Steel box girder bridge support deviation analysis system and method considering temperature effect

Abstract

The invention relates to the technical field of offset analysis, in particular to a steel box girder bridge support offset analysis system and method considering the temperature effect, and the method comprises the following steps: building a three-dimensional temperature field model of a bridge structure based on the collection of temperature data of an area where a bridge is located; the real mechanical property of the material under the temperature field change condition is obtained, and the mechanical parameters of the support structure are calibrated, including the calibration of the steel elasticity modulus, the yield strength and the temperature expansion coefficient; in combination with the three-dimensional temperature field model and the calibrated mechanical parameters, analyzing strain data of the support structure through a thermal-mechanical coupling model; and obtaining a displacement field of the support position based on the strain data of the support structure output by the thermal-mechanical coupling model. According to the method, the analysis deviation caused by neglecting the temperature effect or assuming that the material performance is constant in the prior art is made up.

Description

Technical Field

[0001] The present invention relates to the technical field of offset analysis, and in particular to a steel box girder bridge support offset analysis system and method considering temperature effects. Background Art

[0002] Steel box girder bridges have become an important structural form in modern bridge construction due to their high strength, high rigidity and light weight. However, the bearings, as the connecting components between the bridge and the substructure, directly affect the stress and deformation of the bridge, and their misalignment has a crucial impact on the safety and durability of the bridge.

[0003] In the prior art, the analysis method of support deviation mainly focuses on the statics perspective, and the support deformation is evaluated by determining the mechanical response under the load. However, the support deviation of the steel box girder bridge is not only affected by the load, but also significantly disturbed by the temperature effect. The thermal expansion and contraction of the bridge support due to temperature difference, temperature change, etc. can easily cause horizontal and vertical deviations. In addition, the temperature gradient effect may also lead to non-uniform stress distribution in the support area, causing complex coupled deformation of the support. The existing deviation analysis methods often simplify the temperature effect or assume that the material properties do not change with temperature, resulting in a large deviation between the analysis results and the actual situation. Summary of the invention

[0004] The invention provides a steel box girder bridge support deviation analysis system and method considering temperature effect.

[0005] A method for analyzing the displacement of steel box girder bridge bearings considering temperature effects comprises the following steps:

[0006] S1, construction of temperature field: based on the collection of temperature data of the area where the bridge is located, a three-dimensional temperature field model of the bridge structure is constructed. The characteristics of the temperature field model include:

[0007] a): Horizontal temperature difference in the bearing area: Consider the temperature difference between the bridge bearing area and the adjacent structure;

[0008] b): Vertical temperature difference in the bearing area: Consider the temperature difference above and below the bridge bearing;

[0009] c): Non-uniform temperature distribution: simulate the influence of temperature gradient on the non-uniform stress of the support;

[0010] S2, mechanical parameter calibration: Based on the bridge bearing material data and combined with the temperature field model, the real mechanical properties of the material under the condition of temperature field change are obtained, and the mechanical parameters of the bearing structure are calibrated, including the calibration of the steel elastic modulus, yield strength and temperature expansion coefficient;

[0011] S3, strain analysis under temperature effect: combining the three-dimensional temperature field model and the calibrated mechanical parameters, analyzing the strain data of the support structure through a thermal-mechanical coupling model;

[0012] S4, based on the strain data of the support structure output by the thermal-mechanical coupling model, the strain data is converted into displacement using the elastic mechanics model to obtain the displacement field of the support position, including the horizontal and vertical displacements of the support.

[0013] Optionally, the temperature data is collected through a distributed temperature sensor network. Temperature sensors are arranged in the bridge support area and its adjacent structures to collect real-time temperature data of various parts of the bridge. Based on the collected temperature data, a temperature field model of the bridge structure is established using a three-dimensional finite element method.

[0014] Optionally, the three-dimensional temperature field T(x, y, z, t) is a function of spatial coordinates x, y, z and time t, representing the temperature of the bridge structure at a spatial point (x, y, z) and time t, and is described based on the partial differential heat conduction equation: Among them, k represents the thermal conductivity of the material, reflecting the thermal conductivity of the material, q is the heat source term, which represents the heat input of the support affected by external heat (such as solar radiation, friction heat), ρ represents the density of the material, and c is the specific heat capacity of the material. is the temperature gradient, describing the temperature variation in space, is the time derivative, describing the rate of change of temperature with time.

[0015] Optionally, the horizontal temperature difference ΔT in the support area h It is expressed as:

[0016] ΔT h =T top (x,y,z,t)-T bottom (x, y, z, t), where T top (x, y, z, t) is the temperature of the bridge deck area adjacent to the support, T bottom (x, y, z, t) is the temperature of the box girder bottom plate area adjacent to the support, ΔT h Indicates the temperature difference in the horizontal plane of the support area;

[0017] Vertical temperature difference ΔT in the support area v It is expressed as:

[0018] ΔT v =T upper (x,y,z,t)-T lower (x, y, z, t), where T upper (x, y, z, t) is the temperature of the upper surface of the support, T lower(x, y, z, t) is the temperature of the lower surface of the support, ΔT v Indicates the temperature difference between the upper and lower directions of the support area;

[0019] The gradient of the non-uniform temperature distribution is expressed as: in, They represent the temperature gradients in the x, y, and z spatial directions, respectively, reflecting the non-uniform temperature changes in the support area.

[0020] Optionally, based on the partial differential equation of the three-dimensional temperature field, a finite element discretization method is used to solve the support area by meshing. x ×N y ×N z The temperature field is discretely expressed as:

[0021]

[0022] in, represents the temperature value of the grid point (i, j, k) at the nth moment, Δx, Δy, Δz represent the spatial discrete step length of the grid unit, Δt represents the time step length, k x ,k y ,k z represents the thermal conductivity along the x, y, and z directions, and q is the heat source term at the grid point;

[0023] After solving the finite element discretization method, the three-dimensional temperature field model of the support area is expressed as:

[0024] Where T(x,y,z,t) represents the temperature distribution in the support area, φ i,j,k (x, y, z) represents the grid shape function, which represents the influence weight of the grid point (i, j, k) on the position (x, y, z). is the temperature value of each grid point, N x ,N y ,N z is the number of grid cells.

[0025] Optionally, the mechanical parameter calibration in S2 includes:

[0026] S21, Establishment of temperature mechanical properties relationship model: Based on the bridge bearing material data, the temperature elastic modulus relationship sub-model E(T) and the temperature yield strength relationship sub-model σ are constructed. y (T) and the temperature expansion coefficient relationship sub-model α(T);

[0027] S22, data input of temperature field model: Based on the three-dimensional temperature field model T(x,y,z), obtain the temperature value of each grid point in the support area, and substitute the grid point temperature T(x,y,z) into the temperature mechanical properties relationship model E(T),σ y (T),α(T), calculate the distribution of mechanical parameters of the support area under different temperature conditions:

[0028] E i,j,k =E0(1-k E [T i,j,k -T0]);

[0029]

[0030] α i,j,k =α0(1+k α [T i,j,k -T0]);

[0031] Among them, E i,j,k ,σ y,i,j,k ,α i,j,k are the elastic modulus, yield strength and temperature expansion coefficient of the grid point (i, j, k) in the temperature field;

[0032] S23, calibration of mechanical parameters: weighted average the mechanical parameters of all grid points in the support area to obtain the overall elastic modulus E and yield strength σ of the calibrated mechanical parameters in the support area. y , temperature expansion coefficient α.

[0033] Optionally, the strain analysis under the temperature effect in S3 specifically includes:

[0034] S31, initialization of input data: input the temperature distribution data based on the three-dimensional temperature field model T(x, y, z, t) into the thermal-mechanical coupling model, introduce the calibrated mechanical parameters, including elastic modulus, yield strength and temperature expansion coefficient, define the geometric model Ω and boundary conditions of the support structure, including the force connection of the support fixed end, free end and adjacent bridge parts;

[0035] S32, the thermal-mechanical coupling model uses the following coupled partial differential equations:

[0036] Heat conduction equation:

[0037] Balanced equation:

[0038] Thermal stress calculation equation:

[0039] Thermal expansion strain calculation:

[0040] in, is the stress tensor, ε is the total strain tensor, and ε T is the strain tensor caused by thermal expansion, D is the elastic constant matrix, which is determined by the calibrated elastic modulus E and Poisson's ratio ν, f is the body load, ΔT = T(x, y, z, t) - T0 represents the temperature difference, and I is the unit matrix;

[0041] S33, numerical solution: N based on support area division x ×N y ×N z The unit grid is discretized by finite element, and the discretized thermal-mechanical coupling model equations are expressed as:

[0042] [K T ]{T}={F T};

[0043]

[0044] Among them, [K T ] is the heat transfer coefficient matrix, {T} is the discrete temperature field vector, {F T} is the heat source vector, is the material stiffness matrix, is the stress vector, is the external load vector;

[0045] S34, calculation of strain data in the support area: by solving the thermal-mechanical coupling model equations, the stress of the mesh elements in the support area is obtained and the total strain ε i,j,k , separate the thermal expansion strain from the total strain and calculate the mechanical strain: ε mech =ε-ε T , summarizing the mechanical strains of all mesh elements in the support region.

[0046] Optionally, the S4 specifically includes:

[0047] S41, based on the calculation results of the thermal-mechanical coupling model, obtain the mechanical strain ε of each grid unit in the support structure mech , the mechanical strain is classified and the strain components in the horizontal direction (x, y) and vertical direction (z) of the support are separated and expressed as: ε x ,ε y ,ε z , where ε x ,ε y is the horizontal strain component, ε z is the vertical strain component;

[0048] S42, calculate node displacement based on elastic mechanics model: use elastic mechanics relationship to convert mesh unit strain into node displacement, expressed as: {u} = [D] -1 {ε mech},in, Represents the displacement vector of the node, including the horizontal displacement (u x ,u y ) and vertical displacement (u z ), represents the strain vector of the node, including normal strain and shear strain, [D] is the elastic constant matrix, which is determined by the calibrated elastic modulus E and Poisson's ratio ν;

[0049] S43, construction of the displacement field at the support position: sum up the displacement {u} of each grid node to construct the overall displacement field U(x,y,z) of the support area, which is in the form of: U(x,y,z)={u x (x,y,z),u y (x,y,z),u z (x,y,z)}, and extract the horizontal displacement (u) of the key position of the support from the displacement field. x ,u y ) and vertical displacement (u z );

[0050] S44, calculation of horizontal and vertical displacement of supports:

[0051] Horizontal displacement: The horizontal displacement component u of the support area x ,u y Converted into horizontal displacement Δh, the calculation formula is:

[0052] Vertical displacement: vertical displacement component u in the support area z That is the vertical deviation Δv: Δv = u z .

[0053] Optionally, it also includes the setting of a deviation tolerance range. Based on the bridge design specifications and standards, the allowable range of bearing deviation is set, and an early warning is issued when the horizontal and vertical deviations exceed the range.

[0054] A steel box girder bridge bearing displacement analysis system considering temperature effect is used to implement the above-mentioned steel box girder bridge bearing displacement analysis method considering temperature effect, and includes the following modules:

[0055] Temperature field data acquisition module: collects temperature field data of the support area in real time through the temperature sensor in the support area of ​​the bridge;

[0056] Three-dimensional temperature field modeling module: based on the temperature field data, a three-dimensional temperature field model of the support area is constructed. The characteristics of the three-dimensional temperature field model include: horizontal temperature difference in the support area, vertical temperature difference in the support area, and non-uniform temperature distribution caused by temperature gradient. The model is used to describe the influence of temperature change on the support position and deformation;

[0057] Mechanical parameter calibration module: Based on the mechanical property data of the support material and combined with the three-dimensional temperature field model, the actual mechanical properties of the material under temperature change conditions are obtained, the elastic modulus, yield strength, and temperature expansion coefficient of the steel are calibrated, and the nonlinear response of the steel box girder and the support under temperature change is corrected to ensure that the mechanical behavior of the material accurately reflects the influence of the temperature field;

[0058] Strain analysis and displacement calculation module: combining the three-dimensional temperature field model and the calibrated mechanical parameters, the strain of the support area is calculated through the thermal-mechanical coupling model, and then the displacement of the support is calculated through the elastic mechanics model according to the strain result to obtain the horizontal and vertical displacement of the support;

[0059] Displacement warning module: Based on the displacement data of the bearing, it is compared with the design standards and specifications to evaluate whether the displacement of the bearing exceeds the allowable range. If the displacement exceeds the preset threshold, an alarm is issued.

[0060] Beneficial effects of the present invention:

[0061] The present invention, in combination with the temperature characteristics of the bridge bearing area, constructs a three-dimensional temperature field model based on meteorological data, and refines the description of the horizontal temperature difference, vertical temperature difference and non-uniform temperature distribution in the bearing area. On this basis, the elastic modulus, yield strength and expansion coefficient of the bearing material are dynamically calibrated through the temperature-mechanical property relationship model to ensure that the mechanical properties reflect the true state under actual temperature conditions. The calibration improves the accuracy of the bearing deviation analysis and makes up for the analysis deviation caused by ignoring the temperature effect or assuming constant material properties in the prior art.

[0062] The present invention proposes a support deviation analysis method based on a thermal-mechanical coupling model, combines the temperature field model with the calibrated mechanical parameters, and accurately calculates the strain and stress distribution in the support area by discretizing the heat conduction equation and the equilibrium equation. In addition, the thermal expansion strain and the mechanical strain are separated by an elastic mechanics model to ensure that the deviation calculation only reflects the real mechanical deviation and avoid the interference caused by thermal expansion. The horizontal and vertical deviations of the support are calculated, and a refined analysis of the global displacement field is provided, which solves the problem that the risk of support deviation cannot be accurately assessed in the prior art and provides a scientific basis for support design and long-term operation of bridges. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0064] Figure 1 A schematic diagram of a method flow chart of an embodiment of the present invention;

[0065] Figure 2 It is a schematic diagram of mechanical parameter calibration according to an embodiment of the present invention. DETAILED DESCRIPTION

[0066] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0067] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0068] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0069] like Figure 1-Figure 2 As shown, a method for analyzing the displacement of steel box girder bridge bearings considering temperature effect includes the following steps:

[0070] S1, construction of temperature field: Based on the collection of temperature data in the area where the bridge is located, a three-dimensional temperature field model of the bridge structure is constructed. The characteristics of the temperature field model include:

[0071] a): Horizontal temperature difference in the bearing area: Consider the temperature difference between the bridge bearing area and the adjacent structure (such as the box girder bottom plate and the bridge deck). Especially in an environment with a large temperature gradient, the temperature difference in the bearing area will cause the horizontal displacement of the bearing;

[0072] b): Vertical temperature difference in the bearing area: Consider the temperature difference between the top and bottom of the bridge bearing. Especially in high or low temperature environments, the bearing will cause vertical deformation due to the temperature difference, which will affect its stability and position;

[0073] c): Non-uniform temperature distribution: simulate the influence of temperature gradient on the non-uniform stress of the support;

[0074] S2, mechanical parameter calibration: Based on the bridge bearing material data and combined with the temperature field model, the real mechanical properties of the material under the condition of temperature field change are obtained, and the mechanical parameters of the bearing structure are calibrated, including the calibration of the steel elastic modulus, yield strength and temperature expansion coefficient. The purpose of this calibration step is to correct the nonlinear response of the steel box girder and bearing under temperature change, to ensure that the mechanical behavior of the material under the influence of the temperature field can accurately reflect the actual situation, thereby improving the accuracy of the subsequent deflection analysis;

[0075] S3, strain analysis under temperature effect: combining the three-dimensional temperature field model and the calibrated mechanical parameters, the strain data of the support structure is analyzed through the thermal-mechanical coupling model;

[0076] S4, based on the strain data of the support structure output by the thermal-mechanical coupling model, the strain data is converted into displacement using the elastic mechanics model to obtain the displacement field of the support position, including the horizontal and vertical displacements of the support.

[0077] Temperature data is collected through a distributed temperature sensor network. Temperature sensors are deployed in the bridge support area and its adjacent structures to collect real-time temperature data of various parts of the bridge. Based on the collected temperature data, a three-dimensional finite element method is used to establish a temperature field model of the bridge structure.

[0078] The three-dimensional temperature field T(x,y,z,t) is a function of the spatial coordinates x,y,z and time t, which represents the temperature of the bridge structure at the spatial point (x,y,z) and time t. It is described based on the partial differential heat conduction equation: Among them, k represents the thermal conductivity of the material, which reflects the thermal conductivity of the material; q is the heat source term, which represents the heat input of the support affected by external heat (such as solar radiation and friction heat); ρ represents the density of the material; c is the specific heat capacity of the material, which represents the heat required to increase the unit temperature of the unit mass of the material. is the temperature gradient, describing the temperature variation in space, is the time derivative, describing the rate of change of temperature with time.

[0079] Horizontal temperature difference ΔT in the support area h It is expressed as:

[0080] ΔT h =T top (x,y,z,t)-T bottom (x, y, z, t), where T top (x, y, z, t) is the temperature of the bridge deck area adjacent to the support, T bottom (x, y, z, t) is the temperature of the box girder bottom plate area adjacent to the support, ΔT h Indicates the temperature difference in the horizontal plane of the support area;

[0081] Vertical temperature difference ΔT in the support area v It is expressed as:

[0082] ΔT v =T upper (x,y,z,t)-T lower (x, y, z, t), where T upper (x, y, z, t) is the temperature of the upper surface of the support, T lower (x, y, z, t) is the temperature of the lower surface of the support, ΔT v Indicates the temperature difference between the upper and lower directions of the support area;

[0083] The gradient of non-uniform temperature distribution is expressed as: in, They represent the temperature gradients in the x, y, and z spatial directions, respectively, reflecting the non-uniform temperature changes in the support area.

[0084] Based on the partial differential equation of the three-dimensional temperature field, the finite element discretization method is used to solve it. The support area is divided into N x ×N y ×N z The temperature field is discretely expressed as:

[0085]

[0086] in, represents the temperature value of the grid point (i, j, k) at the nth moment, Δx, Δy, Δz represent the spatial discrete step length of the grid unit, Δt represents the time step length, k x ,k y ,k z represents the thermal conductivity along the x, y, and z directions, and q is the heat source term at the grid point;

[0087] After solving the finite element discretization method, the three-dimensional temperature field model of the support area is expressed as:

[0088] Where T(x,y,z,t) represents the temperature distribution in the support area, φ i,j,k (x, y, z) represents the grid shape function, which represents the influence weight of the grid point (i, j, k) on the position (x, y, z). is the temperature value of each grid point, N x ,N y ,N z is the number of grid cells.

[0089] Mechanical parameter calibration in S2 includes:

[0090] S21, Establishment of temperature mechanical properties relationship model: Based on the bridge bearing material data, the temperature elastic modulus relationship sub-model E(T) and the temperature yield strength relationship sub-model σ are constructed. y (T) and the temperature expansion coefficient relationship sub-model α(T), which is specifically expressed as:

[0091] E(T)=E0(1-k E ΔT);

[0092] σ y (T) = σ y0 (1-k σy ΔT);

[0093] α(T)=α0(1+k α ΔT);

[0094] Where E(T) is the elastic modulus at temperature T, σ y (T) is the yield strength at temperature T, α(T) is the expansion coefficient at temperature T, E0,σ y0 , α0 is the initial elastic modulus, yield strength and expansion coefficient of the material (values ​​under normal temperature conditions, obtained based on existing materials literature for bridge bearings), k E ,k σy ,k α : The influence coefficient of temperature change on the corresponding mechanical parameters, ΔT = T-T0: the temperature difference relative to the reference temperature T0;

[0095] S22, data input of temperature field model: Based on the three-dimensional temperature field model T(x,y,z), obtain the temperature value of each grid point in the support area, and substitute the grid point temperature T(x,y,z) into the temperature mechanical properties relationship model E(T),σ y (T),α(T), calculate the distribution of mechanical parameters of the support area under different temperature conditions:

[0096] E i,j,k =E0(1-k E [T i,j,k -T0]);

[0097]

[0098] α i,j,k =α0(1+k α [T i,j,k -T0]);

[0099] Among them, E i,j,k ,σ y,i,j,k ,α i,j,k are the elastic modulus, yield strength and temperature expansion coefficient of the grid point (i, j, k) in the temperature field;

[0100] S23, calibration of mechanical parameters: weighted average the mechanical parameters of all grid points in the support area to obtain the overall elastic modulus of the mechanical parameters after calibration of the support area. Yield Strength Thermal expansion coefficient

[0101]

[0102] in, are the overall elastic modulus, yield strength and thermal expansion coefficient of the support area after calibration, V i,j,k is the volume of the grid point (i,j,k), N x ,N y ,N z are the number of grid divisions of the temperature field model in the x, y, and z directions respectively.

[0103] The calibrated mechanical parameters Input into subsequent bias analysis.

[0104] The strain analysis under temperature effect in S3 specifically includes:

[0105] S31, initialization of input data: input the temperature distribution data based on the three-dimensional temperature field model T(x, y, z, t) into the thermal-mechanical coupling model, introduce the calibrated mechanical parameters, including elastic modulus, yield strength and temperature expansion coefficient, to ensure that the material properties reflect the real temperature effect, define the geometric model Ω and boundary conditions of the support structure, including the force connection of the fixed end, free end and adjacent bridge parts of the support;

[0106] S32, the thermal-mechanical coupling model uses the following coupled partial differential equations:

[0107] Heat conduction equation, using the partial differential heat conduction equation in three-dimensional temperature field:

[0108] Balanced equation:

[0109] Thermal stress calculation equation:

[0110] Thermal expansion strain calculation:

[0111] in, is the stress tensor, ε is the total strain tensor, and ε T is the strain tensor caused by thermal expansion, D is the elastic constant matrix, which is determined by the calibrated elastic modulus E and Poisson's ratio ν, f is the body load, ΔT = T(x, y, z, t) - T0 represents the temperature difference, and I is the unit matrix;

[0112] S33, numerical solution: N based on support area division x ×N y ×N z The unit grid is discretized by finite element, and the discretized thermal-mechanical coupling model equations are expressed as:

[0113] [K T ]{T}={F T};

[0114]

[0115] Among them, [K T ] is the heat transfer coefficient matrix, {T} is the discrete temperature field vector, {F T} is the heat source vector, is the material stiffness matrix, is the stress vector, is the external load vector;

[0116] S34, calculation of strain data in the support area: by solving the thermal-mechanical coupling model equations, the stress of the mesh elements in the support area is obtained and the total strain ε i,j,k , separate the thermal expansion strain from the total strain and calculate the mechanical strain: ε mech =ε-ε T , summarizing the mechanical strains of all grid cells in the support area, and obtaining the strain distribution of the entire support structure.

[0117] S4 specifically includes:

[0118] S41, based on the calculation results of the thermal-mechanical coupling model, obtain the mechanical strain ε of each grid unit in the support structure mech , the mechanical strain is classified and the strain components in the horizontal direction (x, y) and vertical direction (z) of the support are separated and expressed as: ε x ,ε y ,ε z , where ε x ,ε yis the horizontal strain component, ε z is the vertical strain component;

[0119] S42, calculate node displacement based on elastic mechanics model: use elastic mechanics relationship to convert mesh unit strain into node displacement, expressed as: {u} = [D] -1 {ε mech},in, Represents the displacement vector of the node, including the horizontal displacement (u x ,u y ) and vertical displacement (u z ), represents the strain vector of the node, including normal strain and shear strain, [D] is the elastic constant matrix, which is determined by the calibrated elastic modulus E and Poisson's ratio ν, expressed as:

[0120]

[0121] S43, construction of the displacement field at the support position: sum up the displacement {u} of each grid node to construct the overall displacement field U(x,y,z) of the support area, which is in the form of: U(x,y,z)={u x (x,y,z),u y (x,y,z),u z (x,y,z)}, and extract the horizontal displacement (u) of the key position of the support from the displacement field. x ,u y ) and vertical displacement (u z );

[0122] S44, calculation of horizontal and vertical displacement of supports:

[0123] Horizontal displacement: The horizontal displacement component u of the support area x ,u y Converted into horizontal displacement Δh, the calculation formula is:

[0124] Vertical displacement: vertical displacement component u in the support area z That is the vertical deviation Δv: Δv = u z ;

[0125] Result output: Output the overall displacement field distribution diagram of the support position, including horizontal and vertical displacement distribution, compare the calculated results with the allowable displacement values ​​in the bridge design specifications, and mark the areas where the displacement exceeds the standard.

[0126] It also includes the setting of the deviation tolerance range. Based on the bridge design specifications and standards, the allowable range of bearing deviation is set. When the horizontal and vertical deviations exceed the range, an early warning is issued.

[0127] The steel box girder bridge bearing displacement analysis system considering temperature effect is used to implement the above displacement analysis method, including the following modules:

[0128] Temperature field data acquisition module: collects temperature field data of the support area in real time through the temperature sensor in the support area of ​​the bridge;

[0129] 3D temperature field modeling module: Based on the temperature field data, a 3D temperature field model of the support area is constructed. The characteristics of the 3D temperature field model include: horizontal temperature difference in the support area, vertical temperature difference in the support area, and non-uniform temperature distribution caused by temperature gradient. The model is used to describe the influence of temperature change on the support position and deformation.

[0130] Mechanical parameter calibration module: Based on the mechanical property data of the support material and combined with the three-dimensional temperature field model, the actual mechanical properties of the material under temperature change conditions are obtained, the elastic modulus, yield strength, and temperature expansion coefficient of the steel are calibrated, and the nonlinear response of the steel box girder and support under temperature change is corrected to ensure that the mechanical behavior of the material accurately reflects the influence of the temperature field;

[0131] Strain analysis and displacement calculation module: combining the three-dimensional temperature field model and the calibrated mechanical parameters, the strain of the support area is calculated through the thermal-mechanical coupling model, and then the displacement of the support is calculated through the elastic mechanics model according to the strain result to obtain the horizontal and vertical displacement of the support;

[0132] Displacement warning module: Based on the displacement data of the bearing, it is compared with the design standards and specifications to evaluate whether the displacement of the bearing exceeds the allowable range. If the displacement exceeds the preset threshold, an alarm is issued.

[0133] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0134] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for analyzing the displacement of steel box girder bridge bearings considering temperature effects, characterized in that: The following steps are involved: S1, construction of temperature field: based on the collection of temperature data of the area where the bridge is located, a three-dimensional temperature field model of the bridge structure is constructed. The characteristics of the temperature field model include: a): Horizontal temperature difference in the bearing area: Consider the temperature difference between the bridge bearing area and the adjacent structure; b): Vertical temperature difference in the bearing area: Consider the temperature difference above and below the bridge bearing; c): Non-uniform temperature distribution: simulate the influence of temperature gradient on the non-uniform stress of the support; S2, mechanical parameter calibration: Based on the bridge bearing material data and combined with the temperature field model, the real mechanical properties of the material under the condition of temperature field change are obtained, and the mechanical parameters of the bearing structure are calibrated, including the calibration of the steel elastic modulus, yield strength and temperature expansion coefficient; S3, strain analysis under temperature effect: combining the three-dimensional temperature field model and the calibrated mechanical parameters, analyzing the strain data of the support structure through a thermal-mechanical coupling model; S4, based on the strain data of the support structure output by the thermal-mechanical coupling model, the strain data is converted into displacement using the elastic mechanics model to obtain the displacement field of the support position, including the horizontal and vertical displacements of the support.

2. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 1 is characterized in that: The temperature data is collected through a distributed temperature sensor network. Temperature sensors are arranged in the bridge support area and its adjacent structures to collect real-time temperature data of various parts of the bridge. Based on the collected temperature data, a temperature field model of the bridge structure is established using a three-dimensional finite element method.

3. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 2 is characterized in that: The three-dimensional temperature field T(x, y, z, t) is a function of the spatial coordinates x, y, z and time t, representing the temperature of the bridge structure at the spatial point (x, y, z) and time t, and is described based on the partial differential heat conduction equation: Among them, k represents the thermal conductivity of the material, reflecting the thermal conductivity of the material, q is the heat source term, which represents the heat input of the support affected by external heat, ρ represents the density of the material, and c is the specific heat capacity of the material. is the temperature gradient, describing the temperature variation in space, is the time derivative, describing the rate of change of temperature with time.

4. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 3 is characterized in that: The horizontal temperature difference ΔT in the support area h It is expressed as: ΔT h =T top (x,y,z,t)-T bottom (x, y, z, t), where T top (x, y, z, t) is the temperature of the bridge deck area adjacent to the support, T bottom (x, y, z, t) is the temperature of the box girder bottom plate area adjacent to the support, ΔT h Indicates the temperature difference in the horizontal plane of the support area; Vertical temperature difference ΔT in the support area v It is expressed as: ΔT v =T upper (x,y,z,t)-T lower (x, y, z, t), where T upper (x, y, z, t) is the temperature of the upper surface of the support, T lower (x, y, z, t) is the temperature of the lower surface of the support, ΔT v Indicates the temperature difference between the upper and lower directions of the support area; The gradient of the non-uniform temperature distribution is expressed as: in, They represent the temperature gradients in the x, y, and z spatial directions, respectively, reflecting the non-uniform temperature changes in the support area.

5. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 4 is characterized in that: Based on the partial differential equation of the three-dimensional temperature field, the finite element discretization method is used to solve it. The support area is divided into N x ×N y ×N z The temperature field is discretely expressed as: in, represents the temperature value of the grid point (i, j, k) at the nth moment, Δx, Δy, Δz represent the spatial discrete step length of the grid unit, Δt represents the time step length, k x ,k y ,k z represents the thermal conductivity along the x, y, and z directions, and q is the heat source term at the grid point; After solving the finite element discretization method, the three-dimensional temperature field model of the support area is expressed as: Where T(x,y,z,t) represents the temperature distribution in the support area, φ i,j,k (x, y, z) represents the grid shape function, which represents the influence weight of the grid point (i, j, k) on the position (x, y, z). is the temperature value of each grid point, N x ,N y ,N z is the number of grid cells.

6. The method for analyzing the bearing displacement of a steel box girder bridge considering temperature effect according to claim 5 is characterized in that: The mechanical parameter calibration in S2 includes: S21, Establishment of temperature mechanical properties relationship model: Based on the bridge bearing material data, the temperature elastic modulus relationship sub-model E(T) of steel and the temperature yield strength relationship sub-model σ y (T) and the temperature expansion coefficient relationship sub-model α(T); S22, data input of temperature field model: Based on the three-dimensional temperature field model T(x,y,z), obtain the temperature value of each grid point in the support area, and substitute the grid point temperature T(x,y,z) into the temperature mechanical properties relationship model E(T),σ y (T),α(T), calculate the distribution of mechanical parameters of the support area under different temperature conditions: E i,j,k =E0(1-k E [T i,j,k -T0]); a i,j,k =α0(1+k α [T i,j,k -T0]); Among them, E i,j,k ,σ y,i,j,k ,α i,j,k are the elastic modulus, yield strength and temperature expansion coefficient of the grid point (i, j, k) in the temperature field; S23, calibration of mechanical parameters: weighted average the mechanical parameters of all grid points in the support area to obtain the overall elastic modulus of the mechanical parameters after calibration of the support area. Yield Strength Thermal expansion coefficient 7. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 6 is characterized in that: The strain analysis under the temperature effect in S3 specifically includes: S31, initialization of input data: input the temperature distribution data based on the three-dimensional temperature field model T(x, y, z, t) into the thermal-mechanical coupling model, introduce the calibrated mechanical parameters, including elastic modulus, yield strength and temperature expansion coefficient, define the geometric model Ω and boundary conditions of the support structure, including the force connection of the support fixed end, free end and adjacent bridge parts; S32, the thermal-mechanical coupling model uses the following coupled partial differential equations: Heat conduction equation: Balanced equation: Thermal stress calculation equation: Thermal expansion strain calculation: in, is the stress tensor, ε is the total strain tensor, and ε T is the strain tensor caused by thermal expansion, D is the elastic constant matrix, which is composed of the calibrated elastic modulus and Poisson's ratio ν, f is the body load, represents the temperature difference, I is the unit matrix; S33, numerical solution: N based on support area division x ×N y ×N z The unit grid is discretized by finite element, and the discretized thermal-mechanical coupling model equations are expressed as: [K T ]{T}={F T }; Among them, [K T ] is the heat transfer coefficient matrix, {T} is the discrete temperature field vector, {F T } is the heat source vector, is the material stiffness matrix, is the stress vector, is the external load vector; S34, calculation of strain data in the support area: by solving the thermal-mechanical coupling model equations, the stress of the mesh elements in the support area is obtained and the total strain ε i,j,k , separate the thermal expansion strain from the total strain and calculate the mechanical strain: ε mec j =ε-ε T , summarizing the mechanical strains of all mesh elements in the support region.

8. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 7 is characterized in that: The S4 specifically includes: S41, based on the calculation results of the thermal-mechanical coupling model, obtain the mechanical strain ε of each grid unit in the support structure mech , the mechanical strain is classified and the strain components in the horizontal direction (x, y) and vertical direction (z) of the support are separated and expressed as: x ,ε y ,ε z , where ε x ,ε y is the horizontal strain component, ε z is the vertical strain component; S42, calculate node displacement based on elastic mechanics model: use elastic mechanics relationship to convert mesh unit strain into node displacement, expressed as: {u} = [D] -1 {ε mecj }, where {u}=[u x ,u y ,u z ] T Represents the displacement vector of the node, including the horizontal displacement (u x ,u y ) and vertical displacement (u z ), represents the strain vector of the node, including normal strain and shear strain, [D] is the elastic constant matrix, which is composed of the calibrated elastic modulus and Poisson's ratio ν; S43, construction of the displacement field at the support position: sum up the displacement {u} of each grid node to construct the overall displacement field U(x,y,z) of the support area, which is in the form of: U(x,y,z)={u x (x,y,z),u y (x,y,z),u z (x,y,z)}, and extract the horizontal displacement (u) of the key position of the support from the displacement field. x ,u y ) and vertical displacement (u z ); S44, calculation of horizontal and vertical displacement of supports: Horizontal displacement: The horizontal displacement component u of the support area x ,u y Converted into horizontal displacement Δj, the calculation formula is: Vertical displacement: vertical displacement component u in the support area z That is the vertical deviation Δv: Δv = u z .

9. The method for analyzing the displacement of steel box girder bridge bearings considering temperature effect according to claim 1 is characterized in that: It also includes the setting of the deviation tolerance range. Based on the bridge design specifications and standards, the allowable range of bearing deviation is set. When the horizontal and vertical deviations exceed the range, an early warning is issued.

10. A steel box girder bridge bearing deviation analysis system considering temperature effect, used to implement a steel box girder bridge bearing deviation analysis method considering temperature effect as claimed in any one of claims 1 to 9, characterized in that: Includes the following modules: Temperature field data acquisition module: collects temperature field data of the support area in real time through the temperature sensor in the support area of ​​the bridge; Three-dimensional temperature field modeling module: based on the temperature field data, a three-dimensional temperature field model of the support area is constructed. The characteristics of the three-dimensional temperature field model include: horizontal temperature difference in the support area, vertical temperature difference in the support area, and non-uniform temperature distribution caused by temperature gradient. The model is used to describe the influence of temperature change on the support position and deformation; Mechanical parameter calibration module: Based on the mechanical property data of the support material and combined with the three-dimensional temperature field model, the actual mechanical properties of the material under temperature change conditions are obtained, the elastic modulus, yield strength, and temperature expansion coefficient of the steel are calibrated, and the nonlinear response of the steel box girder and the support under temperature change is corrected to ensure that the mechanical behavior of the material accurately reflects the influence of the temperature field; Strain analysis and displacement calculation module: combining the three-dimensional temperature field model and the calibrated mechanical parameters, the strain of the support area is calculated through the thermal-mechanical coupling model, and then the displacement of the support is calculated through the elastic mechanics model according to the strain result to obtain the horizontal and vertical displacement of the support; Displacement warning module: Based on the displacement data of the bearing, it is compared with the design standards and specifications to evaluate whether the displacement of the bearing exceeds the allowable range. If the displacement exceeds the preset threshold, an alarm is issued.

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