Distribution model and construction method of residual stress field in welding of diagonal brace gusset plate

Abstract

A model for the residual stress distribution of braced gusset plate welding is proposed. The model is composed of the residual vertical stress distribution σ v (x,y) and welding residual transverse stress distribution σ h (x, y); the construction method of the model consists of the following steps: determining the parameters of the diagonal brace node plate, establishing a finite element model for refined welding analysis, simulating the welding thermal effect, extracting the stress distribution matrix, and fitting the data to obtain the corresponding stress distribution. During the construction process, the sequential coupling method is used to analyze the welding residual stress, fully considering the influence of weld thickness and diagonal brace node plate size, and using the Gaussian multi-peak fitting algorithm to obtain the plane vertical stress distribution and plane transverse stress distribution of the welding residual stress, respectively. It has good applicability to the welding residual stress field distribution of the diagonal brace node plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering, and in particular relates to a diagonal brace node plate welding residual stress field distribution model and a construction method. Background Art

[0002] During the brace gusset welding process, non-uniform heating and cooling of the material often generate significant residual stresses. These residual stresses can adversely affect the strength, stiffness, and fatigue life of the structure, and may even lead to premature failure. Therefore, accurately predicting and analyzing the distribution of welding residual stresses in brace gusset welding is crucial for improving structural reliability and safety.

[0003] Existing techniques primarily focus on measuring welding residual stresses and predicting fatigue crack initiation from a microscopic perspective. However, the distribution patterns of residual stress fields in structures such as braced gussets are understudied. This patent, building on existing welding residual stress analysis methods, proposes a new distribution model and construction method for the specialized requirements of braced gusset welding. This method overcomes the limitations of traditional methods and simplifies and summarizes the residual stress field in braced gusset welding. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the above-mentioned existing technology and provide a distribution model of the residual stress field of the diagonal brace node plate welding that simplifies and summarizes the residual stress field of the diagonal brace node plate welding. Another technical problem to be solved by the present invention is to provide a construction method for the distribution model.

[0005] The technical solution adopted to solve the above technical problems is: a diagonal brace node plate welding residual stress field distribution model, which is composed of the welding residual vertical stress distribution σ v (x,y) and welding residual transverse stress distribution σ h (x, y), the welding residual vertical stress distribution σ v (x,y) is:

[0006]

[0007] The welding residual transverse stress distribution σ h (x,y) is:

[0008]

[0009] In formulas (1) and (2), B1 is the width of the gusset plate in mm, B2 is the width of the brace in mm, h1 is the height of the gusset plate in mm, h2 is the height of the brace, and t w is the weld width in mm, x is the horizontal distance, y is the vertical distance, Fv (x), w v1 、w v2 、w h1 、w h2 、w x 、y v1 、y h1 、y h2 is the intermediate variable, q f is the yield strength of the steel plate, which can be any one of 235, 345, and 550, in MPa.

[0010] In the present invention, in formula (1), the w v1 The value range is [6.89,7.33], w v2 The value range is [8.70,9.30], w x The value range of is [0.19, 0.23], the value range of h1 is [200, 400], the unit is mm, the value range of h2 is [100, 200], the unit is mm, the value range of B1 is [300, 800], the unit is mm, the value range of B2 is [100, 500], the unit is mm, t w The value range of is [7,10], the unit is mm; in formula (2), the w h1 The value range of w is [7.95,10.41], h2 The value range is [31.42,37.04].

[0011] In the present invention, in formula (1), the w v1 、w v2 、w x 、h1、h2、B1、B2、t w The value of is: w v1 is 7.11, w v2 is 9.00, w x is 0.21, h1 is 300mm, h2 is 200mm, B1 is 500mm, B2 is 270mm, t w is 8mm; in formula (2), the w h1 、w h2 The value of is: w h1 is 9.18, w h2 It is 34.23.

[0012] The method for constructing the residual stress field distribution model of the brace gusset plate welding of the present invention comprises the following steps:

[0013] Step 1: Determine the parameters of the diagonal brace gusset plate: According to the welding conditions of the diagonal brace gusset plate, determine the height vector h1 = [h 1,1 ,h1,2 ,…,h 1,n ], the width vector of n node plates B1=[B 1,1 ,B 1,2 ,…,B 1,n ], the height vector of n diagonal braces h2=[h 2,1 ,h 2,2 ,…,h 2,n ], the width vector of n diagonal braces B2=[B 2,1 ,B 2,2 ,…,B 2,n ], n weld width vectors t w =[t w,1 ,t w,2 ,…,t w,n ];

[0014] Step 2: Construct a finite element model: Using the n sets of brace gusset plate parameters determined in step 1, construct n brace gusset plate finite element models for welding simulation, where the model is divided into three-dimensional solid elements.

[0015] Step 3: Simulate the welding thermal effect: The model divided by three-dimensional solid elements is used in Abaqus finite element software to simulate the welding thermal effect. The heat source adopts a double ellipsoid heat source model, the element type is a three-dimensional heat transfer solid element, and the "birth and death element method" is used to simulate the formation of the weld.

[0016] Step 4: Extract the stress distribution matrix: Apply the welding process temperature field obtained in step 3 to the same three-dimensional model of the braced node plate, set the obtained temperature field output result as the mechanical boundary condition of the stress field, and change the unit type to a three-dimensional stress unit to determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and transverse stress distribution values ​​according to the mesh division nodes to form a stress distribution matrix, where the vertical stress distribution matrix (σ v1 σ v2 ...σ vi ), σ v,i is the ith vertical stress distribution value, and the transverse stress distribution matrix (σ h1 σ h2 ...σ hi ), σ h,i The i-th transverse stress distribution value is;

[0017] Step 5: Fit the data to obtain the corresponding stress distribution: Use the Gaussian multi-peak fitting algorithm to fit the vertical stress distribution matrix and the transverse stress distribution matrix with the parameter vectors B1, B2, h1, h2, t w Fitting is performed to obtain the welding residual vertical stress distribution σ v (x,y) and welding residual transverse stress distribution σ h(x,y).

[0018] The beneficial effects of the present invention are as follows:

[0019] This paper establishes a finite element model for refined welding analysis, fully considering the influence of factors such as weld thickness and brace gusset plate dimensions. This model is closer to actual welding conditions and improves prediction accuracy. A Gaussian multi-peak fitting algorithm is used to separately determine the residual vertical and transverse stress distributions in welding, further enhancing the model's applicability and accuracy. The proposed method has good applicability for the residual stress field distribution in brace gusset plate welding and can be widely applied to the analysis of various similar welded structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the welding type and welding sequence of the diagonal brace node plate in the model of the present invention.

[0021] Figure 2 This is the vertical welding residual stress distribution curve at the 250mm horizontal position of the 500mm wide node plate.

[0022] Figure 3 This is the transverse welding residual stress distribution curve at the 250mm transverse position of the 500mm wide node plate.

[0023] Figure 4 This is the construction process of the model of the present invention.

[0024] Figure 5 This is the vertical welding residual stress distribution curve at the horizontal position of 150mm in the 300mm wide node plate.

[0025] Figure 6 This is the transverse welding residual stress distribution curve at the 150mm transverse position of the 300mm wide node plate.

[0026] Figure 7 This is the vertical welding residual stress distribution curve at the 400mm horizontal position of the 800mm wide node plate.

[0027] Figure 8 This is the transverse welding residual stress distribution curve at the 400mm transverse position of the 800mm wide node plate. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but the present invention is not limited to these examples.

[0029] Example 1

[0030] exist Figure 1 The invention relates to a welding residual stress distribution model for a diagonal brace node plate, which is composed of the welding residual vertical stress distribution σ v(x,y) and welding residual transverse stress distribution σ h (x,y) composition,

[0031] The welding residual vertical stress distribution σ v (x,y) is:

[0032]

[0033] The welding residual transverse stress distribution σ h (x,y) is:

[0034]

[0035] In formulas (1) and (2), B1 is the width of the gusset plate in mm, B2 is the width of the brace in mm, h1 is the height of the gusset plate in mm, h2 is the height of the brace, and t w is the weld width in mm, x is the horizontal distance, y is the vertical distance, F v (x), w v1 、w v2 、w h1 、w h2 、w x 、y v1 、y h1 、y h2 is the intermediate variable, q f is the yield strength of the steel plate, which can be any one of 235, 345, and 550, in MPa.

[0036] In the present embodiment, in formula (1), w is selected v1 is 7.11, w v2 is 9.00, w x is 0.21, h1 is 300mm, h2 is 200mm, B1 is 500mm, B2 is 270mm, t w is 8mm, and w is selected in formula (2) h1 is 9.18, w h2 =34.23, the corresponding welding residual stress field distribution is constructed, where the welding residual vertical stress field distribution of Q345 steel corresponding to x is 250mm at the longitudinal position is as follows Figure 2 As shown, the distribution of the welding residual transverse stress field at the longitudinal position x of 250 mm is as follows: Figure 3 The vertical and transverse stress peak results for Q235, Q345, and Q550 steels are shown in Table 1.

[0037] Table 1 Results of peak residual stress in welding

[0038]

[0039] like Figure 4 As shown in FIG, the method for constructing the above-mentioned residual stress field distribution model of the braced gusset plate welding comprises the following steps:

[0040] Step 1: Determine the parameters of the diagonal brace gusset plate: According to the welding conditions of the diagonal brace gusset plate, determine the height vector h1 = [h 1,1 ,h 1,2 ,…,h 1,n ], the width vector of n node plates B1=[B 1,1 ,B 1,2 ,…,B 1,n ], the height vector of n diagonal braces h2=[h 2,1 ,h 2,2 ,…,h 2,n ], the width vector of n diagonal braces B2=[B 2,1 ,B 2,2 ,…,B 2,n ], n weld width vectors t w =[t w,1 ,t w,2 ,…,t w,n ];

[0041] Step 2: Construct a finite element model: Using the n sets of brace gusset plate parameters determined in step 1, construct n brace gusset plate finite element models for welding simulation, where the model is divided into three-dimensional solid elements.

[0042] Step 3: Simulate the welding thermal effect: The model divided by three-dimensional solid elements is used in Abaqus finite element software to simulate the welding thermal effect. The heat source adopts a double ellipsoid heat source model, the element type is a three-dimensional heat transfer solid element, and the "birth and death element method" is used to simulate the formation of the weld.

[0043] Step 4: Extract the stress distribution matrix: Apply the welding process temperature field obtained in step 3 to the same three-dimensional model of the braced node plate, set the obtained temperature field output result as the mechanical boundary condition of the stress field, and change the unit type to a three-dimensional stress unit to determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and transverse stress distribution values ​​according to the mesh division nodes to form a stress distribution matrix, where the vertical stress distribution matrix (σ v1 σ v2 ...σ vi ), σ v,i is the ith vertical stress distribution value, and the transverse stress distribution matrix (σ h1 σ h2 ...σ hi ), σ h,i is the i-th transverse stress distribution value;

[0044] Step 5: Fit the data to obtain the corresponding stress distribution: Use the Gaussian multi-peak fitting algorithm to fit the vertical stress distribution matrix and the transverse stress distribution matrix with the parameter vectors B1, B2, h1, h2, t w Fitting is performed to obtain the welding residual vertical stress distribution σ v (x,y) and welding residual transverse stress distribution σ h (x,y).

[0045] Example 2

[0046] The residual stress field distribution model of the brace node plate welding involved in this embodiment is shown in equations (1) and (2), and the construction method is the same as that of embodiment 1.

[0047] In this embodiment, the formula (1) is selected as v1 is 6.89, w v2 is 8.70, w x is 0.19, h1 is 200mm, h2 is 100mm, B1 is 300mm, B2 is 100mm, t w is 7mm, in formula (2), select w h1 is 7.95, w h2 The corresponding welding residual stress field distribution is constructed, where the welding residual vertical stress field distribution of Q345 steel corresponding to x is 150mm at the longitudinal position as shown in the following figure: Figure 5 As shown, the distribution of the welding residual transverse stress field at the longitudinal position x of 150 mm is as follows: Figure 6 The vertical and transverse stress peak results for Q235, Q345, and Q550 steels are shown in Table 2.

[0048] Table 2 Peak values ​​of welding residual stress

[0049]

[0050] Example 3

[0051] The residual stress field distribution model of the brace node plate welding involved in this embodiment is shown in equations (1) and (2), and the construction method is the same as that of embodiment 1.

[0052] In this embodiment, in formula (1), w is selected v1 is 7.33, w v2 9.30, w x is 0.23, h1 is 400mm, h2 is 200mm, B1 is 800mm, B2 is 500mm, t w is 10 mm, and w is selected in formula (2) h1 is 10.41, w h2The corresponding welding residual stress field distribution is constructed, where the welding residual vertical stress field distribution at the longitudinal position x corresponding to Q345 steel is 400mm is as follows: Figure 5 As shown, the distribution of the welding residual transverse stress field at the longitudinal position x of 400 mm is as follows: Figure 6 The vertical and transverse stress peak values ​​for Q235, Q345, and Q550 steels are shown in Table 3.

[0053] Table 3 Peak values ​​of welding residual stress

[0054]

[0055] As shown in Tables 1, 2, and 3, high-yield-strength steel is more likely to generate higher residual stresses during welding. The peak value of the transverse positive stress is significantly higher than the absolute value of the transverse negative stress, indicating that during welding, the steel exhibits primarily tensile stress in the transverse direction, while the compressive stress is relatively small. This stress distribution makes the welded structure more susceptible to tensile deformation or cracking in the transverse direction. The above examples are consistent with actual engineering, indicating that the model has a certain degree of universality under different size and material conditions.

Claims

1. A residual stress field distribution model for brace gusset plate welding, characterized in that: The model is composed of the distribution of welding residual vertical stress Distribution of residual transverse stress in welding composition, The welding residual vertical stress distribution for: The welding residual transverse stress distribution for: In formula (1) and (2), is the width of the gusset plate, in mm, is the width of the diagonal brace, in mm, is the height of the gusset plate in mm, is the height of the diagonal brace, is the weld width in mm, is the horizontal distance, is the longitudinal distance, 、 、 、 、 、 、 、 、 is an intermediate variable, is the yield strength of the steel plate, which can be any one of 235, 345, and 550, in MPa; Among them, in formula (1), the The value range is [6.89,7.33], The value range is [8.70,9.30], The value range is [0.19, 0.23], The value range is [200,400], the unit is mm, The value range is [100,200], the unit is mm, The value range is [300,800], the unit is mm, The value range is [100,500], the unit is mm, The value range of is [7,10], and the unit is mm. In formula (2), the The value range is [7.95,10.41], The value range is [31.42,37.04].

2. The residual stress field distribution model of brace gusset plate welding according to claim 1 is characterized in that: In formula (1), the 、 、 、 、 、 、 、 The value of is: For 7.11, is 9.00, is 0.21, 300mm, 200mm, 500mm, 270mm, is 8mm; in formula (2), the 、 The value of is: is 9.18, It is 34.

23.

3. The method for constructing the residual stress field distribution model of the brace gusset plate welding according to claim 1 is characterized in that It consists of the following steps: Step 1: Determine the parameters of the diagonal brace node plate: According to the welding conditions of the diagonal brace node plate, determine the height vector h1=[ , ,…, ], the width vector of n node plates B1=[ , ,…, ], the height vector of n diagonal braces h2=[ , ,…, ], the width vector of n diagonal braces B2=[ , ,…, ], n weld width vectors t w =[ , ,…, ]; Step 2: Construct a finite element model: Using the n sets of brace gusset plate parameters determined in step 1, construct n brace gusset plate finite element models for welding simulation, where the model is divided into three-dimensional solid elements. Step 3: Simulate the welding thermal effect: The model divided by three-dimensional solid elements is simulated in Abaqus finite element software. The heat source adopts a double ellipsoid heat source model, the element type is a three-dimensional heat transfer solid element, and the "birth and death element method" is used to simulate the formation of the weld. Step 4: Extract the stress distribution matrix: Apply the welding process temperature field obtained in step 3 to the same three-dimensional model of the diagonal brace node plate, set the obtained temperature field output result as the mechanical boundary condition of the stress field, and change the unit type to a three-dimensional stress unit to determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and transverse stress distribution values ​​according to the mesh division nodes to form a stress distribution matrix, where the vertical stress distribution matrix is , is the ith vertical stress distribution value, and the transverse stress distribution matrix , The i-th transverse stress distribution value is; Step 5: Fit the data to obtain the corresponding stress distribution: Use the Gaussian multi-peak fitting algorithm to fit the vertical stress distribution matrix and the transverse stress distribution matrix with the parameter vectors B1, B2, h1, h2, t w Fitting is performed to obtain the distribution of welding residual vertical stress And the distribution of welding residual transverse stress .

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