A method, system and medium for identifying normal contact parameters of mechanical fixed joint surfaces
Through the contour measurement data and fractal model of the contact surface of the bonding surface, taking into account the elastic-plastic deformation factors of the microconvex body, a bonding surface normal contact parameter model was established, which solved the problems of low identification accuracy and cumbersome operation in the traditional method, and achieved high Accurate bonding surface normal contact parameter recognition, suitable for mechanical structural design.
Patent Information
- Application Number
- CN202411263459.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-09-10
AI Technical Summary
In the prior art In mechanical structure design, traditional fractal models fail to accurately identify the contact parameters of the bonding surface, resulting in a large difference between the design and actual operation, and low accuracy.
By obtaining multiple sets of contour measurement data of the contact surface of the bonding surface, calculating the contour structure function and equivalent fractal dimensions, combining the elastic-plastic deformation factors of the microconvex body, establishing a normal contact parameter model for the bonding surface, and calculating the normal stiffness and normal direction Damping.
It realizes high-precision identification of the normal contact parameters of the bonding surface, simplifies the operation process, improves the recognition accuracy, and is suitable for the identification of all fixed bonding surface contact parameters, and is universal.
Smart Images
Figure CN118797846B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of mechanical structure design, and in particular to a method, system and medium for identifying normal contact parameters of a mechanical fixed joint surface. Background Art
[0002] Modern mechanical structure design often uses "virtual prototype" technology to shorten the cycle and save costs. The reliability of the design process mainly depends on whether the established mathematical or simulation model meets the actual engineering needs, that is, the established model must meet the actual working conditions of the mechanical structure. At present, the finite element method is mainly used in mechanical structure modeling to discretize the model and analyze the response with units as elements. The mechanical structure is composed of various components according to the requirements of function, performance and processing requirements. The overall stiffness and damping of the mechanical structure are dominated by the stiffness and damping of the "joint surfaces" between the components. The design simulation model usually binds the components together or sets spring damping units between the joint surfaces based on experience, resulting in a large discrepancy between the actual design or performance analysis of the overall mechanical structure, which has become a bottleneck for the further development of the "virtual prototype" technology in the application of mechanical structure design. Therefore, accurately identifying characteristic parameters such as mechanical joint surface stiffness and damping is the key to breaking this bottleneck. The fractal model based on fractal geometry is independent of scale, and the analysis of surface contact is definite and unique. Therefore, it is often used to characterize and identify the contact parameters of the bonding surface. However, the traditional fractal model (see the literature: Zhang Xueliang. Dynamic Characteristics and Applications of Mechanical Bonding Surfaces [M]. China Science and Technology Press, 2002.) does not consider the elastic-plastic deformation and interaction factors of micro-convex bodies, resulting in a large error between the calculated parameters and the actual parameters, and cannot accurately identify the contact parameters of the bonding surface. Summary of the invention
[0003] Technical problem to be solved by the present invention: In view of the above-mentioned problems in the prior art, a method, system and medium for identifying the normal contact parameters of a mechanical fixed joint surface are provided. The present invention aims to solve the problems of cumbersome operation and low precision of the existing methods for identifying the contact parameters of fixed joint surfaces, and to easily realize high-precision identification of the normal contact parameters of mechanical fixed joint surfaces to provide guidance for the optimization design of mechanical structures.
[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:
[0005] A method for identifying normal contact parameters of a mechanical fixed joint surface comprises the following steps:
[0006] S1, obtaining multiple sets of profile measurement data of two contact surfaces forming a mechanical fixed joint surface;
[0007] S2, respectively calculating the contour structure function of the contact surface for each group of contour measurement data, calculating the equivalent structure function of the mechanical fixed joint surface from the contour structure functions of the two contact surfaces, and calculating the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the equivalent structure function;
[0008] S3, averaging the equivalent fractal dimension and equivalent fractal scale parameter of each group of profile measurement data to obtain the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface;
[0009] S4. Calculate the critical contact area of the micro-convex body based on the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface Maximum contact area with micro-convex body , where the maximum contact area of the micro-convex body is The calculation function expression is:
[0010] ,
[0011] In the above formula, F is the mechanical fixed joint surface load, E is the composite elastic modulus of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, D is the fractal dimension of the mechanically fixed interface, is the radius of curvature of the apex of the microconvex body, H is the hardness, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of is a constant parameter whose size is related to the spectral density and self-affine properties;
[0012] S5. According to the critical contact area of the micro-convex body Maximum contact area with micro-convex body The normal contact parameter model of the joint surface is established and the normal contact parameters of the mechanical fixed joint surface are calculated, including normal stiffness and normal damping. The calculation function expression of normal stiffness is:
[0013]
[0014] In the above formula, is the normal stiffness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, H is the hardness,k Poisson's ratio The function of is a constant parameter whose size is related to the spectral density and the self-affine property.
[0015] Optionally, the function expression for calculating the structure function of the contact surface in step S2 is:
[0016] ,
[0017] In the above formula, is the profile structure function of the contact surface a or b, is the profile function corresponding to the profile measurement data of contact surface a or b, The contact surface a or b passes through the sampling interval The contour function corresponding to the contour measurement data after is the sampling interval, Indicates the spatial average value, a and b are the two contact surfaces of the mechanical fixed joint surface, and the function expression of the contour structure function of the two contact surfaces in step S2 to calculate the equivalent structure function of the mechanical fixed joint surface is:
[0018] ,
[0019] In the above formula, is the equivalent structure function of the mechanically fixed interface, and They are the contour structure functions of the contact surfaces a and b of the mechanically fixed joint, respectively.
[0020] Optionally, calculating the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the equivalent structure function in step S2 includes:
[0021] S2.1, based on the functional relationship between the structure function, the fractal dimension of the mechanically fixed interface and the fractal scale parameter, the equivalent structure function in double logarithmic coordinates is established as shown in the following formula:
[0022]
[0023] In the above formula, is the equivalent structure function of the mechanically fixed interface, is a constant, is the fractal dimension of the i-th group of contour measurement data, is the fractal scale parameter of the i-th group of contour measurement data, and:
[0024] ,
[0025] In the above formula, is the Euler integral of the second kind, is a constant parameter whose size is related to the spectral density and self-affine properties;
[0026] S2.2, based on the equivalent structure function in double logarithmic coordinates, which is a straight line in double logarithmic coordinates, calculate the slope of the straight line and the intercept with the vertical axis ;
[0027] S2.3, calculate the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the following formula:
[0028] ,
[0029] ,
[0030] In the above formula, is the equivalent fractal dimension of the i-th group of contour measurement data, is the equivalent fractal scale parameter of the i-th group of contour measurement data, is the slope of the straight line corresponding to the i-th group of profile measurement data, is the intercept of the straight line corresponding to the i-th group of profile measurement data and the vertical axis.
[0031] Optionally, in step S4, the critical contact area of the micro-convex body is calculated The function expression is:
[0032] ,
[0033] In the above formula, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of H is the hardness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, and:
[0034] ,
[0035] ,
[0036] In the above formula, is Poisson's ratio, E 1. E 2 are the elastic moduli of the two contact surface materials of the mechanical fixed joint surface, and are the Poisson's ratios of the two contact surface materials of the mechanically fixed joint.
[0037] Optionally, the calculation function expression of the normal damping in step S5 is:
[0038]
[0039] In the above formula, is the normal damping, is the interface loss factor, is the normal stiffness, and:
[0040] ,
[0041] ,
[0042] ,
[0043] In the above formula, is the total energy loss on the bonding surface, is the total energy stored on the interface, D is the fractal dimension of the mechanically fixed interface, E is the composite elastic modulus of the mechanically fixed interface, G is the fractal scale parameter of the mechanical fixed interface, H is the hardness, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, k Poisson's ratio function.
[0044] In addition, the present invention also provides a normal contact parameter identification system for a mechanically fixed joint surface, comprising a microprocessor and a memory connected to each other, wherein the microprocessor is programmed or configured to execute the normal contact parameter identification method for a mechanically fixed joint surface.
[0045] In addition, the present invention also provides a computer-readable storage medium, in which a computer program or instruction is stored. The computer program or instruction is programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface through a processor.
[0046] In addition, the present invention also provides a computer program product, including a computer program or instructions, wherein the computer program or instructions are programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface through a processor.
[0047] Compared with the existing fixed joint surface contact parameter identification method, the present invention has the following advantages:
[0048] 1. The input data of the present invention only needs to be the profile measurement data obtained by measuring the surface profile of the bonding surface, which is easy to operate and avoids the reduction of recognition accuracy due to cumbersome experimental operations or multiple experiments.
[0049] 2. The normal contact parameter identification method of the mechanical fixed joint surface proposed in the present invention takes the interaction factors of micro-convex bodies and elastic-plastic deformation factors into consideration in the fractal model, and the theoretical model of the joint surface established has higher accuracy.
[0050] 3. The method for identifying normal contact parameters of mechanical fixed joint surfaces proposed in the present invention is applicable to the identification of contact parameters of all fixed joint surfaces and has the advantage of good versatility. BRIEF DESCRIPTION OF THE DRAWINGS
[0051] Figure 1 Schematic diagram of the basic flow of the method of the embodiment of the present invention.
[0052] Figure 2 These are five groups of profiles in the embodiment of the present invention.
[0053] Figure 3 These are the first three groups of profile measurement data among the five groups of profile measurement data measured in the embodiment of the present invention.
[0054] Figure 4 These are the last two groups of profile measurement data among the five groups of profile measurement data obtained in the embodiment of the present invention.
[0055] Figure 5 ] are equivalent structure functions of five groups of mechanically fixed joint surfaces obtained in the embodiment of the present invention. DETAILED DESCRIPTION
[0056] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0057] like Figure 1 As shown, the method for identifying normal contact parameters of a mechanical fixed joint surface in this embodiment includes the following steps:
[0058] S1, obtaining multiple sets of profile measurement data of two contact surfaces forming a mechanical fixed joint surface;
[0059] S2, respectively calculating the contour structure function of the contact surface for each group of contour measurement data, calculating the equivalent structure function of the mechanical fixed joint surface from the contour structure functions of the two contact surfaces, and calculating the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the equivalent structure function;
[0060] S3, averaging the equivalent fractal dimension and equivalent fractal scale parameter of each group of profile measurement data to obtain the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface;
[0061] S4. The contact of the bonding surface is essentially the contact between many micro-convex bodies on the surface. The relationship between the load and deformation of a single micro-convex body is analyzed, and then the theoretical model of the contact parameters of the bonding surface is established. The critical contact area of the micro-convex body is calculated based on the fractal dimension D and fractal scale parameter G of the mechanical fixed bonding surface. Maximum contact area with micro-convex body ;
[0062] S5. According to the critical contact area of the micro-convex body Maximum contact area with micro-convex body The normal contact parameter model of the joint surface is established and the normal contact parameters of the mechanically fixed joint surface are calculated, including normal stiffness and normal damping.
[0063] In step S1 of this embodiment, the multiple groups of contour measurement data of the two contact surfaces forming the mechanical fixed joint surface are measured by using a measuring device to measure the surface contour (in this embodiment, a VK-X3000 laser microscope system is used). The contour data of the two contact surfaces forming the joint surface need to be measured (in this embodiment, the two structural materials are the same, so only the contour data of one surface is measured). In order to obtain accurate fractal parameters, several groups of contour data Z(x) should be measured. Figure 2 The following are schematic diagrams of five groups of profiles (a) to (e) in this embodiment. The five groups of profile measurement data are measured and the results are as follows: Figure 3 and Figure 4 As shown, Figure 3 are the profile (a) to (c) measurement data of the first three groups among the five groups of profile measurement data measured in this embodiment, Figure 4 The profile (d) and (e) measurement data of the last two groups of the five groups of profile measurement data obtained in this embodiment, x is the horizontal axis of the profile data, z is the vertical axis of the profile data, and the unit of the profile data is μm.
[0064] The functional expression for calculating the structure function of the contact surface in step S2 of this embodiment is:
[0065] ,
[0066] In the above formula, is the profile structure function of the contact surface a or b, is the profile function corresponding to the profile measurement data of contact surface a or b, The contact surface a or b passes through the sampling interval The contour function corresponding to the contour measurement data after is the sampling interval, Indicates the spatial average value, a and b are the two contact surfaces of the mechanical fixed joint surface, and the function expression of the contour structure function of the two contact surfaces in step S2 to calculate the equivalent structure function of the mechanical fixed joint surface is:
[0067] ,
[0068] In the above formula, is the equivalent structure function of the mechanically fixed interface, and are the contour structure functions of the contact surfaces a and b of the mechanically fixed joint surface, respectively. The equivalent structure function of the mechanically fixed joint surface obtained based on 5 sets of contour measurement data in this embodiment is shown in double logarithmic coordinates as Figure 5 As shown, five sets of fitting curves are obtained by fitting the corresponding equivalent surfaces, and the horizontal axis is based on 10. The logarithm of the vertical axis is based on 10 The logarithm of Figure 5 The equivalent fractal parameters fractal dimension D and fractal scale parameter G can be obtained. The functional relationship between the structure function, the fractal dimension D of the mechanical fixed joint surface and the fractal scale parameter G can be expressed as:
[0069]
[0070] In the above formula, is the structure function, is a constant, D is the fractal dimension, G is the fractal scale parameter, The equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data are calculated according to the equivalent structure function in step S2 of this embodiment, including:
[0071] S2.1, based on the functional relationship between the structure function, the fractal dimension of the mechanically fixed interface and the fractal scale parameter, the equivalent structure function in double logarithmic coordinates is established as shown in the following formula:
[0072]
[0073] In the above formula, is the equivalent structure function of the mechanically fixed interface, is a constant, is the fractal dimension of the i-th group of contour measurement data, is the fractal scale parameter of the i-th group of contour measurement data, and:
[0074] ,
[0075] In the above formula, is the Euler integral of the second kind, is a constant parameter whose size is related to the spectral density and self-affine properties (for randomly distributed surfaces, it is often taken as 1.5);
[0076] S2.2, based on the equivalent structure function in double logarithmic coordinates, which is a straight line in double logarithmic coordinates, calculate the slope of the straight line and the intercept with the vertical axis ;
[0077] S2.3, calculate the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the following formula:
[0078] ,
[0079] ,
[0080] In the above formula, is the equivalent fractal dimension of the i-th group of contour measurement data, is the equivalent fractal scale parameter of the i-th group of contour measurement data, is the slope of the straight line corresponding to the i-th group of profile measurement data, is the intercept of the straight line corresponding to the i-th group of profile measurement data and the vertical axis.
[0081] In step S3 of this embodiment, the equivalent fractal dimension and equivalent fractal scale parameter of each group of profile measurement data are averaged respectively, and the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface can be expressed as:
[0082] ,
[0083] ,
[0084] In the above formula, ~ is the equivalent fractal dimension of the 1st to 5th groups of profile measurement data, ~ is the equivalent fractal scale parameter of the 1st to 5th groups of contour measurement data.
[0085] In step S4 of this embodiment, the critical contact area of the micro-protrusion is calculated The function expression is:
[0086] ,
[0087] In the above formula, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of H is the hardness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, and:
[0088] ,
[0089] ,
[0090] ,
[0091] In the above formula, is Poisson's ratio, E 1. E 2 are the elastic moduli of the two contact surface materials of the mechanical fixed joint surface, and are the Poisson's ratios of the two contact surface materials of the mechanically fixed joint.
[0092] The maximum contact area of the micro-protrusions in step S4 of this embodiment The calculation function expression is:
[0093] ,
[0094] In the above formula, F is the mechanical fixed joint surface load, E is the composite elastic modulus of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, D is the fractal dimension of the mechanically fixed interface, is the radius of curvature of the apex of the microconvex body, H To form the hardness of the softer material in the two structures of the bonding surface, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of is a constant parameter whose size is related to the spectral density and the self-affine property.
[0095] The calculation function expression of the normal stiffness in step S5 of this embodiment is:
[0096] ,
[0097] In the above formula, is the normal stiffness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, H is the hardness, k Poisson's ratio The function of is a constant parameter related to the spectral density and self-affine properties. The derivation process of the calculation function expression of the above normal stiffness is as follows:
[0098] Load of a single asperity in the elastic stage after considering the interaction for:
[0099] ,
[0100] In the above formula, is the contact area of the micro-asperity.
[0101] After considering the interaction, the stiffness of a single asperity in the elastic phase is for:
[0102] ,
[0103] In the above formula, is the deformation of the micro-convex body.
[0104] Total stiffness of the joint surface in the elastic stage for:
[0105] ,
[0106] in, is the asperity area distribution density function, and:
[0107] .
[0108] According to the convex body elastic-plastic model proposed by scholars Kogut and Etsion, the relationship between the contact load, contact area, average contact pressure and deformation in the first stage of elastic-plasticity is:
[0109] ,
[0110] In the above formula, is the load of the first stage of elastic-plasticity of a single asperity (Reference: Zhao Y, Liang C. AModel of Asperity Interactions in Elastic-Plastic Contact of Rough Surfaces. J. Trib. 123(4) (2001): 2841. It is found that the effect of asperity interaction can be largely offset by surface plastic deformation, so the interaction factor is not considered in the elastic-plastic stage), is the critical deformation of the micro-convex body, is the average contact pressure of the asperity, is the contact area of the micro-convex body.
[0111] The relationships among contact load, contact area, average contact pressure and deformation in the second stage of elastic-plasticity are:
[0112] ,
[0113] Stiffness of a single asperity in the first stage of elastic-plasticity for:
[0114] ,
[0115] Normal stiffness of the joint surface in the second stage of elastic-plasticity for:
[0116] ,
[0117] Stiffness of a single asperity in the second elastic-plastic region for:
[0118] ,
[0119] In the above formula, is the load in the second stage of elastic-plasticity.
[0120] Normal stiffness of the interface between elastic and plastic zones for:
[0121] ,
[0122] Therefore, the normal stiffness of the joint surface is:
[0123] .
[0124] The calculation function expression of the normal damping in step S5 of this embodiment is:
[0125]
[0126] In the above formula, is the normal damping, is the interface loss factor, is the normal stiffness, and:
[0127] ,
[0128] ,
[0129] ,
[0130] In the above formula, is the total energy loss on the bonding surface, is the total energy stored on the interface, D is the fractal dimension of the mechanically fixed interface, E is the composite elastic modulus of the mechanically fixed interface, Gis the fractal scale parameter of the mechanical fixed interface, H The Brinell hardness of the softer material of the two objects forming the bonding surface. is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, k Poisson's ratio The normal damping loss factor is The derivation process of the calculation function expression is as follows:
[0131] Elastic potential energy of a single asperity for:
[0132] ,
[0133] in, F e is the load of a single asperity in the elastic stage after considering the interaction.
[0134] Total energy stored on the interface for:
[0135] ,
[0136] Energy loss of a single asperity for:
[0137] ,
[0138] in, F p is the load of a single micro-convex body in the plastic stage, and the calculation formula is as follows:
[0139] ,
[0140] Total energy loss at the junction for:
[0141] ,
[0142] Therefore, the calculation function expression of the normal damping loss factor can be obtained as follows:
[0143] .
[0144] In order to verify the normal contact parameter identification method of the mechanical fixed joint surface in this embodiment, the mechanical fixed joint surface load is set in this embodiment. F The contact parameters are 20 N·m, 50 N·m and 80 N·m. The results obtained by comparing the method of this embodiment, the traditional fractal model and the actual normal contact parameters are shown in Table 1.
[0145] Table 1: Comparison of the method of this embodiment, the traditional fractal model and the actual normal contact parameters
[0146]
[0147] As shown in Table 1, compared with the traditional fractal model, the normal stiffness and normal damping obtained by the method of this embodiment are closer to the normal stiffness and normal damping in the actual normal contact parameters.
[0148] In summary, the method of this embodiment obtains contour data by measuring the surface of the bonding surface, obtains fractal parameters by processing the contour data through the structure function method, and obtains the normal stiffness and normal damping of the bonding surface through the fractal model of the normal contact parameters of the bonding surface. The input data of the method of this embodiment only needs the contour measurement data obtained by measuring the surface contour of the bonding surface. The operation is simple and convenient, and it avoids the reduction of recognition accuracy due to cumbersome experimental operation or multiple experiments. The method of this embodiment takes into account the interaction factors of micro-convex bodies and elastic-plastic deformation factors in the fractal model, and the established theoretical model of the bonding surface has higher accuracy. The method of this embodiment is applicable to the identification of contact parameters of all fixed bonding surfaces, and has the advantage of good versatility. The method of this embodiment can effectively solve the problems of cumbersome operation and low accuracy of the existing fixed bonding surface contact parameter identification method, and can identify the normal contact parameters of all mechanical fixed bonding surfaces. The identification method is easy to operate and the results are reliable, so it can provide guidance for the optimization design of mechanical structures.
[0149] In addition, this embodiment also provides a normal contact parameter identification system for a mechanically fixed joint surface, comprising a microprocessor and a memory connected to each other, wherein the microprocessor is programmed or configured to execute the normal contact parameter identification method for a mechanically fixed joint surface.
[0150] In addition, this embodiment also provides a computer-readable storage medium, in which a computer program or instruction is stored. The computer program or instruction is programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface through a processor.
[0151] In addition, this embodiment also provides a computer program product, including a computer program or instructions, which are programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface through a processor.
[0152] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can take the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.
[0153] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.
Claims
1. A method for identifying normal contact parameters of a mechanical fixed joint surface, characterized in that: The steps include: S1, obtaining multiple sets of profile measurement data of two contact surfaces forming a mechanical fixed joint surface; S2, respectively calculating the contour structure function of the contact surface for each group of contour measurement data, calculating the equivalent structure function of the mechanical fixed joint surface from the contour structure functions of the two contact surfaces, and calculating the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the equivalent structure function; S3, averaging the equivalent fractal dimension and equivalent fractal scale parameter of each group of profile measurement data to obtain the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface; S4. Calculate the critical contact area of the micro-convex body based on the fractal dimension D and fractal scale parameter G of the mechanical fixed joint surface Maximum contact area with micro-convex body , where the maximum contact area of the micro-convex body is The calculation function expression is: ， In the above formula, F is the mechanical fixed joint surface load, E is the composite elastic modulus of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, D is the fractal dimension of the mechanically fixed interface, is the radius of curvature of the apex of the microconvex body, H is the hardness, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of is a constant parameter whose size is related to the spectral density and self-affine properties; S5. According to the critical contact area of the micro-convex body Maximum contact area with micro-convex body The normal contact parameter model of the joint surface is established and the normal contact parameters of the mechanical fixed joint surface are calculated, including normal stiffness and normal damping. The calculation function expression of normal stiffness is: In the above formula, is the normal stiffness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, H is the hardness, k Poisson's ratio The function of is a constant parameter whose size is related to the spectral density and the self-affine property.
2. The method for identifying normal contact parameters of a mechanical fixed joint surface according to claim 1, characterized in that: The functional expression for calculating the structure function of the contact surface in step S2 is: ， In the above formula, is the profile structure function of the contact surface a or b, is the profile function corresponding to the profile measurement data of contact surface a or b, The contact surface a or b passes through the sampling interval The contour function corresponding to the contour measurement data after is the sampling interval, Indicates the spatial average value, a and b are the two contact surfaces of the mechanical fixed joint surface, and the function expression of the contour structure function of the two contact surfaces in step S2 to calculate the equivalent structure function of the mechanical fixed joint surface is: ， In the above formula, is the equivalent structure function of the mechanically fixed interface, and They are the contour structure functions of the contact surfaces a and b of the mechanically fixed joint, respectively.
3. The method for identifying normal contact parameters of a mechanical fixed joint surface according to claim 1, characterized in that: Calculating the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the equivalent structure function in step S2 includes: S2.1, based on the functional relationship between the structure function, the fractal dimension of the mechanically fixed interface and the fractal scale parameter, the equivalent structure function in double logarithmic coordinates is established as shown in the following formula: In the above formula, is the equivalent structure function of the mechanically fixed interface, is a constant, is the fractal dimension of the i-th group of contour measurement data, is the fractal scale parameter of the i-th group of contour measurement data, and: ， In the above formula, is the Euler integral of the second kind, is a constant parameter whose size is related to the spectral density and self-affine properties; S2.2, based on the equivalent structure function in double logarithmic coordinates, which is a straight line in double logarithmic coordinates, calculate the slope of the straight line and the intercept with the vertical axis ; S2.3, calculate the equivalent fractal dimension and equivalent fractal scale parameter of each group of contour measurement data according to the following formula: ， ， In the above formula, is the equivalent fractal dimension of the i-th group of contour measurement data, is the equivalent fractal scale parameter of the i-th group of contour measurement data, is the slope of the straight line corresponding to the i-th group of profile measurement data, is the intercept of the straight line corresponding to the i-th group of profile measurement data and the vertical axis.
4. The method for identifying normal contact parameters of a mechanical fixed joint surface according to claim 1, characterized in that: Step S4 calculates the critical contact area of the micro-convex body The function expression is: ， In the above formula, G is the fractal scale parameter of the mechanical fixed interface, k Poisson's ratio The function of H is the hardness, E is the composite elastic modulus of the mechanically fixed interface, D is the fractal dimension of the mechanically fixed interface, and: ， ， In the above formula, is Poisson's ratio, E 1. E 2 are the elastic moduli of the two contact surface materials of the mechanical fixed joint surface, and are the Poisson's ratios of the two contact surface materials of the mechanically fixed joint.
5. The method for identifying normal contact parameters of a mechanical fixed joint surface according to claim 1, characterized in that: The calculation function expression of normal damping in step S5 is: In the above formula, is the normal damping, is the interface loss factor, is the normal stiffness, and: ， ， ， In the above formula, is the total energy loss on the bonding surface, is the total energy stored on the interface, D is the fractal dimension of the mechanically fixed interface, E is the composite elastic modulus of the mechanically fixed interface, G is the fractal scale parameter of the mechanical fixed interface, H is the hardness, is the critical contact area of the micro-asperity, is the maximum contact area of the micro-convex body, k Poisson's ratio function.
6. A system for identifying normal contact parameters of a mechanical fixed joint surface, comprising a microprocessor and a memory connected to each other, characterized in that: The microprocessor is programmed or configured to execute the method for identifying normal contact parameters of a mechanically fixed joint surface as claimed in any one of claims 1 to 5.
7. A computer-readable storage medium having a computer program or instruction stored therein, characterized in that: The computer program or instruction is programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface as claimed in any one of claims 1 to 5 through a processor.
8. A computer program product comprising a computer program or instructions, characterized in that The computer program or instruction is programmed or configured to execute the method for identifying normal contact parameters of a mechanical fixed joint surface as claimed in any one of claims 1 to 5 through a processor.