Assembly joint surface dynamic contact rigidity and damping calculation method and system considering anisotropy

Abstract

The invention discloses a method and a system for calculating dynamic contact rigidity and damping of an assembly joint surface considering anisotropy, and belongs to the field of machine manufacturing. The method comprises the following steps: acquiring three-dimensional shape data of a joint surface, fitting micro-convex bodies with anisotropy, and acquiring characteristic parameters of all the micro-convex bodies; on the basis of the characteristic parameters of the micro-convex bodies and the static contact distance between the two surfaces of the joint surface, the micro-convex bodies capable of being contacted are judged, and static contact parameters of a contact pair formed by the micro-convex bodies capable of being contacted are calculated; based on the static contact parameters of the micro-convex body contact pairs, mechanical models of the micro-convex body contact pairs are established, and static contact loads of the micro-convex body contact pairs are calculated respectively; and calculating the contact rigidity and damping of the joint surface under dynamic disturbance based on the static contact load and disturbance displacement of all the micro-convex body contact pairs. The method provides a theoretical model and a scientific basis for predicting the contact characteristics of the assembly joint surface, and is of great significance in promoting the progress and application of digital design, manufacturing and assembly of the joint surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical manufacturing, in particular to a dynamic contact stiffness and damping calculation method and system of an assembly joint surface considering anisotropy. BACKGROUND

[0002] Assembly joint surfaces are commonly found in large complex mechanical systems in the fields of nuclear power, military industry, aerospace, etc. The contact characteristics (stiffness, damping) of the joint surface are closely related to the static characteristics, dynamic characteristics, and vibration and vibration control of the mechanical system, and are of great significance to the mechanical performance evaluation of the whole machine.

[0003] In order to accurately obtain the contact stiffness and damping coefficients of the joint surface, domestic and foreign scholars have carried out a lot of research work, and the main methods include statistical methods and fractal methods. In terms of statistical methods, based on the GW theory, it is assumed that the surface height obeys Gaussian distribution, and a rough surface contact model is established. The fractal method describes the two-dimensional morphology of the rough surface through a fractal function. Although scholars in various countries have made many effective research results in the field of joint surface contact, there are still some problems that have not been solved. First, the statistical method simplifies the surface morphology too much, ignores the complexity of the actual engineering surface roughness peak with different curvature radii, and the distribution of the roughness peak height often cannot be accurately represented by a specific mathematical formula; secondly, the fractal method, especially the two-dimensional or three-dimensional fractal function, can only extract part of the information of the surface morphology, the simulated surface morphology is quite different from the real surface, and the actual engineering surface usually does not have regular fractal characteristics and cannot meet the fractal law in all scale ranges, which has certain limitations; finally, the micro-convex body at the actual micro-scale changes complexly and has anisotropy, while the above-mentioned method assumes that the micro-convex body is a semicircle or a rotating parabolic body, which is difficult to accurately reflect the anisotropy.

[0004] Therefore, it is necessary to develop a dynamic contact stiffness and damping calculation method that can be based on the real surface morphology of the joint surface and reflect the anisotropy of the micro-convex body. SUMMARY

[0005] In order to solve the problems that the current models for obtaining the contact stiffness and damping coefficients of the joint surface have too many simplifications when simulating the joint surface, are quite different from the real surface morphology, and are difficult to reflect the anisotropy of the micro-convex body contact, the purpose of the present application is to provide a dynamic contact stiffness and damping calculation method of an assembly joint surface considering anisotropy.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions: The present application provides a dynamic contact stiffness and damping calculation method of an assembly joint surface considering anisotropy, comprising: acquire three-dimensional topography data of the bonding surface, divide a plurality of rough peak regions on the bonding surface according to the three-dimensional topography data, fit each rough peak region as anisotropic microconvex, and acquire feature parameters of all microconvexes; judge the microconvexes capable of contacting based on the feature parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface, and calculate the static contact parameters of the contact pairs formed by the microconvexes capable of contacting; establish a mechanical model of the microconvex contact pairs based on the static contact parameters of the microconvex contact pairs, and calculate the static contact load of the microconvex contact pairs respectively; calculate the contact stiffness and damping of the bonding surface under dynamic disturbance based on the static contact load and disturbance displacement of all microconvex contact pairs.

[0007] The dividing of the plurality of rough peak regions on the bonding surface according to the three-dimensional topography data, the fitting of each rough peak region as anisotropic microconvex, and the acquiring of feature parameters of all microconvexes are specifically as follows: convert the three-dimensional topography data into a two-dimensional gray image, divide a plurality of rough peak regions in the bonding surface according to each local minimum value of pixels in the two-dimensional gray image and its influence area, and fit all height point cloud data in each rough peak region as anisotropic elliptic parabolic surface to obtain a plurality of anisotropic microconvexes and acquire feature parameters of all microconvexes. The fitting of all height point cloud data in each rough peak region as anisotropic elliptic parabolic surface to obtain a plurality of anisotropic microconvexes and acquire feature parameters of all microconvexes is specifically as follows:

[0008] The judging of the microconvexes capable of contacting based on the feature parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface is specifically as follows: construct expressions of the microconvexes in the upper surface and the lower surface of the bonding surface based on the feature parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface; calculate the contact point coordinates based on the expressions of the microconvexes in the upper surface and the lower surface of the bonding surface in the case of contact between the microconvexes in the upper surface and the lower surface; calculate the microconvex value in the upper surface and the microconvex in the lower surface by respectively bringing the contact point coordinates into the expressions of the microconvexes in the upper surface and the lower surface of the bonding surface; If the microconvex value in the upper surface is less than the microconvex value in the lower surface, the microconvexes in the upper surface and the lower surface are in contact, and are determined as a microconvex contact pair; otherwise, they are not in contact.

[0009] The static contact parameters include a contact point normal vector, a contact point principal curvature, and a contact point normal displacement, and are calculated as follows: For the micro asperity contact pair, the contact point normal vector of the micro asperity contact pair is calculated, and the formula is as follows:

[0010]

[0011] In the formula: is the contact point gradient vector of the micro asperity in the lower surface; The principal curvature of the micro asperity contact pair is calculated, and the formula is as follows:

[0012] In the formula: is the principal curvature; is the coefficient of the first fundamental form of the surface; L is the coefficient of the second fundamental form of the surface; The contact point normal displacement is calculated according to the contact point normal vector, and the formula is as follows:

[0013] In the formula: is the contact point normal displacement; is the normal downward pressure amount of the contact pair plane; is the component vector of the contact point normal vector in the plane normal direction.

[0014] The static contact parameters based on the micro asperity contact pair are used to establish the mechanical model of the micro asperity contact pair, and the static contact load of the micro asperity contact pair is calculated, specifically: The mechanical model of the micro asperity contact pair is divided into loading stage and unloading stage; According to the contact point normal vector and the principal curvature of the micro asperity contact pair, the mechanical model of the micro asperity contact pair in the loading stage is established;

[0015] In the formula: is the static contact load in the loading stage; is the contact point normal load in the elastic loading stage, is the contact point normal load in the elastic-plastic loading stage, is the contact point normal load in the plastic loading stage; is the contact point normal displacement; is the principal curvature; is the coefficient related to the elastic model, Poisson's ratio and hardness of the material; is the critical deformation variable of elastic-elastic-plastic deformation; is the critical deformation variable of elastic-plastic-plastic deformation; According to the contact point normal vector and principal curvature of the micro-convex body contact pair, a mechanical model of the micro-convex body contact pair in the unloading stage is established:

[0016] In the formula: is the static contact load in the unloading stage; is the contact point normal load in the elastic unloading stage at the maximum load; is the contact point normal load in the elastic-plastic unloading stage at the maximum load; is the maximum load reached before unloading; According to the contact point normal displacement of the micro-convex body contact pair, the deformation state of the micro-convex body contact pair is judged, and is brought into the mechanical model of the micro-convex body contact pair to solve the static contact load of all micro-convex body contact pairs.

[0017] The perturbation displacement of the micro-convex contact pair is specifically:

[0018] In the formula: is the amplitude of the perturbation displacement increment at any time, is the component of the perturbation displacement direction vector in the contact normal direction at any time;

[0019] In the formula: is the contact point normal vector of the micro-convex body contact pair; is the normalized , is the normal vector of the normal and tangential perturbation displacement coupling direction.

[0020] The contact stiffness and damping under the dynamic disturbance of the joint are calculated based on the static contact load of all micro-convex body contact pairs and the perturbation displacement of the micro-convex contact pair, and are specifically: According to the perturbation displacement and static contact load of the micro-convex body contact pair, the mechanical model of the micro-convex body contact pair is Taylor expanded to obtain the dynamic contact load of the micro-convex body contact pair;

[0021] In the formula: is the dynamic contact load; is the static contact load; is the time-varying perturbation displacement; , is the first and second derivatives of the static loading and unloading load expression; when is the loading load expression, is the unloading load expression; According to the dynamic contact load of the micro-convex body contact pair, the dynamic contact stiffness and damping of the micro-convex body contact pair are calculated, and the formula is as follows:

[0022]

[0023] In the formula: is the dynamic contact stiffness; is the equivalent viscous damping coefficient; , is the loading and unloading dynamic load changing with time in one vibration period ; is the vibration frequency of the disturbance load; is the vibration amplitude of the disturbance load; The components of the dynamic contact stiffness and damping vector of each micro-convex body contact pair in a certain direction are summed up to obtain the total dynamic contact stiffness and damping of the joint surface in the direction. The application also provides an assembly joint surface dynamic contact stiffness and damping calculation system considering anisotropy, comprising:

[0024] A micro-convex body fitting module is used to obtain three-dimensional topographic data of the joint surface, divide a plurality of rough peak regions on the joint surface according to the three-dimensional topographic data, fit each rough peak region as a micro-convex body with anisotropy, and obtain characteristic parameters of all micro-convex bodies. A contact parameter calculation module is used to judge the contactable micro-convex bodies based on the characteristic parameters of the micro-convex bodies and the static contact spacing of the two surfaces of the joint surface, and calculate the static contact parameters of the contact pairs formed by the contactable micro-convex bodies. A static contact load calculation module is used to establish a mechanical model of the micro-convex body contact pair based on the static contact parameters of the micro-convex body contact pair, and calculate the static contact load of the micro-convex body contact pair. A contact stiffness and damping solving module is used to calculate the contact stiffness and damping of the joint surface under dynamic disturbance based on the static contact load and disturbance displacement of all micro-convex body contact pairs. The application also provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the above-mentioned assembly joint surface dynamic contact stiffness and damping calculation method considering anisotropy when executing the computer program.

[0025] The application also provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the above-mentioned assembly joint surface dynamic contact stiffness and damping calculation method considering anisotropy when executed by a processor.

[0026] ​

[0027] Compared with the prior art, the present application has the following beneficial technical effects: The present application can accurately obtain the contact behavior difference of the micro asperity in different directions by fitting the micro asperity with anisotropy by using the measured surface topography data and obtaining the micro asperity characteristic parameters, thereby providing strong support for accurately analyzing the contact characteristics, and overcoming the problems of excessive simplification of the surface topography and large difference from the real surface of the traditional model; and then with the aid of Taylor expansion, the calculation of the contact stiffness and damping under dynamic disturbance is realized on the basis of the static contact condition, the prediction of the contact characteristics of the assembled joint is more accurate, and the present application provides a theoretical model and scientific basis for the prediction of the contact characteristics of the assembled joint, which has important significance for promoting the progress and application of the digital design, manufacturing and assembly of the joint. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor on the premise of the drawings.

[0029] Figure 1 The flow chart of the method for calculating the dynamic contact stiffness and damping of the anisotropic assembled joint of the present application; Figure 2 The flow chart of the specific implementation process of the method for calculating the dynamic contact stiffness and damping of the anisotropic assembled joint of the present application; Figure 3 The structural schematic diagram of the system for calculating the dynamic contact stiffness and damping of the anisotropic assembled joint of the preferred embodiment of the present application; Figure 4 The structural schematic diagram of the electronic device of the preferred embodiment of the present application. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be described in more detail below with reference to the drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments described herein, on the contrary, these embodiments are provided to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes, and are not intended to limit the scope of protection of the present application.

[0031] It should be understood that each step described in the method embodiments of the present application can be executed in different order and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0032] The term "include" and variations thereof, as used in this document, mean the same as "comprise" or "comprises." The term "based on" means "based, at least in part, on." The term "one embodiment" means "at least one embodiment." The term "another embodiment" means "at least one additional embodiment." The term "some embodiments" means "at least some embodiments." Related terms shall be construed accordingly. It should be noted that "a" or "an" entity as used herein means "one or more" entities. The terms "first," "second," and the like as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, unless otherwise indicated.

[0033] It should be noted that the terms "one" and "a" or "an" as used herein mean "one or more" unless otherwise explicitly provided. The terms "plurality" and "a plurality" contain the meaning of "multiple" or "a number of."

[0034] The names of the messages or information exchanged between the plurality of devices in the embodiments of the present disclosure are only for illustrative purposes, and are not intended to limit the scope of the messages or information.

[0035] As shown in Figure 1 The present application provides a method for calculating the dynamic contact stiffness and damping of an assembled joint surface considering anisotropy, comprising: S1, obtaining three-dimensional topography data of the joint surface, dividing a plurality of rough peak regions on the joint surface according to the three-dimensional topography data; fitting each rough peak region as a microconvex body with anisotropy, and obtaining characteristic parameters of all microconvex bodies; S2, judging the microconvex bodies that can be contacted based on the characteristic parameters of the microconvex bodies and the static contact spacing of the two surfaces of the joint surface, and calculating the static contact parameters of the contact pairs formed by the microconvex bodies that can be contacted; S3, establishing a mechanical model of the microconvex body contact pairs according to the static contact parameters of the microconvex body contact pairs, and calculating the static contact load of the microconvex body contact pairs, respectively; S4, calculating the contact stiffness and damping of the joint surface under dynamic disturbance based on the static contact load and disturbance displacement of all microconvex body contact pairs.

[0036] Compared with traditional theoretical calculation, finite element method and experimental test method, by the present application, the actual contact surface can be more truly restored by using the measured surface topography data, and the influence of simplification assumptions on the simulation results is avoided. The problem that the traditional model usually oversimplifies the surface topography and ignores the complexity of the surface microstructure, resulting in a large difference between the simulated surface topography and the actual surface, can be solved.

[0037] The application can accurately describe the anisotropy of the surface micro-convex body by fitting the surface micro-convex body, and derive the contact stiffness and damping under dynamic disturbance on the basis of static contact through the Taylor expansion. The application can consider the influence of the dynamic change of the contact surface, flexibly calculate and predict the performance of the contact surface under the actual working conditions on the basis of the static contact model, and provide a more scientific and accurate theoretical basis for the analysis of the contact characteristics. The proposal of the method not only promotes the progress of the digital design, manufacturing and assembly of the joint surface, but also provides strong operability support for practical application, and can greatly improve the assembly accuracy and reliability in engineering practice.

[0038] As shown in Figure 2 Further, in S1, a plurality of rough peak regions are divided on the joint surface according to the three-dimensional topographic data; each rough peak region is fitted as a micro-convex body with anisotropy, and the characteristic parameters of all micro-convex bodies are obtained, specifically: Firstly, the three-dimensional topographic data is converted into a two-dimensional gray image, the gray value in the two-dimensional gray image represents the altitude of the point, and the watershed segmentation method is used to divide a plurality of rough peak regions in the joint surface according to each local minimum value of the pixels in the two-dimensional gray image and the influence area thereof; In each rough peak region, all height point cloud data in the rough peak region are fitted as an elliptic parabolic surface with anisotropy by a binary linear regression method, a plurality of micro-convex bodies with anisotropy are obtained, and the characteristic parameters of all micro-convex bodies are obtained, the characteristic parameters include the vertex coordinates of the micro-convex body and the fitting parameters of the elliptic parabolic surface; The expression of the above elliptic parabolic surface is:

[0039] Wherein, a, b, c are the fitting parameters of the elliptic parabolic surface.

[0040] The method based on the real shape fitting of the joint surface obtains the micro-convex body of the elliptic parabolic surface, can accurately reflect the anisotropy characteristics of the joint surface, provides more accurate micro-convex body characteristic parameters, and avoids the over-simplification in the traditional method, thereby providing more accurate data for subsequent contact analysis.

[0041] Further, in S2, the micro-convex bodies capable of being contacted are judged based on the characteristic parameters of the micro-convex bodies and the static contact distance between the two surfaces of the joint surface, specifically: The expressions of the micro-convex bodies in the upper surface and the lower surface of the joint surface are respectively:

[0042]

[0043]

[0044] In the formula, It is the absolute difference of the x-coordinates of the vertices of the micro-convexities in the upper and lower surfaces; It is the absolute difference of the y-coordinates of the vertices of the micro-convexities in the upper and lower surfaces; , , This is the negative of the fitting parameters for the upper surface; d This refers to the static contact distance between the upper and lower surfaces. , , These are the fitting parameters for the lower surface; Assuming that the micro-protrusions on the upper and lower surfaces are in contact, the contact point should satisfy the condition that the micro-protrusions on the upper and lower surfaces have the same z-value at the contact point, i.e. Then we have:

[0045] The coordinates of the contact point are solved using a quadratic equation and the determinant method. , As shown below:

[0046]

[0047]

[0048] The micro-protrusions on the upper surface are calculated by substituting them into the expressions for the micro-protrusions on the upper and lower surfaces of the mating surface, respectively. Values ​​and micro-protrusions in the lower surface The calculation formula is as follows:

[0049]

[0050]

[0051] If the micro-protrusions on the upper surface The value is less than the micro-protrusions in the lower surface. If the value is positive, the micro-protrusions on the upper and lower surfaces come into contact and are identified as a micro-protrusion contact pair; otherwise, they do not make contact.

[0052] Furthermore, in S2, the static contact parameters of the contact pair formed by the contactable micro-protrusions are calculated. The static contact parameters include the contact point normal vector, the contact point principal curvature, and the contact point normal displacement. The specific calculations are as follows: For a micro-protrusion contact pair that is in contact, calculate the normal vector of the contact point of the micro-protrusion contact pair. The calculation formula is as follows:

[0053]

[0054] In the formula: is the contact point gradient vector of the microconvex body in the lower surface; The calculation formula of the principal curvature of the microconvex body contact pair is as follows:

[0055] In the formula: is the principal curvature; is the coefficient of the first fundamental form of the surface; L is the coefficient of the second fundamental form of the surface; The contact point normal displacement is calculated according to the contact point normal vector, and the calculation formula is as follows:

[0056] In the formula: is the contact point normal displacement; is the normal downward displacement of the contact pair plane; is the component vector of the contact point normal vector in the plane normal direction.

[0057] Further, according to the static contact parameters of the microconvex body contact pair in S3, a mechanical model of the microconvex body contact pair is established, and the static contact load of the microconvex body contact pair is calculated, specifically: The mechanical model of the microconvex body contact pair is divided into a loading stage and an unloading stage; The deformation state of the microconvex body in the loading stage is divided into three stages of elasticity, elasto-plasticity and plasticity, and a mechanical model of the microconvex body contact pair in the loading stage is established according to the contact point normal vector and the principal curvature of the microconvex body contact pair;

[0058] In the formula: is the static contact load in the loading stage; is the contact point normal load in the elastic loading stage, is the contact point normal load in the elasto-plastic loading stage; is the contact point normal load in the plastic loading stage; is the contact point normal displacement; is the principal curvature; is a coefficient related to the elastic model, Poisson's ratio and hardness of the material; is the critical deformation variable of the elastic-elasto-plastic deformation; is the critical deformation variable of the elasto-plastic-plastic deformation; According to the contact point normal vector and principal curvature of the micro-convex body contact pair, a mechanical model of the micro-convex body contact pair in the unloading stage is established:

[0059] In the formula: is the static contact load in the unloading stage; is the contact point normal load in the elastic unloading stage at the maximum load; is the contact point normal load in the elastic-plastic unloading stage at the maximum load; is the maximum load reached before unloading; According to the contact point normal displacement of the micro-convex body contact pair, the deformation state of the micro-convex body contact pair is judged, and is brought into the mechanical model of the micro-convex body contact pair to solve the static contact load of all micro-convex body contact pairs.

[0060] Further, the contact stiffness and damping under the dynamic disturbance of the joint surface are calculated based on the static contact load and the disturbance displacement of all micro-convex body contact pairs in S4, and the specific steps are as follows: The disturbance displacement acting on the micro-convex contact pair is calculated, and the calculation method is as follows:

[0061] In the formula: is the amplitude of the disturbance displacement increment at any time;

[0062]

[0063]

[0064] is the component of the disturbance displacement direction vector in the contact normal direction at any time;

[0065] In the formula: is the contact point normal vector of the micro-convex body contact pair; is the normalized , is the normal vector acting in the coupling direction of the normal and tangential disturbance displacement, and the calculation method is as follows:

[0066] According to the disturbance displacement and the static contact load of the micro-convex body contact pair, the mechanical model of the micro-convex body contact pair is Taylor expanded to obtain the dynamic contact load of the micro-convex body contact pair;

[0067] In the formula: For dynamic contact loads; This is a static contact load; The displacement is a disturbance that varies with time. , These are the first and second derivatives of the static loading and unloading load expressions; when The time is the expression for the applied load. The time is the unloading load expression; The dynamic contact stiffness and damping of the micro-assailant contact pair are calculated based on the dynamic contact load, using the following formulas:

[0068]

[0069] In the formula: For dynamic contact stiffness; It is the equivalent viscous damping coefficient; , One oscillation cycle Dynamic loading and unloading loads that change over time; The vibration frequency of the disturbance load; The amplitude of the disturbance load; The components of the dynamic contact stiffness and damping vector of each pair of micro-protrusion contact pairs in a specific direction are summed to obtain the overall dynamic contact stiffness and damping of the mating surface in that direction.

[0070] Compared with traditional theoretical calculations, finite element methods, and experimental testing methods, this invention can solve problems such as excessive simplification of surface morphology in current models, large differences between simulated and real surface morphology, complex modeling processes, and difficulty in reflecting the anisotropy of micro-protrusion contact. It enables the fitting of anisotropic micro-protrusions on the surface using measured surface morphology data and the acquisition of micro-protrusion parameters. With the help of Taylor expansion, it can calculate the contact stiffness and damping under dynamic disturbances based on static contact conditions. This provides a theoretical model and scientific basis for predicting the contact characteristics of assembly mating surfaces, and is of great significance for promoting the advancement and application of digital design, manufacturing, and assembly of mating surfaces.

[0071] like Figure 3 As shown, another objective of this invention is to provide a calculation system for the dynamic contact stiffness and damping of anisotropic assembly mating surfaces, comprising: The micro-protrusion fitting module is used to acquire the three-dimensional morphology data of the bonding surface, divide the bonding surface into several rough peak regions based on the three-dimensional morphology data, fit each rough peak region into anisotropic micro-protrusions, and acquire the characteristic parameters of all micro-protrusions. The contact parameter calculation module is configured to determine the micro asperities capable of contacting based on the feature parameters of the micro asperities and the static contact spacing of the two surfaces of the joint surface, and calculate the static contact parameters of the contact pairs formed by the micro asperities capable of contacting. The static contact load calculation module is configured to establish a mechanical model of the micro asperity contact pairs according to the static contact parameters of the micro asperity contact pairs, and calculate the static contact loads of the micro asperity contact pairs respectively. The contact stiffness and damping solving module is configured to calculate the contact stiffness and damping of the joint surface under dynamic disturbance based on the static contact loads of all the micro asperity contact pairs and the disturbance displacement.

[0072] As Figure 4 illustrated, a third object of the present application is to provide an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for calculating the dynamic contact stiffness and damping of the anisotropic assembly joint surface when executing the computer program.

[0073] The method for calculating the dynamic contact stiffness and damping of the anisotropic assembly joint surface comprises: S1, obtaining three-dimensional topography data of the joint surface, dividing a plurality of rough peak regions on the joint surface according to the three-dimensional topography data, fitting each rough peak region as a micro asperity with anisotropy, and obtaining feature parameters of all the micro asperities; S2, determining the micro asperities capable of contacting based on the feature parameters of the micro asperities and the static contact spacing of the two surfaces of the joint surface, and calculating the static contact parameters of the contact pairs formed by the micro asperities capable of contacting; S3, establishing a mechanical model of the micro asperity contact pairs according to the static contact parameters of the micro asperity contact pairs, and calculating the static contact loads of the micro asperity contact pairs respectively; S4, calculating the contact stiffness and damping of the joint surface under dynamic disturbance based on the static contact loads of all the micro asperity contact pairs and the disturbance displacement.

[0074] A fourth object of the present application is to provide a computer readable storage medium storing a computer program, wherein the computer program is executable on a processor to implement the steps of the method for calculating the dynamic contact stiffness and damping of the anisotropic assembly joint surface.

[0075] The method for calculating the dynamic contact stiffness and damping of the anisotropic assembly joint surface comprises: S1, obtaining three-dimensional topography data of the joint surface, dividing a plurality of rough peak regions on the joint surface according to the three-dimensional topography data, fitting each rough peak region as a micro asperity with anisotropy, and obtaining feature parameters of all the micro asperities; S2, judging the micro asperities that can be contacted based on the characteristic parameters of the micro asperities and the static contact spacing of the two surfaces of the joint surface, and calculating the static contact parameters of the contact pairs formed by the micro asperities that can be contacted; S3, establishing the mechanical model of the micro asperity contact pairs according to the static contact parameters of the micro asperity contact pairs, and respectively calculating the static contact load of the micro asperity contact pairs; S4, calculating the contact stiffness and damping of the joint surface under dynamic disturbance based on the static contact load and the disturbance displacement of all the micro asperity contact pairs.

[0076] Those skilled in the art will 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 an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0077] The present application is described with reference to 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 flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams 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 apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0078] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a process for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1steps of the functions specified in the one or more blocks.

[0080] It should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or equivalent replaced without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be covered in the protection scope of the claims of the present application.

Claims

1. A method for calculating dynamic contact stiffness and damping of an assembled joint surface considering anisotropy, characterized by, The method comprises the following steps: Obtain the three-dimensional topography data of the bonding surface, and divide a plurality of rough peak regions on the bonding surface according to the three-dimensional topography data; fit each rough peak region as anisotropic microconvex, and obtain the characteristic parameters of all microconvexes; Determine the microconvexes that can be contacted based on the characteristic parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface, and calculate the static contact parameters of the contact pairs formed by the microconvexes that can be contacted; Based on the static contact parameters of the microconvex contact pairs, a mechanical model of the microconvex contact pairs is established, and the static contact loads of the microconvex contact pairs are calculated respectively; Based on the static contact loads and the perturbation displacement of all microconvex contact pairs, the contact stiffness and damping under the dynamic perturbation of the bonding surface are calculated.

2. The method of claim 1, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The method of dividing a plurality of rough peak regions on the bonding surface according to the three-dimensional topography data, fitting each rough peak region as anisotropic microconvex, and obtaining the characteristic parameters of all microconvexes, specifically comprises the following steps: Convert the three-dimensional topography data into a two-dimensional gray image, and divide a plurality of rough peak regions on the bonding surface according to each local minimum value of the pixels in the two-dimensional gray image and the influence area thereof; In each rough peak region, all height point cloud data in the rough peak region are fitted as anisotropic elliptic parabolic surface through a binary linear regression method to obtain a plurality of anisotropic microconvexes, and the characteristic parameters of all microconvexes are obtained, including the vertex coordinates of the microconvexes and the fitting parameters of the elliptic parabolic surface.

3. The method of claim 1, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The method of determining the microconvexes that can be contacted based on the characteristic parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface, specifically comprises the following steps: Based on the characteristic parameters of the microconvexes and the static contact spacing of the two surfaces of the bonding surface, expressions of the microconvexes in the upper surface and the lower surface of the bonding surface are constructed; In the case that the microconvexes in the upper surface and the lower surface are in contact, the coordinates of the contact points are calculated based on the expressions of the microconvexes in the upper surface and the lower surface of the bonding surface. The coordinates of the contact point are brought into the expression of the micro-asperities in the upper and lower surfaces of the interface respectively to calculate the micro-asperities in the upper surface of the interface and the micro-asperities in the lower surface of the interface ; If the value of the microconvexity in the upper surface is less than the value of the microconvexity in the lower surface then the microconvexities in the upper and lower surfaces come into contact, defining a microconvexity contact pair; otherwise they do not.

4. The method of claim 1, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The static contact parameters include the normal vector of the contact point, the principal curvature of the contact point, and the normal displacement of the contact point, and are calculated as follows: For the microconvex contact pairs that are in contact, the normal vector of the contact point of the microconvex contact pairs is calculated, and the formula is as follows: wherein: is the gradient vector of the contact point of the microconvexity in the lower surface; The principal curvature of the microconvex contact pairs is calculated, and the formula is as follows: wherein: is the principal curvature; is the coefficient of the first fundamental form of the surface; L is the coefficient of the second fundamental form of the surface; The normal displacement of the contact point is calculated according to the normal vector of the contact point, and the formula is as follows: where: is the contact point normal displacement; is the contact pair plane normal down displacement; is the contact point normal vector component in the plane normal direction.

5. The method of claim 4, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The method of establishing a mechanical model of the microconvex contact pairs based on the static contact parameters of the microconvex contact pairs and calculating the static contact loads of the microconvex contact pairs, specifically comprises the following steps: The mechanical model of the microconvex contact pairs is divided into a loading stage and an unloading stage; A mechanical model of the microconvex contact pairs in the loading stage is established according to the normal vector of the contact point and the principal curvature of the microconvex contact pairs; wherein: is the static contact load for the loading phase; is the contact point normal load for the elastic loading phase, is the contact point normal load for the elastic-plastic loading phase; is the contact point normal load for the plastic loading phase; is the contact point normal displacement; is the principal curvature; is a coefficient related to the elastic model, Poisson's ratio, hardness of the material; is the critical deformation for elastic-elastic plastic deformation; is the critical deformation for elastic-plastic-plastic deformation; A mechanical model of the microconvex contact pairs in the unloading stage is established according to the normal vector of the contact point and the principal curvature of the microconvex contact pairs: wherein: is the static contact load at unloading; is the contact point normal load at the maximum load in the elastic unloading phase; is the contact point normal load at the maximum load in the elastic-plastic unloading phase; is the maximum load reached before unloading; According to the normal displacement of the contact point of the microconvex contact pairs, the deformation state of the microconvex contact pairs is determined, which is brought into the mechanical model of the microconvex contact pairs to solve the static contact loads of all microconvex contact pairs.

6. The method of claim 1, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The perturbation displacement of the microconvex contact pairs is as follows: wherein: is the perturbation displacement increment amplitude at any instant of time, is the component of the perturbation displacement direction vector in the contact normal direction at any instant of time; wherein: is the contact point normal vector of the micro-asperity contact pair; is the normalized , is the normal vector of the normal and tangential perturbation displacement coupling direction action.

7. The method of claim 1, wherein the dynamic contact stiffness and damping of the assembled joint interface are calculated considering anisotropy. The static contact load of all asperity contact pairs and the perturbation displacement of the asperity contact pairs are combined with the contact stiffness and damping under dynamic perturbation of the interface, and specifically: According to the perturbation displacement and the static contact load of the asperity contact pairs, the dynamic contact load of the asperity contact pairs is obtained by Taylor expansion of the mechanical model of the asperity contact pairs; wherein: is the dynamic contact load; is the static contact load; is the perturbed displacement as a function of time; , is the first and second derivative of the static loading and unloading load expression; when is the loading load expression, is the unloading load expression; According to the dynamic contact load of the asperity contact pairs, the dynamic contact stiffness and damping of the asperity contact pairs are calculated, and the formula is as follows: wherein: is the dynamic contact stiffness; is the equivalent viscous damping coefficient; , is the vibration period is the time-varying loading and unloading dynamic load within the structure; is the vibration frequency of the disturbing load; is the vibration amplitude of the disturbing load; The components of the dynamic contact stiffness and damping vectors of each asperity contact pair in a specific direction are summed to obtain the overall dynamic contact stiffness and damping of the interface in the direction.

8. A system for calculating the dynamic contact stiffness and damping of anisotropic assembly mating surfaces, characterized in that, It comprises: The micro-asperity fitting module is used for obtaining three-dimensional topographic data of the interface, dividing a plurality of rough peak regions on the interface according to the three-dimensional topographic data, fitting each rough peak region as an anisotropic micro-asperity, and obtaining characteristic parameters of all micro-asperities; The contact parameter calculation module is used for judging the contactable micro-asperities based on the characteristic parameters of the micro-asperities and the static contact spacing of the two surfaces of the interface, and calculating the static contact parameters of the contact pairs formed by the contactable micro-asperities; The static contact load calculation module is used for establishing a mechanical model of the micro-asperity contact pairs based on the static contact parameters of the micro-asperity contact pairs, and calculating the static contact load of the micro-asperity contact pairs, respectively; The contact stiffness and damping solving module is used for calculating the contact stiffness and damping under dynamic perturbation of the interface based on the static contact load of all micro-asperity contact pairs and the perturbation displacement.

9. An electronic device, comprising: The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the steps of the anisotropic assembly interface dynamic contact stiffness and damping calculation method in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the steps of the anisotropic assembly interface dynamic contact stiffness and damping calculation method in any one of claims 1-7.

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