Steel plate girder bridge web gap welding residual stress field distribution model and construction method

Abstract

A steel plate girder bridge web gap welding residual stress field distribution model is composed of welding residual vertical stress distribution sigma v (x, y) and welding residual transverse stress distribution sigma h (x, y). The construction method of the model comprises the following steps: determining parameters of the web gap of the steel plate girder bridge, establishing a finite element model for welding fine analysis, performing welding heat effect simulation, extracting a stress distribution matrix, and fitting data to obtain corresponding stress distribution; in the construction process, the welding residual stress is analyzed by adopting a sequential coupling method, the influence of the thickness of a welding seam, the size of a web stiffening rib and a web gap is fully considered, and plane vertical stress distribution and plane transverse stress distribution of the welding residual stress are respectively obtained by utilizing a Gaussian multi-peak fitting algorithm; the method has good applicability to the distribution of the welding residual stress field of the web stiffening rib.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to a model and construction method for the distribution of residual stress field in the welding gap of the web of a steel plate girder bridge. Background Technology

[0002] During the welding of the web gaps in steel plate girder bridges, a large amount of residual stress is often generated due to the non-uniform heating and cooling of the material. These residual stresses can adversely affect the strength, stiffness, and fatigue life of the structure, and may even lead to premature failure. Therefore, for the welding of the web gaps in steel plate girder bridges, accurate prediction and analysis of the distribution of welding residual stress is crucial for improving the reliability and safety of the structure.

[0003] Existing technologies primarily focus on measuring welding residual stress to predict fatigue crack initiation from a microscopic perspective, but research on the distribution of residual stress fields in structures like the web gaps of steel plate girder bridges is insufficient. This patent, based on existing welding residual stress analysis methods, proposes a new distribution model and construction method specifically for the unique requirements of welding web gaps in steel plate girder bridges. This method overcomes the limitations of traditional methods and simplifies and summarizes the welding residual stress field of steel plate girder bridge web gaps. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a simplified and generalized distribution model of the residual stress field of the welded web gap of a steel plate girder bridge. Another technical problem to be solved by the present invention is to provide a method for constructing this distribution model.

[0005] The technical solution adopted to solve the above-mentioned technical problems is: a model for the distribution of residual stress field from welding in the web gap of a steel plate girder bridge. This model is based on the distribution of vertical residual stress σ from welding. v (x,y) and the distribution of residual transverse stress σ from welding h Composed of (x,y),

[0006] The weld residual vertical stress distribution σ v (x,y) is:

[0007]

[0008] In equation (1), B1 is the width of the web in mm, B2 is the width of the stiffener in mm, h1 is the height of the web in mm, and t w The weld width is expressed in mm (t). f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), G v (tf ), x v1 x v2 w v1 w v2 w x b1, b2, b3, b4, C, and β are intermediate variables, and q f The yield strength of the steel plate is any one of 235, 345, and 550, in MPa.

[0009] The weld residual transverse stress distribution σ h (x,y) is:

[0010]

[0011] In equation (2), B1 is the width of the web in mm, h1 is the height of the web in mm, h2 is the height of the stiffener in mm, and t w The weld width is expressed in mm (t). f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), F h (y), G h (t f ), x h1 x h2 w x w h1 w h2 b2, c1, and c2 are intermediate variables, and q f The yield strength of the steel plate is taken as any one of 235, 345, and 550, with the unit being MPa.

[0012] In formula (1) of this invention, w v1 The value range of w is [47.01, 58.43]. v2 The value range of w is [37.75, 46.72]. x The values ​​of are [5.13, 5.17], h1 is [300, 600] (unit: mm), h2 is [270, 570] (unit: mm), B1 is [500, 700] (unit: mm), B2 is [5, 18] (unit: mm), and t... w The value range is [8, 15], and the unit is mm. t f The value of w can be any one of 30, 60, or 90, and the unit is mm; in formula (2), w h1 The value range of w is [5.96, 11.22]. h2 The value range is [154.74, 225.91].

[0013] In formula (1) of this invention, w v1 w v2 w x h1, h2, B1, B2, t w The value of is: w v1 It is 52.72, w v2 The value is 42.23, w x The value is 5.15, h1 is 470mm, h2 is 440mm, B1 is 600mm, B2 is 12mm, and t is... w It is 10mm, t f It is 30mm; in formula (2), the w h1 w h2 The value of is: w h1 It is 9.18, w h2 It is 34.23.

[0014] The method for constructing the residual stress field distribution model of the web gap welding of steel plate girder bridge of the present invention consists of the following steps:

[0015] Step 1: Determine the parameters of the web gap of the steel plate girder bridge: Based on the welding condition of the web gap of the steel plate girder bridge, determine the height vector h1 of the n web plates = [h 1,1 ,h 1,2 ,…,h 1,n ], the width vector B1 of the n web plates = [B 1,1 B 1,2 ,…,B 1,n ], the height vector of n stiffening ribs h2=[h 2,1 ,h 2,2 ,…,h 2,b ], the width vector B2 of the n stiffening ribs = [B 2,1 B 2,2 ,…,B 2,b ], n weld width vectors t w =[t w,1 ,t w,2 ,…,t w,n ], n web space vectors t f =[t f,1 ,t f,2 ,…,t f,n ];

[0016] Step 2: Constructing the finite element model: Using the n sets of steel plate girder bridge web gap parameters determined in Step 1, construct n finite element models of the steel plate girder bridge web gap for welding simulation. The model is divided into three-dimensional solid elements.

[0017] Step 3: Perform welding thermal effect simulation: The welding thermal effect between the web and stiffeners is simulated in Abaqus finite element software after the model has been divided into three-dimensional solid elements. The heat source adopts the double ellipsoidal heat source model, the element type is three-dimensional heat transfer solid element, and the "birth and death element method" is used to simulate the formation of the weld.

[0018] Step 4: Extract the stress distribution matrix: Apply the welding process temperature field obtained in Step 3 to the 3D model of the steel plate girder bridge web gap from Step 2. Set the obtained temperature field output as the mechanical boundary condition of the stress field, and change the element type to a 3D stress element. Determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and n horizontal stress distribution values ​​based on the mesh nodes, forming stress distribution matrices respectively. The vertical stress distribution matrix is ​​(σ... v1 σ v2 ...σ vi ), σ v,i For the i-th vertical stress distribution value, the transverse stress distribution matrix is ​​(σ h1 σ h2 ...σ hi ), σ h,i This represents the i-th transverse stress distribution value;

[0019] 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 horizontal stress distribution matrix obtained in Step 4 with the parameter vectors B1, B2, h1, h2, t obtained in Step 1. w and the independent variable web gap vector t f By fitting the data, the vertical stress distribution σ of the welding residue was obtained. v (x,y) and the distribution of residual transverse stress σ from welding h (x,y).

[0020] The beneficial effects of this invention are as follows:

[0021] This invention establishes a refined finite element model for welding analysis. The model fully considers the influence of factors such as weld thickness and the web gap size of plate girder bridges, making the model closer to actual welding conditions and improving prediction accuracy. The Gaussian multi-peak fitting algorithm is used to obtain the vertical and transverse stress distributions of welding residues, further improving the model's applicability and accuracy. It has good applicability to the distribution of welding residual stress fields in the web gaps of plate girder bridges and can be widely applied to the analysis of various similar welded structures. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the welding method for the web gap of a steel plate girder bridge in the model of this invention.

[0023] Figure 2 The curve shows the distribution of vertical welding residual stress at the longitudinal position of 30mm when the web height is 470mm and the web gap is 30mm.

[0024] Figure 3 The curve shows the distribution of transverse welding residual stress at the longitudinal position of 30mm when the web height is 470mm and the web gap is 30mm.

[0025] Figure 4 The curve shows the distribution of vertical welding residual stress at the longitudinal position of 60mm when the web height is 470mm and the web gap is 60mm.

[0026] Figure 5 The curve shows the distribution of transverse welding residual stress at the longitudinal position of 60mm when the web height is 470mm and the web gap is 60mm.

[0027] Figure 6 The curve shows the distribution of vertical welding residual stress at the longitudinal 90mm position when the web height is 470mm and the web gap is 90mm.

[0028] Figure 7 The curve shows the distribution of transverse welding residual stress at the longitudinal 90mm position when the web height is 470mm and the web gap is 90mm.

[0029] Figure 8 This is a flowchart illustrating the model construction process of the present invention.

[0030] Figure 9 The curve shows the distribution of vertical welding residual stress at the longitudinal position of 30mm when the web height is 300mm and the web gap is 30mm.

[0031] Figure 10 The curve shows the distribution of transverse welding residual stress at the longitudinal position of 30mm when the web height is 300mm and the web gap is 30mm.

[0032] Figure 11 The curve shows the distribution of vertical welding residual stress at the longitudinal position of 30mm when the web height is 600mm and the web gap is 30mm.

[0033] Figure 12 The curve shows the distribution of transverse welding residual stress at the longitudinal position of 30mm when the web height is 600mm and the web gap is 30mm.

[0034] Figure 13 This is a finite element model of the web gap of a welded simulated steel plate beam bridge constructed in step 2 of the construction method of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to these embodiments.

[0036] Example 1

[0037] exist Figure 1 The present invention relates to a model for the distribution of residual stress field from welding in the web gap of a steel plate girder bridge, characterized in that the model is based on the distribution of vertical residual welding stress σ. v (x,y) and the distribution of residual transverse stress σ from welding h Composed of (x,y),

[0038] The weld residual vertical stress distribution σ v (x,y) is:

[0039]

[0040] In equation (1), B1 is the width of the web in mm, B2 is the width of the stiffener in mm, h1 is the height of the web in mm, and t w The weld width is expressed in mm (t). f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), G v (t f ), x v1 x v2 w v1 w v2 w x b1, b2, b3, b4, C, and β are intermediate variables, and q f The yield strength of the steel plate is any one of 235, 345, and 550, in MPa.

[0041] The weld residual transverse stress distribution σ h (x,y) is:

[0042]

[0043] In equation (2), B1 is the width of the web in mm, h1 is the height of the web in mm, h2 is the height of the stiffener in mm, and t w The weld width is expressed in mm (t). f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), F h (y), G h (t f ), x h1 x h2 w x wh1 w h2 b2, c1, and c2 are intermediate variables, and q f The yield strength of the steel plate is taken as any one of 235, 345, and 550, with the unit being MPa.

[0044] In this embodiment, equation (1) is selected as w v1 It is 52.72, w v2 The value is 42.23, w x The value is 5.15, h1 is 470mm, h2 is 440mm, B1 is 600mm, B2 is 12mm, and t is... w The value is 10mm; in equation (2), w is selected. h1 It is 9.18, w h2 The value is 34.23. A corresponding welding residual stress field distribution model is constructed, where the web gap t for Q345 steel is... f The distribution of residual vertical stress field at a longitudinal distance of 30mm is shown in the figure. Figure 2 As shown, the distribution of residual transverse stress field at a longitudinal distance of 30 mm is as follows: Figure 3 As shown; web space t f The distribution of residual vertical stress field at a longitudinal distance of 60mm is shown in the figure. Figure 4 As shown, the distribution of residual transverse stress field at a longitudinal distance of 60 mm is as follows. Figure 5 As shown; web space t f The distribution of residual vertical stress field at a longitudinal distance of 90mm is as follows: Figure 6 As shown, the distribution of residual transverse stress field at a longitudinal distance of 90 mm is as follows: Figure 7 As shown. The web clearance t corresponding to Q235, Q345, and Q550 steels is... f The peak stress results for the vertical and horizontal directions are shown in Table 1 when the longitudinal distance is 30mm and the vertical distance is 30mm.

[0045] Table 1 Peak values ​​of welding residual stress

[0046]

[0047] like Figure 8 As shown, the method for constructing the residual stress field distribution model of the web gap welding of the steel plate girder bridge consists of the following steps:

[0048] Step 1: Determine the parameters of the web gap of the steel plate girder bridge: Based on the welding condition of the web gap of the steel plate girder bridge, determine the height vector h1 of the n web plates = [h 1,1 ,h 1,2 ,…,h 1,n ], the width vector B1 of the n web plates = [B 1,1B 1,2 ,…,B 1,n ], the height vector of n stiffening ribs h2=[h 2,1 ,h 2,2 ,…,h 2,n ], the width vector B2 of the n stiffening ribs = [B 2,1 B 2,2 ,…,B 2,n ], n weld width vectors t w =[t w,1 ,t w,2 ,…,t w,n ], n web space vectors t f =[t f,1 ,t f,2 ,…,t f,n ];

[0049] Step 2: Constructing the Finite Element Model: Using the n sets of web gap parameters of the steel plate girder bridge determined in Step 1, construct n finite element models of the web gap of the steel plate girder bridge for welding simulation, as follows: Figure 13 As shown, the model is divided into three-dimensional solid units;

[0050] Step 3: Perform welding thermal effect simulation: The welding thermal effect between the web and stiffeners is simulated in Abaqus finite element software after the model has been divided into three-dimensional solid elements. The heat source adopts the double ellipsoidal heat source model, the element type is three-dimensional heat transfer solid element, and the "birth and death element method" is used to simulate the formation of the weld.

[0051] Step 4: Extract the stress distribution matrix: Apply the welding process temperature field obtained in Step 3 to the 3D model of the steel plate girder bridge web gap from Step 2. Set the obtained temperature field output as the mechanical boundary condition of the stress field, and change the element type to a 3D stress element. Determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and n horizontal stress distribution values ​​based on the mesh nodes, forming stress distribution matrices respectively. The vertical stress distribution matrix is ​​(σ... v1 σ v2 ...σ vi ), σ v,i For the i-th vertical stress distribution value, the transverse stress distribution matrix is ​​(σ h1 σ h2 ...σ hi ), σ h,i This represents the i-th transverse stress distribution value;

[0052] 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 horizontal stress distribution matrix obtained in Step 4 with the parameter vectors B1, B2, h1, h2, t obtained in Step 1. wand the independent variable web gap vector t f By fitting the data, the vertical stress distribution σ of the welding residue was obtained. v (x,y) and the distribution of residual transverse stress σ from welding h (x,y).

[0053] Example 2

[0054] The residual stress field distribution model of the web gap welding of the steel plate girder bridge involved in this embodiment is shown in equations (1) and (2), and the construction method is the same as that in embodiment 1.

[0055] In this embodiment, w is selected from equation (1). v1 It is 47.01, w v2 It is 37.75, w x The value is 5.13, h1 is 300mm, h2 is 270mm, B1 is 500mm, B2 is 5mm, and t is... w The value is 8mm. In formula (2), w is selected. h1 It is 5.96, w h2 The value is 154.74. The web gap t is constructed. f The model shows the distribution of welding residual stress field at a distance of 30mm, where the vertical stress field distribution of welding residual stress at a longitudinal distance of 30mm for Q345 steel is as follows. Figure 9 As shown, the distribution of residual transverse stress field at a longitudinal distance of 30 mm is as follows: Figure 10 As shown. Among them, the web clearance t corresponds to Q235, Q345, and Q550 steel. f The peak stress results for the vertical and horizontal directions are shown in Table 2 when the longitudinal distance is 30mm and the vertical distance is 30mm.

[0056] Table 2 Peak values ​​of welding residual stress

[0057]

[0058] Example 3

[0059] The residual stress field distribution model of the web gap welding of the steel plate girder bridge involved in this embodiment is shown in equations (1) and (2), and the construction method is the same as that in embodiment 1.

[0060] In this embodiment, w is selected from equation (1). v1 It is 58.43, w v2 It is 46.72, w x The value is 5.17, h1 is 600mm, h2 is 570mm, B1 is 700mm, B2 is 18mm, and t is... w The value is 15mm, and w is selected in formula (2). h1 It is 11.22, w h2 The value is 225.91. The web gap t is constructed.f The model shows the distribution of welding residual stress field at a longitudinal distance of 30mm for Q345 steel. Figure 11 As shown, the distribution of residual transverse stress field at a longitudinal distance of 30 mm is as follows: Figure 12 As shown. Among them, the web clearance t corresponds to Q235, Q345, and Q550 steel. f The peak stress results for the vertical and horizontal directions are shown in Table 3 when the longitudinal distance is 30mm and the vertical distance is 30mm.

[0061] Table 3 Peak values ​​of welding residual stress

[0062]

[0063]

[0064] As shown in Tables 1, 2, and 3, high-yield-strength steel significantly increases the peak value of welding residual stress, and the residual stress field exhibits a unique bi-tensile stress peak distribution characteristic in the transverse direction: two significant tensile stress peaks coexist, indicating the existence of multiple high-stress regions in the structure. This will significantly increase the risk of transverse deformation and multi-point cracking. Figures 2-7 It is evident that the web gap size has a critical controlling effect on the residual stress distribution: a small gap (30 mm) results in a high-stress bimodal distribution, a medium gap (60 mm) effectively suppresses stress concentration, while a large gap (90 mm) leads to an increase in transverse tensile stress due to accumulated heat input. The above examples are consistent with actual engineering projects, indicating that this model has a certain degree of universality under different size and material conditions.

Claims

1. A model for the distribution of residual stress field from welding gaps in the web of a steel plate girder bridge, characterized in that, The model is based on the vertical stress distribution σ of welding residue. v (x,y) and the distribution of residual transverse stress σ from welding h Composed of (x,y), The weld residual vertical stress distribution σ v (x,y) is: In equation (1), B1 is the width of the web in mm, B2 is the width of the stiffener in mm, h1 is the height of the web in mm, and t w The weld width is expressed in mm, t f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), G v (t f ), x v1 x v2 w v1 w v2 w x b1, b2, b3, b4, C, and β are intermediate variables, and q f The yield strength of the steel plate is any one of 235, 345, and 550, in MPa. The weld residual transverse stress distribution σ h (x,y) is: In equation (2), B1 is the width of the web in mm, h1 is the height of the web in mm, h2 is the height of the stiffener in mm, and t w The weld width is expressed in mm, t f The web gap is in mm, where x is the transverse distance and y is the longitudinal distance. F v (y), F h (y), G h (t f ), x h1 x h2 w x w h1 w h2 b2, c1, and c2 are intermediate variables, and q f The yield strength of the steel plate is taken as any one of 235, 345, and 550, with the unit being MPa.

2. The residual stress field distribution model for web stiffener welding according to claim 1, characterized in that: In equation (1), w v1 The value range of w is [47.01, 58.43]. v2 The value range of w is [37.75, 46.72]. x The values ​​of are [5.13, 5.17], h1 is [300, 600] (unit: mm), h2 is [270, 570] (unit: mm), B1 is [500, 700] (unit: mm), B2 is [5, 18] (unit: mm), and t... w The value range is [8, 15], and the unit is mm. t f The value of w can be any one of 30, 60, or 90, and the unit is mm; in formula (2), w h1 The value range of w is [5.96, 11.22]. h2 The value range is [154.74, 225.91].

3. The residual stress field distribution model for the web gap welding of a steel plate girder bridge according to claim 1, characterized in that: In equation (1), w v1 w v2 w x h1, h2, B1, B2, t w The value of is: w v1 It is 52.72, w v2 It is 42.23, w x The value is 5.15, h1 is 470mm, h2 is 440mm, B1 is 600mm, B2 is 12mm, and t is... w It is 10mm, t f It is 30mm; in formula (2), the w h1 w h2 The value of is: w h1 It is 9.18, w h2 It is 34.

23.

4. The method for constructing the residual stress field distribution model of the web gap welding of a steel plate girder bridge as described in claim 1, characterized in that... It consists of the following steps: Step 1: Determine the parameters of the web gap of the steel plate girder bridge: Based on the welding condition of the web gap of the steel plate girder bridge, determine the height vector h1 of the n web plates = [h 1,1 ,h 1,2 ,…,h 1,n ], the width vector B1 of the n web plates = [B 1,1 B 1,2 ,…,B 1,n ], the height vector of n stiffening ribs h2=[h 2,1 ,h 2,2 ,…,h 2,n ], the width vector B2 of the n stiffening ribs = [B 2,1 B 2,2 ,…,B 2,n ], n weld width vectors t w =[t w,1 ,t w,2 ,…,t w,n ], n web space vectors t f =[t f,1 ,t f,2 ,…,t f,n ]; Step 2: Constructing the finite element model: Using the n sets of steel plate girder bridge web gap parameters determined in Step 1, construct n finite element models of the steel plate girder bridge web gap for welding simulation. The model is divided into three-dimensional solid elements. Step 3: Perform welding thermal effect simulation: The welding thermal effect between the web and stiffener is simulated in the Abaqus finite element software after the model has been divided into three-dimensional solid elements. The heat source adopts the double ellipsoidal heat source model, the element type is 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 3D model of the steel plate girder bridge web gap from Step 2. Set the obtained temperature field output as the mechanical boundary condition of the stress field, and change the element type to a 3D stress element. Determine the welding residual stress distribution after welding. Extract n vertical stress distribution values ​​and n horizontal stress distribution values ​​based on the mesh nodes, forming stress distribution matrices respectively. The vertical stress distribution matrix is ​​(σ... v1 σ v2 ...σ vi ), σ v,i For the i-th vertical stress distribution value, the horizontal stress distribution matrix is ​​(σ h1 σ h2 ...σ hi ), σ h,i This represents the i-th transverse stress distribution value; 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 horizontal stress distribution matrix obtained in Step 4 with the parameter vectors B1, B2, h1, h2, t obtained in Step 1. w and the independent variable web gap vector t f By fitting the data, the vertical stress distribution σ of the welding residue was obtained. v (x,y) and the distribution of residual transverse stress σ from welding h (x,y).

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