一种焊接残余应力的控制方法和金属结构

Abstract

This application provides a method for controlling welding residual stress and a metal structure to reduce the impact of residual stress on the steel structure during construction and improve the control effect of residual stress on the steel structure. The method for controlling welding residual stress includes establishing a finite element model based on the material, dimensions, and welding parameters of the metal structure using a programming language; the programming language embeds welding construction sequence principles and generates multiple birth and death elements according to the welding construction sequence, predicting the residual stress and deformation values ​​of the metal structure after welding according to the multiple birth and death element sequences; if the residual stress or deformation values ​​do not meet the requirements, stiffeners are added to the metal structure to generate a new metal structure, a new finite element model is established, and the residual stress or deformation values ​​corresponding to the newly generated birth and death element sequences are analyzed until the residual stress and deformation values ​​meet the requirements, and the metal structure is welded according to the corresponding birth and death element sequences.

Description

Technical Field

[0001] This application relates to the field of welding process technology, and in particular to a method for controlling welding residual stress and a metal structure. Background Technology

[0002] With the advancement of technology, large industrial equipment has gradually become an essential tool for challenging construction or operations. In air-floating vibration isolation foundations for large equipment, a high-rigidity platform with a steel frame is required on top of the isolator to increase counterweight, improve foundation stiffness, and achieve better vibration reduction. Residual stress in the steel structure during construction is a significant cause of warping and deformation defects in the high-rigidity platform. Currently, controlling the welding residual stress in the high-rigidity platform's steel structure typically involves improving welding methods or incorporating stress-relieving structures during construction.

[0003] Currently, methods for releasing stress by improving welding techniques include: thermal aging, loading, ultrasonic impact, and hammering. Methods involving stress-relieving structures include: setting stress-relieving holes or stress-relieving seams. However, in practical engineering, due to limitations imposed by equipment shape and size and site constraints, high-rigidity pedestals are usually not perfectly regular hexahedrons, but may be irregular structures such as T-shaped, stepped, L-shaped, and F-shaped. The residual stress in these structures is more complex and more difficult to control, and existing technologies are insufficient to effectively control the residual stress in irregularly shaped steel structures. Summary of the Invention

[0004] This application provides a method for controlling welding residual stress and a metal structure, which reduces the impact of residual stress on the metal structure during construction and improves the control effect of residual stress on the metal structure.

[0005] In a first aspect, this application provides a method for controlling welding residual stress, which involves predicting areas with large welding residual stress or deformation values, adding reinforcing ribs to these areas, and adjusting welding parameters to ensure that the welding residual stress or deformation values ​​meet welding requirements.

[0006] The welding residual stress control method provided by this invention includes:

[0007] A finite element model of the metal structure was established using a programming language based on its material, dimensions, and welding parameters.

[0008] The programming language incorporates welding construction sequence principles, and generates multiple sequences of birth and death elements based on these principles. It then predicts the residual stress and deformation values ​​of the metal structure after welding based on these multiple sequences of birth and death elements.

[0009] If the residual stress or deformation value does not meet the requirements, stiffeners are added to the metal structure to generate a new metal structure. The finite element model is re-established, and the residual stress or deformation value corresponding to the regenerated birth and death element sequence is analyzed until the residual stress and deformation value meet the requirements. The metal structure is then welded according to the corresponding birth and death element sequence.

[0010] Preferably, if the residual stress or deformation value does not meet the requirements, reinforcing ribs are added to the metal structure to generate a new metal structure. The selected sequence of birth and death elements with the lowest residual stress value is the target birth and death element sequence. If the maximum residual stress value corresponding to the target birth and death element sequence is less than or equal to a first preset value, the deformation value of the metal structure welded using the target birth and death element sequence is allowed. If the deformation value is less than or equal to a second preset value, the metal structure is welded using the target birth and death element sequence. If the deformation value is greater than the second preset value, a first reinforcing rib is set in the area where the deformation value is greater than the second preset value to form a new metal structure. If the maximum residual stress value corresponding to the target birth and death element sequence is greater than the first preset value, a second reinforcing rib is set in the area where the residual stress value is greater than the first preset value to form a new metal structure. After repeatedly performing the above process, reinforcing ribs can be added to areas where welding residual stress may exist before welding, reducing the impact of residual stress.

[0011] Optionally, the dense weld region is determined in the finite element model based on the weld location; the dense weld region with the shortest weld distance is the initial region, and a sequence of birth and death elements is generated from the initial region, with the distance between the preceding and following birth and death elements in the sequence being one span length.

[0012] Preferably, the metal structure is divided into multiple 1m*1m target regions. Regions within these target regions where the minimum spacing between welds is less than or equal to a third preset value are considered densely welded regions. Dividing the metal structure into multiple target regions allows for optimization of the welding life / death unit sequence.

[0013] Optionally, the third preset value mentioned in the above technical solution can be 900mm.

[0014] Optionally, in one technical solution, the aforementioned metal structure includes multiple staggered metal rods, which form multiple grid areas arranged in an array. Welds are performed at the intersections of the metal rods to form welds. The grid area at the outermost corner of the metal structure is the initial region. A sequence of birth and death units is generated starting from the initial region, with the distance between the preceding and subsequent birth and death units in the sequence being one span.

[0015] Optionally, after welding, areas with residual stress values ​​greater than or equal to a fourth preset value may be tapped. This releases stress in areas with high local residual stress after welding, reducing the impact of the stress on the metal structure.

[0016] Preferably, the programming language mentioned above can be Python. Python has a fast computation speed, enabling rapid analysis of residual stress values ​​in various regions; moreover, Python has high compatibility and can be applied to a variety of different finite element analysis software.

[0017] Optionally, the finite element model can be any finite element model generated by any solver in the command stream of the finite element analysis software or the Python programming language.

[0018] Optionally, the metal structure is an air-floating vibration isolation table.

[0019] In the technical solution of this invention, a programming language is embedded with the welding construction sequence principle. The programming language generates multiple sequences of dead and alive elements based on this principle, and predicts the residual stress and deformation values ​​of the metal structure after welding according to these sequences. This solution can predict the residual stress and deformation values ​​of the metal structure under different welding schemes before welding, and interfere with areas with large residual stress and deformation values, selecting the optimal scheme to weaken the impact of welding residual stress.

[0020] This solution effectively controls residual stress in target areas of metal structures. Before construction, a finite element model is used to predict areas with excessive residual stress and deformation, allowing for modifications to the original metal structure in those areas to reduce the impact of residual stress and deformation. Simultaneously, during welding, reinforcing ribs can be added to areas where values ​​in the dead or alive elements exceed preset values, forming a new metal structure. This solution not only enables scientific and precise control of welding residual stress in metal structures but also reduces the investment of manpower, materials, equipment, and time in actual engineering projects for welding residual stress control. Furthermore, it solves the warping quality problem caused by welding residual stress in metal structures. Attached Figure Description

[0021] Figure 1 This is a partial structural schematic diagram of a stress relief hole according to an embodiment of the prior art;

[0022] Figure 2 This is a partial structural schematic diagram of a stress relief joint according to an embodiment of the prior art;

[0023] Figure 3 This is a schematic diagram of the construction process according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of a metal structure according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of a metal structure according to another embodiment of the present invention.

[0026] Figure label:

[0027] Existing technology section:

[0028] 0D - Stress relief hole; 01 - Steel beam;

[0029] 02-Plywood; 03-Steel plate wall;

[0030] 05-Stress relief joint;

[0031] This invention includes:

[0032] 1-Work area; 2-Initial area;

[0033] 3-Metal rod; 4-Grid area. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0035] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0036] References to “an embodiment” or “a specific embodiment” as used in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0037] To facilitate understanding of the welding residual stress control method and metal structure provided in this application, its application scenario is first introduced below. Currently, in large-scale equipment air-floating vibration isolation tables, to increase counterweight, improve foundation stiffness, and obtain better vibration reduction effects, a metal structure with a steel frame needs to be designed on the upper part of the vibration isolator. However, the residual stress of the steel structure during construction is an important cause of warping and deformation quality defects in the metal structure. Therefore, to control the welding residual stress of the metal structure, current construction methods typically employ improved welding methods or stress relief structures. However, due to the size and site limitations of equipment in actual engineering projects, the welding residual stress becomes diverse and complex, and existing technologies are insufficient to effectively control it. This application not only effectively controls welding residual stress but also performs data analysis for various working conditions and simulates the construction process to determine the optimal welding scheme before welding construction; it enables effective control of welding residual stress for various sizes and sites.

[0038] Figure 1 This is a schematic diagram of a metal structure with stress relief holes in the prior art. Figure 2 This is a schematic diagram of a structure with a stress relief joint in the prior art. For example... Figure 1 and Figure 2 As shown, in a prior art, stress relief holes 0D or stress relief seams 05 can be provided in a metal structure. The stress relief seam structure specifically includes: a steel beam 01 with opposing clamping plates 02. A clamping space is formed between the inner sides of the clamping plates 02, and a casting space is formed between the outer sides of the clamping plates 02 and the top of the steel beam 01. A steel plate wall 03 is installed within the clamping space; a stress relief seam 05 with a certain gap is left between the bottom of the steel plate wall 03 and the steel beam 01; the stress relief holes are round or square holes, and the stress relief seams are straight or curved seams. Although the above structure can effectively release or control stress, it needs to be pre-installed in the construction area, and the manufacturing process is complex, time-consuming, and costly.

[0039] To address the aforementioned problems, reduce operational difficulty, decrease manpower, material resources, and financial resources required for operations, and improve stress control and release, this application provides a method for controlling welding residual stress and a metal structure. To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description will be provided below with reference to the accompanying drawings.

[0040] Figure 3 This is a schematic diagram of a construction process according to an embodiment of this application, such as... Figure 3 As shown, the welding residual stress control method provided in this application embodiment is used for welding metal structures. The control method specifically includes:

[0041] A finite element model of the metal structure is established using a programming language based on its material, dimensions, and welding parameters.

[0042] The programming language incorporates welding construction sequence principles, and generates multiple sequences of birth and death elements based on these principles. It then predicts the residual stress and deformation values ​​of the metal structure after welding based on these multiple sequences of birth and death elements.

[0043] If the residual stress or deformation value does not meet the requirements, stiffeners are added to the metal structure to generate a new metal structure. The finite element model is re-established, and the residual stress or deformation value corresponding to the newly generated birth and death element sequence is analyzed until the residual stress and deformation value meet the requirements. The metal structure is then welded according to the corresponding birth and death element sequence.

[0044] In a specific embodiment, the re-established finite element model refers to the new metal structure generated after adding reinforcing ribs, the difference from the original metal structure being the presence or absence of reinforcing ribs. Then, a new finite element model is established using a programming language, and a new sequence of birth and death elements is generated based on this new finite element model until the welded metal structure can meet the stress and deformation values.

[0045] In summary, the above control method includes the following steps: establishing a finite element model, determining the initial welding position, generating a sequence of dead and alive elements, adding reinforcing ribs to change the metal structure, re-establishing the finite element model, and repeating the above process.

[0046] In this application, software modeling and simulation analysis are used to analyze the residual stress and deformation values ​​corresponding to different welding methods, and the optimal solution is selected for welding the metal structure. This solution enables scientific and precise control of the welding residual stress in the metal structure, reducing the investment of manpower, materials, equipment, and time in actual engineering for controlling welding residual stress, and solving the warping quality problem of metal structures caused by welding residual stress.

[0047] Specifically, the welding parameters mentioned in the above embodiments may include parameters such as welding current, welding voltage, welding speed, welding electrode spacing, and welding electrode angle.

[0048] In specific embodiments, the shape of the reinforcing ribs is not limited and can be designed and selected according to actual needs. For example, the reinforcing ribs may include triangular reinforcing ribs, circular reinforcing ribs, or rectangular reinforcing ribs, etc.

[0049] In a specific embodiment, the programming language mentioned above can be Python. This programming language has a fast calculation speed and can quickly analyze the residual stress values ​​of each region; moreover, Python has high compatibility and can be applied to a variety of different finite element analysis software.

[0050] In optional embodiments, finite element models can be generated using the following software: LUSAS, MSCNastran, Ansys, Abaqus, LMS-Samtech, Algor, Femap, NX-Nastran, Hypermesh, COMSOL, Multiphysics, or FEPG, or any solver in the command stream of the Python programming language can be used to generate finite element models.

[0051] In one specific embodiment, Ansys finite element software can be used to generate the finite element model. Ansys finite element software is suitable for the target object, has a high calculation speed, and provides relatively reliable calculation results.

[0052] When implementing the above control methods, if the residual stress or deformation values ​​do not meet the requirements, stiffeners are added to the metal structure to generate a new metal structure, specifically including:

[0053] The birth and death element sequence with the smallest residual stress value is selected as the target birth and death element sequence. If the maximum residual stress value corresponding to the target birth and death sequence is less than or equal to the first preset value, the deformation value of the metal structure welded using the target birth and death element sequence is analyzed. If the deformation value is less than or equal to the second preset value, the metal structure is welded using the target birth and death element sequence. If the deformation value is greater than the second preset value, a first reinforcing rib is set in the area where the deformation value is greater than the second preset value to form a new metal structure.

[0054] If the maximum residual stress value corresponding to the above target life and death unit sequence is greater than the first preset value, a second reinforcing rib is set in the area where the residual stress value is greater than the first preset value to form a new metal structure.

[0055] In this embodiment, if the maximum residual stress value corresponding to the target life-death sequence is less than or equal to a first preset value, the residual stress of the metal structure welded using the target life-death sequence is considered to meet the requirements. Then, it is determined whether the deformation value meets the requirements. If the deformation value is less than or equal to a second preset value, the deformation value of the metal structure welded using the target life-death sequence is also considered to meet the requirements. If the deformation value is greater than the second preset value, the metal structure welded using the target life-death sequence is considered not to meet the requirements. A first reinforcing rib is then placed at the location where the deformation value does not meet the requirements, forming a new metal structure. A finite element model is then created based on the new metal structure to analyze whether the welding method of the new metal structure meets the requirements. If the maximum residual stress value corresponding to the target life-death sequence is greater than the first preset value, the residual stress of the metal structure welded using the target life-death sequence is considered not to meet the requirements. In this case, a second reinforcing rib is placed in the area where the residual stress value is greater than the first preset value, forming a new metal structure. A finite element model is then created based on the new metal structure to analyze whether the welding method of the new metal structure meets the requirements. This approach allows for detailed analysis of the residual stress and deformation values ​​of metal structures, and the targeted addition of reinforcing ribs to address related issues. It also involves recreating the finite element model until a satisfactory metal structure and welding sequence are achieved. This facilitates obtaining optimized welding procedures and metal structures with both residual stress and deformation values ​​meeting requirements.

[0056] Figure 4 This is a schematic diagram of a metal structure in one embodiment of the present invention; as shown. Figure 4 As shown, the principle for determining the welding construction sequence can be based on practical work experience or selected using a programming language. In this embodiment, the metal structure includes multiple staggered metal rods 3, which form multiple arrayed grid areas 4. Welds are performed at the intersections of the metal rods 3 to form weld seams. The specific methods for determining the welding construction sequence principle using different approaches are described below.

[0057] In one possible embodiment, the principle of determining the welding construction sequence is used using a programming language, specifically including:

[0058] Based on the location of the weld, the dense weld area is determined in the above finite element model;

[0059] The weld-dense region with the shortest weld distance is the initial region 2. The birth and death unit sequence is generated starting from the initial region 2. The distance between the preceding and following birth and death units in the birth and death unit sequence is one span.

[0060] In this embodiment, when determining the dense weld area, the metal structure can be divided into multiple 1m*1m target areas. The area within these target areas where the minimum spacing between welds is less than or equal to a third preset value is considered a dense weld area. Each target area includes welds, and the area within the target area where the minimum spacing between welds is less than or equal to the third preset value is considered a dense weld area. Typically, multiple dense weld areas are selected, with the area having the shortest weld distance designated as initial area 2. Specifically, the birth and death unit sequence can be generated initially from the weld at the upper left corner of initial area 2. The distance between the preceding and following birth and death units in the birth and death unit sequence is one span. Specifically, any preceding and following birth and death units are diagonally opposite each other. Please refer to... Figure 4 Generate a sequence of birth and death units according to the numerical labels in the diagram. Specifically, this involves dividing the metal structure's grid area 4 into multiple work areas 1, each spanning two horizontally. Each work area 1 comprises two columns of grid areas 4, and these work areas 1 are arranged sequentially horizontally. For example... Figure 4 As shown, within the same work area 1, subsequent birth and death units are generated by extending diagonally to both sides from the previous birth and death unit. Then, the sequence extends diagonally to grid area 4 in the adjacent work area 1 to generate the next subsequent birth and death unit. Within work area 1, the birth and death unit sequence is generated along a zigzag line. The Arabic numerals in grid area 4 indicate the order of the birth and death sequence, or the welding order; the same number can be welded simultaneously.

[0061] In a specific embodiment, the aforementioned third preset value is 900mm. That is, the area where the minimum spacing of the welds is less than or equal to 900mm is a dense weld area. For example, the aforementioned third preset value can be 300mm, 350mm, 500mm, 600mm, 650mm, 800mm, or 880mm, etc., and this application does not impose specific limitations on it.

[0062] Figure 5 This is a schematic diagram illustrating the generation of the birth and death unit sequence when the starting region is the upper left corner of the metal structure, according to an embodiment of the present invention; as shown... Figure 5 The principle for determining the welding sequence based on actual work experience, as shown, specifically includes: starting with the grid area 4 at the outermost edge of the corner of the metal structure as the initial region 2; generating the birth and death unit sequence from the initial region 2, with the distance between the preceding and following birth and death units in the birth and death unit sequence being one span. In a specific embodiment, the grid area 4 at the outermost edge of the corner of the metal structure can be the outermost grid area 4 at the upper left corner, or it can be the outermost grid area 4 at the upper right corner, lower left corner, or lower right corner; this application does not impose specific limitations on this. Figure 5Taking the outermost grid area 4 at the top left corner of the metal structure as an example, this scheme can also divide the grid area 4 of the metal structure into multiple working areas 1 in units of two horizontal spans. Each working area 1 includes two columns of grid areas 4, and multiple working areas 1 are arranged sequentially along the horizontal direction. Figure 5 As shown, within the same work area 1, the sequence of birth and death units is generated by extending diagonally to both sides from the previous birth / death unit. Then, it extends diagonally to grid area 4 in the adjacent work area 1 to generate the next subsequent birth / death unit. Within work area 1, the birth / death unit sequence is generated along a zigzag line. Any previous and subsequent birth / death units are also diagonally opposite each other, specifically according to... Figure 5 The sequence of birth and death units is generated by using the numerical identifiers in the middle.

[0063] After welding the metal structure using the birth and death unit sequence generated by the above control method, areas with residual stress values ​​greater than or equal to the fourth preset value can be tapped to further release residual stress in locations with high residual stress. Specifically, the aforementioned fourth preset value can be designed and selected based on the metal structure dimensions, actual engineering requirements, and work experience.

[0064] Based on the same inventive concept, this application also provides a metal structure formed by welding using the aforementioned method for controlling welding residual stress. This metal structure exhibits low residual stress, minimal deformation, and can be used without requiring prolonged placement.

[0065] Specifically, the aforementioned metal structure can be a high-rigidity pedestal, especially an irregularly shaped high-rigidity pedestal. For example, an air-bearing vibration isolation table; this application does not limit this.

[0066] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling welding residual stress, characterized in that, Used for welding metal structures, including: A finite element model of the metal structure was established using a programming language based on its material, dimensions, and welding parameters. The programming language is embedded with welding construction sequence principles. Based on these principles, the programming language generates multiple sequences of birth and death units and predicts the residual stress and deformation values ​​of the metal structure after welding according to these sequences. The metal structure is divided into multiple working areas along the horizontal span, each of which includes two columns. These working areas are arranged sequentially along the horizontal direction. Within the same working area, subsequent birth and death units are generated by extending from the previous sequence of birth and death units to the diagonal positions on both sides, and then by extending to the diagonal positions of adjacent working areas to generate the next sequence of birth and death units. The working area can be any one of the multiple working areas. The sequence of birth and death elements with the smallest residual stress value is selected as the target birth and death element sequence. If the maximum residual stress value corresponding to the target birth and death element sequence is less than or equal to a first preset value, the deformation value of the metal structure welded using the target birth and death element sequence is analyzed. If the deformation value is less than or equal to a second preset value, the metal structure is welded using the target birth and death element sequence. If the deformation value is greater than the second preset value, a first reinforcing rib is set in the area where the deformation value is greater than the second preset value to form a new metal structure. If the maximum residual stress value corresponding to the target birth and death element sequence is greater than the first preset value, a second reinforcing rib is set in the area where the residual stress value is greater than the first preset value to form a new metal structure. The finite element model is re-established, and the residual stress value or deformation value corresponding to the regenerated birth and death element sequence is analyzed until the residual stress value and deformation value meet the requirements. The metal structure is then welded according to the corresponding birth and death element sequence.

2. The control method as described in claim 1, characterized in that, The determination of the welding construction sequence principle includes: The dense weld area is determined in the finite element model based on the weld location; The weld-dense region with the shortest weld distance is the initial region. The birth and death unit sequence is generated starting from the initial region, and the distance between the preceding and following birth and death units in the birth and death unit sequence is one span.

3. The control method as described in claim 2, characterized in that, The metal structure is divided into multiple 1m The target area is 1m, and the area in the target area where the minimum spacing of the welds is less than or equal to a third preset value is the weld-dense area.

4. The control method as described in claim 3, characterized in that, The third preset value is 900mm.

5. The control method as described in claim 1, characterized in that, The determination of the welding construction sequence principle includes: The metal structure includes multiple staggered metal rods, which form multiple grid areas arranged in an array. The metal rods are welded together at their intersections to form welds. The initial region is the grid area at the outermost edge of the corner of the metal structure; the birth and death unit sequence is generated starting from the initial region, and the distance between the preceding birth and death unit and the following birth and death unit in the birth and death unit sequence is one span.

6. The control method as described in claim 1, characterized in that, After welding, the area with residual stress value greater than or equal to the fourth preset value is tapped.

7. The control method as described in claim 1, characterized in that, The programming language is Python.

8. The control method as described in claim 1, characterized in that, The finite element model can be any finite element model generated by any solver in the command stream of finite element analysis software or the Python programming language.

9. A metal structure, characterized in that, The metal structure is formed by welding using the control method described in any one of claims 1 to 8.

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