Method for determining inherent strain in additive manufacturing and simulated manufacturing method of 3D (three-dimensional) object

Abstract

The invention discloses a method for determining inherent strain in additive manufacturing, a simulation manufacturing method of a 3D object, an additive manufacturing simulation system, computer equipment, a computer readable storage medium and a computer program product. The method for determining the inherent strain in additive manufacturing comprises the following steps that the deformation amount of a printing piece which is printed through a preset metal material and corresponds to an arc-shaped thin-wall structure is obtained; wherein the horizontal offset of at least two measuring points on the side edge of the printed piece is used as the deformation; and taking the deformation amount as an input to determine an inherent strain value corresponding to the preset metal material by using an inherent strain calibration network.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and specifically to a method for determining inherent strain in additive manufacturing, a method for simulating manufacturing of 3D objects, an additive manufacturing simulation system, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] In the field of metal additive manufacturing (also known as metal 3D printing), the existence of inherent strain causes the printed 3D objects to deform, which in turn causes the printed 3D objects to be inconsistent with the expected 3D objects (or inconsistent with the 3D model corresponding to the 3D objects), reducing printing accuracy and increasing printing costs.

[0003] Therefore, determining the inherent strain of the printing material before actual printing to accurately predict the deformation of the 3D object is helpful to improve printing accuracy. For example, by determining the inherent strain of the printing material before actually printing the 3D object, the deformation of the 3D object can be accurately predicted, and then the deformation caused by the inherent strain can be compensated by optimizing the printing model, so that the printed 3D object meets the expectations / standards. However, since the inherent strains of different printing materials are different and cannot be directly measured, it is difficult to accurately predict the deformation of 3D components. For example, industrial fields such as aerospace have extremely high requirements for safety and reliability, and any minor defects may lead to catastrophic consequences.

[0004] Therefore, how to determine the inherent strain value of the printing material in additive manufacturing to accurately predict the deformation of 3D objects and ensure the quality and consistency of 3D printed parts is a technical problem that needs to be urgently solved in the application of simulation technology in the 3D printing process. Summary of the invention

[0005] In view of the shortcomings of the related technologies mentioned above, the purpose of the present application is to provide a method for determining inherent strain in additive manufacturing, a simulation manufacturing method for 3D objects, an additive manufacturing simulation system, a computer device, a computer-readable storage medium and a computer program product, so as to solve the technical problem of how to accurately predict the deformation of 3D objects to ensure the quality and consistency of 3D printed parts.

[0006] To achieve the above-mentioned purpose and other related purposes, the first aspect disclosed in the present application discloses a method for determining inherent strain in additive manufacturing, comprising the following steps: obtaining the deformation amount of a printout corresponding to an arc-shaped thin-walled structure printed using a preset metal material; wherein the horizontal offset of at least two measuring points located on the side of the printout is used as the deformation amount; and the deformation amount is used as input to determine the inherent strain value corresponding to the preset metal material using an inherent strain calibration network.

[0007] The second aspect of the present application discloses a simulation manufacturing method for a 3D object, comprising simulating printing a 3D model based on the inherent strain value determined by the method for determining the inherent strain in additive manufacturing as described in any embodiment of the first aspect of the present application to form a simulation part of the 3D object.

[0008] The third aspect of the present application discloses an additive manufacturing simulation system, comprising: an inherent strain calibration module, used to obtain the deformation of a printout corresponding to an arc-shaped thin-walled structure printed using a preset metal material, and to use the deformation as input to determine the inherent strain value corresponding to the preset metal material using an inherent strain calibration network; wherein the horizontal offset of at least two measuring points located on the side of the printout is used as the deformation; and a simulation module, used to simulate printing of a 3D model based on the inherent strain value output by the inherent strain calibration module to form a simulation of a 3D object.

[0009] The fourth aspect of the present application discloses a computer device, comprising: a storage device for storing at least one program; a processing device connected to the storage device, for calling the at least one program from the storage device and executing it to implement the method for determining the inherent strain in additive manufacturing as described in any embodiment of the first aspect, or to implement the simulation manufacturing method of the 3D object as described in the second aspect.

[0010] The fifth aspect of the present application discloses a computer-readable storage medium storing at least one program, which, when called and executed by a processor of a computer, implements a method for determining inherent strain in additive manufacturing as described in any embodiment of the first aspect, or implements a method for simulating manufacturing of a 3D object as described in the second aspect.

[0011] In a sixth aspect, the present application discloses a computer program product. When the computer program product is run on a computer, the computer executes the method for determining inherent strain in additive manufacturing as described in any embodiment of the first aspect, or implements the simulation manufacturing method of a 3D object as described in the second aspect.

[0012] In summary, the method for determining inherent strain in additive manufacturing, the method for simulating manufacturing of 3D objects, the additive manufacturing simulation system, computer equipment, computer-readable storage medium and computer program product disclosed in the present application determine the inherent strain value of a preset metal material by inputting the horizontal offset of at least two measuring points on the side of a printed part corresponding to an arc-shaped thin-walled structure as the deformation into the inherent strain calibration network. Since the horizontal offset of the measuring point is only related to the inherent strain and does not need to be measured after cutting, the present application can not only accurately determine the inherent strain value in additive manufacturing for accurately predicting the deformation that may occur in the 3D object in the actual printing operation, thereby ensuring the quality and consistency of the 3D printed parts, but also improves the calculation speed of determining the inherent strain value through the inherent strain calibration network. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific features of the invention involved in this application are shown in the attached claims. The features and advantages of the invention involved in this application can be better understood by referring to the exemplary embodiments and drawings described in detail below. The drawings are briefly described as follows:

[0014] Figure 1 Shown is a schematic diagram of a construction volume in a computer three-dimensional space in one embodiment of the present application.

[0015] Figure 2 It is a schematic diagram showing how to determine the warpage value of a cantilever structure in the related art.

[0016] Figure 3 It is a schematic flow chart of a method for determining inherent strain in additive manufacturing in one embodiment of the present application.

[0017] Figure 4 Shown is a schematic diagram of a curved thin-wall structure in one embodiment of the present application.

[0018] Figure 5 A schematic diagram showing the horizontal offset of a measuring point corresponding to a fourth position marker in an embodiment of the present application is shown.

[0019] Figure 6 Shown is a thermal distribution diagram of the horizontal offset of a print portion in one embodiment of the present application.

[0020] Figure 7 Shown is a schematic diagram of an interface of a first calibration window in one embodiment of the present application.

[0021] Figure 8 In one embodiment of the present application, the user enters in the first calibration window Figure 6 Schematic diagram of the interface showing the deformation of the printed part.

[0022] Fig. 9 The display is input in the first calibration window of another embodiment of the present application Figure 6 The deformation of the printed part and the interface diagram of the printing material are shown.

[0023] Fig.10 It is a schematic flow chart of a method for determining inherent strain in additive manufacturing in another embodiment of the present application.

[0024] Fig.11 It is a flowchart of step S130 in one embodiment of the present application.

[0025] Fig.12 Shown is a schematic diagram of an interface of a second calibration window in one embodiment of the present application.

[0026] Fig.13 Shown is a schematic diagram of a second calibration window after verification is completed in one embodiment of the present application.

[0027] Fig.14 Shown is a module block diagram of an additive manufacturing simulation system in one embodiment of the present application.

[0028] Fig.15 Shown is a schematic diagram of the structure of a computer device in one embodiment of the present application. DETAILED DESCRIPTION

[0029] The following is a description of the embodiments of the present application by specific specific embodiments, and those familiar with the technology can easily understand the advantages of the present application and the technical effects that can be achieved by the content disclosed in this specification. In the following description, some embodiments can refer to the drawings pointed to. It should be understood that other embodiments without drawing drawings can also be used, and specific steps, modules or units, electrical and operational changes can be made without departing from the spirit and scope of the present application. The detailed description below should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims published by the present application. The terms used herein are only for describing specific embodiments and are not intended to limit the present application.

[0030] Although the terms first, second or third etc. are used to describe various elements or parameters in this article in some instances, these elements or parameters should not be limited by these terms. These terms are only used to distinguish an object or parameter from another object or parameter, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first position marker can be referred to as the second position marker, and similarly, the second position marker can be referred to as the first position marker, without departing from the scope of the various described embodiments, the first position marker and the second position marker are both position markers on the side of the arc-shaped thin-walled structure, but unless the context clearly indicates otherwise, they are not the same position marker. Similar situations also include the first calibration window and the second calibration window, and the first simulation component and the second simulation component.

[0031] Furthermore, as used in this article, the singular forms "one", "an" and "the" are intended to also include plural forms, unless there is an indication to the contrary in the context. It should be further understood that the terms "comprising", "including" indicate the presence of the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. For example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, the term "and / or" that may be used hereinafter, describes the association relationship of associated objects, indicating that three kinds of relationships may exist, for example, A and / or B, which can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", if not otherwise specified, generally represents that the associated objects before and after are a kind of "and / or" relationship. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two.

[0032] Some nouns or terms used in each embodiment of the present application are explained below, and the nouns or terms are also used as a part of the content of the invention. It will be appreciated by those skilled in the art that, unless otherwise defined, all terms including technical terms and scientific terms used herein have the same meaning as the general understanding of the technicians in the field to which the present application belongs. It should also be understood that those terms such as those defined in general dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and unless specifically defined as herein, will not be interpreted with an idealized or overly formal meaning.

[0033] The construction volume described in the embodiments of the present application is a space corresponding to the printing space of the 3D printing device, and the 3D model placed in the construction volume can be manufactured in the printing space. The construction volume is in a computer three-dimensional space corresponding to the actual printing space, and the computer three-dimensional space has a coordinate system. In the embodiments, a corner of the construction volume can be used as the origin of the coordinates to form the coordinate system of the computer three-dimensional space. Please refer to Figure 1 , which is a schematic diagram of a construction volume in a three-dimensional computer space in one embodiment of the present application, wherein a construction volume V is formed in the three-dimensional computer space R. Figure 1 The lower left corner of the build volume V is taken as the coordinate origin O, thereby forming a coordinate system XYZ of the computer three-dimensional space. The surface of the build volume V on the XOY plane corresponds to the printing surface of the actual printing platform. In the embodiments of the present application, the XOY plane is also referred to as the reference plane. In addition, the direction parallel to the XOY plane in the computer three-dimensional space R and the direction parallel to the printing surface of the printing platform in the printing space are referred to as horizontal directions, and the direction perpendicular to the XOY plane in the computer three-dimensional space R and the direction perpendicular to the printing surface in the printing space are referred to as vertical directions.

[0034] The 3D model described in the embodiments of the present application can use three-dimensional coordinate data to describe its position and shape in the three-dimensional space of the computer. The three-dimensional coordinate data includes, for example, a starting position of the 3D model, and each offset position determined according to the relative position relationship between each position in the 3D model space and the starting position, or a positioning position determined according to each offset position and the starting position surface. Among them, the starting position, offset position and positioning position can all be exemplified as three-dimensional coordinate values ​​described by means of a computer three-dimensional space coordinate system. The 3D model can be pre-stored in a model library, and the 3D model can be imported into the computer three-dimensional space from the model library. For example, the 3D model can be imported from the model library into the build volume in the computer three-dimensional space, or it can be imported into the computer three-dimensional space and then moved to the build volume.

[0035] The inherent strain value described in the embodiments of the present application is a quantitative value of the inherent strain. The inherent strain represents all final strains except elastic strain generated on the printed part during the additive manufacturing (also known as 3D printing) process. In other words, the inherent strain refers to the permanent strain generated by the physical, chemical or microstructural changes of the printed material itself without external loads during the additive manufacturing process. Due to the existence of inherent strain, the printed part will be permanently deformed. For example, the inherent strain value includes the inherent strain value ε in the X direction xx , the inherent strain value ε in the Y direction yy , and the inherent strain value ε in the Z direction zz Among them, the X-direction inherent strain value εxx It is the quantitative value of the inherent strain in the direction corresponding to the X direction of the build volume in the printing space, and the Y direction inherent strain value ε yy It is the quantitative value of the inherent strain in the direction corresponding to the Y direction of the build volume in the printing space, and the inherent strain value ε in the Z direction zz It is a quantified value of the inherent strain in the print space in the direction corresponding to the Z direction of the build volume.

[0036] The complex printing parameters of different materials, as well as the difficulty in controlling thermal stress and deformation problems during the printing process, can affect the performance and reliability of the printed parts. In particular, metal 3D printing represented by the SLM process will undergo multiple thermal cycles, that is, laser melting and subsequent cooling during the printing process will cause repeated thermal expansion and contraction of the material, and each layer of thermal cycle printed will produce new stress and deformation, especially for metal materials with high thermal conductivity, this effect is more significant. The unevenness and cumulative effect of thermal cycles and the multiple effects of factors such as thermal stress and residual stress can cause large warping deformation and even cracking of parts. At the same time, various material parameters of metal materials, such as parameters such as thermal expansion coefficient, thermal conductivity and elastic modulus, and related equipment parameters, such as laser power, scanning speed and scanning strategy, may affect the printing results. As described in the background technology, it is difficult to accurately predict the deformation of 3D objects because the inherent strain cannot be directly measured.

[0037] In order to determine the inherent strain, the related art usually sets a cantilever structure as a test sample, first prints the cantilever structure using a preset printing material and a preset printing process, and then performs multiple iterations based on the deformation of the cantilever structure as an input value to determine the inherent strain value that meets the convergence condition. Figure 2 , which is a schematic diagram of determining the warpage value of a cantilever structure in the related art. As shown in the figure, the cantilever structure 50 is a test sample printed by a preset printing material and a printing process. Before actually measuring the warpage value of the cantilever structure 50, in order to release the residual stress in the cantilever structure 50, the bottom of the cantilever structure 50 needs to be cut, for example, along Figure 2 The cutting surface indicated by the dotted arrow E is cut, and then the warpage value after cutting is measured, which is as shown in FIG. Figure 2 The △d shown is the measured warpage deformation value, and then the inverse problem solving method is used to iterate by continuously and tentatively adjusting the inherent strain value, so that the inherent strain value that meets the convergence condition is used as the inherent strain of the corresponding printing material to predict the deformation of the 3D object.

[0038] However, this method requires additional cutting, which increases the complexity of the process on the one hand, and on the other hand, during the cutting process, the cantilever structure 50 will be heated by cutting, and factors such as aging, creep, and stress relaxation caused by unreasonable cutting and measurement time will affect the warping deformation value of the cantilever structure 50. These factors are influencing factors other than the inherent strain, which makes the measured warping deformation value unreliable when used to determine the inherent strain value, and has low accuracy or even cannot be used.

[0039] In addition, when using the warping deformation value of the cantilever structure 50 in the Z direction to calibrate the anisotropic inherent strain, it is necessary to place the 3D model of the cantilever structure 50 in the X direction and the Y direction respectively, so as to print out two cantilever structures 50 for two cuttings and two measurements, which increases the complexity of the operation and introduces unreliable factors.

[0040] Furthermore, since the inverse problem solving method requires multiple iterative calculations to obtain the inherent strain value corresponding to the warping deformation value, the calculation amount is large, the calculation speed is slow, and the rationality of the pre-input inherent strain initial value is high. When the gap between the inherent strain initial value and the actual inherent strain value is large, it may be impossible to obtain an accurate inherent strain value because the preset number of iterations is stopped.

[0041] In view of this, the present application discloses a method for determining inherent strain in additive manufacturing, a simulation manufacturing method for 3D objects, an additive manufacturing simulation system, a computer device, a computer-readable storage medium and a computer program product. The present application mainly determines the inherent strain value of a preset metal material by inputting the horizontal offset of at least two measuring points on the side of a printed part corresponding to an arc-shaped thin-walled structure as a deformation amount into an inherent strain calibration network. Since the horizontal offset of the measuring point is only related to the inherent strain and does not need to be measured after cutting, the present application can not only accurately determine the inherent strain value in additive manufacturing for accurately predicting the deformation that may occur in the 3D object in the actual printing operation, thereby ensuring the quality and consistency of the 3D printed parts, but also improves the calculation speed of determining the inherent strain value through the inherent strain calibration network.

[0042] The present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments and technical effects obtained by ordinary technicians in this field without making creative work should belong to the scope of protection of this application. "An implementation method", "implementation method" or similar words mentioned in the whole text of this specification mean that the specific features, structures or characteristics described together with the implementation method are included in at least one implementation method of the present application. Therefore, in the whole text of this specification, the appearance of the phrases "in one implementation method", "in an implementation method" and similar words may (but not necessarily) relate to the same implementation method.

[0043] In some embodiments, the present application provides a method for determining inherent strain in additive manufacturing. The method for determining inherent strain in additive manufacturing can be executed by a computer device configured with an additive manufacturing simulation system. The additive manufacturing simulation system is a software tool or software module that can process data. The method for determining inherent strain in additive manufacturing is executed with the help of an operating environment provided by the hardware device and / or operating system in the computer device.

[0044] In the present application, the additive manufacturing is, for example, 3D printing manufacturing of metal materials represented by the SLM (Selective Laser Melting) process, but it is not a limitation of the present application. Examples of the processes used in the additive manufacturing may also be LBM (Laser Beam Melting), SLS (Selective Laser Sintering), DMLS (Direct Metal Laser Sintering), MBJ (Sintering of a Metal Binder Jetting), etc.

[0045] In one embodiment, the computer device can be configured as an electronic device, that is, the method for determining the inherent strain in additive manufacturing is executed by the electronic device. For example, the electronic device includes desktop computers, laptops, tablet computers, smart TVs, smart phones, tablets, industrial computers (such as industrial computers of additive manufacturing equipment / 3D printing equipment), etc. The electronic device can also be an electronic device composed of a host with multiple virtual machines and a human-computer interaction device corresponding to each virtual machine (such as a touch screen, keyboard and mouse).

[0046] In one embodiment, the computer device may be configured as a server, that is, the method for determining the inherent strain in additive manufacturing is executed by the server. The server may be arranged on one or more physical servers according to various factors such as function and load. In some examples, the server may be a server based on a cloud architecture, and the server refers to a cloud computing platform provided by a cloud computing provider, and the cloud computing platform can provide services such as IaaS (Infrastructure-as-a-Service), PaaS (Platform-as-a-Service), and SaaS (Software-as-a-Service). Among them, the cloud computing platform includes a public cloud, a private cloud, and a hybrid cloud. In some examples, the server may be composed of a distributed or centralized server cluster. For example, the server cluster is composed of at least one physical server. Multiple virtual servers are configured in each physical server, each virtual server runs at least one functional module in the system, and each virtual server communicates through a network.

[0047] See also Figure 3 , which is a flow chart of a method for determining inherent strain in additive manufacturing in one embodiment of the present application. As shown in the figure, the method for determining inherent strain in additive manufacturing includes step S110 and step S120. The following takes the method for determining inherent strain in additive manufacturing executed by a computer device as an example to illustrate various embodiments.

[0048] In step S110, a computer device obtains a deformation amount of a printed part corresponding to a curved thin-wall structure printed using a preset metal material.

[0049] Before executing step S110, it is necessary to first use a preset metal material to print out a printout corresponding to the arc-shaped thin-walled structure described in step S110, so as to determine the deformation amount of the printout. The arc-shaped thin-walled structure has a corresponding 3D model. Specifically, the additive manufacturing device (also referred to as a 3D printing device) calls the to-be-printed data corresponding to the arc-shaped thin-walled structure to perform additive manufacturing on the preset metal material to print out a printout corresponding to the arc-shaped thin-walled structure.

[0050] In some embodiments, the arc-shaped thin-walled structure is a three-dimensional structure with a relatively thin thickness and an overall arc surface. In one example, the ratio of the thickness of the arc-shaped thin-walled structure to its height is less than 1 / 10. Preferably, the ratio of the thickness of the arc-shaped thin-walled structure to its height is configured in the range of 1 / 145 to 1 / 25. For example, the thickness range of the arc-shaped thin-walled structure is configured to be 1-3mm, and the height range of the arc-shaped thin-walled structure is configured to be 75-145mm. In another example, the ratio of the thickness of the arc-shaped thin-walled structure to the arc length of its bottom edge or the arc length of its top edge is less than 1 / 10. Preferably, the ratio of the thickness of the arc-shaped thin-walled structure to the arc length of its bottom edge or the arc length of its top edge is configured in the range of 1 / 80 to 3 / 50. For example, the thickness range of the arc-shaped thin-walled structure is configured to be 1-3mm, and the arc length range of the bottom edge or the arc length range of the top edge of the arc-shaped thin-walled structure is configured to be 50-80mm.

[0051] In one embodiment, see Figure 4 , which is a schematic diagram of an arc-shaped thin-walled structure in an embodiment of the present application. As shown in the figure, the arc-shaped thin-walled structure 1 includes a bottom edge 11, a top edge 10, and two side edges (12a, 12b) located opposite to each other between the bottom edge 11 and the top edge 10. The bottom edge 11 and the top edge 10 are arc-shaped, and the two side edges (12a, 12b) can have a curvature or be a straight line. Accordingly, based on Figure 4 The printed part of the curved thin-walled structure 1 shown in the figure also has a corresponding bottom edge, top edge, and two side edges. It should be noted that the bottom edge of the curved thin-walled structure 1 corresponds to the edge that needs to be placed on the XOY plane during printing, and the top edge of the curved thin-walled structure is the edge away from the XOY plane relative to the bottom edge. Correspondingly, the bottom edge of the printed part is located on the printing surface, and the top edge of the printed part is the edge away from the printing surface.

[0052] For example, the arc-shaped thin-walled structure 1 is configured to be formed by winding a planar structure, wherein the planar structure has a bottom edge, a top edge, and two side edges connecting the bottom edge and the top edge, and the winding is bent so that the bottom edge and the top edge of the planar structure form a Figure 4 The arc shown in the figure, the two sides of the plane structure correspond to Figure 4 It should be understood that in order to ensure that the formed arc-shaped thin-walled structure can be stably located on the plane, the bottom edge of the plane structure is configured as a straight line, and the top edge and two side edges of the plane structure can be configured as an arc or a straight line, and of course can also be other irregular shapes.

[0053] In one embodiment, if Figure 4As shown, the arc-shaped thin-walled structure 1 is configured as a structure expanding from the top to the bottom. This structure can lower the center of gravity of the arc-shaped thin-walled structure, thereby improving the stability of the arc-shaped thin-walled structure, and further enhance the self-supporting ability of the arc-shaped thin-walled structure, so that when printing the print, the print can be stably located on the printing surface. In one example, the arc-shaped thin-walled structure is configured as a gradually expanding curved surface structure, that is, the arc-shaped thin-walled structure expands gradually from the top edge to the bottom edge.

[0054] As mentioned above, additive manufacturing of a preset metal material based on the data to be printed corresponding to the arc-shaped thin-walled structure can print out a printout corresponding to the arc-shaped thin-walled structure. In one embodiment, the deformation amount of the printout in step S110 is determined by the horizontal offset of at least two measuring points located on the side of the printout as the deformation amount. In this way, configuring at least two measuring points on the side can effectively reflect the deformation of the printout and facilitate measurement, which is conducive to the convenience and accuracy of determining the inherent strain. Specifically, due to the existence of inherent strain, the printout will have a concave-convex deformation compared to the desired arc-shaped thin-walled structure, and the deformation generated on the side of the printout generally includes a convex deformation protruding outward (deformation corresponding to the positive horizontal offset described below) and an inward concave deformation (deformation corresponding to the negative deformation described below). Therefore, configuring at least two measuring points on the side of the printout can effectively reflect the concave-convex deformation of the printout.

[0055] Furthermore, in order to facilitate the measurement personnel or the measurement equipment to find the measurement points, and to make the actual measurement points correspond to the simulated measurement points of the 3D model in determining the inherent strain, in some embodiments, at least two position marks are configured on the side of the arc-shaped thin-walled structure so that at least two measurement points are formed on the side of the printed part. In one example, at least two position marks are configured on one of the two side edges of the arc-shaped thin-walled structure so that at least two measurement points are formed on the corresponding side of the printed part. In another example, at least two position marks are respectively configured on both sides of the arc-shaped thin-walled structure so that at least two measurement points are formed on both sides of the printed part. In this way, the user can pre-set at least two measurement points on any side of the printed part through a computer device to calculate the deformation amount of the printed part, so as to avoid the problem of the measurement point on one side being accidentally damaged and requiring reprinting, thereby improving the success rate of determining the deformation amount of the printed part in one printing. In the following embodiments, at least two position marks are respectively configured on the two sides of the arc-shaped thin-walled structure, and only the position mark on one side is selected to be used in the determination of the inherent strain value as an example for description.

[0056] In one embodiment, one of the at least two position marks corresponds to the positive maximum deformation position of the side edge, and the other corresponds to the reverse maximum deformation position of the side edge, that is, at least one of the configured position marks corresponds to the positive maximum deformation position, and the other corresponds to the reverse maximum deformation position, so that at least one of the measurement points on the print is the positive maximum deformation position, and the other is the reverse maximum deformation position. For example, the positive maximum deformation position of the side edge can be determined based on the position of the maximum positive horizontal offset of the print obtained by multiple simulated printing or multiple actual printing of the arc-shaped thin-walled structure; similarly, the reverse maximum deformation position of the side edge is determined by the position of the maximum reverse horizontal offset of the print obtained by multiple simulated printing or multiple actual printing of the arc-shaped thin-walled structure. For example, the position of one of the at least two position markers can be determined based on the position where the maximum positive horizontal offset appears multiple times during simulated printing or actual printing of an arc-shaped thin-walled structure, or the average position of the position where the maximum positive horizontal offset appears each time, and the position of the other position marker can be determined based on the position where the maximum reverse horizontal offset appears multiple times during simulated printing or actual printing of an arc-shaped thin-walled structure, or the average position of the position where the maximum reverse horizontal offset appears each time, etc.

[0057] For example, the position marks may be configured as two, three, four, five, six, or more, so that a corresponding number of measuring points are formed on the side of the printed piece. Figure 4 As shown in the figure, the two sides of the arc-shaped thin-walled structure include a first position mark 13a, a second position mark 13b, a third position mark 13c and a fourth position mark 13d ( Figure 4 In the figure, only the position marks on the side 12a are indicated by numbers, and the position marks on the side 12b are not numbered). These four position marks (13a, 13b, 13c, 13d) can form four measurement points. In other embodiments, in order to simplify user operation, two or three position marks can also be configured on the side of the arc-shaped thin-walled structure. In order to further increase the accuracy of the determined inherent strain value, more than four position marks can also be configured on the side of the arc-shaped thin-walled structure.

[0058] In such Figure 4In the embodiment where four position marks are arranged, taking the side 12a as an example, the first position mark 13a is located at any position from the bottom to 2 / 12 of the side 12a, the second position mark 13b is located at any position from 3 / 12 to 5 / 12 of the side 12a, the third position mark 13c is located at any position from 6 / 12 to 8 / 12 of the side 12a, and the fourth position mark 13d is located at any position from 9 / 12 to 11 / 12 of the side 12a. Taking the height of the arc-shaped thin-walled structure as 125mm as an example, the first position mark 13a is located on the side 12a and its height is 11mm, the second position mark 13b is located on the side 12a and its height is 36mm, the third position mark 13c is located on the side 12a and its height is 71mm, and the fourth position mark 13d is located on the side 12a and its height is 101mm.

[0059] In one embodiment, the position marker is configured as a thin sheet structure protruding from the side. Figure 4 As shown, the thin sheet structure is configured as a semicircular thin sheet structure, but it is not limited thereto. In other embodiments, the thin sheet structure may be a thin sheet structure of a regular shape such as a polygonal thin sheet structure (such as a triangular thin sheet structure, a square thin sheet structure, or a diamond thin sheet structure) or a thin sheet structure of an irregular shape. It should be noted that the position mark may also be a color mark. In other words, the color of the position mark is different from the color at other positions of the arc-shaped thin-walled structure, so that the color of the printed measurement point is different from the color of other positions of the print.

[0060] In one embodiment, after a printout corresponding to the arc-shaped thin-walled structure is printed out using a preset metal material, it is necessary to determine the horizontal offset of at least two measurement points on the side of the printout as the deformation of the printout. The horizontal offset is the distance between the actual measurement point of the printout and its theoretical measurement point (e.g., the position mark corresponding to the measurement point) on the horizontal plane (a plane parallel to the printing surface). The positive horizontal deviation refers to the outward offset of the actual measurement point relative to the theoretical measurement point, which can also be understood as the distance from the theoretical measurement point to the outside of the arc surface, which is positive. The negative offset refers to the inward offset of the actual measurement point relative to the theoretical measurement point, which can also be understood as the distance from the theoretical measurement point to the inside of the arc surface, which is negative. For example, please refer to Figure 5 , which is a schematic diagram showing the horizontal offset of the measuring point in one embodiment of the present application. The horizontal offset is described by taking the fourth position mark 13d as an example. The measuring point W1 is marked as the measuring point corresponding to the fourth position mark 13d on the printout, which is the actual measuring point of the printout. The fourth position mark 13d is the theoretical measuring point. Figure 5As shown, the measuring point W1 is offset outward relative to the fourth position mark 13d, and the distance H1 between the two is the horizontal offset of the measuring point W1. The horizontal offset is from the fourth position mark 13d to the outside of the arc surface, and the horizontal offset is regarded as a positive horizontal offset. It should be noted that Figure 5 The measurement point W1 is marked only for the convenience of explanation and illustration, and does not mean that the measurement point W1 must be at the position shown in the figure.

[0061] In order to determine the horizontal offset described in the above embodiment. In one embodiment, after printing out the printout corresponding to the arc-shaped thin-walled structure, the user scans the printout through a scanning device to obtain the three-dimensional coordinate data of the printout, and then determines the horizontal offset of the measuring point based on the three-dimensional coordinate data of the printout. In one example, the three-dimensional coordinate data scanned by the scanning device can be obtained by an electronic device (such as a laptop, a desktop computer, a tablet computer, a smart TV, a smart phone, a tablet computer, an industrial computer, etc.) through communication connection with the scanning device or by user import, and the electronic device calculates the horizontal offset of the measuring point based on the obtained three-dimensional coordinate data of the printout and the pre-stored three-dimensional coordinate data of the arc-shaped thin-walled structure expected to be printed. For example, after unifying the coordinate system and registering or aligning the three-dimensional coordinate data, the horizontal offset of the measuring point is calculated based on the three-dimensional coordinate data of a measuring point of the printout and the three-dimensional coordinate data of the position mark corresponding to the measuring point in the arc-shaped thin-walled structure. Wherein, the scanning device can be, for example, an optical scanning device or a contact scanning device. The optical scanning device is exemplified by a 3D scanner based on structured light or laser, and the contact scanning device is exemplified by a probe-type three-dimensional coordinate measuring machine. It should be noted that the electronic device may be independent of the computer device that executes the method for determining the inherent strain in additive manufacturing, or may be communicatively connected to the computer device, or may be configured as the computer device.

[0062] In one embodiment, the electronic device also displays the calculated horizontal offset of the measuring point to the user through a display device of the electronic device.

[0063] In one embodiment, the electronic device further calculates the horizontal offset of each point on the entire or a portion of the printed part (e.g., half of the printed part) including the measuring point based on the acquired three-dimensional coordinate data of the printed part and the three-dimensional coordinate data of the arc-shaped thin-walled structure. Calculating the horizontal offset of the entire printed part can completely determine the deformation of each point on the printed part, and calculating the horizontal offset of the portion of the printed part including the measuring point can not only determine the horizontal offset of at least two measuring points on the side, but also reduce the amount of calculation.

[0064] In order to facilitate the user to observe the deformation distribution of the printed part, the electronic device also generates a thermal distribution map of the horizontal offset based on the calculated horizontal offset of each point on the printed part. In one example, the electronic device generates a thermal distribution map of the horizontal offset of the entire printed part. In another example, the electronic device generates a thermal distribution map of the horizontal offset of a portion of the printed part. For example, see Figure 6 , which is a thermal distribution diagram of the horizontal offset of the printed part in one embodiment of the present application, as shown in the figure, Figure 6 The corresponding printout is made using Figure 4 The curved thin-walled structure shown in FIG. 1 is printed, and different colors on the thermal distribution diagram of the horizontal offset of the printed part represent different horizontal offsets. The size of the horizontal offset corresponding to a specific color and the unit of the horizontal offset can be referred to the color bar in the thermal distribution diagram; further, the thermal distribution diagram of the horizontal offset also shows the following Figure 4 The horizontal offsets of the four measuring points corresponding to the first position mark 13a, the second position mark 13b, the third position mark 13c, and the fourth position mark 13d are -0.273429, 0.732612, 1.116727, and 0.545061, respectively.

[0065] After obtaining the horizontal offsets of at least two measuring points on one side of the printed part, step S110 is performed using the horizontal offsets of the at least two measuring points as the deformation of the printed part. Figure 6 As shown, the print includes 4 measuring points, and the horizontal offsets of the 4 measuring points (0.545061, 1.116727, 0.732612, -0.273429) are used as the deformation of the print. In the following embodiments, the print includes 4 measuring points as an example for description.

[0066] In one embodiment, the computer device provides a first calibration window for the user to input the deformation amount, and obtains the deformation amount input in the first calibration window according to a trigger operation. Specifically, the first calibration window provides at least one input area for the user to input the deformation amount. After the user inputs the deformation amount, the computer device obtains the deformation amount input in the first calibration window based on the user's trigger operation in the first calibration window. The trigger operation includes but is not limited to clicking (for example, clicking with an input device such as a mouse, or touching with a finger, etc.), long pressing, or repeated touching, etc. It should be understood that a user performing a trigger operation on an object can be referred to as the user triggering the object. For example, a user triggering a hot key area (such as the "Confirmation" area described later, etc.) indicates that the user has performed a trigger operation on the hot key area.

[0067] In one example, at least two input areas corresponding to at least two measuring points are displayed in the first calibration window, and the user enters the horizontal offset of the corresponding measuring point in the corresponding input area to complete the input of the deformation amount. After completing the input of the deformation amount, the computer device obtains the deformation amount entered by the user in the first calibration window according to the trigger operation of the user in the first calibration window. For example, see Figure 7 and Figure 8 , Figure 7 The interface diagram of the first calibration window in one embodiment of the present application is shown. Figure 8 In one embodiment of the present application, the user enters in the first calibration window Figure 6 The interface diagram of the deformation of the printed part is shown in Figure 7 The first calibration window shown includes input areas for the arc-shaped thin-walled structure corresponding to the print and the horizontal offsets of the four measuring points, wherein the input area corresponding to the rear side of "Horizontal Offset (13a)" should be used to input the horizontal offset of the measuring point corresponding to the first position mark 13a, and similarly, the input areas corresponding to "Horizontal Offset (13b)", "Horizontal Offset (13c)", and "Horizontal Offset (13d)" should be used to input the horizontal offsets of the measuring points corresponding to the second position mark 13b, the third position mark 13c, and the fourth position mark 13d, respectively. The user enters Figure 7 In the input area of ​​the first calibration window shown in the figure, input the horizontal offset in sequence to complete the input of the deformation. After the deformation input is completed, the interface is as follows: Figure 8 As shown, Figure 8 The horizontal offsets of the measurement points corresponding to the first position mark 13a, the second position mark 13b, the third position mark 13c, and the fourth position mark 13d are respectively -0.273429, 0.732612, 1.116727, and 0.545061. Figure 8 The trigger operation in the "Confirm" area in the calibration window obtains the deformation entered in the first calibration window.

[0068] It should be understood that Figure 7 and Figure 8 The layout and input content of the first calibration window shown are only an example and are not limitations of the present application. In another example, the first calibration window may also display only one input area, in which the user sequentially inputs the horizontal offsets of at least two measuring points according to input rules; wherein the input rules include the input order of the horizontal offsets of the measuring points and the spacing rules between the horizontal offsets of any two measuring points, and the spacing rules are exemplified by spacing with spaces, symbols, letters, etc.

[0069] It should be noted that when the deformation amount of the printed part is pre-stored in the computer device, the computer device can retrieve the pre-stored deformation amount of the printed part through the triggering operation of the user on the calling area displayed on the interface. In this way, there is no need for the user to manually input the deformation amount, thereby avoiding the situation where the determined inherent strain value does not match the actual situation due to manual input errors.

[0070] In one embodiment, the first calibration window further includes a printing material option for setting the printing material; among them, the printing material option is the triggering area for viewing the available printing materials. In other words, after triggering the printing material option, the available printing materials can be viewed. Specifically, the preset metal material used for printing the printed part described above is used as the printing material, and the printing material option is triggered to select the preset metal material to complete the setting of the printing material. For example, please refer to Fig. 9 , which shows the interface diagram of the deformation amount of the printed part and the printing material input in the first calibration window in another embodiment of the present application. As shown in the figure, the pentagram area is the printing material option. The user can trigger the pentagram area to view the available printing materials (for example, a drop-down menu can be provided to display the printing materials for the user to set), and then can select the preset metal material to set the printing material in the printing material input area ( Figure 6 the bar area after the Chinese character "material" in). As Fig. 9 shown, the preset metal material AISI10Mg is used as the printing material. In this embodiment, after the user completes the input of the deformation amount and the printing material (i.e., the preset metal material of the printed part), the computer device simultaneously obtains the deformation amount of the printed part and the printing material based on a single triggering operation of the user. For example, please refer to Fig. 9 , after the user inputs or selects the deformation amount and the printing material of the printed part in the first calibration window, the computer device can obtain the deformation amount of the printed part and the printing material based on a single triggering operation of the user on the Fig. 9 "Confirm" area in. Fig. 9

[0071] After the computer device executes step S110 to obtain the deformation amount of the printed part, it can execute step S120 by using the inherent strain calibration network.

[0072] In one embodiment, the inherent strain calibration network is a pre-trained neural network model. Furthermore, the method for determining the inherent strain in additive manufacturing further includes the step of training a neural network to obtain the inherent strain calibration network.

[0073] In order to train the inherent strain calibration network, the computer device needs to obtain training samples first. However, due to the high cost of 3D printing, the actual printing process is complicated, and there is currently no efficient and accurate calculation method for determining the inherent strain value based on the actual printed deformation. Therefore, determining the training sample based on actual printing is not only costly, inefficient, and time-consuming, but the obtained training sample is also inaccurate, which in turn affects the accuracy of the subsequent inherent strain calibration network predicting the inherent strain value. For this reason, the method for determining the inherent strain in additive manufacturing of the present application also includes the step of using a curved thin-walled structure for simulated printing to obtain a training sample.

[0074] In one embodiment, the computer device first generates a plurality of simulated inherent strain values ​​for simulating printing, wherein each simulated inherent strain value includes an inherent strain value ε in the X direction. xx , the inherent strain value ε in the Y direction yy , and the inherent strain value ε in the Z direction zz , the multiple simulated inherent strain values ​​can be randomly generated or generated within a preset generation range (i.e., the value range of the inherent strain values ​​in three directions). In an embodiment of the present application, the multiple simulated inherent strain values ​​are generated within a preset range, for example, the value range of the inherent strain value corresponding to the pre-estimated metal material is used as the preset generation range; further, a preset generation range can be configured for each metal material to generate multiple simulated inherent strain values ​​corresponding to multiple metal materials, so that the accuracy of the inherent strain calibration network in predicting the inherent strain value can be improved.

[0075] For ease of explanation, in the following embodiments, the multiple simulated inherent strain values ​​are generated based on a preset generation range. In one example, the additive manufacturing process is based on the slice data and printed layer by layer, and the thickness of each layer is very small, so the inherent strain value ε in the Z direction of each simulated inherent strain value is zz Both can be set to 0.

[0076] After obtaining the simulated inherent strain value, the computer device performs simulated printing based on the simulated inherent strain value to obtain a first simulated part. In a specific embodiment, the computer device obtains the performance parameters of multiple printing materials, and for each performance parameter of the printing material, multiple simulated inherent strain values ​​are used to print out multiple first simulated parts corresponding to the arc-shaped thin-walled structure; further, the computer device also determines the deformation of each first simulated part (i.e., the horizontal offset of the measurement point corresponding to the position mark of the arc-shaped thin-walled structure on the first simulated part). In one example, the performance parameters of the printing material include Young's modulus and Poisson's ratio. It should be noted that in other embodiments, in order to more accurately reflect the performance of the printing material, the performance parameters of the printing material may also include thermal conductivity, thermal expansion coefficient, specific heat capacity, and density. Since the inherent strain in additive manufacturing is mainly caused by the performance parameters of the printing material itself, the printing process parameters have little effect on the inherent strain. Therefore, in the embodiment provided in the present application, the printing process parameters of the multiple first simulated parts obtained by simulated printing can be configured as different printing process parameters or configured as the same printing process parameters.

[0077] The computer device uses the input or received multiple sets of deformation amounts of the first simulation part, the simulated inherent strain values, and the performance parameters of the printed material with corresponding relationships as training samples. Among them, a set of deformation amounts of the first simulation part, the simulated inherent strain values, and the performance parameters of the printed material with corresponding relationships are related simulation data corresponding to the same simulated printing. In one embodiment, the deformation amounts of the first simulation part, the simulated inherent strain values, and the performance parameters of the printed material are all correspondingly configured with preset labels for indicating the corresponding relationships.

[0078] After obtaining the training samples, the computer device uses the training samples to train a neural network to obtain the inherent strain calibration network. In one embodiment, the computer device divides the training samples into multiple batches, each batch includes multiple groups (e.g., 32, 64 groups, etc.) of corresponding deformations of the first simulation parts, simulated inherent strain values, and performance parameters of the printed materials. In the training process based on each batch, the multiple groups of corresponding deformations of the first simulation parts and the performance parameters of the printed materials in the batch are input into the neural network so that the neural network outputs multiple predicted inherent strain values. Further, a loss is calculated based on the multiple predicted inherent strain values ​​output by the neural network and the multiple simulated inherent strain values ​​corresponding to the deformation of the input first simulation parts, and the network parameters of the neural network are adjusted based on the loss until the loss converges. The neural network with converged loss is the inherent strain calibration network. Among them, the neural network is exemplified by BP neural network, convolutional neural network, or NAR dynamic neural network, etc., and the loss is exemplified by root mean square error or cross entropy, etc.

[0079] The computer device performs step S120 based on the obtained intrinsic strain calibration network. In step S120, the computer device uses the deformation as input to determine the intrinsic strain value corresponding to the preset metal material using the intrinsic strain calibration network.

[0080] In one embodiment, the computing device uses the deformation amount of the printed part and the performance parameters of the printing material (i.e., the preset metal material of the printed part) as inputs of the inherent strain calibration network. The inherent strain calibration network can determine or output the inherent strain value corresponding to the preset metal material based on the input deformation amount and the performance parameters of the printing material.

[0081] In this embodiment, the computer device pre-stores the printing material and its corresponding performance parameters, so that when the printing material is obtained, the computer device can determine the performance parameters corresponding to the printing material. Fig. 9 After the horizontal offsets of the four measurement points of the print (0.545061, 1.116727, 0.732612, -0.273429) and the printing material of the print (i.e., AISI10Mg) are determined, the performance parameters corresponding to AISI10Mg can be determined. After the four horizontal offsets and the performance parameters corresponding to AISI10Mg are input into the inherent strain calibration network, the inherent strain calibration network can output the inherent strain value corresponding to AISI10Mg. Specifically, Fig. 9 The input of the inherent strain calibration network is the inherent strain value ε in the X direction output xxThe inherent strain value ε in the Y direction is -0.006759. yy The inherent strain value ε in the Z direction is -0.006633. zz The inherent strain value determined by the inherent strain calibration network can quickly obtain the inherent strain value of the preset metal material without multiple iterative calculations, thereby improving the calculation speed of the inherent strain value.

[0082] See also Fig.10 , which is a flow chart of a method for determining inherent strain in additive manufacturing in another embodiment of the present application. As shown in the figure, the computer device also executes step S130 based on the inherent strain value obtained in step S120.

[0083] In step S130, the computer device performs simulated printing based on the inherent strain value using the arc thin-wall structure in the build volume to verify the inherent strain value. In one embodiment, in order to simplify the user operation, when determining the inherent strain value, the computer device automatically performs simulated printing based on the inherent strain value to verify the inherent strain value. In another embodiment, after obtaining the inherent strain value, the computer device performs simulated printing based on the inherent strain value based on the user's trigger operation to verify the inherent strain value.

[0084] See also Fig.11 , which is a flow chart of step S130 in one embodiment of the present application. As shown in the figure, step S130 includes step S1300 and step S1301.

[0085] In step S1300, a computer device executes a second simulation part by simulating and printing a second simulation part in a building volume using an arc-shaped thin-wall structure based on an inherent strain value, and determines a deformation amount of the second simulation part.

[0086] In one embodiment, the computer device performs simulated printing in the construction volume using the to-be-printed data of the arc-shaped thin-walled structure based on the determined inherent strain value, the preset metal material, and the printing process parameters corresponding to the printed part, so as to simulate printing out a second simulated part corresponding to the arc-shaped thin-walled structure; further, the computer device determines the deformation of the second simulated part based on the second simulated part and the arc-shaped thin-walled structure. In one example, the computer device determines the horizontal offset of at least two measured points on the side of the second simulated part based on the three-dimensional coordinate data of at least two measured points on the second simulated part and the three-dimensional coordinate data of at least two corresponding position marks on the arc-shaped thin-walled structure, so as to use the horizontal offset of at least two measured points as the deformation of the second simulated part. In another example, the computer device also calculates the horizontal offset of all points on the second simulated part based on the three-dimensional coordinate data of all points in the second simulated part and the arc-shaped thin-walled structure, so as to use the horizontal offset of all points on the second simulated part as the deformation of the second simulated part.

[0087] In step S1301, the computer device verifies the inherent strain value based on the deformation amount of the second simulation member.

[0088] In an embodiment in which the horizontal offset of at least two measuring points on the side of the arc-shaped thin-walled structure is used as the deformation of the second simulation part, the computer device calculates the difference between the horizontal offset of at least two measuring points on the side of the second simulation part and the horizontal offset of at least two corresponding measuring points on the printed part. When the value obtained by the difference calculation meets the preset conditions, the inherent strain value is verified to be passed, that is, the accuracy of the inherent strain value meets the requirements; otherwise, the verification fails, that is, the accuracy of the inherent strain value does not meet the requirements.

[0089] The difference calculation includes but is not limited to: calculating the absolute value of the difference, calculating the absolute value of the sum of the difference, calculating the absolute value of the average after the difference, or calculating the standard deviation after the difference, etc. The preset condition includes but is not limited to: all the values ​​obtained by the difference calculation meet the preset threshold, or the values ​​exceeding the preset proportion of all the values ​​obtained by the difference calculation meet the preset threshold (for example, more than 70% of the 10 values ​​obtained by the difference calculation meet the preset threshold). In one example, the difference is calculated as the absolute value after calculating the difference respectively, the preset threshold is Y, the side includes a first measuring point, a second measuring point, a third measuring point, and a fourth measuring point, and when the absolute value of the difference between the horizontal offset of the first measuring point of the second simulation part and the horizontal offset of the first measuring point of the print, the absolute value of the difference between the horizontal offset of the second measuring point of the second simulation part and the horizontal offset of the second measuring point of the print, the absolute value of the difference between the horizontal offset of the third measuring point of the second simulation part and the horizontal offset of the third measuring point of the print, and the absolute value of the difference between the horizontal offset of the fourth measuring point of the second simulation part and the horizontal offset of the fourth measuring point of the print are all less than Y, the inherent strain value verification is passed, otherwise, the verification fails.

[0090] In an embodiment in which the horizontal offset of all points on the second simulation member is used as the deformation of the second simulation member, the computer device verifies the inherent strain value based on the difference between the deformation of the second simulation member and the horizontal offset of all points on the print. In one example, the inherent strain value can be verified based on the horizontal offset of all points on the second simulation member and the print and the difference calculation method in the above embodiment. The specific verification method is similar to that described above and will not be repeated here.

[0091] In one embodiment, the step S130 further includes providing a second calibration window to display the verification progress and the inherent strain value. Specifically, during the process of the computer device executing the steps S1300 and S1301, the computer device provides a second calibration window, in which the verification progress and the inherent strain value are displayed. The verification progress can be represented by a number such as a percentage and / or a progress bar. In one example, see Fig.12 , which is a schematic diagram of an interface of a second calibration window in one embodiment of the present application, Fig.12 The verification progress is indicated by a progress bar and percentage. Fig.12 The intrinsic variable value determined in step S120, i.e., the intrinsic strain value ε in the X direction, is also shown in FIG. xx is -0.006759, and the inherent strain value ε in the Y direction yy is -0.006633, and the inherent strain value ε in the Z direction zzis 0.000000.

[0092] Furthermore, in one embodiment, the computer device also displays a verification result when the verification is completed. The verification result is identification information indicating that the verification passed or identification information indicating that the verification failed. The identification information can be text and / or an image, etc. In one example, the identification information of the verification passed is represented by the text "calibration passed", "calibration successful", "verification passed", "verification successful", "pass", or "success", etc., and the identification information of the verification failed is represented by the text "calibration failed", "calibration unsuccessful", "verification failed", "verification unsuccessful", "failed", or "failed", etc. For example, see Fig.13 Combined with Fig.12 , Fig.13 The diagram shows a second calibration window after verification is completed in one embodiment of the present application, as shown in the figure, Fig.13 The second calibration window shown in the verification is completed by Fig.12 The text "Verification Success" is displayed in the place where the text "Verification Progress" is displayed in Fig.12 "Success" is displayed at the position where the percentage is displayed in the progress bar to indicate that the inherent strain value has been verified. In another example, the identification information of the passed verification is represented by a check mark image, a smiling face image, etc., and the identification information of the failed verification can be represented by a cross image, a crying face image, etc.

[0093] In one embodiment, when the verification is successful, a saving area for indicating the saving of the verified inherent strain value is also displayed on the second calibration window for the user to trigger. Specifically, the computer device saves the inherent strain value of the preset metal material based on the user's triggering operation in the saving area for use in simulation printing. For example, Fig.13 As shown, when the verification is successful, the area corresponding to the text "Save Results" on the second calibration window is the saving area. After the user triggers the "Save Results" area, the computer device saves the verified inherent strain value of AISI10Mg based on the user's triggering operation.

[0094] In one embodiment, the step S130 further comprises the step of presenting the second simulation part in the building volume when the verification is completed, wherein the corresponding deformation amount is marked on the measurement points of the second simulation part. Fig.13When the verification is completed, the second simulation part 2 is displayed in the construction volume V. The horizontal offset of the measurement point P1 corresponding to the first position mark in the second simulation part is 0.278254, the horizontal offset of the measurement point P2 corresponding to the second position mark in the second simulation part is 0.744011, the horizontal offset of the measurement point P3 corresponding to the third position mark in the second simulation part is 1.127038, and the horizontal offset of the measurement point P4 corresponding to the fourth position mark in the second simulation part is 0.547803. Please refer to Figure 6 and Fig.13 , Fig.13 The measuring points P2, P3, and P4 are Figure 6 The differences in the horizontal offsets of the measurement points corresponding to the printed parts (0.732612, 1.116727, and 0.545061) are all in the micron level. This can verify that the inherent strain value obtained by the method for determining the inherent strain in additive manufacturing of the present application has a high accuracy.

[0095] In one embodiment, the second simulation part is displayed in a heat map distribution manner to present the deformation distribution of the second simulation part. Specifically, different colors in the second simulation part displayed in the heat map distribution manner represent different horizontal offsets, and then the computer device can intuitively present the deformation distribution of the second simulation part for the user to view.

[0096] The present application also provides a method for simulating the manufacture of a 3D object in some embodiments, the method for simulating the manufacture of the 3D object is executed by the computer device, and the method for simulating the manufacture of the 3D object simulates the printing of the 3D model based on the inherent strain value determined by the method for determining the inherent strain in additive manufacturing described in any of the aforementioned embodiments to form a simulated part of the 3D object. In order to facilitate the distinction from the first simulated part and the second simulated part in the aforementioned embodiments, the simulated part in the simulated manufacture method is referred to as the third simulated part.

[0097] In one embodiment, the computer device uses a preset metal material, an inherent strain value corresponding to the preset metal material, and a user-configured printing process parameter to simulate printing of the 3D model to form the third simulated part. The deformation of the 3D object actually printed based on the 3D model can be predicted based on the deformation of the third simulated part.

[0098] Further, the 3D model is optimized based on the deformation of the simulated printed third simulation part, so that the deformation of the 3D object actually printed based on the 3D model meets the preset requirements. The 3D model can be a 3D model of any part that the user needs to actually print, such as aerospace parts, automobile parts, industrial equipment parts, etc.

[0099] In some embodiments, the present application also provides an additive manufacturing simulation system, which can be deployed in a computer device, for example, as a software tool or software module that can process data, and performs data processing with the help of the operating environment provided by the hardware device and / or operating system in the computer device.

[0100] In order to more prominently emphasize the independence of the operation of the functional units, many of the functional units described in this specification have been labeled as modules. For example, a module can be implemented as a hardware circuit, which includes a custom VLSI circuit, a gate array, or an off-the-shelf semiconductor (such as a logic chip, transistor, or other discrete component). A module can also be implemented in a programmable hardware device, such as a field programmable gate array, programmable array logic, a programmable logic device, or the like.

[0101] Among them, each module can also be implemented in software run by different types of processors. For example, a module of executable code can include one or more physical or logical blocks of computer instructions, which are organized as objects, programs or functions. However, the executable files of the modules do not have to be physically located together, but can include different commands stored in different locations, which, when logically connected together, include the modules and achieve the specified goals of the modules.

[0102] Of course, the module of executable code can be one or many instructions, and can even be distributed in several different code segments, distributed in different programs and distributed in multiple storage devices. Similarly, operation data can be identified and shown in the module, and the operation data can be embodied in any suitable form and organized in any suitable type of data structure. The operation data can be collected as a single data set, or can be distributed in different locations (including different storage devices), and can exist at least partially as electrical signals in a system or network. When a module or a portion of a module is implemented in software, the software portion is stored on one or more computer-readable media.

[0103] See also Fig.14 , which is a block diagram of an additive manufacturing simulation system in an embodiment of the present application. As shown in the figure, the additive manufacturing simulation system 3 includes an inherent strain calibration module 30 and a simulation module 31. The inherent strain calibration module 30 is used to obtain the deformation of a printed part corresponding to an arc-shaped thin-walled structure printed using a preset metal material, and use the deformation as an input to determine the inherent strain value corresponding to the preset metal material using an inherent strain calibration network. The simulation module 31 is used to simulate the printing of the 3D model based on the inherent strain value output by the inherent strain calibration module to form a simulated part of the 3D object.

[0104] In one embodiment, the additive manufacturing simulation system further includes a training module (not shown), wherein the training module is used to train a neural network to obtain the inherent strain calibration network.

[0105] In one embodiment, the additive manufacturing simulation system further includes a verification module (not shown), which is used to perform simulated printing using the curved thin-walled structure in a build volume based on the inherent strain value to verify the inherent strain value.

[0106] In one embodiment, the inherent strain calibration module 30, the simulation module 31, the training module, and the verification module respectively coordinate and execute the method for determining the inherent strain in additive manufacturing and the method for simulating manufacturing of 3D objects disclosed in any of the aforementioned embodiments of the present application according to the functions described above, see Figures 1 to 13 Any embodiments described in related manner will not be described in detail here.

[0107] The present application also provides a computer device. In an embodiment, the computer device is used to implement the method for determining inherent strain in additive manufacturing or the method for simulating manufacturing of 3D objects described in any of the above embodiments. In one embodiment, the computer device is a device capable of performing digital calculations, logical processing, and information processing on data, which can be a server, a laptop computer, a desktop computer, an edge device, etc. The embodiments of the present application do not make specific limitations, and the embodiments of the present application do not limit the number of processors and memories in the computing device.

[0108] See also Fig.15 , which is a schematic diagram of the structure of a computer device in one embodiment of the present application, wherein the computer device 4 includes a storage device 40 and a processing device 41 connected to the storage device 40; further, the computer device also includes a communication interface 42.

[0109] In one embodiment, the storage device 40, the processing device 41, and the communication interface 42 communicate with each other via a bus. The bus may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.15 The bus is represented by only one line, but it does not mean that there is only one bus or one type of bus. The bus may include a path for transmitting information between various components of the computing device (for example, storage devices, processing devices, communication interfaces).

[0110] In some embodiments, the storage device 40 is used to store at least one program, and the at least one program can be executed by the processing device 41 to coordinate the storage device 40 to implement the method for determining the inherent strain in additive manufacturing or the method for simulating the manufacturing of 3D objects described in any of the above embodiments. The memory may include a volatile memory (Volatile Memory), such as a random access memory (Random Access Memory, RAM). The memory may also include a non-volatile memory (Non-Volatile Memory), such as a read-only memory (Read-only Memory, ROM), a random access memory (Random Access Memory, RAM), a flash memory, a programmable read-only memory (Programmable Read-Only Memory, PROM), an erasable programmable read-only memory (Erasable Programmable Read-Only Memory, EPROM), an electrically erasable programmable read-only memory (Electric Erasable Programmable Read-Only Memory, EEPROM), a mechanical hard disk (Hard Disk Drive, HDD) or a solid state drive (Solid State Drive, SSD).

[0111] In some embodiments, the processing device 41 includes one or more processors. The processing device 41 can be operable to perform data read and write operations with the storage device 40. The processing device can include any one or more processors such as a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP) or a digital signal processor (DSP). For another example, it can also be an application-specific integrated circuit (ASIC), a discrete gate or transistor logic device, or a discrete hardware component, which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application.

[0112] In some embodiments, the communication interface 42 includes at least one interface unit, each of which is used to output a visual interface, receive a human-computer interaction event generated according to the operation of a technician, etc. For example, the communication interface 42 includes but is not limited to: a serial interface such as an HDMI interface or a USB interface, or a parallel interface, etc. In one embodiment, the communication device 42 also includes a network communication unit, which is a device for transmitting data using a wired or wireless network, examples of which include but are not limited to: an integrated circuit including a network card, a local area network module such as a WiFi module or a Bluetooth module, a wide area network module such as a mobile network, etc.

[0113] The present application also provides a computer-readable and writable storage medium storing at least one program, wherein the at least one program is executed and implemented when called to implement the method for determining inherent strain in additive manufacturing or the method for simulating manufacturing of 3D objects described in any of the above embodiments, see Figures 1 to 13 Any embodiments described in related manner will not be described in detail here.

[0114] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device equipped with the storage medium to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0115] Those of ordinary skill in the art can understand that all or part of the processes in the methods described in the above embodiments can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0116] In the embodiments provided in the present application, the computer readable and writable storage medium may include a read-only memory, a random access memory, an EEPROM, a CD-ROM or other optical disk storage device, a disk storage device or other magnetic storage device, a flash memory, a USB flash drive, a mobile hard disk, or any other medium that can be used to store a desired program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if the instruction is sent from a website, a server or other remote source using a coaxial cable, an optical fiber cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, optical fiber cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. However, it should be understood that computer readable and writable storage media and data storage media do not include connections, carriers, signals, or other temporary media, but are intended to be non-temporary, tangible storage media. Disk and disc, as used in this application, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

[0117] The present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the method for determining inherent strain in additive manufacturing or the method for simulating manufacturing of 3D objects in any of the above-mentioned embodiments.

[0118] If the method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device equipped with the storage medium to execute all or part of the steps of the method described in each embodiment of the present application.

[0119] In one or more exemplary aspects, the functions described in the computer program of the method for determining inherent strain in additive manufacturing or the method for simulating manufacturing of 3D objects described in the present application can be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored or transmitted as one or more instructions or codes to a computer-readable medium. The steps of the method or algorithm disclosed in the present application can be embodied in a processor-executable software module, wherein the processor-executable software module can be located on a tangible, non-temporary computer-readable and writable storage medium. A tangible, non-temporary computer-readable and writable storage medium can be any available medium that can be accessed by a computer.

[0120] The flowchart and block diagram in the accompanying drawings described in the present application illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. Based on this, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be realized by a dedicated hardware-based system that performs a specified function or operation, or can be realized by a combination of dedicated hardware and computer instructions.

[0121] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0122] In summary, the method for determining inherent strain in additive manufacturing, the method for simulating manufacturing of 3D objects, the additive manufacturing simulation system, the computer device, the computer-readable storage medium and the computer program product disclosed in the present application determine the inherent strain value of a preset metal material by inputting the horizontal offset of at least two measuring points on the side of a printed part corresponding to an arc-shaped thin-walled structure as the deformation into the inherent strain calibration network. Since the horizontal offset of the measuring point is only related to the inherent strain and does not need to be measured after cutting, the present application can not only accurately determine the inherent strain value in additive manufacturing for accurately predicting the deformation of 3D objects, but also improve the accuracy of the determination through the inherent strain calibration network. The calculation speed of the inherent strain value is improved. Furthermore, by respectively configuring at least two position marks on the two sides of the arc-shaped thin-walled structure, the problem of the need for reprinting due to accidental damage of the measuring point on one side is avoided, thereby improving the success rate of determining the deformation amount of the printed part in one printing; further, by using the arc-shaped thin-walled structure to perform simulated printing to obtain training samples, the cost of determining the training samples can be reduced and the accuracy and efficiency of the training samples can be improved; further, verifying the inherent strain value through simulated printing can ensure that the inherent strain value applied to the simulated manufacturing method of the 3D object is credible, so as to reduce the experimental cost / trial and error cost.

[0123] The above embodiments are merely illustrative of the inventive essence of the present application and the beneficial effects obtained, and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the principles and scope of the present application. Therefore, all equivalent modifications or changes achieved by a person with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for determining inherent strain in additive manufacturing, characterized in that: The following steps are involved: Obtaining a deformation amount of a printed part corresponding to an arc-shaped thin-walled structure printed using a preset metal material; wherein the horizontal offset of at least two measuring points located on the side of the printed part is used as the deformation amount; The deformation is used as an input to determine an inherent strain value corresponding to the preset metal material using an inherent strain calibration network.

2. The method for determining inherent strain in additive manufacturing according to claim 1, characterized in that: At least two position marks are arranged on the side of the arc-shaped thin-wall structure so that at least two measuring points are formed on the side of the printed part.

3. The method for determining inherent strain in additive manufacturing according to claim 2, characterized in that: The position mark is configured as a thin sheet structure protruding from the side.

4. The method for determining inherent strain in additive manufacturing according to claim 2, characterized in that: One of the at least two position markers corresponds to a positive maximum deformation position of the side edge, and the other corresponds to a negative maximum deformation position of the side edge.

5. The method for determining inherent strain in additive manufacturing according to claim 2, characterized in that: The position marks are configured as four so that four measuring points are formed on the side of the print. Taking the bottom of the arc-shaped thin-walled structure as a reference, the first position mark is located at any position from the bottom to 2 / 12 of the side of the arc-shaped thin-walled structure, the second position mark is located at any position from 3 / 12 to 5 / 12 of the side of the arc-shaped thin-walled structure, the third position mark is located at any position from 6 / 12 to 8 / 12 of the side of the arc-shaped thin-walled structure, and the fourth position mark is located at any position from 9 / 12 to 11 / 12 of the side of the arc-shaped thin-walled structure.

6. The method for determining inherent strain in additive manufacturing according to claim 2, characterized in that: The arc-shaped thin-wall structure is configured as a structure expanding from the top to the bottom.

7. The method for determining inherent strain in additive manufacturing according to claim 1, characterized in that: Acquiring a deformation amount of a printout printed using a preset metal material includes providing a first calibration window for a user to input the deformation amount, and acquiring the deformation amount input in the first calibration window according to a trigger operation.

8. The method for determining inherent strain in additive manufacturing according to claim 7, characterized in that: The first calibration window also includes a printing material option for setting the printing material.

9. The method for determining inherent strain in additive manufacturing according to claim 1, characterized in that: The method also includes the step of training a neural network to obtain the intrinsic strain calibration network.

10. The method for determining inherent strain in additive manufacturing according to claim 1, characterized in that: The step of training a neural network to obtain the inherent strain calibration network includes: training a neural network using training samples to obtain the inherent strain calibration network; wherein the training samples include a plurality of groups of corresponding deformation amounts of a first simulation part, simulated inherent strain values, and performance parameters of a printed material, and the first simulation part is obtained by simulated printing using the arc-shaped thin-wall structure, the simulated inherent strain values, and the performance parameters of the printed material.

11. The method for determining inherent strain in additive manufacturing according to claim 1, characterized in that: The method further includes performing simulation printing using the arc-shaped thin-walled structure in a building volume based on the inherent strain value to verify the inherent strain value.

12. The method for determining inherent strain in additive manufacturing according to claim 11, characterized in that: The step of performing simulated printing in a build volume using the curved thin-walled structure based on the inherent strain value to verify the inherent strain value comprises: Printing a second simulation part in a building volume using the arc-shaped thin-walled structure simulation based on the inherent strain value, and determining a deformation amount of the second simulation part; The inherent strain value is verified based on the deformation amount of the second simulation member.

13. The method for determining inherent strain in additive manufacturing according to claim 12, characterized in that: The step of performing simulated printing using the curved thin-walled structure in a build volume based on the inherent strain value to verify the inherent strain value further includes: providing a second calibration window to display the verification progress and the inherent strain value.

14. The method for determining inherent strain in additive manufacturing according to claim 13, characterized in that: The step of performing simulated printing in a build volume using the arc-shaped thin-walled structure based on the inherent strain value to verify the inherent strain value also includes: presenting the second simulation part in the build volume when the verification is completed, wherein the corresponding horizontal offset is marked on the measuring point of the second simulation part.

15. The method for determining inherent strain in additive manufacturing according to claim 14, characterized in that: The second simulation part is displayed in a thermal map distribution manner to present the deformation distribution of the second simulation part.

16. A method for simulating manufacturing of a 3D object, characterized in that: The method comprises simulating printing a 3D model based on the inherent strain value determined by the method for determining the inherent strain in additive manufacturing according to any one of claims 1 to 15 to form a simulation part of the 3D object.

17. An additive manufacturing simulation system, characterized in that: include: An inherent strain calibration module is used to obtain the deformation of a printed part corresponding to an arc-shaped thin-walled structure printed using a preset metal material, and use the deformation as an input to determine the inherent strain value corresponding to the preset metal material using an inherent strain calibration network; wherein the horizontal offset of at least two measuring points located on the side of the printed part is used as the deformation; The simulation module is used to simulate printing of the 3D model based on the inherent strain value output by the inherent strain calibration module to form a simulation part of the 3D object.

18. A computer device, characterized in that: include: A storage device for storing at least one program; A processing device, connected to the storage device, is used to call the at least one program from the storage device and implement the method for determining the inherent strain in additive manufacturing as described in any one of claims 1 to 15, or implement the simulation manufacturing method of a 3D object as described in claim 16 when executing it.

19. A computer-readable storage medium, characterized in that: At least one program is stored, and when the at least one program is called and executed by a processor of a computer, the method for determining the inherent strain in additive manufacturing as described in any one of claims 1 to 15 is implemented, or the method for simulating manufacturing of a 3D object as described in claim 16 is implemented.

20. A computer program product, characterized in that When the computer program product runs on a computer, the computer is enabled to execute the method for determining inherent strain in additive manufacturing as claimed in any one of claims 1 to 15, or to implement the method for simulating manufacturing of a 3D object as claimed in claim 16.

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