Arc additive design-simulation-reinforcement-construction integration method for curved metal thin shell

Abstract

The invention relates to an electric arc additive design-simulation-reinforcement-construction integration method for a curved metal thin shell, which comprises the following steps of: adopting a metal wire, and obtaining a three-dimensional structure model of a metal thin shell structure by utilizing the curved surface shape optimization design of a shell unit; simulating and predicting the deposition of the exposed thin shell structure; simulating and predicting the deposition of the reinforced thin-shell structure; and reinforcing thin-shell metal 3D printing construction. The method has the beneficial effects that the stress and deformation distribution and amplitude of the exposed thin shell structure are obtained through deposition simulation prediction with low cost, and reinforcement measures are set based on the stress and deformation distribution and amplitude, so that excessive deformation in the printing process of the electric arc additive process is avoided to a great extent, and the service life of the electric arc additive process is prolonged. Printing failure and printing repositioning caused by excessive deformation are avoided, and the forming quality and the material performance of the metal forming structural part are effectively guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of additive manufacturing technology, and particularly relates to an arc additive design-simulation-reinforcement-construction integrated method for a curved metal thin shell. BACKGROUND

[0002] The arc additive manufacturing (WAAM) technology forms a complex metal structure by melting a metal wire through an arc heat source and layer-by-layer accumulation. In the WAAM process, due to the movement of the heat source and the rapid heating and cooling of the material, a complex thermal-mechanical behavior is generated, which affects the forming quality and material performance of the metal structure. How to effectively control the defects of the formed structure in the WAAM process is particularly crucial. The generation of residual stress and deformation of the formed structure is mainly caused by the constraint of thermal expansion and cold contraction of the additive part.

[0003] The curved metal thin shell structure is widely used in the fields of building, automobile and aviation, and is suitable for being made by the WAAM process to achieve high material utilization and good complex workpiece forming capability; however, due to the thin wall thickness of the structure, residual stress and excessive deformation are more likely to occur in the WAAM process. The existing research on the thermal-mechanical behavior of the WAAM process is mainly based on experiments, but experimental research is time-consuming and laborious, and cannot monitor the stress distribution change in real time in the WAAM process. With the improvement of computer performance, three-dimensional transient thermal-mechanical coupling numerical models are gradually applied to the simulation research of the arc welding process, and the arc welding and the arc additive process have certain similarities. Through numerical simulation, the thermal-mechanical parameter prediction of the arc additive process can be effectively obtained, and based on this, reinforcement measures are set, so as to greatly reduce the stress and deformation of the thin shell structure in the WAAM process.

[0004] In summary, it is necessary to research an arc additive design-simulation-reinforcement-construction integrated method for a curved metal thin shell, so as to realize the integrated method of optimized design, simulation prediction and reinforcement construction of a large-size curved metal thin shell structure in the arc additive manufacturing process. SUMMARY

[0005] The present application aims to overcome the deficiencies in the prior art and provide an arc additive design-simulation-reinforcement-construction integrated method for a curved metal thin shell.

[0006] In a first aspect, an arc additive design-simulation-reinforcement-construction integrated method for a curved metal thin shell is provided, comprising:

[0007] S1, shape optimization design of a thin shell structure: adopting a metal wire, using the curved shape of a shell element for shape optimization design, to obtain a three-dimensional structure model of a metal thin shell structure;

[0008] S2, bare shell structure deposition simulation prediction: based on the three-dimensional structure model obtained in S1, under the condition of not setting the reinforcing structure, the event sequence and the guided heat source are used to carry out the curve deposition simulation of the bare shell structure, and the residual stress and deformation distribution simulation prediction results are obtained;

[0009] S3, reinforcing shell structure deposition simulation prediction: based on the simulation results of S2, reinforcing structures are set in the areas where the stress and deformation of the shell structure are too large, and curve deposition simulation is carried out, to obtain the stress and deformation distribution simulation prediction results of the reinforced shell structure;

[0010] S4, reinforced shell metal 3D printing construction: based on the reinforced shell structure obtained in S3, the metal 3D printing construction is carried out by using the electric arc additive manufacturing printing equipment.

[0011] As preferred, in S1, the metal wire material includes stainless steel, carbon steel and aluminum alloy, in the form of wire material; the curved surface shape optimization design is realized in the computer program based on the node displacement progressive form finding method of three-node plane shell element.

[0012] As preferred, S2 includes:

[0013] S201, using event sequence and double-ellipsoid heat source model, the electric arc additive manufacturing process optimization process simulation analysis is carried out on the bare shell structure; during the process optimization process simulation, the curved surface geometry of the bare shell structure is re-oriented, so that its surface normal direction is parallel to the substrate plane; the curve path of each deposition layer is set to be always parallel to the substrate plane, and corresponds to different curve geometry along the z direction; the curve paths of different deposition layers are all set to start deposition from the same side of the curved surface shell structure;

[0014] The surface at the bottom of the bare shell structure and the substrate connection is completely constrained by using embedded boundary conditions to simulate fixed support;

[0015] S202, obtain the process optimization process simulation results of the bare shell structure, the process optimization process simulation results include stress distribution simulation prediction results and deformation distribution simulation prediction results; the stress distribution simulation prediction results include the stress distribution nephogram along the z direction of the front side and the back side, the stress distribution nephogram along the x direction of the front side and the back side, and the three-dimensional axis side Mises stress distribution nephogram containing deformation shape; the deformation simulation prediction results include the deformation curve results of different cross section heights, which are selected at intervals.

[0016] As preferred, S3 includes:

[0017] S301, according to the simulation result of S202, a reinforcing structure is arranged on the exposed thin shell structure, the reinforcing structure is divided into two forms of stiffening rib plate and support beam; a plurality of stiffening rib plates are arranged on the convex side of the curved surface of the exposed thin shell structure, the stiffening rib plates are arranged at positions with large stress distribution to constrain the y-direction bending of the deposition layer on the top of the thin shell; a plurality of support beams are arranged on the concave side of the curved surface of the exposed thin shell structure, the support beams are always parallel to the substrate plate, and the beam ends of the support beams are arranged at positions with large stress distribution to constrain the inward bending of the middle transition area;

[0018] When the finite element simulation is performed, the beam end constraint of the support beam is simulated by limiting the displacement of the node area along the length direction of the support beam;

[0019] S302, simulation prediction of the reinforced thin shell structure is performed to obtain a deformation prediction result.

[0020] Preferably, in S4, the thin shell structure is sliced and layered along three axial directions during the electric arc additive manufacturing process; then, the support beams and the stiffening rib plates are welded at specific cross-sectional heights to obtain a reinforced thin shell structure; and the metal 3D printing construction is performed on the reinforced thin shell structure by using the electric arc additive manufacturing printing equipment to obtain a metal 3D printing object.

[0021] In S4, the reverse reconstruction technology is used in the electric arc additive process: before construction, the original model is imported into the CAM software special for electric arc additive, and a workpiece coordinate system with the printing platform as the origin is defined; 3D point cloud scanning is performed on the constructed part of the structure, and geometric parameters including the deposition layer height and the deformation amount are extracted from the scanned model data;

[0022] The constructed part scanned by the three-dimensional scanner is cut from the original model to generate a remaining model required for subsequent construction; the workpiece coordinate origin is dynamically recalibrated to the top surface of the constructed part, so that the unprinted residual part can be sequentially deposited;

[0023] The specific workflow of the reinforced thin shell metal 3D printing construction is: deposition, scanning, model updating and coordinate recalibration; through the reverse reconstruction technology, defect compensation is performed in the actual printing process of the electric arc additive manufacturing, and the metal 3D printing construction of the reinforced thin shell structure is accurately controlled.

[0024] In a second aspect, a curved surface metal thin shell prepared by the method of any one of the first aspect is provided.

[0025] In a third aspect, an electric arc additive design-simulation-reinforcement-construction integrated system of a curved surface metal thin shell is provided, which is used to execute the method of any one of the first aspect, and comprises:

[0026] An optimization design module is used to design a three-dimensional structure model of a metal thin shell structure by using a metal material and optimizing the design of the curved surface shape of a shell element;

[0027] The first prediction module is configured to simulate the curve deposition of the bare thin-shell structure based on the three-dimensional structure model obtained by the optimization design module and the event sequence and the guided heat source without setting the reinforcing structure, to obtain the simulation prediction result of the residual stress and deformation distribution;

[0028] The second prediction module is configured to set the reinforcing structure in the area where the stress and deformation of the thin-shell structure are too large based on the simulation result of the first prediction module and to simulate the curve deposition, to obtain the simulation prediction result of the stress and deformation distribution of the reinforced thin-shell structure.

[0029] The printing construction module is configured to perform the metal 3D printing construction based on the reinforced thin-shell structure obtained by the second prediction module by using the electric arc additive manufacturing printing equipment.

[0030] In a fourth aspect, a computer storage medium is provided, and the computer storage medium stores a computer program; when the computer program runs on a computer, the computer program causes the computer to execute the method of any one of the first aspect.

[0031] In a fifth aspect, an electronic device is provided, and the electronic device comprises:

[0032] A memory is configured to save a computer program.

[0033] A processor is configured to execute the computer program to implement the method of any one of the first aspect.

[0034] The beneficial effects of the present application are as follows:

[0035] 1. The arc additive design-simulation-reinforcement-construction integrated method of the curved metal thin-shell provided by the present application, through the curved shape optimization design, obtains the optimized curved geometric model of the metal thin-shell structure; through the event sequence and the guided heat source method, the curve deposition simulation of the bare thin-shell structure is performed, the simulation prediction of the residual stress and deformation distribution is realized; through the deposition simulation prediction result of the bare thin-shell structure, the stiffening rib plate and the beam end constraint reinforcement measures are set, so that the stress and deformation distribution of the reinforced thin-shell structure in the arc additive process optimization process is effectively reduced; through the 3D printing construction of the reinforced thin-shell structure, the effectiveness verification of the arc additive design-simulation-reinforcement-construction integrated method of the curved metal thin-shell is realized.

[0036] 2. The arc additive design-simulation-reinforcement-construction integrated method for curved metal thin shell provided by the application, through low-cost deposition simulation prediction, obtains the stress and deformation distribution and amplitude of the bare thin shell structure, and reinforcement measures are set based on this, thereby greatly avoiding excessive deformation in the printing process of the arc additive process, avoiding printing failure and printing relocation due to excessive deformation, and effectively guaranteeing the forming quality and material performance of the metal formed structure; and providing a new integrated effective way for high-quality, high-precision and high-performance forming and construction of curved metal thin shell structures. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a flow chart of the arc additive design-simulation-reinforcement-construction integrated method for curved metal thin shell provided by the application;

[0038] Figure 2 is a schematic diagram of the geometric shape optimization design of the curved metal thin shell;

[0039] Figure 3 is a model schematic diagram of the arc additive process simulation of the bare thin shell structure;

[0040] Figure 4a is a front and back side z-direction stress distribution nephogram of the arc additive process simulation of the bare thin shell structure;

[0041] Figure 4b is a front and back side x-direction stress distribution nephogram of the arc additive process simulation of the bare thin shell structure;

[0042] Figure 4c is a three-dimensional axis measurement Mises stress distribution nephogram (including deformation shape) of the arc additive process simulation of the bare thin shell structure;

[0043] Figure 5a is a deformation curve schematic diagram of the arc additive process simulation of the bare thin shell structure at z=50mm cross-sectional height;

[0044] Figure 5b is a deformation curve schematic diagram of the arc additive process simulation of the bare thin shell structure at z=150mm cross-sectional height;

[0045] Figure 5c is a deformation curve schematic diagram of the arc additive process simulation of the bare thin shell structure at z=300mm cross-sectional height;

[0046] Figure 6 is a simulation model schematic diagram of the stiffened rib plate and beam end constraint reinforced thin shell structure;

[0047] Figure 7 is a three-dimensional axis measurement deformation distribution nephogram of the arc additive process simulation of the reinforced thin shell structure;

[0048] Figure 8a is a comparison of deformation curves of the simulation of the exposed, reinforced thin-shell structure arc additive process at z = 100 mm cross-sectional height;

[0049] Figure 8b is a comparison of deformation curves of the simulation of the exposed, reinforced thin-shell structure arc additive process at z = 200 mm cross-sectional height;

[0050] Figure 8c is a comparison of deformation curves of the simulation of the exposed, reinforced thin-shell structure arc additive process at z = 300 mm cross-sectional height;

[0051] Figure 9a is a schematic and printed physical diagram of beam end constraint reinforcement of a reinforced thin-shell structure;

[0052] Figure 9b is a schematic and printed physical diagram of stiffened ribbed plate reinforcement of a reinforced thin-shell structure;

[0053] Figure 9c is a physical diagram of removing the stiffened ribbed plate and support beam after printing the curved metal thin-shell structure. DETAILED DESCRIPTION

[0054] The application will be further described below in conjunction with the examples. The following examples are only used to help understand the application. It should be pointed out that for ordinary people in the technical field, some modifications can be made without departing from the principles of the application, and these improvements and modifications also fall within the scope of protection of the claims of the application.

[0055] Example 1

[0056] To solve the problems of the prior art, the embodiment 1 of the present application provides an arc additive design-simulation-reinforcement-construction integrated method for curved metal thin-shell, as shown in Figure 1 , which comprises:

[0057] S1, thin-shell structure shape optimization design: adopting metal wire material, using the curved shape optimization design of shell element, obtaining a three-dimensional structure model of the metal thin-shell structure.

[0058] Specifically, as shown in Figure 2As shown, the optimization design domain of the curved metal thin shell structure is set as length L x width B x height H, and is printed and built by using the electric arc additive manufacturing process; the metal material is determined according to actual requirements, and relates to stainless steel, carbon steel, aluminum alloy and the like; the structural stiffness and bearing performance are considered in the optimization design process, and the architectural aesthetics of the curved thin shell is also taken into account; the curved metal thin shell structure is modeled by using a three-node plane thin shell element, the geometric shape of the curved thin shell is optimized by using a self-compiled program based on the node displacement progressive form-finding method in the MATLAB software, and the optimized curved geometric model is obtained; the process logic of the node displacement progressive form-finding method includes defining the load and boundary conditions, solving the node displacement under the reverse load, calculating the structure volume and updating the node coordinates.

[0059] S2, exposed thin shell structure deposition simulation prediction: based on the three-dimensional structure model obtained in S1, the curve deposition simulation of the exposed thin shell structure is carried out by using the event sequence and the guided heat source without setting the reinforcing structure, and the residual stress and deformation distribution simulation prediction results are obtained.

[0060] S2 includes:

[0061] S201, as Figure 3 shown, the event sequence and the double-ellipsoid heat source model are used to simulate and analyze the electric arc additive manufacturing process optimization process of the exposed thin shell structure; when the process optimization process is simulated, the geometric shape of the exposed thin shell structure is re-oriented, so that the surface normal direction is parallel to the substrate plane. At this time, the contact range of the exposed thin shell structure with the substrate is the smallest, which effectively adapts to the electric arc additive manufacturing process; the stacking direction of each deposition layer is aligned with the vertical z-axis, the curve deposition path of each deposition layer is always located on the x-y plane, and all starts from the same side of the curved thin shell structure to leave sufficient interlayer cooling time.

[0062] In the electric arc additive manufacturing process of the exposed thin shell structure, significant out-of-plane bending deformation will occur; in order to accurately capture the out-of-plane bending deformation, the grid element is subdivided to 4 or more along the thickness direction of the thin shell structure; in order to balance the simulation accuracy and calculation efficiency, relatively coarse grids are used in the other two plane directions of the thin shell structure surface; the height of each deposition layer is 5 mm, and the moving speed of the heat source is 10 mm / s; due to the long curve printing path, the initial deposition area of each deposition layer has been sufficiently cooled when the deposition layer is completed; the interlayer cooling time interval in the simulation model is optimized to 50 s, thereby improving the printing efficiency; the surface at the connection between the bottom of the exposed thin shell structure and the substrate is completely constrained by using the embedded boundary condition to simulate the fixed support.

[0063] For curved thin-shell structures, the printing path of the deposition layer in each cross section is a curve, and the curved geometry of the cross-sectional deposition layer also changes with height, that is, the printing path of each deposition layer is a different curve; the inherent complexity in this path planning design makes curved thin-shell structures particularly suitable for using event sequence and guided heat source methods to achieve simulation prediction; by extracting the node positions of the first and last deposition layers, the node coordinates of the intermediate deposition layers are calculated by interpolation; combined with a specific offset, and taking into account deposition speed and time factors, an event sequence block is generated for curved deposition simulation; the event sequence block follows the centerline of each deposition layer as the planned path and moves at the welding gun speed.

[0064] S202, such as Figures 4a-4c As shown, the process optimization simulation results of the exposed thin shell structure are obtained, and the process optimization simulation results include stress distribution simulation prediction results and deformation distribution simulation prediction results.

[0065] The stress distribution simulation prediction results include the stress distribution cloud diagram along the z direction of the front and rear sides, the stress distribution cloud diagram along the x direction of the front and rear sides, and the three-dimensional axial Mises stress distribution cloud diagram including the deformed shape. Figures 5a-5c As shown, the deformation simulation prediction results include deformation curve results at different cross-sectional heights, and the cross-sectional heights are selected at a certain interval.

[0066] S3. Simulation prediction of deposition of reinforced thin shell structure: Based on the simulation results of S2, a reinforcement structure is set in the area where the stress and deformation of the thin shell structure are too large and a curve deposition simulation is performed to obtain the simulation prediction results of the stress and deformation distribution of the reinforced thin shell structure.

[0067] S4. Reinforced thin shell metal 3D printing construction: Based on the reinforced thin shell structure obtained in S3, metal 3D printing construction is performed using arc additive manufacturing printing equipment.

[0068] Example 2:

[0069] Based on Example 1, Example 2 of the present application provides a more specific arc additive design-simulation-reinforcement-construction integrated method for a curved metal shell, including:

[0070] S1. Thin shell structure shape optimization design: Using metal materials and utilizing the surface shape optimization design of shell elements, a three-dimensional structural model of the metal thin shell structure is obtained.

[0071] S2. Deposition simulation prediction of exposed thin shell structure: Based on the three-dimensional structural model obtained in S1, without setting up a reinforcement structure, the curve deposition simulation of the exposed thin shell structure is performed using the event sequence and guided heat source to obtain the simulation prediction results of residual stress and deformation distribution.

[0072] S3, reinforced thin-shell structure deposition simulation prediction: based on the simulation results of S2, set reinforcement structures in the areas where the stress and deformation of the thin-shell structure are excessive and perform curve deposition simulation to obtain stress and deformation distribution simulation prediction results of the reinforced thin-shell structure; the excessive refers to the stress exceeding 50% of the yield strength and the maximum stress area, and the deformation exceeding 10% of the structural size in the corresponding direction and the maximum deformation area.

[0073] S3 includes:

[0074] S301, according to the simulation results of S202, a plurality of stiffening rib plates are arranged on the convex side of the curved surface of the bare thin-shell structure, and a plurality of support beams are arranged on the concave side of the curved surface of the bare thin-shell structure.

[0075] Specifically, as shown in the figure, Figure 6 the deformation mode of the bare thin-shell structure is divided into y-direction bending of the top deposition layer of the thin shell and inward bending of the intermediate transition area; in order to reduce these deformations, the beam end of the stiffening rib plate and the support beam are respectively introduced to constrain the two reinforcement structures during the electric arc additive process of the bare thin-shell structure; a plurality of stiffening rib plates are arranged on the convex side of the curved surface of the bare thin-shell structure, the stiffening rib plates are uniformly distributed along the height (z direction) and are arranged at the positions where the stress distribution is large, and are mainly used to limit the y-direction bending of the top deposition layer of the thin shell; a plurality of support beams are arranged on the concave side of the curved surface of the bare thin-shell structure, the support beams are located on the xy plane, the beam end constraints of the support beams are arranged at the positions where the stress distribution is large, and are mainly used to limit the inward bending of the intermediate transition area; when performing finite element simulation, the beam end constraints of the support beams are simulated by limiting the displacement of the node area along the length direction of the support beam.

[0076] S302, simulation prediction of the reinforced thin-shell structure is performed to obtain deformation prediction results.

[0077] As shown in the figure, Figure 7 , Figures 8a-8c the deformation of the reinforced thin-shell structure is mainly concentrated between adjacent stiffening rib plates, and the deformation amplitude is much smaller than that of the bare thin-shell structure; the deformation of the reinforced thin-shell structure can be effectively compensated for defects in the actual WAAM printing process through the reverse reconstruction technology of the structural model.

[0078] S4, reinforced thin-shell metal 3D printing construction: based on the reinforced thin-shell structure obtained in S3, a metal 3D printing construction is performed by using an electric arc additive manufacturing printing equipment.

[0079] As shown in FIG. 9, for the reinforced thin-shell structure, a metal 3D printing construction is performed by using an electric arc additive manufacturing printing equipment to obtain a metal 3D printing physical object; after the electric arc additive process simulation and reinforcement integrated prediction of the metal thin-shell structure, a structural construction is performed by 3D printing Figure 9c); the WAAM printing equipment includes a printing nozzle mounted on a mechanical arm and a movable sliding platform below; during the arc additive process, the thin shell structure is sliced along three axis directions; then, support beams (stiffening beams, Figure 9a ) and stiffening ribs ( Figure 9b ) are welded at specific cross-sectional heights; these reinforcement structures effectively reduce deformation during printing, and the final reinforcement thin shell structure has much smaller deformation than the naked thin shell structure;

[0080] The reverse reconstruction technique is used in the WAAM process; before construction, the original model is imported into the arc additive special CAM software to define the workpiece coordinate system with the printing platform as the origin, so as to program the slicing and welding gun trajectory; the whole process starts from the deposition layer in contact with the base plate at the bottom, and then the 3D point cloud scanning is performed on the constructed part structure to generate a digital twin model; the geometric parameters are extracted from the scanned model data, including the deposition layer height and the deformation amount;

[0081] The constructed part scanned by the three-dimensional scanner is cut from the original model to generate the remaining model required for subsequent construction; the workpiece coordinate origin is dynamically recalibrated to the top surface of the constructed part, so that the unprinted residual part can be deposited in turn; the specific workflow of the reinforced thin shell metal 3D printing construction is: deposition, scanning, model updating and coordinate recalibration, which effectively reduces the cumulative thermal deformation and prevents defects such as collapse caused by insufficient support; through the reverse reconstruction technology, defect compensation is carried out in the actual printing process of WAAM, and the reinforced thin shell structure metal 3D printing construction is precisely controlled.

[0082] In addition, the application also provides an analysis application of the arc additive design-simulation-reinforcement-construction integrated method of the curved surface metal thin shell in an aluminum alloy curved surface bridge structure model.

[0083] As shown in Figure 2 , Figure 3 , the aluminum alloy bridge structure is a curved surface thin shell structure, and the model geometric size is: design domain length L = 2.0 m, width B = 1.2 m, height H = 0.42 m, and a low curb is arranged at the edge to enhance the safety and coordination of the structure; the metal material is Al4043 aluminum alloy wire. The grid size of the simulation model is 10 mm x 5 mm x 1.5 mm; the single deposition layer height is 5 mm, the moving heat source speed is 10 mm / s, the interlayer cooling time is taken as 50 s, and the bottom is fixedly constrained; the bridge structure WAAM process parameters are shown in Table 1. The curve deposition simulation prediction is carried out by using the event sequence and guided heat source method.

[0084] Table 1 Bridge structure WAAM process parameters

[0085]

[0086] As shown in Figures 4a-4c , in the stress prediction result of the WAAM process simulation of the bare thin shell structure, there is a significant compressive stress along the z direction on the front side and a tensile stress along the z direction on the back side in the middle bending transition zone (x = 0 vicinity); the two sides of the bending transition zone are two nearly straight section zones; residual stress is easy to accumulate in the bending transition zone, and then bending moment is generated; the maximum Mises stress reaches 263 MPa, and the stress range exceeding 200 MPa is large; as shown in Figures 5a-5c , in the deformation prediction result of the WAAM process simulation of the bare thin shell structure, with the increase of the height, the constraint effect of the bottom layer is weakened, resulting in significant rotational deformation in the middle bending transition zone; the maximum deformation amplitude exceeds 100 mm.

[0087] As shown in Figure 7 , Figures 8a-8c , in the deformation prediction result of the WAAM process simulation of the reinforced thin shell structure, the maximum deformation amplitude is only 15 mm, which is much smaller than the deformation amplitude of the bare thin shell structure.

[0088] As shown in Figures 9a-9c , the reinforced thin shell structure is reinforced by stiffened rib plates and support beams, and the final printed shaped part is obtained.

[0089] It should be noted that the same or similar parts in this embodiment as in Embodiment 1 can be mutually referenced, and will not be described in detail in this application.

[0090] Embodiment 3:

[0091] On the basis of Embodiment 2, the application embodiment 3 provides an arc additive design-simulation-reinforcement-construction integrated system for a curved metal thin shell, comprising:

[0092] An optimization design module is used to optimize the design of the curved shape of the shell element by using metal materials, so as to obtain a three-dimensional structure model of the metal thin shell structure.

[0093] A first prediction module is used to simulate the curve deposition of the bare thin shell structure by using event sequences and guided heat sources based on the three-dimensional structure model obtained by the optimization design module without setting a reinforcement structure, so as to obtain residual stress and deformation distribution simulation prediction results.

[0094] A second prediction module is used to set a reinforcement structure in the area where the stress and deformation of the thin shell structure are too large and to simulate the curve deposition, so as to obtain stress and deformation distribution simulation prediction results of the reinforced thin shell structure based on the simulation results of the first prediction module.

[0095] A printing construction module is used to perform metal 3D printing construction by using an arc additive manufacturing printing equipment based on the reinforced thin shell structure obtained by the second prediction module.

[0096] It should be noted that the system provided in this embodiment corresponds to the method provided in Embodiment 2, and therefore, in this embodiment, the same or similar parts as in Embodiment 2 can be referred to each other, and will not be described herein again.

[0097] In summary, the arc additive design-simulation-reinforcement-construction integrated method of the curved metal thin shell provided by the present application realizes the optimization of the curved surface geometry of the metal thin shell structure through the curved surface shape optimization design; realizes the simulation prediction of the residual stress and deformation distribution through the curve deposition simulation of the exposed thin shell structure by the event sequence and the guided heat source method; sets the stiffening rib plate and beam end constraint reinforcement measures through the deposition simulation prediction result of the exposed thin shell structure, thereby effectively reducing the stress and deformation distribution in the WAAM process optimization process of the reinforced thin shell structure; and realizes the effectiveness verification of the arc additive design-simulation-reinforcement-construction integrated method of the curved metal thin shell through the 3D printing construction of the reinforced thin shell structure. And through actual verification, the method of the present application is effective.

Claims

1. An integrated method for arc additive design, simulation, reinforcement and construction of curved metal shells, characterized in that: include: S1. Thin shell structure shape optimization design: Using metal wire and the surface shape optimization design of shell elements, a three-dimensional structural model of the metal thin shell structure is obtained; S2. Deposition simulation prediction of exposed thin shell structure: Based on the three-dimensional structural model obtained in S1, without setting up a reinforcement structure, the curve deposition simulation of the exposed thin shell structure is performed using the event sequence and guided heat source to obtain the simulation prediction results of residual stress and deformation distribution; S3, reinforcement thin shell structure deposition simulation prediction: Based on the simulation results of S2, a reinforcement structure is set in the area where the stress and deformation of the thin shell structure are too large and a curve deposition simulation is performed to obtain the stress and deformation distribution simulation prediction results of the reinforced thin shell structure; S4. Reinforced thin shell metal 3D printing construction: Based on the reinforced thin shell structure obtained in S3, metal 3D printing construction is performed using arc additive manufacturing printing equipment.

2. The arc additive design-simulation-reinforcement-construction integrated method for curved metal shells according to claim 1, characterized in that: In S1, the metal wire material includes stainless steel, carbon steel and aluminum alloy, and is in the form of wire; the surface shape optimization design is implemented in a computer program based on a node displacement progressive form-finding method of a three-node plane thin shell element.

3. The arc additive design-simulation-reinforcement-construction integrated method for curved metal shells according to claim 2, characterized in that S2 include: S201. Using event sequence and double ellipsoid heat source model, the arc additive manufacturing process optimization process of exposed thin shell structure is simulated and analyzed; During the process optimization simulation, the curved surface geometry of the exposed thin shell structure was reoriented so that its surface normal was parallel to the substrate plane. The curved path of each deposition layer was set to always be parallel to the substrate plane and correspond to different curved geometries along the z-direction. The curved paths of different deposition layers were set to start deposition from the same side of the curved thin shell structure. The surface where the bottom of the exposed thin shell structure connects to the substrate is fully constrained using embedded boundary conditions to simulate fixed support. S202, obtaining a process optimization simulation result of the exposed thin shell structure, wherein the process optimization simulation result includes a stress distribution simulation prediction result and a deformation distribution simulation prediction result; The stress distribution simulation prediction results include stress distribution cloud maps along the z-direction of the front and rear sides, stress distribution cloud maps along the x-direction of the front and rear sides, and three-dimensional axial Mises stress distribution cloud maps including deformed shapes; the deformation simulation prediction results include deformation curve results at different cross-sectional heights, and the cross-sectional heights are selected at certain intervals.

4. The arc additive design-simulation-reinforcement-construction integrated method for curved metal shells according to claim 3, characterized in that S3 include: S301. According to the simulation results of S202, a reinforcement structure is set for the exposed thin shell structure. The reinforcement structure is divided into two forms: stiffening ribs and support beams. A plurality of stiffening ribs are set on the convex side of the curved surface of the exposed thin shell structure. The stiffening ribs are arranged at the location with greater stress distribution to constrain the y-direction bending of the deposited layer on the top of the thin shell. A plurality of support beams are set on the concave side of the curved surface of the exposed thin shell structure. The support beams are always parallel to the substrate plate. The ends of the support beams are arranged at the location with greater stress distribution to constrain the inward bending of the intermediate transition zone. During finite element simulation, the beam end constraint of the support beam is simulated by limiting the displacement of the node area along the length direction of the support beam; S302: Perform simulation prediction of the reinforced thin shell structure to obtain deformation prediction results.

5. The arc additive design-simulation-reinforcement-construction integrated method for curved metal shells according to claim 4, characterized in that: In S4, during the arc additive manufacturing process, the thin shell structure is sliced ​​and layered along three axes; then, the support beams and stiffening ribs are welded at a specific cross-sectional height to obtain a reinforced thin shell structure; for the reinforced thin shell structure, metal 3D printing is carried out using arc additive manufacturing printing equipment to obtain a metal 3D printed object.

6. The arc additive design-simulation-reinforcement-construction integrated method for curved metal shells according to claim 5, characterized in that: In S4, reverse reconstruction technology is used in the arc additive manufacturing process: before construction, the original model is imported into arc additive manufacturing-specific CAM software to define the workpiece coordinate system with the printing platform as the origin; 3D point cloud scanning is performed on the built part of the structure, and geometric parameters, including deposited layer height and deformation, are extracted from the scanned model data; The built part of the 3D scan is cut away from the original model to generate the remaining model required for subsequent construction; the workpiece coordinate origin is dynamically recalibrated to the top surface of the built part, allowing the unprinted residual parts to be deposited sequentially; The specific workflow for the 3D printing construction of reinforced thin-shell metals is as follows: deposition, scanning, model update, and coordinate recalibration; Through reverse reconstruction technology, defects are compensated during the actual printing process of arc additive manufacturing, and metal 3D printing construction of reinforced thin shell structures is carried out.

7. A curved metal thin shell prepared by the method according to any one of claims 1 to 6.

8. Arc additive design-simulation-reinforcement-construction integrated system for curved metal shells, characterized by: Used to perform the method according to any one of claims 1 to 6, comprising: The optimization design module is used to use metal materials and optimize the surface shape of shell elements to obtain a three-dimensional structural model of the metal thin shell structure; The first prediction module, based on the three-dimensional structural model obtained in the optimization design module, uses the event sequence and guided heat source to perform curve deposition simulation of the exposed thin shell structure without setting up a reinforcement structure, and obtains the simulation prediction results of residual stress and deformation distribution; The second prediction module, based on the simulation results of the first prediction module, sets a reinforcement structure in the area of ​​the thin shell structure where the stress and deformation are too large and performs a curve deposition simulation to obtain the stress and deformation distribution simulation prediction results of the reinforced thin shell structure; The printing and construction module is used to perform metal 3D printing construction based on the reinforced thin shell structure obtained by the second prediction module using arc additive manufacturing printing equipment.

9. A computer storage medium, characterized in that The computer storage medium stores a computer program; when the computer program is run on a computer, the computer executes the method according to any one of claims 1 to 6.

10. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the method according to any one of claims 1 to 6.

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