Method, device and equipment for determining residual stress field of thick plate blank

Abstract

The invention discloses a method, a device and equipment for determining a residual stress field of a thick plate blank. Comprising the following steps: fixing a to-be-measured thick plate blank on a numerical control machine tool processing table top according to a specified mode, and determining an initial coordinate of the to-be-measured thick plate blank; determining the grooving processing depth of the to-be-measured thick plate blank, and determining a grooving deformation sequence according to the grooving processing depth and the initial coordinates; and determining the residual stress field of the to-be-measured thick plate blank according to the grooving processing depth and the grooving deformation sequence. A to-be-measured thick plate blank is fixed to a numerical control machine tool machining table top according to a cantilever structure, the to-be-measured thick plate blank is gradually machined according to the grooving machining depth to obtain a grooving deformation sequence, and finally the grooving machining depth and the grooving deformation sequence are combined with a stress reverse algorithm to determine residual stress distribution. Measurement of the residual stress field of the blank is achieved on a structural part machining site, quantitative characterization is provided for factory inspection of the blank, and data input is provided for evaluation and prediction of subsequent machining deformation and numerical control process design.

Description

Technical Field

[0001] The invention relates to the technical field of numerical control machining, and in particular to a method, a device and equipment for determining the residual stress field of a thick plate blank. Background Art

[0002] At present, the manufacturing of aircraft integral frame beam structural parts widely uses thick plate blanks such as aluminum alloy and titanium alloy, which are obtained by removing a large amount of metal materials through CNC milling. In the front process of thick plate blank manufacturing, a residual stress field distributed along the depth will be generated in the blank material. This residual stress field is usually symmetrically distributed about the middle plane of the sheet thickness, and is self-balanced in the blank, so it does not appear on the outside.

[0003] Regarding the measurement of residual stress distribution inside thick plate blanks, most of the known methods need to be completed in the laboratory, such as deep hole drilling, cutting, neutron diffraction, etc. The relevant instrument preparation and testing process is time-consuming and costly, and cannot be implemented conveniently and quickly at the production and processing site. Summary of the invention

[0004] The present invention provides a method, a device and equipment for determining the residual stress field of a thick plate blank, so as to measure the residual stress field of a workpiece blank at a structural component processing site.

[0005] According to one aspect of the present invention, a method for determining residual stress field of a thick plate blank is provided, the method comprising:

[0006] Fix the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner, and determine the initial coordinates of the thick plate blank to be measured;

[0007] Determine the slotting depth of the thick plate blank to be measured, and determine the slotting deformation sequence according to the slotting depth and the initial coordinates;

[0008] The residual stress field of the thick plate blank to be tested is determined according to the groove processing depth and the groove deformation sequence.

[0009] Optionally, the designated method is a cantilever structure, and the thick plate blank to be measured is fixed on the processing table of the CNC machine tool in the designated manner, including: clamping the center of the thick plate blank to be measured by the clamping device of the processing table of the CNC machine tool; clamping one side of the thick plate blank to be measured by a pressure plate to fix the thick plate blank to be measured on the processing table of the CNC machine tool according to the cantilever structure.

[0010] Optionally, determining the initial coordinates of the thick plate blank to be measured includes: constructing a coordinate system for the CNC machine tool processing table; using the upper surface of the free end of the thick plate blank corresponding to the thick plate blank to be measured as the point to be measured; and obtaining the coordinates of the point to be measured based on the coordinate system as the initial coordinates.

[0011] Optionally, determining the grooving depth of the thick plate blank to be measured includes: obtaining the thickness of the thick plate blank to be measured and the number of processing times preset by the user; determining the ratio of the thickness to the number of processing times, and using the ratio as the grooving depth.

[0012] Optionally, a slotting deformation sequence is determined according to the slotting processing depth and the initial coordinates, including: slotting the thick plate blank to be measured one by one according to the slotting processing depth and the number of processing times to obtain the changed coordinates of the points to be measured; calculating the coordinate difference between the changed coordinates and the initial coordinates to determine the slotting deformation; and arranging the slotting deformations in sequence according to the number of processing times to generate a slotting deformation sequence.

[0013] Optionally, the residual stress field of the thick plate blank to be measured is determined according to the groove processing depth and the groove deformation sequence, including: constructing a finite element model algorithm, and determining the deformation coefficient according to the finite element model algorithm; determining the unknown coefficient based on the stress inverse algorithm through the groove processing depth, the groove deformation sequence and the deformation coefficient; obtaining a preset residual stress field algorithm, and substituting the unknown coefficient into the preset residual stress field algorithm to determine the residual stress field.

[0014] Optionally, constructing a finite element model algorithm includes: obtaining attribute information of the thick plate blank to be tested, wherein the attribute information includes constitutive parameters of the blank material, workpiece geometry and clamping method; obtaining an initial algorithm model, and inputting the attribute information as boundary conditions into the initial algorithm model to generate a finite element model algorithm.

[0015] According to another aspect of the present invention, there is provided a device for determining residual stress field of a thick plate blank, the device comprising:

[0016] The thick plate blank fixing and coordinate determination module is used to fix the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner and determine the initial coordinates of the thick plate blank to be measured;

[0017] A slotting depth and deformation sequence determination module is used to determine the slotting depth of the thick plate blank to be measured, and to determine the slotting deformation sequence according to the slotting depth and the initial coordinates;

[0018] The residual stress field determination module is used to determine the residual stress field of the thick plate blank to be measured according to the groove processing depth and the groove deformation sequence.

[0019] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0020] at least one processor; and

[0021] a memory communicatively connected to the at least one processor; wherein,

[0022] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute a method for determining residual stress field of a thick plate blank as described in any embodiment of the present invention.

[0023] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement a method for determining residual stress field of a thick plate blank as described in any embodiment of the present invention when executed.

[0024] The technical solution of the embodiment of the present invention is to fix the thick plate blank to be measured on the processing table of a CNC machine tool according to a cantilever structure, and successively process the thick plate blank to be measured according to the groove processing depth to obtain the groove deformation sequence, and finally determine the residual stress distribution by combining the groove processing depth and the groove deformation sequence with the stress inverse algorithm, thereby realizing the measurement of the residual stress field of the blank at the structural part processing site, providing quantitative representation for the blank factory inspection, and providing data input for the evaluation and prediction of subsequent processing deformation and CNC process design.

[0025] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is a flow chart of a method for determining residual stress field of a thick plate blank provided in accordance with the first embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a method for fixing a thick plate blank to be tested according to the first embodiment of the present invention;

[0029] Figure 3 is a flow chart of another method for determining residual stress field of thick plate blank provided in Embodiment 2 of the present invention;

[0030] Figure 4 This is a schematic diagram of a thick plate blank residual stress field testing process provided in accordance with the second embodiment of the present invention;

[0031] Figure 52 is a schematic structural diagram of a device for determining residual stress field of a thick plate blank provided in accordance with a third embodiment of the present invention;

[0032] Figure 6 It is a structural schematic diagram of an electronic device for implementing a method for determining residual stress field of a thick plate blank according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] Embodiment 1

[0036] Figure 1 A flowchart of a method for determining the residual stress field of a thick plate blank is provided for the first embodiment of the present invention. This embodiment is applicable to the case where the residual stress field of a workpiece blank is measured at a structural part processing site. The method can be performed by a device for determining the residual stress field of a thick plate blank. The device for determining the residual stress field of a thick plate blank can be implemented in the form of hardware and / or software. The device for determining the residual stress field of a thick plate blank can be configured in a computer controller. Figure 1 As shown, the method includes:

[0037] S110, fixing the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner, and determining the initial coordinates of the thick plate blank to be measured.

[0038] Among them, the thick plate blank refers to the processing raw material of the integral frame beam structure of the aircraft, and the residual stress refers to the self-balanced internal stress that remains in the object after eliminating the external force or uneven temperature field, which can cause residual stress in mechanical processing and strengthening processes. The residual stress field in this embodiment specifically refers to the residual stress field distributed along the depth generated in the blank material during the front process (rolling forming, solution heat treatment, aging treatment and pre-stretching treatment, etc.) of the thick plate blank manufacturing. This residual stress is often introduced during the front forming and heat treatment process of the blank, and causes deformation of the workpiece in subsequent CNC processing.

[0039] Specifically, in CNC machining, the workpiece warps due to the partial release and rebalancing of the residual stress in the blank during material removal. Such machining deformation caused by residual stress in the blank often requires additional cutting or heat treatment processes to gradually eliminate it. Severe machining deformation may even cause the workpiece to be scrapped due to out-of-tolerance. Therefore, it is beneficial to obtain the residual stress distribution in the sheet blank before CNC machining. On the one hand, it provides an important quantitative characterization for the blank factory inspection in batch production, and on the other hand, it provides data input for the evaluation and prediction of subsequent machining deformation and CNC process design.

[0040] Optionally, the designated method is a cantilever structure, and the thick plate blank to be measured is fixed on the processing table of the CNC machine tool in the designated manner, including: clamping the center of the thick plate blank to be measured by the clamping device of the processing table of the CNC machine tool; clamping one side of the thick plate blank to be measured by a pressure plate to fix the thick plate blank to be measured on the processing table of the CNC machine tool according to the cantilever structure.

[0041] Specifically, when the thick plate blank to be measured is fixed on the CNC machine tool processing table according to the cantilever structure, it is necessary to first clamp the center of the thick plate blank to be measured by the clamping device of the CNC machine tool processing table, and then clamp one side of the thick plate blank to be measured by the pressure plate.

[0042] For example, Figure 2 A schematic diagram of a fixing method for a thick plate blank to be measured is provided for this embodiment 1, wherein δ represents the deformation amount, Figure 2 The figure shows a schematic diagram of fixing a thick plate blank on a CNC machine tool processing table using a clamping device: the pressing plate and the pressing block complete three-point positioning and clamping in the middle of the plate, and press one side of the plate to form a cantilever structure with one side fixed and the other side free.

[0043] Optionally, determining the initial coordinates of the thick plate blank to be measured includes: constructing a coordinate system for the CNC machine tool processing table; using the upper surface of the free end of the thick plate blank corresponding to the thick plate blank to be measured as the point to be measured; and obtaining the coordinates of the point to be measured based on the coordinate system as the initial coordinates.

[0044] Specifically, a coordinate system can be constructed for the CNC machine tool processing table, and then the upper surface of the free end of the thick plate blank to be measured is used as the measurement point, that is, the initial coordinates of the upper surface of the free end of the blank in the initial positioning and clamping state are obtained through the machine tool probe and the CNC system.

[0045] S120, determining the notching depth of the thick plate blank to be measured, and determining the notching deformation sequence according to the notching depth and the initial coordinates.

[0046] Optionally, determining the grooving depth of the thick plate blank to be measured includes: obtaining the thickness of the thick plate blank to be measured and the number of processing times preset by the user; determining the ratio of the thickness to the number of processing times, and using the ratio as the grooving depth.

[0047] Specifically, the grooving processing depth can be a depth specified by the user. The controller will groove the thick plate blank to be processed one by one according to the grooving processing depth. The user can preset the number of processing times. The controller will obtain the thickness of the thick plate blank to be measured and calculate the ratio of the thickness and the number of processing times to determine the single grooving processing depth. For example, the thickness of the thick plate blank to be processed can be 50 mm. When the number of processing times is 50 times, the grooving processing depth is 1 mm.

[0048] Optionally, a slotting deformation sequence is determined according to the slotting processing depth and the initial coordinates, including: slotting the thick plate blank to be measured one by one according to the slotting processing depth and the number of processing times to obtain the changed coordinates of the points to be measured; calculating the coordinate difference between the changed coordinates and the initial coordinates to determine the slotting deformation; and arranging the slotting deformations in sequence according to the number of processing times to generate a slotting deformation sequence.

[0049] Specifically, the controller can perform slotting on the thick plate blank to be tested one by one according to the slotting depth and the number of processing times, that is, the CNC machine tool performs slotting processing at a specified slotting depth at the central position of the thick plate blank, so that the free end of the blank is deformed due to the release of local residual stress in the slotting area, and the change coordinates of the upper surface of the free end of the blank after the slotting processing can be obtained through the machine tool probe and the CNC system, and the coordinate difference between the change coordinates and the initial coordinates can be calculated to determine the slotting deformation. Until the slot depth reaches the specified position of the blank thickness, the slotting deformations can be arranged in sequence according to the number of processing times to generate a slotting deformation sequence.

[0050] S130, determining the residual stress field of the thick plate blank to be measured according to the groove processing depth and the groove deformation amount sequence.

[0051] Specifically, the controller can determine the residual stress distribution in the thick plate blank by using the stress inverse algorithm according to the slotting depth and the corresponding slotting deformation sequence. The residual stress field is expressed by the following formula (1):

[0052]

[0053] Wherein, formula (1) uses polynomial series expansion to express the residual stress distribution of the blank along the thickness direction, σ(z) is the residual stress distribution in the thick plate blank, A j is the unknown coefficient to be determined, P j (z) is the polynomial basis function. For the residual stress distribution problem of thick plate blank, Legendre polynomials of order 2 or above can be used for approximation, because the distribution of the polynomial basis function naturally satisfies the internal force balance and moment balance conditions.

[0054] The technical solution of the embodiment of the present invention is to fix the thick plate blank to be measured on the processing table of a CNC machine tool according to a cantilever structure, and successively process the thick plate blank to be measured according to the groove processing depth to obtain the groove deformation sequence, and finally determine the residual stress distribution by combining the groove processing depth and the groove deformation sequence with the stress inverse algorithm, thereby realizing the measurement of the residual stress field of the blank at the structural part processing site, providing quantitative representation for the blank factory inspection, and providing data input for the evaluation and prediction of subsequent processing deformation and CNC process design.

[0055] Embodiment 2

[0056] Figure 3 This is a flow chart of a method for determining the residual stress field of a thick plate blank provided in the second embodiment of the present invention. Based on the first embodiment, this embodiment specifically describes the process of determining the residual stress field of the thick plate blank to be measured according to the groove processing depth and the groove deformation sequence. Among them, the specific contents of steps S210-S220 are roughly the same as steps S110-S120 in the first embodiment, so they will not be repeated in this embodiment. Figure 3 As shown, the method includes:

[0057] S210, fixing the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner, and determining the initial coordinates of the thick plate blank to be measured.

[0058] Optionally, the designated method is a cantilever structure, and the thick plate blank to be measured is fixed on the processing table of the CNC machine tool in the designated manner, including: clamping the center of the thick plate blank to be measured by the clamping device of the processing table of the CNC machine tool; clamping one side of the thick plate blank to be measured by a pressure plate to fix the thick plate blank to be measured on the processing table of the CNC machine tool according to the cantilever structure.

[0059] Optionally, determining the initial coordinates of the thick plate blank to be measured includes: constructing a coordinate system for the CNC machine tool processing table; using the upper surface of the free end of the thick plate blank corresponding to the thick plate blank to be measured as the point to be measured; and obtaining the coordinates of the point to be measured based on the coordinate system as the initial coordinates.

[0060] S220, determining the notching depth of the thick plate blank to be measured, and determining the notching deformation sequence according to the notching depth and the initial coordinates.

[0061] Optionally, determining the grooving depth of the thick plate blank to be measured includes: obtaining the thickness of the thick plate blank to be measured and the number of processing times preset by the user; determining the ratio of the thickness to the number of processing times, and using the ratio as the grooving depth.

[0062] Optionally, a slotting deformation sequence is determined according to the slotting processing depth and the initial coordinates, including: slotting the thick plate blank to be measured one by one according to the slotting processing depth and the number of processing times to obtain the changed coordinates of the points to be measured; calculating the coordinate difference between the changed coordinates and the initial coordinates to determine the slotting deformation; and arranging the slotting deformations in sequence according to the number of processing times to generate a slotting deformation sequence.

[0063] S230, constructing a finite element model algorithm, and determining a deformation coefficient according to the finite element model algorithm.

[0064] Optionally, constructing a finite element model algorithm includes: obtaining attribute information of the thick plate blank to be tested, wherein the attribute information includes constitutive parameters of the blank material, workpiece geometry and clamping method; obtaining an initial algorithm model, and inputting the attribute information as boundary conditions into the initial algorithm model to generate a finite element model algorithm.

[0065] Specifically, the controller can obtain the attribute information of the thick plate blank to be tested as the boundary condition input into the initial algorithm model to generate a finite element model algorithm. The attribute information includes the constitutive parameters of the blank material, the workpiece geometry and the clamping method, so as to realize the finite element solution of the deformation coefficient corresponding to different groove depths under the stress distribution of Legendre polynomial basis functions of order 2 or above.

[0066] Specifically, the deformation coefficient can be determined according to the constructed finite element model algorithm, and the deformation coefficient is expressed by the following formula (2):

[0067]

[0068] Among them, C ij is the deformation coefficient, Δh i is the slotting depth, P j (z) is the polynomial basis function, δ(Δh i ) is the slotting deformation. The above formula is obtained by finite element program based on linear elastic calculation of thick plate blank at different orders of polynomial function P j (z) Successive slotting depth Δh under internal stress distribution i The corresponding deformation coefficient is as follows.

[0069] S240, determining the unknown coefficients based on the stress inverse algorithm according to the slotting processing depth, the slotting deformation sequence and the deformation coefficient.

[0070] Specifically, the undetermined coefficient is determined based on the stress inverse algorithm through the slotting processing depth, the slotting deformation sequence and the deformation coefficient. The slotting deformation corresponding to the slotting depth is first determined according to the deformation coefficient, and is expressed by the following formula (3):

[0071]

[0072] Among them, δ(Δh i ) is the slotting deformation, C ij is the deformation coefficient, Δh i is the slotting depth, A is the unknown coefficient to be determined. In order to ensure the precision of the inverse calculation of stress distribution in space, a small successive slotting depth is used. The number of groups of measured free end deformation is often much larger than the order m of the polynomial function used. The above slotting depth-free end deformation relationship constitutes a set of overdetermined linear equations. In the sense of least squares, the unknown coefficient is expressed by the following formula (4):

[0073] {A}=[(C T C) -1 C T ]{δ} (4)

[0074] Among them, A is the unknown coefficient to be determined, C is the deformation coefficient, and δ is the slotting deformation.

[0075] S250, obtaining a preset residual stress field algorithm, and substituting the undetermined coefficients into the preset residual stress field algorithm to determine the residual stress field.

[0076] Specifically, the unknown coefficients are substituted into the preset residual stress field algorithm to determine the residual stress field, and the residual stress field is finally expressed by the following formula (5):

[0077] σ(z)=[P][(C T C) -1 C T ]{δ} (5)

[0078] Among them, σ(z) is the residual stress distribution in the thick plate blank, C is the deformation coefficient, δ is the notching deformation, and P is the polynomial basis function.

[0079] Specific implementation method: Figure 4 A schematic diagram of a thick plate blank residual stress field test process is provided for this embodiment. Figure 4In the method, after the thick plate blank to be tested is clamped according to the cantilever structure, the coordinate value of the upper surface of the free end of the blank can be obtained by the machine tool probe as the initial coordinate. When the slotting depth reaches the specified position, the deformation sequence corresponding to the slotting depth is obtained. At the same time, the controller will obtain the constitutive parameters of the blank material, the workpiece geometry, the clamping method and other boundary conditions to input the finite element model, and solve the finite element solution of the deformation coefficient corresponding to different slot depths under the stress distribution of Legendre polynomial basis functions of order 2 or above, and finally solve the overdetermined equation to obtain the residual stress distribution. This method can directly realize the in-situ test of the residual stress distribution of thick plate blanks on CNC machine tools at the processing site, provide an important quantitative characterization method for the factory inspection of thick plate blanks in batch production, and input the initial stress distribution conditions for the prediction and control process of stress release deformation of parts in subsequent CNC processing.

[0080] The technical solution of the embodiment of the present invention is to fix the thick plate blank to be measured on the processing table of a CNC machine tool according to a cantilever structure, and successively process the thick plate blank to be measured according to the groove processing depth to obtain the groove deformation sequence, and finally determine the residual stress distribution by combining the groove processing depth and the groove deformation sequence with the stress inverse algorithm, thereby realizing the measurement of the residual stress field of the blank at the structural part processing site, providing quantitative representation for the blank factory inspection, and providing data input for the evaluation and prediction of subsequent processing deformation and CNC process design.

[0081] Embodiment 3

[0082] Figure 5 This is a schematic diagram of the structure of a device for determining residual stress field of a thick plate blank provided in the third embodiment of the present invention. Figure 5 As shown, the device includes: a thick plate blank fixing and coordinate determination module 310, which is used to fix the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner and determine the initial coordinates of the thick plate blank to be measured; a slotting processing depth and deformation sequence determination module 320, which is used to determine the slotting processing depth of the thick plate blank to be measured, and determine the slotting deformation sequence according to the slotting processing depth and the initial coordinates; a residual stress field determination module 330, which is used to determine the residual stress field of the thick plate blank to be measured according to the slotting processing depth and the slotting deformation sequence.

[0083] Optionally, the thick plate blank fixing and coordinate determination module 310 specifically includes: a thick plate blank fixing unit, used to: clamp the center of the thick plate blank to be measured by the clamping device of the CNC machine tool processing table; clamp one side of the thick plate blank to be measured by a pressure plate to fix the thick plate blank to be measured on the CNC machine tool processing table according to a cantilever structure.

[0084] Optionally, the thick plate blank fixing and coordinate determination module 310 specifically includes: an initial coordinate determination unit, used to: construct a coordinate system for the CNC machine tool processing table; use the upper surface of the free end of the thick plate blank corresponding to the thick plate blank to be measured as the point to be measured; and obtain the coordinates of the point to be measured based on the coordinate system as the initial coordinates.

[0085] Optionally, the slotting depth and deformation sequence determination module 320 specifically includes: a slotting depth determination unit, used to: obtain the thickness of the thick plate blank to be measured and the number of processing times preset by the user; determine the ratio of the thickness and the number of processing times, and use the ratio as the slotting depth.

[0086] Optionally, the slotting processing depth and deformation sequence determination module 320 specifically includes: a deformation sequence determination unit, which is used to: slot the thick plate blank to be tested one by one according to the slotting processing depth and the number of processing times to obtain the changed coordinates of the points to be tested; calculate the coordinate difference between the changed coordinates and the initial coordinates to determine the slotting deformation; and arrange the slotting deformations in sequence according to the number of processing times to generate a slotting deformation sequence.

[0087] Optionally, the residual stress field determination module 330 specifically includes: a deformation coefficient determination unit, used to: construct a finite element model algorithm, and determine the deformation coefficient according to the finite element model algorithm; an undetermined coefficient determination unit, used to: determine the undetermined coefficient based on the stress inverse algorithm through the groove processing depth, the groove deformation sequence and the deformation coefficient; a residual stress field determination unit, used to: obtain a preset residual stress field algorithm, and substitute the undetermined coefficient into the preset residual stress field algorithm to determine the residual stress field.

[0088] Optionally, the deformation coefficient determination unit specifically includes: a finite element model algorithm construction sub-unit, used to: obtain the attribute information of the thick plate blank to be tested, wherein the attribute information includes the constitutive parameters of the blank material, the workpiece geometry and the clamping method; obtain the initial algorithm model, and input the attribute information as a boundary condition into the initial algorithm model to generate a finite element model algorithm.

[0089] The technical solution of the embodiment of the present invention is to fix the thick plate blank to be measured on the processing table of a CNC machine tool according to a cantilever structure, and successively process the thick plate blank to be measured according to the groove processing depth to obtain the groove deformation sequence, and finally determine the residual stress distribution by combining the groove processing depth and the groove deformation sequence with the stress inverse algorithm, thereby realizing the measurement of the residual stress field of the blank at the structural part processing site, providing quantitative representation for the blank factory inspection, and providing data input for the evaluation and prediction of subsequent processing deformation and CNC process design.

[0090] A device for determining residual stress field of a thick plate blank provided in an embodiment of the present invention can execute a method for determining residual stress field of a thick plate blank provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0091] Embodiment 4

[0092] Figure 6 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0093] like Figure 6 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0094] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0095] The processor 11 can be various general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 11 executes the various methods and processes described above, such as a method for determining the residual stress field of a thick plate blank. That is: the thick plate blank to be measured is fixed on the processing table of a CNC machine tool in a specified manner, and the initial coordinates of the thick plate blank to be measured are determined; the groove processing depth of the thick plate blank to be measured is determined, and the groove deformation sequence is determined according to the groove processing depth and the initial coordinates; the residual stress field of the thick plate blank to be measured is determined according to the groove processing depth and the groove deformation sequence.

[0096] In some embodiments, a method for determining a residual stress field of a thick plate blank may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for determining a residual stress field of a thick plate blank described above may be executed. Alternatively, in other embodiments, the processor 11 may be configured to execute a method for determining a residual stress field of a thick plate blank by any other appropriate means (e.g., by means of firmware).

[0097] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0098] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0099] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer 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 foregoing.

[0100] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0101] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0102] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0103] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0104] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining residual stress field of thick plate blank, characterized in that: include: Fixing the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner, and determining the initial coordinates of the thick plate blank to be measured; Determine the slotting depth of the thick plate blank to be measured, and determine the slotting deformation sequence according to the slotting depth and the initial coordinates; The residual stress field of the thick plate blank to be measured is determined according to the groove processing depth and the groove deformation sequence.

2. The method according to claim 1, characterized in that The specified method is a cantilever structure, The method of fixing the thick plate blank to be tested on the processing table of the CNC machine tool in a specified manner includes: The center of the thick plate blank to be measured is clamped by the clamping device of the CNC machine tool processing table; One side of the thick plate blank to be measured is clamped by a pressing plate, so that the thick plate blank to be measured is fixed on the processing table of the CNC machine tool according to the cantilever structure.

3. The method according to claim 1, characterized in that The step of determining the initial coordinates of the thick plate blank to be measured comprises: Constructing a coordinate system for the CNC machine tool processing table; The upper surface of the free end of the blank corresponding to the thick plate blank to be measured is used as a point to be measured; The coordinates of the point to be measured are acquired based on the coordinate system as the initial coordinates.

4. The method according to claim 3, characterized in that The step of determining the groove processing depth of the thick plate blank to be measured comprises: Obtaining the thickness of the thick plate blank to be measured and the number of processing times preset by the user; The ratio of the thickness to the number of processing times is determined, and the ratio is used as the groove processing depth.

5. The method according to claim 4, characterized in that The step of determining the slotting deformation sequence according to the slotting processing depth and the initial coordinates includes: The thick plate blank to be measured is slotted one by one according to the slotting processing depth and the processing times to obtain the change coordinates of the points to be measured; Calculating the coordinate difference between the changed coordinate and the initial coordinate to determine the slotting deformation amount; The slotting deformation amounts are arranged in sequence according to the number of processing times to generate the slotting deformation amount sequence.

6. The method according to claim 1, characterized in that The method of determining the residual stress field of the thick plate blank to be measured according to the groove processing depth and the groove deformation sequence includes: Construct a finite element model algorithm, and determine the deformation coefficient according to the finite element model algorithm; Determine the coefficient to be determined based on the stress inverse algorithm through the groove processing depth, the groove deformation sequence and the deformation coefficient; A preset residual stress field algorithm is obtained, and the undetermined coefficients are substituted into the preset residual stress field algorithm to determine the residual stress field.

7. The method according to claim 6, characterized in that The finite element model construction algorithm comprises: Acquiring property information of the thick plate blank to be measured, wherein the property information includes constitutive parameters of the blank material, workpiece geometry and clamping method; An initial algorithm model is obtained, and the attribute information is input into the initial algorithm model as a boundary condition to generate the finite element model algorithm.

8. A device for determining residual stress field of thick plate blank, characterized in that: include: A thick plate blank fixing and coordinate determination module is used to fix the thick plate blank to be measured on the processing table of the CNC machine tool in a specified manner and determine the initial coordinates of the thick plate blank to be measured; A slotting depth and deformation sequence determination module is used to determine the slotting depth of the thick plate blank to be measured, and determine the slotting deformation sequence according to the slotting depth and the initial coordinates; The residual stress field determination module is used to determine the residual stress field of the thick plate blank to be measured according to the groove processing depth and the groove deformation sequence.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the method according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that: The computer storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method according to any one of claims 1 to 7 when executed.

Images