A deformation control method and device for trajectory welding of aircraft engine bracket based on DIC

Abstract

The present invention discloses a deformation control method and device for trajectory welding of an aero-engine bracket based on DIC. The deformation control method comprises: establishing a finite element model of the engine bracket; the finite element model of the engine bracket is spliced ​​together by a spherical joint model, a support rod model, and a single-fork joint model; performing multiple welding simulations on the splicing position to select an initial welding scheme, wherein the initial welding scheme includes the number of welding segments, a welding sequence, and welding parameters; adding a 3D-DIC measuring device during a trajectory welding test using the initial welding scheme to obtain full-process and full-area three-dimensional strain data of a base material sample and a weld sample during the welding process; using DIC to measure the strain data near the weld and comparing it with the simulation results of the initial welding scheme to verify the accuracy of the finite element model and calculation conditions through welding parameter verification at multiple reference points and multiple time periods, and obtaining the optimal welding scheme through finite element simulation.

Description

Technical Field

[0001] The present invention relates to the field of welding residual stress and deformation control, and in particular to a deformation control method and device for trajectory welding of an aero-engine bracket based on DIC. Background Art

[0002] Helicopter turboshaft engine mounts are critical welded structural components used to mount the engine, bearing significant static and dynamic loads. With the development of modern helicopters, the requirements for engine mounts are becoming increasingly stringent. Quality issues with these mounts can severely impact engine performance and even cause the entire helicopter system to fail.

[0003] Currently, the production of helicopter engine brackets still faces multiple challenges. First, due to irrational welding sequence and parameter design, large welding distortion and difficulty in post-weld alignment can lead to low production yields and slow production progress. Second, existing manual arc welding, due to manual instability, results in poor welding quality and large welding distortion. This makes post-weld flame alignment labor intensive and requires long heating times, increasing the negative impact of flame alignment on weld microstructure and properties, and reducing the yield of helicopter engine brackets. The rise of automated welding can address these issues. Automated welding, performed by robots, reduces human intervention and improves welding speed and efficiency. Automated welding is now widely used across various industrial sectors. Automated welding technology is not only used in pipeline assembly in complex environments, but also in shipbuilding and the welding of liquefied natural gas membrane storage tanks. Using automated orbital welding instead of manual argon arc welding for engine brackets can reduce human intervention and improve both the yield and quality rate of engine brackets. However, there is no prior experience with orbital welding for engine brackets, and the specific welding parameters and processes still require continuous experimentation and exploration. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problems existing in the prior art and to propose a deformation control method and device for trajectory welding of an aero-engine bracket based on DIC, so as to reduce the test cost and shorten the test time.

[0005] To achieve the above object, the present invention provides a technical solution: a deformation control method for trajectory welding of an aero-engine bracket based on DIC, the deformation control method specifically comprising the following steps:

[0006] Step 1: Perform thermo-elastic-plastic finite element analysis on the engine bracket welding based on ABAQUS software to establish the engine bracket finite element model; the engine bracket finite element model is composed of three parts: the spherical joint model, the support rod model, and the single fork joint model;

[0007] Step 2: Perform multiple welding simulations on the joints of the spherical joint model, the support rod model, and the single fork joint model to select an initial welding plan. The initial welding plan includes the number of welding segments, welding sequence, and welding parameters.

[0008] Step 3: Add 3D-DIC measurement equipment during the welding test using the initial welding plan to obtain 3D-DIC measurement strain data of the base material sample and the weld sample during welding;

[0009] Step 4: Based on the 3D-DIC strain data and the simulation results of the initial welding plan, the strain values ​​of the weld structure measured by 3D-DIC during the simulation process and the test are compared to optimize the accuracy of the simulation process and modify the welding parameters to obtain the optimal welding plan.

[0010] Step 5: Carry out production test according to the best welding plan.

[0011] Furthermore, selecting the initial welding scheme in step 2 specifically includes the following steps:

[0012] After the finite element model is established, the temperature field and stress field generated by the full circle welding of the splicing position are simulated in the finite element model according to the three different preset welding parameters;

[0013] By comparing the post-weld temperature field, post-weld residual stress and deformation, the welding parameters of the track welding of the engine bracket with the minimum residual stress and deformation are analyzed;

[0014] Combined with the actual range of adjustable welding parameters available in trajectory welding, the temperature and stress fields generated by segmented welding at the splicing position are simulated in the finite element model;

[0015] By comparing the post-weld temperature field, post-weld residual stress and deformation, the number of welding segments and the welding sequence of the trajectory welding of the engine bracket with the minimum residual stress and deformation are analyzed.

[0016] Furthermore, the specific method for obtaining 3D-DIC measurement strain data of the base material sample and the weld sample during the welding process in step 3 is: using the initial welding plan to conduct a welding test on the welding position of the engine bracket, and at the same time using 3D-DIC measurement equipment to perform full-field, full-range, and full-process strain measurement to obtain three-dimensional strain data of the entire welding process.

[0017] Furthermore, in step 4, the accuracy of the simulation process is optimized and the welding parameters are corrected to obtain the optimal welding solution. The specific method is as follows: the strain data calculated by the finite element model using the initial welding solution is verified with the three-dimensional strain data of the 3D-DIC measurement equipment, and the finite element model using the initial welding solution is corrected in the entire field, the entire domain, and the entire process.

[0018] Furthermore, the finite element model of the initial welding scheme is used to perform full-field, full-area, and full-process corrections, including multiple corrections of the simulation model with welding time as the axis and any position of the engine bracket as the correction range, until the calculation results of the simulation model are infinitely close to the 3D-DIC measurement deformation results of the welding test.

[0019] The present invention also discloses a deformation control device for trajectory welding of an aero-engine bracket based on DIC, the device comprising: an establishment module for establishing a finite element model of the engine bracket; the finite element model of the engine bracket is composed of three parts: a spherical joint model, a support rod model, and a single fork joint model;

[0020] Simulation module: used to perform multiple welding simulations on the joint positions of the spherical joint model, support rod model, and single fork joint model, and select the initial welding plan, which includes the number of welding segments, welding sequence, and welding parameters;

[0021] Measurement module: used to add 3D-DIC measurement equipment during the welding test using the initial welding plan to obtain 3D-DIC measurement data of the base material sample and the weld sample during the welding process;

[0022] Correction module: This module is used to compare the strain values ​​near the weld measured by 3D-DIC during simulation and during testing based on the 3D-DIC measurement data and the simulation results of the initial welding plan, thereby optimizing the accuracy of the simulation process and correcting the welding parameters to obtain the optimal welding plan.

[0023] Production module: used to produce tests according to the best welding plan.

[0024] Furthermore, the simulation module selects the initial welding plan, specifically including the following steps:

[0025] After the finite element model is established, the temperature field and stress field generated by the full circle welding of the splicing position are simulated in the finite element model according to the three different preset welding parameters;

[0026] By comparing the post-weld temperature field, post-weld residual stress and deformation, the welding parameters of the track welding of the engine bracket with the minimum residual stress and deformation are analyzed;

[0027] Combined with the actual range of adjustable welding parameters available in trajectory welding, the temperature and stress fields generated by segmented welding at the splicing position are simulated in the finite element model;

[0028] By comparing the post-weld temperature field, post-weld residual stress and deformation, the number of welding segments and the welding sequence of the trajectory welding of the engine bracket with the minimum residual stress and deformation are analyzed.

[0029] Furthermore, the specific method for obtaining 3D-DIC measurement strain data of the base material sample and the weld sample during the welding process in the measurement module is: using the initial welding plan to conduct a welding test on the welding position of the engine bracket, and at the same time using 3D-DIC measurement equipment to perform full-field, full-range, and full-process strain measurement to obtain three-dimensional strain data of the entire welding process.

[0030] Furthermore, the correction module optimizes the accuracy of the simulation process and uses this to correct the welding parameters to obtain the optimal welding solution. The specific method is: use the three-dimensional strain data of the 3D-DIC measurement equipment to verify the strain data calculated by the finite element model using the initial welding solution, and then perform full-field, full-domain, and full-process corrections on the finite element model using the initial welding solution.

[0031] Beneficial effects of the present invention:

[0032] 1. The present invention performs thermo-elastoplastic finite element analysis on the welding of the engine bracket based on ABAQUS software, and verifies the trajectory welding model through welding experiments, highlighting the rationality and authenticity of the simulation model.

[0033] 2. The present invention further illustrates, through comparison of simulation analysis results, that three-stage segmented welding is superior to four-stage and single-pass continuous welding, and optimizes the residual stress and deformation of engine bracket welding better than other solutions, providing a strong theoretical basis for engine bracket welding.

[0034] 3. This patent uses 3D-DIC to measure the real-time three-dimensional strain of the entire welded engine bracket, verifying the measurement results with the simulation results. By guiding and correcting the finite element simulation through the measurement results of the entire area and multiple time periods, it can maximize the solution to the inherent problems of inaccuracy and uncertainty in the simulation results, enhance the connection with actual experiments, and provide favorable high-precision data support for subsequent process optimization.

[0035] 4. This study is close to actual engineering applications, providing theoretical guidance for the selection of welding parameters for similar parts and technical support for welding deformation control. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0037] Figure 1a This is a structural diagram of the engine bracket model;

[0038] Figure 1b Extract virtual path diagram for engine bracket data;

[0039] Figure 2aIt is a schematic diagram of the welding sequence of three-stage segment welding;

[0040] Figure 2b It is a schematic diagram of the welding sequence of four-stage segment welding;

[0041] Figure 3 This is the comparison diagram of the axial residual stress of the first weld;

[0042] Figure 4 This is the comparison diagram of the axial strain of the first weld;

[0043] Figure 5 The figure is a comparison chart of finite element analysis and results. DETAILED DESCRIPTION

[0044] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0045] Track welding not only improves welding efficiency but also ensures weld quality. Track welding is simple to operate, offers a high first-pass weld yield, and is unaffected by human factors. It also stabilizes weld deformation and improves product yield. Different welding sequences can lead to changes in residual stress and strain after welding. A suitable welding sequence can effectively reduce the generation of residual stress and deformation. Welding deformation is an inevitable phenomenon during welding. After welding, the engine bracket must be placed in a specific fixture to inspect the weld deformation and verify compliance with welding standards. Therefore, predicting and controlling weld deformation and residual stress changes during the welding process is crucial. Digital image correlation (DIC) is an optical measurement system that provides multi-dimensional (2D or 3D, depending on hardware components, measurement, and data processing techniques), full-process, non-contact measurement of the material's contour, displacement, vibration, and strain. Applied to the welding of helicopter engine brackets, it enables full-scale, full-area, three-dimensional measurement of weld deformation, significantly contributing to engine bracket deformation control. Numerical simulation of welding offers extremely high accuracy and reliability in tracking welding. At the same time, 3D-DIC is applied to very small to large measurement areas, and its results can be bidirectionally adapted with finite element analysis software, and the results of the two can be quantitatively compared. The introduction of this method to measure deformation during welding is conducive to the accurate verification of simulation results, improves the accuracy of finite element analysis results, and increases the feasibility of the present invention. The present invention uses finite element software in combination with actual trajectory welding tests, and uses 3D-DIC equipment to perform full-process and full-area three-dimensional measurements of the actual test, and verifies the measurement results and computer simulations throughout the entire process and domain, and corrects the computer simulation model and calculation conditions to the maximum extent in a physical sense, thereby effectively improving the accuracy of computer simulation. The purpose of the invention is to guide the welding of actual engine brackets with high-precision finite element simulation results, reduce the cost of welding tests, and shorten the time of engine bracket welding production tests.

[0046] Example 1

[0047] The present invention discloses a deformation control method for trajectory welding of an aero-engine bracket based on DIC, comprising the following steps:

[0048] Step 1: Use ABAQUS finite element software to establish the engine bracket finite element model:

[0049] like Figure 1a As shown, the finite element model of the engine bracket is composed of three parts: a spherical joint model, a support rod model, and a single fork joint model; the splicing positions of the spherical joint model, the support rod model, and the single fork joint model are the welding positions to be welded.

[0050] Step 2: Optimize welding sequence:

[0051] After the finite element model was established, three different welding parameters were set and compared based on experience. Specifically, ABAQUS software was used to numerically simulate the temperature and stress fields generated by full-circle welding of the engine bracket using these three different welding parameters. Subsequently, by comparing the post-weld temperature field, residual stress, and deformation, the most optimal orbital welding parameters for the engine bracket were identified.

[0052] The temperature field and stress field generated by multi-segment welding of the engine bracket using the above-mentioned trajectory welding parameters are numerically simulated. During the simulation process, a sequential coupling method is used to first calculate and analyze the welding temperature field, and then the results are imported into the structural model to calculate the stress field. Since changing the welding sequence can change the welding residual stress and deformation, a reasonable welding sequence can further improve the welding stability and yield of the engine bracket. Therefore, by comparing the post-weld temperature field, post-weld residual stress and deformation, the most suitable number of segments for the engine bracket and the welding sequence under this number of segments are analyzed. The welding sequence is as follows: Figure 2a and Figure 2b As shown. The welding sequence here refers to the order in which one section is carried out first and which one is carried out next when multiple sections are required to complete the same connection position. At the same time, there are three schemes for three-stage segment welding according to the welding sequence. This patent prefers the segment welding sequence of 123.

[0053] Step 3: Introduce 3D-DIC to track welding measurement correction simulation:

[0054] Conduct actual trajectory welding experiments. Using the welding parameters from step two, 3D-DIC equipment was used to measure welding deformation. The equipment's binocular high-resolution camera captured full-field, full-area 3D graphics data of the base material and weld specimen during welding in real time. This graphics data was processed using DIC software to obtain full-scale strain data for the bracket base material and the vicinity of the weld during the welding process. The DIC strain data was compared and verified with the strain data from finite element simulations. Using the DIC data as a benchmark, the finite element simulation model and calculation conditions were modified to obtain a numerical simulation model and calculation conditions that were consistent with actual conditions.

[0055] Through multiple multi-parameter segmented welding tests, multiple comparisons and verifications were carried out using 3D-DIC measurement strain data and finite element simulation strain data, multiple corrections were made to the finite element model and its calculation conditions, and high-precision optimization of the finite element model and calculation conditions was achieved, which can be used to further guide actual welding tests.

[0056] Step 4: Guide the actual welding test based on the modified finite element model:

[0057] Since orbital welding is essentially TIG welding, the engine bracket weld surface is cleaned before spot welding to secure the spherical boss, single-prong boss, and support rod. A retaining ring appropriately sized for the engine bracket is then used to clamp and seal the bracket, while the tungsten needle is aligned with the weld. Using a high-precision finite element model optimized with DIC and calculation conditions, the optimal welding parameters and segmented welding plan are analyzed. The optimal current, voltage, and welding speed are then entered into the equipment, and argon is selected as the shielding gas. The orbital welding equipment then operates according to the programmed settings and the welding process is completed.

[0058] The present invention also discloses a deformation control device for track welding of an aero-engine bracket based on DIC, comprising:

[0059] Establishment module: used to establish the finite element model of the engine bracket; the finite element model of the engine bracket is composed of three parts: the spherical joint model, the support rod model and the single fork joint model;

[0060] Simulation module: used to perform multiple welding simulations on the joint positions of the spherical joint model, support rod model, and single fork joint model, and select the initial welding plan, which includes the number of welding segments, welding sequence, and welding parameters;

[0061] Measurement module: used to add 3D-DIC measurement equipment during the welding test using the initial welding plan to obtain 3D-DIC measurement data of the base material sample and the weld sample during the welding process;

[0062] Correction module: This module is used to compare the strain values ​​near the weld measured by 3D-DIC during simulation and during testing based on the 3D-DIC measurement data and the simulation results of the initial welding plan, thereby optimizing the accuracy of the simulation process and correcting the welding parameters to obtain the optimal welding plan.

[0063] Production module: used to produce tests according to the best welding plan.

[0064] Furthermore, the simulation module selects the initial welding plan, specifically including the following steps:

[0065] After the finite element model is established, the temperature field and stress field generated by the full circle welding of the splicing position are simulated in the finite element model according to the three different preset welding parameters;

[0066] By comparing the post-weld temperature field, post-weld residual stress and deformation, the trajectory welding parameters of the engine bracket with the minimum residual stress and deformation are analyzed;

[0067] Combined with the actual range of adjustable welding parameters available for trajectory welding, the temperature and stress fields generated by segmented welding at the splicing position are simulated in the finite element model;

[0068] By comparing the post-weld temperature field, post-weld residual stress and deformation, the number of welding segments and the welding sequence of the trajectory welding of the engine bracket with the minimum residual stress and deformation are analyzed.

[0069] Furthermore, the specific method for obtaining 3D-DIC measurement strain data of the base material sample and the weld sample during the welding process in the measurement module is: using the initial welding plan to conduct a welding test on the welding position of the engine bracket, and at the same time using 3D-DIC measurement equipment to perform full-field, full-range, and full-process strain measurement to obtain three-dimensional strain data of the entire welding process.

[0070] Furthermore, the correction module optimizes the accuracy of the simulation process and uses this to correct the welding parameters to obtain the optimal welding solution. The specific method is: use the three-dimensional strain data of the 3D-DIC measurement equipment to verify the strain data calculated by the finite element model using the initial welding solution, and then perform full-field, full-domain, and full-process corrections on the finite element model using the initial welding solution.

[0071] In order to verify the effectiveness and accuracy of the finite element simulation to guide the actual trajectory welding test, the residual stress on the weld surface of the engine bracket was measured using an X-ray stress tester. Figure 5 As shown, the finite element results agree well with the measured results, and the residual stress trends are consistent between the two. However, there is a certain error between the experimental data and the numerical predictions. This is due to the inherent fluctuations in the welding results and the measurement error of the X-ray diffractometer. The average error between the measured values ​​at six points and the simulated values ​​is 8.9%, which is within a reasonable range.

[0072] Example 2

[0073] The present invention provides a track welding method for an engine bracket based on single-pass continuous welding:

[0074] Step 1: Using ABAQUS software, we simulated the temperature and stress fields generated by continuous welding of a full-circle engine bracket using a single pass. We then analyzed the optimal welding parameters for orbital welding of the engine bracket by comparing the post-weld temperature field, residual stress, and deformation.

[0075] Step 2: Use acetone to wipe the surfaces of the two welding joints to clean the surface dirt around the welding joints.

[0076] Step three: There is no need to bevel the weld. Just align the spherical boss, single-prong boss and support rod at the weld joint. Use spot welding to fix the position of each joint at three points.

[0077] Step 4: Install the fixed engine bracket onto the special welding fixture, which completely fixes the ball joint and the single fork joint.

[0078] Step 5: Select a track welding fixture with a radius of 10mm, clamp it on the first weld, and align the tungsten needle with the weld.

[0079] Step 6: Install the 3D-DIC measurement equipment near the welding equipment to collect real-time strain changes during the welding process.

[0080] Step 7: Set the welding voltage to 10V, the current to 80A, and the welding speed to 1mm / s on the track welding equipment. Then start the welding equipment and work according to the preset program, and wait for the welding to be completed.

[0081] Step 8: After all welding is completed, remove the engine bracket from the special fixture.

[0082] In step nine, for subsequent weld samples, another set of optimized parameters was used, and steps three through six were repeated. For these multiple tests, the strain data measured using 3D-DIC and the strain data from finite element simulation were compared and verified, enabling multiple revisions to the finite element model and its calculation conditions, resulting in high-precision optimization of the finite element model and calculation conditions. Simultaneously, through optimization calculations using finite element simulation, the optimal single-weld welding parameters were further screened and determined to be a welding voltage of 10V, a current of 80A, and a welding speed of 1.5mm / s, which were used to guide actual welding tests.

[0083] Example 3

[0084] The present invention provides a track welding method for an engine bracket based on segmented welding:

[0085] Step 1: Using ABAQUS software, we simulated the temperature and stress fields generated by a multi-stage welding test of the engine bracket. We then analyzed the optimal trajectory welding parameters for the engine bracket by comparing the post-weld temperature field, residual stress, and deformation.

[0086] Step 2: Use acetone to wipe the surface of the two weld joints in a circle to clean the surface dirt around the welds.

[0087] Step three: There is no need to bevel the weld. Just align the spherical boss, single-prong boss and support rod at the weld. Use spot welding to fix the position of each weld at three points.

[0088] Step 4: Install the fixed engine bracket onto the special welding fixture, which completely fixes the ball joint and the single fork joint.

[0089] Step 5: Select a track welding fixture with a radius of 10mm, clamp it on the first weld, and align the tungsten needle with the weld.

[0090] Step 6: Install the 3D-DIC measurement equipment near the welding equipment to collect real-time strain changes during the welding process.

[0091] Step 7: Set the voltage to 10V, the current to 80A, and the welding speed to 1.5mm / s on the track welding equipment. Then start the welding equipment and wait for the welding to complete.

[0092] Step 8: After all welding is completed, remove the engine bracket from the special fixture.

[0093] Step 9: In subsequent weld samples, repeat steps 3 to 6 by changing the welding order to achieve three-stage and four-stage welding methods, such as Figure 2a and Figure 2b For the above multiple tests, the strain data measured by 3D-DIC equipment and the strain data of finite element simulation were compared and verified, and the finite element model and its calculation conditions were modified multiple times to obtain high-precision optimization of the finite element model and calculation conditions.

[0094] Use the optimized finite element simulation method to conduct segmented welding tests to find the best welding solution. Figure 1b As shown, a virtual path L1 perpendicular to the two welds is established on the finite element model grid of the engine bracket to extract the stress and strain data in the axial direction. The path L1 passes through the midpoint of the third section of the three-section segment weld and the starting point of the second section of the four-section segment weld.

[0095] The determined optimal single weld parameters are used to simulate segmented welding. Figure 3 、 Figure 4 As shown in Table 1, Table 1 shows the displacement of the measurement points.

[0096] Table 1

[0097]

[0098] The simulation results of single-pass continuous welding show that the peak axial stress at the support rod of the first weld is 58.5 MPa, and the peak axial stress at the spherical joint is 164 MPa. The axial strain at the starting point of the first weld is 0.022. The displacement of the center point of the upper surface of the single-pass joint is 0.185 mm in the X direction, 0.029 mm in the Y direction, and 0.232 mm in the Z direction.

[0099] The simulation results of the three-stage segmented welding show that the peak axial stress at the support rod of the first weld is 34.7 MPa, and the peak axial stress at the spherical joint is 110 MPa. The axial strain at the starting point of the first weld is 0.012. The displacement of the center point of the upper surface of the single-pronged joint is 0.068 mm in the X direction, 0.043 mm in the Y direction, and 0.232 mm in the Z direction.

[0100] The simulation results of the four-stage segmented welding show that the peak axial stress at the support rod of the first weld is 46.1 MPa, and the peak axial stress at the spherical joint is 128.3 MPa. The axial strain at the starting point of the first weld is 0.025. The displacement of the center point of the upper surface of the single-pronged joint is 0.111 mm in the X direction, 0.119 mm in the Y direction, and 0.225 mm in the Z direction.

[0101] From the above numerical simulation results, it can be seen that the peak axial stress of the three-stage segmented welding at the first weld support rod is reduced by 24.7% compared with the four-stage segmented welding, and the peak axial stress of the three-stage segmented welding is reduced by 40.6% compared with the single-pass continuous welding; at the first weld spherical joint, the peak axial stress of the three-stage segmented welding is reduced by 14.3% compared with the four-stage segmented welding, and the peak axial stress of the three-stage segmented welding is reduced by 32.9% compared with the single-pass continuous welding; the first weld is welded from the beginning. At the point, the three-stage weld reduced the axial strain by 52% compared to the four-stage weld, and by 45.5% compared to the single-pass continuous weld. In the X-direction, the displacement of the three-stage weld was reduced by 38.7% compared to the four-stage weld, and by 63.2% compared to the single-pass continuous weld. In the Y-direction, the displacement of the three-stage weld was reduced by 63.8% compared to the four-stage weld, and increased by 32.6% compared to the single-pass continuous weld. In the Z-direction, the displacement of the three schemes was similar.

[0102] Therefore, finite element simulation screened and determined that the best welding scheme was a three-stage jump welding form with a welding voltage of 10 V, a current of 80 A, and a welding speed of 1.5 mm / s. The best welding scheme will guide the actual welding test.

[0103] In summary, the present invention performs thermo-elastoplastic finite element analysis on engine bracket welding based on ABAQUS software, and verifies the trajectory welding simulation model through welding experiments coordinated with 3D-DIC, highlighting the rationality and authenticity of the simulation model.

[0104] Secondly, this patent prefers 3D-DIC to measure the real-time three-dimensional strain of the entire process and entire area of ​​the welded engine bracket, verifies the measurement results with the simulation results, and guides the correction of the finite element simulation through the measurement results of the entire area and multiple time periods, thereby maximally solving the inherent problems of inaccuracy and uncertainty in the simulation results, improving the connection with actual experiments, and providing favorable high-precision data support for subsequent process optimization.

[0105] In addition, the present invention selects the optimal welding parameters through two-way comparison of simulation analysis and test results, and further illustrates that three-stage segmented welding is better than four-stage and single-pass continuous welding. It optimizes the residual stress and deformation of aero-engine bracket welding than other schemes, providing a strong theoretical basis for aero-engine bracket welding.

[0106] Finally, this study is close to actual engineering applications, providing theoretical guidance for the selection of welding parameters for similar parts and technical support for welding deformation control.

[0107] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A deformation control method for track welding of an aero-engine bracket based on DIC, characterized by: The deformation control method specifically comprises the following steps: Step 1: Perform thermo-elastic-plastic finite element analysis on the engine bracket welding based on ABAQUS software to establish the engine bracket finite element model; the engine bracket finite element model is composed of three parts: the spherical joint model, the support rod model, and the single fork joint model; Step 2: Perform multiple welding simulations on the joints of the spherical joint model, the support rod model, and the single fork joint model to select an initial welding plan. The initial welding plan includes the number of welding segments, welding sequence, and welding parameters. Step 3: Add 3D-DIC measurement equipment during the welding test using the initial welding plan to obtain 3D-DIC measurement strain data of the base material sample and the weld sample during welding; Step 4: Based on the 3D-DIC strain data and the simulation results of the initial welding plan, the strain values ​​of the welded structure measured by 3D-DIC during the simulation and the test are compared to optimize the accuracy of the simulation process. The number of welding segments, welding sequence, and welding parameters are then modified to obtain the optimal welding plan. Step 5: Carry out production test according to the best welding plan.

2. The deformation control method for trajectory welding of an aircraft engine bracket based on DIC according to claim 1, characterized in that: The initial welding plan selected in step 2 specifically includes the following steps: After the finite element model is established, the temperature field and stress field generated by the full circle welding of the splicing position are simulated in the finite element model according to the three different preset welding parameters; By comparing the post-weld temperature field, post-weld residual stress and deformation, the trajectory welding parameters of the engine bracket with the minimum residual stress and deformation are analyzed; Combined with the actual range of adjustable welding parameters available for trajectory welding, the temperature and stress fields generated by segmented welding at the splicing position are simulated in the finite element model; By comparing the post-weld temperature field, post-weld residual stress and deformation, the number of segments and the welding sequence of the trajectory welding of the engine bracket with the minimum residual stress and deformation are analyzed.

3. The deformation control method for track welding of an aircraft engine bracket based on DIC according to claim 1, characterized in that: The specific method for obtaining 3D-DIC measurement strain data of the base material sample and the weld sample during welding in step 3 is: using the initial welding plan to conduct a welding test on the welding position of the engine bracket, and at the same time using 3D-DIC measurement equipment to perform full-field, full-range, and full-process strain measurement to obtain three-dimensional strain data for the entire welding process.

4. The deformation control method for track welding of an aircraft engine bracket based on DIC according to claim 1, characterized in that: In step 4, the accuracy of the simulation process is optimized and the number of welding segments, welding sequence, and welding parameters are corrected to obtain the optimal welding solution. The specific method is as follows: the three-dimensional strain data of the 3D-DIC measuring device is used to verify the strain data calculated by the finite element model using the initial welding solution, that is, containing different combinations of the number of segments, welding sequence, and welding parameters, and the finite element model using the initial welding solution is corrected in the entire field, the entire domain, and the entire process.

5. The deformation control method for trajectory welding of an aircraft engine bracket based on DIC according to claim 4, characterized in that: The finite element model using the initial welding scheme, that is, containing different numbers of segments, welding sequences and welding parameter combinations, is corrected throughout the entire field, the entire area and the entire process. This includes using the welding time as the reference axis and any position of the engine bracket as the correction range, and performing multiple corrections on the simulation model until the calculation results of the simulation model are infinitely close to the 3D-DIC measurement deformation results of the welding test.

6. A deformation control device for track welding of aircraft engine brackets based on DIC, characterized by: Includes: Building module: used to build the finite element model of the engine bracket; the finite element model of the engine bracket is composed of three parts: the spherical joint model, the support rod model and the single fork joint model; Simulation module: used to perform multiple welding simulations on the joint positions of the spherical joint model, support rod model, and single fork joint model, and select the initial welding plan, which includes the number of welding segments, welding sequence, and welding parameters; Measurement module: used to add 3D-DIC measurement equipment during the welding test using the initial welding plan to obtain 3D-DIC measurement data of the base material sample and the weld sample during the welding process; Correction module: This module is used to compare the strain near the weld measured by 3D-DIC during simulation with that measured during the test based on the 3D-DIC measurement data and the simulation results of the initial welding plan, optimize the accuracy of the simulation process, and use this to correct the number of welding segments, welding sequence, and welding parameters to obtain the optimal welding plan. Production module: used to produce tests according to the best welding plan.

7. The deformation control device for track welding of an aircraft engine bracket based on DIC according to claim 6, characterized in that: The simulation module selects the initial welding plan, which specifically includes the following steps: After the finite element model is established, the temperature field and stress field generated by the full circle welding of the splicing position are simulated in the finite element model according to the three different preset welding parameters; By comparing the post-weld temperature field, post-weld residual stress and deformation, the trajectory welding parameters of the engine bracket with the minimum residual stress and deformation are analyzed; Combined with the actual range of adjustable welding parameters available for trajectory welding, the temperature and stress fields generated by segmented welding at the splicing position are simulated in the finite element model; By comparing the post-weld temperature field, post-weld residual stress and deformation, the number of segments and the welding sequence of the trajectory welding of the engine bracket with the minimum residual stress and deformation are analyzed.

8. The deformation control device for track welding of an aircraft engine bracket based on DIC according to claim 6, characterized in that: The specific method used in the measurement module to obtain 3D-DIC measurement strain data for the base material sample and the weld sample during the welding process is: using the initial welding plan to conduct welding tests on the welding position of the engine bracket, and at the same time using 3D-DIC measurement equipment to perform full-field, full-range, and full-process strain measurement to obtain three-dimensional strain data for the entire welding process.

9. The deformation control device for track welding of an aircraft engine bracket based on DIC according to claim 6, characterized in that: The correction module optimizes the accuracy of the simulation process and uses this to correct the number of welding segments, welding sequence, and welding parameters to obtain the optimal welding solution. The specific method is as follows: the three-dimensional strain data of the 3D-DIC measuring device is used to verify the strain data calculated by the finite element model using the initial welding solution, that is, containing different combinations of the number of segments, welding sequence, and welding parameters, and the finite element model using the initial welding solution is corrected in the entire field, the entire domain, and the entire process.

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