamic pressure structure includes two friction bodies moving relative to each other, a liquid film is formed between the friction bodies, and a plurality of rectangular textures are arranged at opposite ends of the friction bodies, wherein a point on the opposite surface of the friction bodies is the origin of the texture, and the length of the texture is l x , the arc length corresponding to the x-axis is α k , the width of the texture is l y , the arc corresponding to the width of the y-axis is β k , the height of the texture is h k , the α k The radian range is -5000~5000μrad, the β k The radian range is -5000~5000μrad, and the h k The length range is -5 to 5 μm; The algorithm comprises the following steps: A. Constructing a mathematical model The friction body is simplified into two parallel plates, the length and width of the parallel plates are L and B respectively, the thickness of the liquid film between the two parallel plates is h0, and a parameter-independent rectangular texture is set on the lower parallel plate; The gaps between textures on the x-axis and y-axis are equal to the length of a single texture on the x-axis and y-axis, respectively, and the distances of the remaining areas on the boundary of the computational domain in the x-axis and y-axis directions are equal to half of the corresponding length of a single texture; The lower friction body is taken as the reference, and the upper friction body moves in the positive direction of the x-axis at a speed U; B. Calculate the film thickness h tex h tex =h k +x k and(α k )+y k and(β k ) (k=1,2,…,N) Among them, h tex is the total film thickness of each texture, and the spatial coordinate system parameter of each texture is x k ,y k , α k , β k and h k (k=1,2,...,N), k is the total number of textures, h k is the depth of the kth texture at the origin of the coordinate system, α k is the kth texture length and x k The arc between the axes, β k is the kth texture width and y k The arc between the axes; h=h0+h tex Where h is the film thickness of the entire area of ​​the friction pair surface; C. Derivation and transformation C1. Based on the force balance analysis of the microelement and the continuity condition of the fluid, the general form of the Reynolds equation is derived as follows: Where η is the dynamic viscosity of the liquid; C2. Assuming that the influence of uniform temperature distribution of fluid is negative, the film viscosity is limited in the calculation area, and the change of liquid viscosity with time and position is ignored, the above formula is simplified as follows: C3. Use dimensionless expression of the Reynolds equation as follows: in, p0 is standard atmospheric pressure; C4. When the liquid flows to the edge of the calculation area, the liquid film begins to break. Assuming that the pressure generated by the liquid is zero at this time, the following formula is obtained: p| x＝0 =p| x＝L =p| y＝0 =p| y＝B =0 C5. Calculate the bearing capacity W generated by the liquid as follows: W = ∫∫pdxdy.

2. The algorithm for increasing the sliding auxiliary dynamic pressure structure according to claim 1 is characterized in that: When the α k , β k and h k When the value of is positive, the texture is pit-like; when the α k , β k and h k When the value of is negative, the texture is a convex platform type; the texture near the liquid film inlet area is a pit type, and the texture near the liquid film outlet is a convex platform type.

3. The algorithm for increasing the sliding auxiliary dynamic pressure structure according to claim 2 is characterized in that: The distribution range of the pit-like texture is inverted U-shape, and the highest point of the boss-like texture is generally biased towards the central area of ​​the liquid film.

4. The algorithm for increasing the sliding auxiliary dynamic pressure structure according to claim 1 is characterized in that: After step C5, the method further includes: D. Adaptive genetic algorithm for optimization D1. Parameter coding Mapping the parameters of the texture to multiple physical quantities and interspersing binary data for encoding, constructing chromosomes, and balancing the parameters of the texture in the genetic process; D2. Adaptive selection strategy Use the carrying capacity Fitness as the fitness value, as shown in the following formula. Before the selection process of each generation, the survival of the fittest is carried out first; Fitness=W=∫∫pdxdy D3. Adaptive mutation strategy The mutation probability p m Set it as the relationship with the population algebra as follows: Among them, p m is the adaptive mutation probability, G e is the generation of the population, ε is the defined adaptive adjustment coefficient; Return to step C3 and recalculate to C5.

5. The algorithm for increasing the sliding auxiliary dynamic pressure structure according to claim 1 is characterized in that: In the step B, N is the number of textures after being halved.

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