Calculation method for lateral bearing capacity of large steel pipe support frame structure based on finite element analysis

Abstract

The present invention discloses a calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis. The present invention relates to the technical field of bearing capacity analysis. The method includes the following steps: collecting the geometric parameters and material parameters of the steel pipe support frame, and establishing a geometric structure model and a finite element analysis model; by applying an initial lateral load, calculating the horizontal slip amount, shear stress and local maximum compressive stress of the connecting components to obtain the contribution index of the slip effect; combining the geometric characteristics and material characteristic parameters to characterize the contribution index of the local buckling effect; collecting parameters such as environmental temperature and wind speed, and calculating the contribution index of the environmental effect; comprehensively correcting the initial lateral load by the three types of contribution indexes to obtain an accurate lateral bearing capacity value. This method comprehensively considers the slip effect, local buckling and environmental factors, improves the calculation accuracy and applicability, and provides a scientific basis for the design and safety assessment of the steel pipe support frame.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing capacity analysis, and particularly to a method for calculating the lateral bearing capacity of a large steel pipe support structure based on finite element analysis. Background Technique

[0002] As an important part of large-scale structural engineering, steel pipe supports are widely used in fields such as bridge construction, tunnel engineering, and high-rise buildings. Their structural safety and load-bearing performance directly affect the stability and reliability of the overall project. However, traditional calculation methods for the bearing capacity of steel pipe supports are usually based on simplified theoretical models, which ignore the influence of various complex factors in actual projects, resulting in insufficient calculation accuracy. For example, the lateral bearing capacity of a steel pipe support not only depends on its geometric shape and material properties, but is also significantly affected by the slip effect of node connection components, local buckling effect, and environmental factors (such as temperature and wind load). However, traditional methods often only consider ideal boundary conditions and uniform load distribution, and fail to comprehensively reflect the complex mechanical behavior in actual working conditions. This deviation between theory and practice may lead to overly conservative designs or insufficient risk assessments, thus affecting the economy and safety of the structure.

[0003] In addition, the node connection part of the steel pipe support is usually a weak link in mechanical properties, and its slip amount, shear stress, and local compressive stress have an important impact on the bearing capacity of the overall structure. When dealing with the non-linear behavior of these connection components, existing methods often adopt simplified assumptions and it is difficult to accurately evaluate the contribution of slip to the overall performance of the structure. At the same time, the local buckling effect of the steel pipe support also has a significant impact on the lateral bearing capacity, especially in the case of a relatively thin wall thickness or a large height-to-diameter ratio, local buckling may significantly reduce the load-bearing capacity of the structure. Existing theoretical methods are difficult to comprehensively consider the combined effects of slip effect, local buckling effect, and environmental factors, resulting in a large deviation between the calculated bearing capacity and the actual situation.

[0004] In summary, the existing technology urgently needs a more comprehensive and accurate calculation method to solve the above problems. This method not only needs to consider the geometric parameters and material properties of the steel pipe support, but also needs to comprehensively consider the influence of slip effect of connection components, local buckling effect, and complex environmental parameters such as environmental temperature and wind speed, so as to improve the accuracy and reliability of bearing capacity calculation.

[0005] In the prior art, the patent with publication number CN114169206B discloses a finite element calculation method for the remaining bearing capacity of a steel-concrete composite beam. The method includes: S1. Establish a finite element model of the steel-concrete composite beam, and merge the stud with the top surface of the steel beam; S2. Calculate the constitutive parameters of the finite element model of the steel-concrete composite beam after it has withstood a set number of fatigue loads, and update the material properties therein; S3. Take the upper limit value of the fatigue load as the static load, define the analysis step, and submit the analysis; S4. Judge whether the steel-concrete composite beam has suffered fatigue failure according to the fatigue failure criterion of the composite beam. If the steel-concrete composite beam has not suffered fatigue failure, obtain the load-displacement curve by displacement loading control, and output the remaining bearing capacity value of the steel-concrete composite beam at this time, and increase the number of loading times, and repeat steps S2-S3 until the steel-concrete composite beam suffers fatigue failure; simplify the fatigue loading process to improve the calculation efficiency. However, the fatigue performance and the remaining bearing capacity in this method are significantly affected by environmental factors (such as temperature, humidity, corrosion, etc.), and this method does not mention the consideration of these factors. For example, the fatigue performance of concrete may decrease with the increase of temperature, and steel may also accelerate fatigue damage due to corrosion. If these factors are ignored, there may be large errors in the calculation results. Therefore, the accuracy and effectiveness of the bearing capacity analysis are reduced.

[0006] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure, and thus it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0007] The purpose of the present invention is to provide a calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis to solve the problems raised in the above background art.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis, the specific steps include:

[0010] Collect the geometric parameters of the steel pipe support to be analyzed, and based on the obtained geometric parameters of the steel pipe support to be analyzed, establish a geometric structure model of the steel pipe support to be analyzed. Collect the material characteristic parameters of the steel pipe support to be analyzed, and according to the obtained material characteristic parameters, combine with the geometric structure model of the steel pipe support to be analyzed to construct a finite element analysis model of the steel pipe support to be analyzed;

[0011] By establishing a finite element analysis model of the steel pipe support frame to be analyzed, analyze the mechanical characteristic parameters of the connection components of the steel pipe support frame to be analyzed under the condition of applying the initial rated lateral load, and calculate the slip effect contribution index based on the mechanical characteristic parameters of the connection components. The mechanical characteristic parameters of the connection components include the horizontal slip amount, the shear stress on the contact surface, and the local maximum compressive stress;

[0012] Characterize the local buckling effect contribution index through the geometric parameters of the steel pipe support frame to be analyzed, combined with the material characteristic parameters of the steel pipe support frame to be analyzed. The geometric parameters of the steel pipe support frame to be analyzed include the wall thickness, length, and outer diameter of the support frame steel pipe, and the material characteristic parameters of the steel pipe support frame to be analyzed include the elastic modulus and Poisson's ratio of the support frame steel pipe;

[0013] Collect the environmental parameters of the working environment of the steel pipe support frame to be analyzed, calculate the environmental effect contribution index based on the environmental parameters, and correct the initial rated lateral load according to the obtained environmental effect contribution index, combined with the slip effect contribution index and the local buckling effect contribution index, to obtain the accurate value of the rated lateral load, which is used as the lateral bearing capacity of the structure of the steel pipe support frame to be analyzed. The environmental parameters include the environmental temperature and the environmental wind speed.

[0014] Furthermore, the method for establishing the geometric structure model of the steel pipe support frame to be analyzed is as follows: establish a geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed. Specifically, according to the known design data, obtain the connection positions of the support frame steel pipes, the total height and width of the support frame, and combine the geometric parameters of the support frame, including the wall thickness, length, and outer diameter of the support frame steel pipe, as well as the number of support frame steel pipes and the spacing between them, to complete the establishment of the geometric model. The specific steps include: drawing the geometric shape of each steel pipe according to the dimensions and design requirements; modeling the connection parts between the steel pipes; adjusting the positions, angles, and connection methods of the components;

[0015] Based on the material characteristic parameters of the steel pipe support frame to be analyzed, set the physical properties of the materials in the geometric model, construct a finite element analysis model of the steel pipe support frame to be analyzed, and perform uniform mesh division at the locations of the connection components of the support frame steel pipes in the established finite element analysis model. Each mesh has the same size and shape for stress analysis.

[0016] Furthermore, calculate the slip effect contribution index based on the mechanical characteristic parameters of the connection components. The formula for calculating the slip effect contribution index is as follows:

[0017]

[0018] In the formula, F slip is the slip effect contribution index, δ maxis the maximum horizontal sliding displacement among all the connecting components in the support frame, τ is the maximum shear stress on the contact surfaces of all the connecting components in the support frame, τ max is the critical value of the shear stress of the connecting component, where the critical value of the shear stress of the connecting component is obtained by correcting the shear strength of the initial connecting component through the contact area and friction coefficient between the connecting component and the steel pipe. The formula based on which the critical value of the shear stress of the connecting component is calculated is:

[0019]

[0020] In the formula, τ0 is the shear strength of the initial connecting component, μ is the friction coefficient between the connecting component and the steel pipe, A is the contact area between the connecting component and the steel pipe, A YZ is the set threshold of the contact area.

[0021] Furthermore, through the geometric parameters of the steel pipe support frame to be analyzed and in combination with the material characteristic parameters of the steel pipe support frame to be analyzed, the contribution index of the local buckling effect is characterized. The specific formula based on which the contribution index of the local buckling effect is calculated is:

[0022]

[0023] In the formula, F buck is the contribution index of the local buckling effect, v is the Poisson's ratio of the steel pipe, R is the outer diameter of the steel pipe, t is the wall thickness of the steel pipe, E is the elastic modulus of the steel pipe, σ loc is the local maximum compressive stress, σ crit is the critical buckling stress.

[0024] Furthermore, the critical buckling stress σ crit is calculated based on the plate and shell theory. The formula based on which the critical buckling stress is specifically calculated is:

[0025]

[0026] In the formula, k b is the buckling coefficient.

[0027] Furthermore, the environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the contribution index of the environmental effect is calculated based on the environmental parameters. The formula based on which the contribution index of the environmental effect is calculated is:

[0028]

[0029] In the formula, HJ is the contribution index of the environmental effect, P wind is the wind pressure, C d is the drag coefficient, A eff is the maximum effective windward area, T is the working environment temperature of the steel pipe support frame, T0 is the standard temperature, where the maximum effective windward area Aeff The formula for calculation is as follows:

[0030] A eff = A max *cosθ

[0031] In the formula, A max is the lateral area of the steel pipe support frame, specifically characterized by the product of the height and width of the steel pipe support frame, and θ is the wind direction angle;

[0032] Among them, the wind pressure P wind is calculated based on the wind speed. The specific calculation formula is as follows:

[0033]

[0034] In the formula, ρ is the air density, and V max is the maximum wind speed in the working environment of the steel pipe support frame.

[0035] Furthermore, based on the obtained environmental effect contribution index, combined with the slip effect contribution index and the local buckling effect contribution index, the initial rated lateral load is corrected to obtain the accurate value of the rated lateral load. The formula for calculating the accurate value of the rated lateral load is as follows:

[0036]

[0037] In the formula, ZH′ is the accurate value of the rated lateral load, ZH0 is the initial rated lateral load, ω1, ω2, and ω3 are the weight coefficients of the slip effect contribution index, the local buckling effect contribution index, and the environmental effect contribution index respectively. Among them, ω1 > ω2 > ω3 and ω1, ω2, and ω3 are all greater than 0.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] First, the present invention establishes a geometric structure model and a material property model of the steel pipe support frame, and details the mechanical characteristics of the node connection components by means of finite element analysis, quantifying the contribution of the slip effect to the lateral bearing capacity. By introducing the slip effect contribution index, the influence of the slip amount, shear stress, and local maximum compressive stress at the node connection part is accurately evaluated, thus avoiding the calculation errors caused by neglecting the node slip effect in the traditional method. Secondly, in combination with the geometric parameters and material properties of the steel pipe support frame, the influence of the local buckling effect on the bearing capacity is accurately characterized. Through a comprehensive analysis of geometric parameters such as the wall thickness, length, and outer diameter of the structure, as well as material properties such as the elastic modulus and Poisson's ratio, the weakening effect of local buckling on the overall bearing performance is effectively predicted, thereby further improving the accuracy of the calculation results. In addition, the influence of the working environment in which the steel pipe support frame is located in the actual project on its bearing performance is also comprehensively considered. By collecting environmental parameters such as ambient temperature and wind speed and calculating the environmental effect contribution index, the errors caused by neglecting environmental factors in the traditional calculation method can be corrected, ensuring that the calculation results are closer to the actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

[0042] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those with ordinary skills in the field to which the present invention belongs. The "first", "second", and similar terms used in the present invention do not indicate any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0043] Embodiment:

[0044] Please refer to Figure 1 , the present invention provides a technical solution:

[0045] A method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis, the specific steps including:

[0046] Step 1: Collect the geometric parameters of the steel pipe support frame to be analyzed. Based on the obtained geometric parameters of the steel pipe support frame to be analyzed, establish a geometric structure model of the steel pipe support frame to be analyzed. Collect the material characteristic parameters of the steel pipe support frame to be analyzed. According to the obtained material characteristic parameters and combined with the geometric structure model of the steel pipe support frame to be analyzed, construct a finite element analysis model of the steel pipe support frame to be analyzed.

[0047] The method for establishing the geometric structure model of the steel pipe support frame to be analyzed is as follows: Establish a geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed. Specifically, according to the known design data, obtain the connection positions of the support frame steel pipes, the total height and width of the support frame, and combine the geometric parameters of the support frame, including the wall thickness, length, and outer diameter of the support frame steel pipes, as well as the number of support frame steel pipes and the spacing between them, to complete the establishment of the geometric model. The specific steps include: Draw the geometric shape of each steel pipe according to the dimensions and design requirements; Model the connection parts between the steel pipes; Adjust the position, angle, and connection method of the components.

[0048] Based on the material characteristic parameters of the steel pipe support frame to be analyzed, set the physical properties of the materials in the geometric model, and construct a finite element analysis model of the steel pipe support frame to be analyzed. In the established finite element analysis model, perform a unified mesh division on the locations of the connection components of the support frame steel pipes. Each mesh has the same size and shape and is used for stress analysis.

[0049] Determine the geometric dimensions of the steel pipe support frame, including the diameter, wall thickness, and length of the steel pipes, as well as the connection methods between the steel pipes (such as welding, bolts, snap fasteners, etc.); clarify the components of the support frame (such as main beams, diagonal braces, cross beams, etc.) and the positions of the connection points; Use CAD software (such as SolidWorks, AutoCAD, or CATIA) to construct a three-dimensional geometric model to ensure that the dimensions are accurate and conform to the design drawings; Import the constructed geometric model into finite element software (such as ANSYS, ABAQUS, COMSOL, or HyperMesh). Ensure that the imported model is correct and check for duplicate faces, isolated edges, or geometric defects.

[0050] The connection components of the steel pipes (welding areas or bolt connection areas) need to be finely meshed. The size and shape of each mesh element should be as consistent as possible. Select an appropriate mesh size. Usually, the mesh size is 1 / 10 of the local minimum characteristic size; In areas with stress concentration such as connection nodes, perform mesh refinement to improve the analysis accuracy; In areas far from the connection parts (such as the middle section of the steel pipe), the mesh density can be appropriately reduced to save computing resources. Specifically, the mesh division tool of the finite element software (such as the Meshing module of ANSYS, the mesh generator of ABAQUS, etc.) can be used to automatically or manually divide the mesh, and set unified mesh division control parameters, including element size, element type, and mesh growth rate.

[0051] Step 2: By establishing a finite element analysis model of the steel tube support frame to be analyzed, the force characteristic parameters of the connecting components of the steel tube support frame to be analyzed are analyzed when the initial rated lateral load is applied, and the slip effect contribution index is calculated based on the force characteristic parameters of the connecting components. The force characteristic parameters of the connecting components include the horizontal slip amount, the shear stress on the contact surface, and the local maximum compressive stress.

[0052] The initial rated lateral load is the maximum lateral bearing capacity obtained by testing under ideal conditions.

[0053] The slip effect contribution index is calculated based on the force characteristic parameters of the connection parts, where the slip effect contribution index is calculated based on the formula:

[0054]

[0055] In the formula, F slip is the slip effect contribution index, δ max is the maximum horizontal slip of all the connecting parts in the support frame, τ is the maximum shear stress on the contact surface of all the connecting parts in the support frame, and τ max is the critical value of shear stress of the connection component.

[0056] It should be noted that the slip effect contribution index F slip The influence of connection component sliding on bearing capacity is characterized by combining the maximum horizontal slip of the connection component and the maximum shear stress on the contact surface of the connection component. slip The larger the value is, the more serious the sliding of the connecting parts is, the greater the shear stress is, and the greater the possibility of instability is. Therefore, the larger the sliding effect contribution index is, the more dangerous the support frame is. Therefore, the sliding effect contribution index is inversely proportional to the lateral bearing capacity.

[0057] In the support frame, the slip of the connecting parts will significantly affect the stiffness, stability and force distribution of the overall structure. The slip effect is the phenomenon that the connecting parts produce relative movement after the structure is loaded. This phenomenon directly affects the bearing capacity of the structure. When the connecting parts slip, the overall stiffness of the support frame structure decreases, and the bearing capacity decreases accordingly. Excessive slip or contact surface shear stress exceeding the limit value may cause the connection parts to be damaged, thereby reducing the bearing capacity of the structure. Therefore, the horizontal slip of the connecting parts and the slip effect contribution index F slip The larger the value, the more unstable the support frame is. max ) represents the proportional relationship and can avoid numerical anomalies when the slip is too large, while ensuring the physical rationality of the formula within the small slip range.

[0058] The maximum shear stress τ on the contact surfaces of all connecting components within the support frame reflects the ability of the connecting components to resist shear forces and is an important factor determining the bearing capacity of the support frame. When the shear stress is small, the stress state of the connecting components is relatively stable, and the weakening effect on the structural bearing capacity is small. When the shear stress approaches or exceeds the critical value τ max the stress state of the connecting components deteriorates sharply, and local failure may occur, significantly reducing the bearing capacity of the support frame. Therefore, the maximum shear stress τ on the contact surfaces of all connecting components within the support frame is proportional to the slip effect contribution index F slip The larger its value, the more unstable the support frame. The proportional relationship is characterized by an exponential function The exponential function is set to reflect the non-linear exacerbating effect of shear stress on the slip effect. When the shear stress τ within the support frame approaches τ max the value of the exponential function increases rapidly, indicating a significant enhancement of the weakening effect of shear stress on the bearing capacity.

[0059] Among them, the maximum horizontal slip δ max of all connecting components within the support frame and the maximum shear stress τ on the contact surfaces of all connecting components within the support frame are obtained through finite element analysis of the established finite element analysis model. Each connecting component is analyzed according to the divided grid to obtain the maximum value.

[0060] The critical shear stress value of the connecting component is obtained by correcting the initial shear strength of the connecting component through the contact area and friction coefficient between the connecting component and the steel pipe. The formula based on which the critical shear stress value of the connecting component is calculated is:

[0061]

[0062] In the formula, τ0 is the initial shear strength of the connecting component, μ is the friction coefficient between the connecting component and the steel pipe, A is the contact area between the connecting component and the steel pipe, and A YZ is the set contact area threshold.

[0063] When the friction coefficient μ increases, the frictional force between the contact surfaces increases accordingly. The frictional force can resist the slip of the connecting component, thereby enhancing the shear strength. Therefore, the friction coefficient μ between the connecting component and the steel pipe is proportional to τ max The exponential form e μ is used to emphasize the non-linear enhancement effect of the friction coefficient on the shear strength, that is, the influence of the friction coefficient on the shear strength is not uniform, but accelerates with the increase of μ. The friction effect is introduced in the form of a square root to reflect that the influence of the frictional force on the shear strength is limited and does not increase infinitely. This treatment makes the growth of the friction enhancement effect gradually flatten out, which is in line with the actual engineering phenomenon.

[0064] The larger the contact area, the higher the shear stress that the connecting component can withstand. This is because the increase in the contact area can disperse the shear load, thereby reducing the stress per unit area of the contact surface. When the contact area is less than a certain threshold, the effect of the contact area on enhancing the shear strength is limited. This may be due to the uneven contact surface or the insufficient contact area to evenly distribute the load. Therefore, the contact area A between the connecting component and the steel pipe and τ max are in direct proportion. The set contact area threshold A YZ is used to distinguish the effective contact area and the ineffective contact area. Only the part of the contact area exceeding the threshold will significantly enhance the shear strength. Therefore, the proportional relationship is expressed by (A - A YZ ).

[0065] Among them, the friction coefficient μ is a material property between the contact surfaces of the connecting component and the steel pipe, reflecting the magnitude of the frictional resistance between the two under relative sliding or shear force. The determination of the friction coefficient usually considers the following factors and methods: The friction coefficient between steel and steel has a certain range, usually μ = 0.15 to 0.45 (depending on the surface finish and lubrication conditions); The reference data of the friction coefficient commonly used in engineering can be consulted from relevant design manuals, such as "Mechanical Design Manual" or the material mechanics standard database. The set contact area threshold A YZ can be set according to the actual stress area in combination with expert experience.

[0066] Step 3: Characterize the contribution index of the local buckling effect through the geometric parameters of the steel pipe support frame to be analyzed, in combination with the material characteristic parameters of the steel pipe support frame to be analyzed, where the geometric parameters of the steel pipe support frame to be analyzed include the wall thickness, length, and outer diameter of the support frame steel pipe, and the material characteristic parameters of the steel pipe support frame to be analyzed include the elastic modulus and Poisson's ratio of the support frame steel pipe.

[0067] Characterize the contribution index of the local buckling effect through the geometric parameters of the steel pipe support frame to be analyzed, in combination with the material characteristic parameters of the steel pipe support frame to be analyzed, where the specific formula based on which the contribution index of the local buckling effect is calculated is:

[0068]

[0069] In the formula, F buck is the contribution index of the local buckling effect, v is the Poisson's ratio of the steel pipe, R is the outer diameter of the steel pipe, t is the wall thickness of the steel pipe, E is the elastic modulus of the steel pipe, σ loc is the local maximum compressive stress, and σ crit is the critical buckling stress.

[0070] In the formula, the contribution index of the local buckling effect F buckUsed to characterize the local buckling effect of the steel pipe of the support frame, that is, the importance of the local buckling on the overall performance of the steel pipe support frame, where the local buckling effect contribution index F buck The larger it is, the greater the possibility of the occurrence of the local buckling effect, the more serious the local buckling effect generated, and the greater the reduction in bearing capacity.

[0071] The form of the first part in the formula Directly comes from the buckling theory of thin-walled circular pipes, especially derived according to the critical conditions of local buckling of shell structures in elasticity mechanics. Specifically, the larger outer diameter makes the shell of the steel pipe more likely to buckle due to local stress concentration. Therefore, the square of the outer diameter of the steel pipe R 2 Is proportional to the local buckling effect contribution index; the increase in wall thickness enhances the ability of the steel pipe to resist local buckling, and the local buckling effect contribution index is inversely proportional to the cube of the wall thickness t 3 Is inversely proportional; the higher the elastic modulus E, the greater the stiffness of the material, and the less likely the structure is to buckle. The local buckling effect contribution index is inversely proportional to E; the Poisson's ratio v reflects the relationship between the lateral deformation and the longitudinal deformation of the material, and its influence is considered through (1 - v 2 )

[0072] σ loc Represents the maximum compressive stress value borne by the steel pipe support frame in a specific area. Local stress concentration is the main driving factor leading to local buckling, especially in the case where the steel pipe is unevenly loaded laterally or has an irregular geometry.

[0073] When the local compressive stress σ loc Is close to or exceeds the critical buckling stress σ crit , the possibility of local buckling of the steel pipe increases significantly, and the impact on the overall structural performance is also more significant. Therefore, the local buckling effect contribution index is proportional to the local compressive stress σ loc . Local buckling is a highly non-linear phenomenon, and its influence will increase significantly near the critical state (i.e., σ loc ≈σ crit ). The exponential function Describes that the closer the local compressive stress is to the critical buckling stress, the more significant the influence of the local buckling effect on the overall performance becomes.

[0074] Among them, the local maximum compressive stress is obtained through the above-mentioned finite element analysis.

[0075] The critical buckling stress σ crit Is calculated based on the plate and shell theory, and the formula based on which the critical buckling stress is specifically calculated is:

[0076]

[0077] In the formula, k bis the buckling coefficient. Among them, the buckling coefficient k b is generally between 0.5 and 2.0, and can be analyzed and corrected according to different materials.

[0078] Step 4: Collect the environmental parameters of the working environment of the steel pipe support frame to be analyzed, calculate the environmental effect contribution index based on the environmental parameters, and according to the obtained environmental effect contribution index, combined with the slip effect contribution index and the local buckling effect contribution index, correct the initial rated lateral load to obtain the accurate value of the rated lateral load, which is used as the lateral bearing capacity of the steel pipe support frame structure to be analyzed. The environmental parameters include environmental temperature and environmental wind speed.

[0079] Collect the environmental parameters of the working environment of the steel pipe support frame to be analyzed, and calculate the environmental effect contribution index based on the environmental parameters. The formula for calculating the environmental effect contribution index is:

[0080]

[0081] In the formula, HJ is the environmental effect contribution index, P wind is the wind pressure, C d is the drag coefficient, A eff is the maximum effective windward area, T is the working environment temperature of the steel pipe support frame, and T0 is the standard temperature.

[0082] Among them, the environmental effect contribution index HJ analyzes the bearing capacity of the support frame through the combined wind load and temperature. The larger the environmental effect contribution index HJ, the greater the external environmental load and the stronger the weakening effect on the bearing capacity of the support frame.

[0083] Among them, the larger the wind pressure and the maximum effective windward area, the greater the wind load borne, so the environmental effect contribution index is proportional to the wind pressure and the maximum effective windward area.

[0084] The higher the temperature, the greater the impact on the strength and stiffness of the steel pipe of the support frame. The higher the temperature, the smaller the strength and stiffness of the steel pipe of the support frame, so the bearing capacity of the support frame decreases. Therefore, the environmental effect contribution index is proportional to the working environment temperature of the steel pipe support frame.

[0085] Among them, the standard temperature T0 is generally 25°C. The drag coefficient can be set by referring to relevant materials and combined with the specific working environment, and the general range is between 0.1 and 0.5.

[0086] Among them, the maximum effective windward area A eff The formula for calculation is:

[0087] A eff = A max *cosθ

[0088] In the formula, Amax is the lateral area of the steel pipe support frame, specifically characterized by the product of the height and width of the steel pipe support frame, and θ is the wind direction angle;

[0089] Among them, the wind pressure P wind is calculated based on the wind speed, and the specific calculation formula is:

[0090]

[0091] In the formula, ρ is the air density, and V max is the maximum wind speed in the working environment of the steel pipe support frame.

[0092] According to the obtained environmental effect contribution index, combined with the slip effect contribution index and the local buckling effect contribution index, the initial rated lateral load is corrected to obtain the accurate value of the rated lateral load. The formula for calculating the accurate value of the rated lateral load is:

[0093]

[0094] In the formula, ZH′ is the accurate value of the rated lateral load, ZH0 is the initial rated lateral load, and ω1, ω2, and ω3 are the weight coefficients of the slip effect contribution index, the local buckling effect contribution index, and the environmental effect contribution index respectively. Among them, ω1 > ω2 > ω3 and ω1, ω2, and ω3 are all greater than 0.

[0095] Since the above is to illustrate the correlation between each parameter and the accurate value ZH′ of the rated lateral load, it will not be elaborated here.

[0096] Among them, the slip effect contribution index, the local buckling effect contribution index, and the environmental effect contribution index are all inversely proportional to the accurate value of the rated lateral load. Since the larger the slip effect contribution index, it may lead to the instability of the support frame and cause safety problems, while the local buckling effect contribution index indirectly represents the deformation effect of the support frame. Comparing with the environmental effect contribution index, it is only an additional load of the environment and has a greater impact on the lateral bearing capacity. Therefore, ω1 > ω2 > ω3 and ω1, ω2, and ω3 are all greater than 0.

[0097] The above formulas are all dimensionless and take their numerical values for calculation. The formula is obtained by collecting a large amount of data for software simulation to get a formula closest to the real situation. The preset parameters in the formula are set by technicians in this field according to the actual situation.

[0098] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the examples described in connection with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0099] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units. They may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] As described above, the above is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and all of them should be covered by the protection scope of the present application.

Claims

1. A calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis, characterized in that, The specific steps include: Collect the geometric parameters of the steel pipe support frame to be analyzed. Based on the obtained geometric parameters of the steel pipe support frame to be analyzed, establish a geometric structure model of the steel pipe support frame to be analyzed. Collect the material characteristic parameters of the steel pipe support frame to be analyzed. According to the obtained material characteristic parameters and in combination with the geometric structure model of the steel pipe support frame to be analyzed, construct a finite element analysis model of the steel pipe support frame to be analyzed. The method for establishing the geometric structure model of the steel pipe support frame to be analyzed is as follows: Establish a geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed. Specifically, based on the known design data, obtain the connection positions of the support frame steel pipes, the total height and width of the support frame, and in combination with the geometric parameters of the support frame, including the wall thickness, length, and outer diameter of the support frame steel pipes, as well as the number of support frame steel pipes and the spacing between them, complete the establishment of the geometric model. The specific steps include: Draw the geometric shape of each steel pipe according to the dimensions and design requirements; Model the connection parts between the steel pipes; Adjust the position, angle, and connection method of the components. Based on the material characteristic parameters of the steel pipe support frame to be analyzed, set the physical properties of the materials in the geometric model and construct a finite element analysis model of the steel pipe support frame to be analyzed. In the established finite element analysis model, perform a unified mesh division at the locations of the connection components of the support frame steel pipes. Each mesh has the same size and shape and is used for stress analysis. Through the established finite element analysis model of the steel pipe support frame to be analyzed, analyze the stress characteristic parameters of the connection components of the steel pipe support frame to be analyzed under the condition of applying the initial rated lateral load. Based on the stress characteristic parameters of the connection components, calculate the slip effect contribution index. The stress characteristic parameters of the connection components include the horizontal slip amount, the shear stress on the contact surface, and the local maximum compressive stress. Among them, the formula for calculating the slip effect contribution index is: Where, F slip is the contribution index of the slip effect, δ max is the maximum horizontal slip in all connecting components within the support frame, τ is the maximum shear stress on the contact surfaces of all connecting components within the support frame, τ max is the critical shear stress value of the connecting component, where the critical shear stress value of the connecting component is obtained by correcting the initial shear strength of the connecting component through the contact area and friction coefficient between the connecting component and the steel pipe. The formula based on which the critical shear stress value of the connecting component is calculated is: where τ0 is the shear strength of the initial connection component, μ is the friction coefficient between the connection component and the steel pipe, A is the contact area between the connection component and the steel pipe, and A YZ is the set contact area threshold value; Characterize the local buckling effect contribution index through the geometric parameters of the steel pipe support frame to be analyzed in combination with the material characteristic parameters of the steel pipe support frame to be analyzed. Among them, the geometric parameters of the steel pipe support frame to be analyzed include the wall thickness, length, and outer diameter of the support frame steel pipes, and the material characteristic parameters of the steel pipe support frame to be analyzed include the elastic modulus and Poisson's ratio of the support frame steel pipes. Collect the environmental parameters of the working environment of the steel pipe support frame to be analyzed. Calculate the environmental effect contribution index based on the environmental parameters. According to the obtained environmental effect contribution index, in combination with the slip effect contribution index and the local buckling effect contribution index, correct the initial rated lateral load to obtain the accurate value of the rated lateral load, and use this as the lateral bearing capacity of the structure of the steel pipe support frame to be analyzed. The environmental parameters include the environmental temperature and the environmental wind speed.

2. The lateral bearing capacity calculation method of a large steel pipe support structure based on finite element analysis according to claim 1, characterized in that: Characterize the local buckling effect contribution index through the geometric parameters of the steel pipe support frame to be analyzed in combination with the material characteristic parameters of the steel pipe support frame to be analyzed. Among them, the specific formula for calculating the local buckling effect contribution index is: Where, F buck is the contribution index of local buckling effect, v is the Poisson's ratio of the steel pipe, R is the outer diameter of the steel pipe, t is the wall thickness of the steel pipe, E is the elastic modulus of the steel pipe, σ loc is the local maximum compressive stress, and σ crit is the critical buckling stress.

3. The lateral bearing capacity calculation method of a large steel pipe support structure based on finite element analysis according to claim 2, characterized in that: The critical buckling stress σ crit is calculated based on the plate and shell theory, and the formula for calculating the critical buckling stress specifically is as follows: where k b is the buckling coefficient.

4. A calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis according to claim 2, characterized in that: Collect the environmental parameters of the working environment of the steel pipe support frame to be analyzed. Calculate the environmental effect contribution index based on the environmental parameters. Among them, the formula for calculating the environmental effect contribution index is: In the formula, HJ is the environmental effect contribution index, P wind is the wind pressure, C d is the drag coefficient, A eff is the maximum effective windward area, T is the working environmental temperature of the steel pipe support frame, T0 is the standard temperature, where the maximum effective windward area A eff The formula for calculation is as follows: A eff = A max * cosθ Where A max is the side area of the steel pipe support frame, specifically characterized by the product of the height and width of the steel pipe support frame, and θ is the wind direction angle; Among them, the wind pressure P wind is calculated based on the wind speed, and the specific calculation formula is as follows: where ρ is the air density and V max is the maximum wind speed in the working environment of the steel pipe support frame.

5. A calculation method for the lateral bearing capacity of a large steel pipe support structure based on finite element analysis according to claim 4, characterized in that: According to the obtained environmental effect contribution index, combined with the slip effect contribution index and the local buckling effect contribution index, the initial rated lateral load is corrected to obtain the accurate value of the rated lateral load. The formula based on which the accurate value of the rated lateral load is calculated is as follows: In the formula, ZH′ is the accurate value of the rated lateral load, ZH0 is the initial rated lateral load, ω1, ω2, and ω3 are the weight coefficients of the slip effect contribution index, the local buckling effect contribution index, and the environmental effect contribution index respectively. Among them, ω1 > ω2 > ω3 and ω1, ω2, and ω3 are all greater than 0.

Images