Method, device and equipment for determining stress concentration coefficient of surface elliptical pit

Abstract

The invention relates to the technical field of stress correlation, in particular to a method, a device and equipment for determining a stress concentration coefficient of a surface elliptical pit. The method comprises the following steps: on the basis of a Gurtin-Murdoc surface model, establishing an elliptical coordinate system: constructing incident wave displacement, reflected wave displacement and scattered wave displacement into a Mathieu function series form; constructing a non-classical boundary condition of the semi-elliptical surface; substituting the displacement based on the Mathieu function series form into a non-classical boundary condition so as to convert the non-classical boundary condition into a nonlinear equation containing a scattering wave displacement undetermined coefficient; expanding the nonlinear equation into a Fourier series, cutting off the Fourier series at a preset series to obtain a linear equation set about an undetermined coefficient, and solving the undetermined coefficient; and determining the stress concentration coefficient of the semielliptical groove based on the undetermined coefficient.

Description

Technical Field

[0001] The present application relates to the field of stress-related technologies, and in particular to a method, device and equipment for determining a stress concentration coefficient of an elliptical pit on a surface. Background Art

[0002] With the increasing miniaturization of components and devices in micro- or nano-scale electromechanical systems, the importance of understanding the behavior of materials and structures at small scales has been steadily increasing. At small scales, the surfaces and interfaces of solids may significantly affect their physical and mechanical properties due to the significant ratio of surface / interface area to volume. Experiments and atomistic simulations have shown that the surface / interface stiffness can be softer or harder than the classical surface / interface assumptions. In order to quantitatively evaluate the surface / interface effects, Gurtin and co-workers established a theoretical model (now called the Gurtin-Murdoch surface model) to describe the surface / interface effects. A linearized surface / interface stress-strain relationship was introduced. According to the Gurtin-Murdoch surface model, while the bulk of the material obeys the traditional equilibrium and constitutive equations, the surface and interface of the material are considered to be "membrane-like" elastic layers, which are independent of the bulk and have specific elastic constants and surface tension. Shenoy developed a method based on atomistic simulations to determine the surface elastic constants of metal crystals and pointed out a possible experimental method to measure surface elastic properties. Miller and Shenoy used the Gurtin-Murdoch surface model to derive theoretical results for the overall tensile, bending, and torsional properties of nanoplates, beams, or rods with surface elasticity, and verified the applicability of these results through atomistic simulations.

[0003] The model of elastic wave propagation in an elastic half-plane or half-space is of great significance for studying the scattering of elastic waves on the surface of materials and the propagation characteristics near the surface of materials. In order to simplify the analysis of elastic wave propagation in an elastic half-plane or half-space, it is usually assumed that the surface of the half-plane or half-space is smooth and flat. However, the reality is that the surface of materials or solids at any length scale is unconditionally rough, with pits or protrusions on the surface (for example, the mountains and valleys on the surface of the earth, the micro-nanoscale bumps on the surface of metals).

[0004] There are already literatures on calculating the dynamic stress concentration factor of semicircular grooves on half-plane surfaces, but these existing schemes cannot calculate the dynamic stress of elliptical grooves. Summary of the invention

[0005] In view of this, the embodiments of the present application are directed to providing a method, device and apparatus for determining a stress concentration factor of an elliptical pit on a surface, so as to calculate the dynamic stress of the elliptical groove.

[0006] The present application provides a method for determining a stress concentration factor of an elliptical pit on a surface, comprising:

[0007] Based on the Gurtin-Murdoc surface model, an elliptical coordinate system is established with the center of the semi-ellipse as the origin:

[0008] x=ccoshξcosη

[0009] y=csinhξsinη

[0010] Among them, x and y are the horizontal and vertical coordinates of the plane rectangular coordinate system, respectively, and c is the semi-focal length of the ellipse.

[0011] ξ and η are the radial coordinate and angular coordinate of the elliptical coordinate system, respectively;

[0012] The incident wave displacement, reflected wave displacement and scattered wave displacement are constructed in the form of Mathieu function series;

[0013]

[0014] Among them, u (i) ,u (r) and u (s) are the incident wave displacement, reflected wave displacement and scattered wave displacement respectively; U is the displacement amplitude, i is the imaginary unit, θ is the incident angle, ce m (n) and se m (η) is the m-order Mathieu function, and is the j-th type m-order modified Mathieu function. m is the coefficient to be determined.

[0015] Construct nonclassical boundary conditions for semi-elliptical surfaces;

[0016] Substituting the incident wave displacement, the reflected wave displacement and the scattered wave displacement in the form of Mathieu function series into the non-classical boundary condition to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement;

[0017] Expand the nonlinear equation into a Fourier series and truncate it at a preset series to obtain a system of linear equations about the unknown coefficients and solve for the unknown coefficients;

[0018] The preset levels are

[0019] N = 10

[0020] The stress concentration factor of the semi-elliptical groove is determined based on the unknown coefficients.

[0021] In some embodiments, in the non-classical boundary condition for constructing the semi-elliptical surface, the formula of the non-classical boundary condition is as follows:

[0022] The nonclassical boundary conditions for a semi-elliptical surface are formulated as follows:

[0023]

[0024] Where ξ0 is the radial coordinate of the semi-ellipse boundary, is the surface stress, σ ξz is the matrix stress.

[0025] In some embodiments, the formula of the nonlinear equation is as follows:

[0026]

[0027] Where u is the full-field displacement. sur and μ represent the surface shear modulus and bulk shear modulus, respectively.

[0028] In some embodiments, the linear equations are as follows:

[0029]

[0030] In some embodiments, the stress concentration factor of the semi-elliptical groove is determined based on the undetermined coefficient:

[0031] Substituting the unknown coefficients into the following equations, the stress concentration factor is obtained;

[0032]

[0033] Where DSCF is the stress concentration factor.

[0034] In some embodiments, the preset number of levels is ten.

[0035] The present application also provides a device for determining a stress concentration factor of an elliptical pit on a surface, comprising:

[0036] Create a module to establish an elliptical coordinate system based on the Gurtin-Murdoc surface model and with the center of the semi-ellipse as the origin:

[0037] x=ccoshξcosη

[0038] y=csinhξsinη

[0039] A construction module for constructing the incident wave displacement, the reflected wave displacement and the scattered wave displacement into a Mathieu function series form;

[0040]

[0041] Where the incident angle is θ, the wave number is k, the semi-major axis is a, and the radial coordinate of the ellipse is

[0042] Semi-elliptical groove of ξ0, μ

[0043] and μ sur are the bulk shear modulus and the surface shear modulus respectively; A m is the unknown coefficient; the incident wave displacement is u (i) , the reflected wave displacement is u (r) and the scattered wave displacement is u (s) ;

[0044] Building blocks, also used to construct nonclassical boundary conditions on semi-elliptical surfaces;

[0045] A substitution module is used to substitute the incident wave displacement, the reflected wave displacement and the scattered wave displacement into the non-classical boundary condition based on the Mathieu function series form, so as to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement;

[0046] A solution module, used for expanding the nonlinear equation into a Fourier series, and truncating it at a preset series, to obtain a linear equation system about the undetermined coefficients, and solve the undetermined coefficients;

[0047] A determination module is used to determine the stress concentration factor of the semi-elliptical groove based on the unknown coefficient.

[0048] The present application also provides an electronic device, comprising:

[0049] A processor, and a memory for storing a program executable by the processor;

[0050] The processor is used to implement the above-mentioned method for determining the stress concentration coefficient of the surface elliptical pit by running the program in the memory.

[0051] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes the above-mentioned method for determining the stress concentration coefficient of the surface elliptical pit.

[0052] The present application also provides a computer program product, including a computer program, which implements the above-mentioned method for determining the stress concentration coefficient of the surface elliptical pit when executed by a processor.

[0053] The present application provides a method for determining the stress concentration coefficient of a surface elliptical pit. First, based on the Gurtin-Murdoc surface model and with the center of the semi-ellipse as the origin, an elliptical coordinate system is established: the incident wave displacement, the reflected wave displacement and the scattered wave displacement are constructed in the form of a Mathieu function series; the non-classical boundary conditions of the semi-elliptical surface are constructed; the incident wave displacement, the reflected wave displacement and the scattered wave displacement in the form of a Mathieu function series are substituted into the non-classical boundary conditions to convert the non-classical boundary conditions into a nonlinear equation containing the unknown coefficients of the scattered wave displacement; the nonlinear equation is expanded into a Fourier series, and truncated at a preset series to obtain a linear equation system about the unknown coefficients, and the unknown coefficients are solved; the stress concentration coefficient of the semi-elliptical groove is determined based on the unknown coefficients. In this way, the stress concentration coefficient of the surface elliptical pit can be obtained by calculating the incident angle, the semi-major axis, the wave number, the elliptical radial coordinate, the body shear modulus and the surface shear modulus, so as to calculate the dynamic stress of the elliptical groove based on the stress concentration coefficient of the surface elliptical pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0055] Figure 1 It is a flow chart of a method for determining a stress concentration factor of an elliptical pit on a surface provided by an embodiment of the present application.

[0056] Figure 2 This is a SH wave incident model provided by an embodiment of the present application.

[0057] Figure 3 It is an elliptical coordinate system provided by an embodiment of the present application.

[0058] Figure 4 is the stress boundary condition obtained in this example;

[0059] Figure 5 is the distribution of DSCF obtained in this example on the edge of the elliptical hole.

[0060] Figure 6 It is a schematic structural diagram of a device for determining a stress concentration factor of an elliptical pit on a surface provided by an embodiment of the present application.

[0061] Figure 7 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Application Overview

[0064] There are already literatures on calculating the dynamic stress concentration factor of semicircular grooves on half-plane surfaces, but these existing schemes cannot calculate the dynamic stress of elliptical grooves.

[0065] In order to solve the above problems, the present application provides a solution, based on the Gurtin-Murdoc surface model, to establish an elliptical coordinate system with the center of the semi-ellipse. The displacements of the incident wave, reflected wave and scattered wave are written in the form of Mathieu function series; the non-classical boundary conditions of the semi-elliptical surface are derived; the displacement field is substituted into the boundary conditions to obtain a nonlinear equation containing the unknown coefficients of the scattered wave displacement. The boundary conditions are expanded into a Fourier series, and appropriately truncated to obtain a linear equation system about the unknown coefficients, and the unknown coefficients are solved. The known displacement is entered into the dynamic stress concentration coefficient formula to obtain the dynamic stress concentration coefficient of the semi-elliptical groove. In this way, the stress concentration coefficient of the surface elliptical pit can be obtained, so as to calculate the dynamic stress of the elliptical groove based on the stress concentration coefficient of the surface elliptical pit.

[0066] After introducing the basic principles of the present application, various non-limiting embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0067] Exemplary Methods

[0068] Figure 1 FIG. 1 is a flow chart of a method for determining a stress concentration factor of an elliptical pit on a surface provided by an embodiment of the present application. Figure 1 As shown, the method includes the following contents.

[0069] Step S110, based on the Gurtin-Murdoc surface model and taking the center of the semi-ellipse as the origin, an elliptical coordinate system is established; |

[0070] The specific formula is as follows:

[0071] x=ccoshξcosη

[0072] y=csinhξsinη

[0073] Among them, x and y are the horizontal and vertical coordinates of the plane rectangular coordinate system, c is the semi-focal length of the ellipse, ξ and η are the radial and angular coordinates of the ellipse coordinate system, respectively;

[0074] Step S120, constructing the incident wave displacement, the reflected wave displacement and the scattered wave displacement into a Mathieu function series form;

[0075]

[0076] where the incident angle is θ, the wave number is k, the semi-major axis is a, the radial coordinate of the ellipse is ξ0, μ and μ sur are the bulk shear modulus and the surface shear modulus respectively; A m is the unknown coefficient; the incident wave displacement is u (i) , the reflected wave displacement is u (r) and the scattered wave displacement is u (s) ;

[0077] Step S130, constructing non-classical boundary conditions of the semi-elliptical surface;

[0078] Step S140, substituting the incident wave displacement, the reflected wave displacement and the scattered wave displacement in the form of a Mathieu function series into the non-classical boundary condition to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement;

[0079] Step S150, expanding the nonlinear equation into a Fourier series, and truncating it at a preset series to obtain a linear equation system about undetermined coefficients, and solving the undetermined coefficients;

[0080] Step S160, determining the stress concentration coefficient of the semi-elliptical groove based on the unknown coefficient.

[0081] In this way, the stress concentration coefficient of the surface elliptical pit can be obtained, so as to calculate the dynamic stress of the elliptical groove based on the stress concentration coefficient of the surface elliptical pit.

[0082] Further, see Figure 2-5 , a specific implementation example is used for explanation: SH wave is incident at an incident angle θ and wave number k into a semi-elliptical groove with a semi-major axis a and an elliptical radial coordinate ξ0. The specific values ​​and material parameters are:

[0083] μ=256kPa,μ sur =0.126N / m,

[0084] a=1μm,ξ0=0.8047,

[0085]

[0086] where μ and μsur are the bulk shear modulus and the surface shear modulus, respectively.

[0087] Incident wave u (i) , reflected wave u (r) and the scattered wave u (s) The displacements are:

[0088] Step 1: Incident wave u (i) , reflected wave u (r) and the scattered wave u (s) The displacements are:

[0089]

[0090] Among them A m is the coefficient to be determined.

[0091] Step 2: The stress boundary condition of the semi-elliptical groove surface is

[0092]

[0093] Where ξ0 is the radial coordinate of the semi-ellipse boundary, is the surface stress, σ ξz is the matrix stress.

[0094] Step 3: The stress boundary condition of the semi-elliptical groove surface is expressed as displacement:

[0095]

[0096] Where u is the full-field displacement, which is an infinite series with undetermined coefficients.

[0097] μ sur and

[0098] μ represents the surface shear modulus and bulk shear modulus, respectively.

[0099] Step 4: Truncating the infinite series of displacement field u (Formula (4) 1) and expanding the boundary condition (Formula (4) 2) into a Fourier series, we can obtain the unknown coefficient A m The linear equations

[0100]

[0101] Wherein, N represents the number of terms of the infinite series truncated. The preset series number N is 10, which is sufficient to meet the convergence and accuracy requirements.

[0102] Arrange the third equation above to get the unknown coefficient A0-A N The linear system of equations.

[0103]

[0104] where c ij for In the integral result of A j The previous coefficient, b i for The constant term in the integral result of . The unknown coefficient A0-A can be obtained by formula (6) N .

[0105] Step 5: Substitute the determined coefficient A0-A N Substituting the truncated displacement expression u (Formula (5) 1), the dynamic stress concentration factor DSCF of the semi-elliptical groove is obtained:

[0106]

[0107] J is defined as k is the wave number of the incident wave.

[0108] With such a setting, the surface elliptical pit stress concentration coefficient can be calculated through the incident angle, semi-major axis, wave number, ellipse radial coordinate, body shear modulus and surface shear modulus, so as to calculate the elliptical groove dynamic stress based on the surface elliptical pit stress concentration coefficient.

[0109] Exemplary Devices

[0110] The device embodiments of the present application can be used to execute the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0111] Figure 6 The block diagram of a device for determining a stress concentration factor of an elliptical pit on a surface provided by an embodiment of the present application is shown. Figure 6 As shown, the device comprises:

[0112] A module 61 is established for establishing an elliptical coordinate system based on the Gurtin-Murdoc surface model and taking the center of the semi-ellipse as the origin:

[0113] x=ccoshξcosη

[0114] y=csinhξsinη

[0115] Among them, x and y are the horizontal and vertical coordinates of the plane rectangular coordinate system, respectively, and c is the semi-focal length of the ellipse.

[0116] ξ and η are the radial coordinate and angular coordinate of the elliptical coordinate system, respectively;

[0117] A construction module 62 is used to construct the incident wave displacement, the reflected wave displacement and the scattered wave displacement into a Mathieu function series form;

[0118]

[0119] The incident angle is

[0120] θ, wave number is k, semi-major axis is a, radial coordinate of the ellipse is ξ0

[0121] The semi-elliptical grooves, μ and μ sur are the bulk shear modulus and the surface shear modulus respectively; A m

[0122] is the unknown coefficient; the incident wave displacement is u (i) , the reflected wave displacement is u (r) and the scattered wave displacement is u (s) ;

[0123] Construction module 62 is also used to construct non-classical boundary conditions for semi-elliptical surfaces;

[0124] A substitution module 63 is used to substitute the incident wave displacement, the reflected wave displacement and the scattered wave displacement in the form of a Mathieu function series into the non-classical boundary condition to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement;

[0125] A solution module 64 is used to expand the nonlinear equation into a Fourier series, and truncate it at a preset series to obtain a linear equation system about the undetermined coefficients, and solve the undetermined coefficients;

[0126] The determination module 65 is used to determine the stress concentration factor of the semi-elliptical groove based on the unknown coefficient.

[0127] In some embodiments, in the non-classical boundary condition for constructing the semi-elliptical surface, the formula of the non-classical boundary condition is as follows:

[0128] The nonclassical boundary conditions for a semi-elliptical surface are formulated as follows:

[0129]

[0130] In some embodiments, the formula of the nonlinear equation is as follows:

[0131]

[0132] Where u is the full-field displacement.

[0133] In some embodiments, the linear equations are as follows:

[0134]

[0135] In some embodiments, the stress concentration factor of the semi-elliptical groove is determined based on the undetermined coefficient:

[0136] Substituting the unknown coefficients into the following equations, the stress concentration factor is obtained;

[0137]

[0138] Where DSCF is the stress concentration factor.

[0139] In some embodiments, the preset level is

[0140] N = 10

[0142] Exemplary Electronic Devices

[0143] Below, reference Figure 7 To describe an electronic device according to an embodiment of the present application. Figure 7 A block diagram of an electronic device according to an embodiment of the present application is illustrated.

[0144] like Figure 7 As shown, electronic device 700 includes one or more processors 710 and memory 720 .

[0145] The processor 710 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 700 to perform desired functions.

[0146] The memory 720 may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 710 may run the program instructions to implement the surface elliptical pit stress concentration factor determination method of each embodiment of the present application described above and / or other desired functions. Various contents such as category correspondences may also be stored in the computer-readable storage medium.

[0147] In one example, the electronic device 700 may further include: an input device 730 and an output device 740 , and these components are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0148] In addition, the input device 730 may also include, for example, a keyboard, a mouse, an interface, etc. The output device 740 may output various information to the outside, including analysis results, etc. The output device 740 may include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto, etc.

[0149] Of course, to simplify, Figure 7 Only some of the components in the electronic device related to the present application are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0150] Exemplary computer program products and computer-readable storage media

[0151] In addition to the above-mentioned methods and devices, an embodiment of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method for determining the stress concentration coefficient of a surface elliptical pit according to various embodiments of the present application described in the above-mentioned "Exemplary Method" section of this specification.

[0152] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0153] In addition, an embodiment of the present application may also be a computer-readable storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the processor executes the steps of the method for determining the stress concentration coefficient of a surface elliptical pit according to various embodiments of the present application described in the above “Exemplary Method” section of this specification.

[0154] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0155] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for determining the stress concentration factor of a surface elliptical pit, characterized in that: include: Based on the Gurtin-Murdoc surface model, an elliptical coordinate system is established with the center of the semi-ellipse as the origin: x=ccoshξcosη y=csinhξsinη Among them, x and y are the horizontal and vertical coordinates of the plane rectangular coordinate system, c is the semi-focal length of the ellipse, ξ and η are the radial and angular coordinates of the ellipse coordinate system, respectively; The incident wave displacement, reflected wave displacement and scattered wave displacement are constructed in the form of Mathieu function series; Among them, u (i) ,u (r) and u (s) are the incident wave displacement, reflected wave displacement and scattered wave displacement respectively; U is the displacement amplitude, i is the imaginary unit, θ is the incident angle, ce m (n) and se m (η) is the m-order Mathieu function, and is the j-th type m-order modified Mathieu function, A m is the coefficient to be determined; Construct nonclassical boundary conditions for semi-elliptical surfaces; Substituting the incident wave displacement, the reflected wave displacement and the scattered wave displacement in the form of Mathieu function series into the non-classical boundary condition to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement; Expand the nonlinear equation into a Fourier series and truncate it at a preset series to obtain a system of linear equations about the unknown coefficients and solve for the unknown coefficients; The stress concentration factor of the semi-elliptical groove is determined based on the unknown coefficients.

2. The method for determining the stress concentration factor of a surface elliptical pit according to claim 1, characterized in that: In the non-classical boundary condition for constructing the semi-elliptical surface, the formula of the non-classical boundary condition is as follows: The nonclassical boundary conditions for a semi-elliptical surface are formulated as follows: Where ξ0 is the radial coordinate of the semi-ellipse boundary, is the surface stress, σ ξz is the matrix stress.

3. The method for determining the stress concentration factor of a surface elliptical pit according to claim 2, characterized in that: The formula of the nonlinear equation is as follows: Where u is the full-field displacement, μ sur and μ represent the surface shear modulus and bulk shear modulus, respectively.

4. The method for determining the stress concentration factor of a surface elliptical pit according to claim 3, characterized in that: The formula of the linear equation system is as follows: Here, N represents the number of terms that the infinite series is truncated.

5. The method for determining the stress concentration factor of a surface elliptical pit according to claim 4, characterized in that: The stress concentration factor of the semi-elliptical groove is determined based on the undetermined coefficient: Substituting the unknown coefficients into the following equations, the stress concentration factor is obtained; Where DSCF is the stress concentration factor and J is defined as k is the wave number of the incident wave.

6. The method for determining the stress concentration factor of a surface elliptical pit according to claim 5, characterized in that: The preset number of levels is 10.

7. A device for determining stress concentration factor of elliptical pits on a surface, characterized in that: include: Create a module to establish an elliptical coordinate system based on the Gurtin-Murdoc surface model and with the center of the semi-ellipse as the origin: x=ccoshξcosη y=csinhξsinη Among them, x and y are the horizontal and vertical coordinates of the plane rectangular coordinate system, c is the semi-focal length of the ellipse, ξ and η are the radial and angular coordinates of the ellipse coordinate system, respectively; A construction module for constructing the incident wave displacement, the reflected wave displacement and the scattered wave displacement into a Mathieu function series form; Among them, among them, u (i) ,u (r) and u (s) are the incident wave displacement, reflected wave displacement and scattered wave displacement respectively; U is the displacement amplitude, i is the imaginary unit, θ is the incident angle, ce m (n) and se m (η) is the m-order Mathieu function, and is the j-th type m-order modified Mathieu function; A m is the coefficient to be determined; Building blocks, also used to construct nonclassical boundary conditions on semi-elliptical surfaces; A substitution module is used to substitute the incident wave displacement, the reflected wave displacement and the scattered wave displacement into the non-classical boundary condition based on the Mathieu function series form, so as to transform the non-classical boundary condition into a nonlinear equation containing unknown coefficients of the scattered wave displacement; A solution module, used for expanding the nonlinear equation into a Fourier series, and truncating it at a preset series, to obtain a linear equation system about the undetermined coefficients, and solving the undetermined coefficients; A determination module is used to determine the stress concentration factor of the semi-elliptical groove based on the unknown coefficient.

8. An electronic device, characterized in that: include: A processor, and a memory for storing a program executable by the processor; The processor is used to implement the method for determining the stress concentration factor of the surface elliptical pits according to any one of claims 1 to 6 by running the program in the memory.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, enables the processor to execute the method for determining the stress concentration factor of an elliptical pit on a surface according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for determining a stress concentration factor of an elliptical pit on a surface according to any one of claims 1 to 6 is implemented.

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