Finite element analysis-based lateral bearing capacity calculation method for large steel pipe support frame structure

Abstract

The invention discloses a method for calculating lateral bearing capacity of a large steel pipe supporting frame structure based on finite element analysis, and relates to the technical field of bearing capacity analysis. The method includes the following steps that geometric parameters and material parameters of the steel pipe supporting frame are collected, and a geometric structure model and a finite element analysis model are established; by applying an initial lateral load, calculating the horizontal slip amount, the shear stress and the local maximum pressure stress of the connecting part to obtain a slip effect contribution index; representing a local buckling effect contribution index in combination with geometrical characteristics and material characteristic parameters; collecting parameters such as environment temperature and wind speed, and calculating an environment effect contribution index; and correcting the initial lateral load by combining the three contribution indexes to obtain an accurate lateral bearing capacity value. According to the method, the slip effect, local buckling and environmental factors are comprehensively considered, the calculation precision and applicability are improved, and a scientific basis is provided for design and safety evaluation of the steel pipe supporting frame.

Description

Technical Field

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

[0002] As an important component of large-scale structural engineering, steel tube supports are widely used in bridge construction, tunnel engineering, high-rise buildings and other fields. Their structural safety and bearing performance directly affect the stability and reliability of the overall project. However, traditional methods for calculating the bearing capacity of steel tube supports are usually based on simplified theoretical models. These methods ignore the influence of various complex factors in actual engineering, resulting in insufficient calculation accuracy. For example, the lateral bearing capacity of steel tube supports depends not only on its geometry and material properties, but also on 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 fully reflect the complex mechanical behavior in actual working conditions. This deviation between theory and practice may lead to overly conservative design or insufficient risk assessment, thus affecting the economy and safety of the structure.

[0003] In addition, the node connection part of the steel tube support frame is usually the weak link in mechanical properties, and its slip, shear stress and local compressive stress have an important influence on the bearing capacity of the overall structure. Existing methods often use simplified assumptions when dealing with the nonlinear behavior of these connection components, 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 tube support frame also has a significant impact on the lateral bearing capacity, especially in the case of thin wall thickness or large aspect ratio, local buckling may significantly reduce the 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 bearing capacity calculation results 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 frame, but also needs to comprehensively consider the slip effect of the connecting parts, the local buckling effect, and the influence of complex environmental parameters such as ambient temperature and wind speed, so as to improve the accuracy and reliability of the bearing capacity calculation.

[0005] In the prior art, the publication number CN114169206B discloses a finite element calculation method for the residual bearing capacity of a steel-concrete composite beam, which includes: S1, establishing a finite element model of a steel-concrete composite beam, merging the studs with the top surface of the steel beam; S2, calculating the constitutive parameters of the finite element model of the steel-concrete composite beam after the fatigue load is subjected to a set number of times, and updating the material properties therein; S3, taking the upper limit of the fatigue load as the static load, defining the analysis step, and submitting the analysis; S4, judging whether the steel-concrete composite beam has fatigue failure according to the fatigue failure criterion of the composite beam, if the steel-concrete composite beam has not fatigue failure, then obtaining the load-displacement curve by displacement loading control, and outputting the residual bearing capacity value of the steel-concrete composite beam at this time, and increasing the number of loading times, repeating steps S2-S3 until the steel-concrete composite beam has fatigue failure; simplifying the fatigue loading process and improving the calculation efficiency. However, the fatigue performance and residual bearing capacity in this method are significantly affected by environmental factors (such as temperature, humidity, corrosion, etc.), and the method does not mention the consideration of these factors. For example, the fatigue performance of concrete may decrease with increasing temperature, and fatigue damage of steel may be accelerated due to corrosion. If these factors are ignored, the calculation results may have large errors, thus reducing the accuracy and effectiveness of the bearing capacity analysis.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

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

[0008] To achieve the above object, the present invention provides the following technical solutions: A method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis, the specific steps comprising: Collecting geometric parameters of the steel pipe support frame to be analyzed, establishing a geometric structure model of the steel pipe support frame to be analyzed based on the acquired geometric parameters of the steel pipe support frame to be analyzed, collecting material characteristic parameters of the steel pipe support frame to be analyzed, and constructing a finite element analysis model of the steel pipe support frame to be analyzed based on the acquired material characteristic parameters and the geometric structure model of the steel pipe support frame to be analyzed; By establishing a finite element analysis model of the steel pipe support frame to be analyzed, the force characteristic parameters of the connection components of the steel pipe support frame to be analyzed are analyzed under the condition of applying the initial rated lateral load, and the slip effect contribution index is calculated based on the force characteristic parameters of the connection components. The force characteristic parameters of the connection components include horizontal slip, shear stress on the contact surface, and local maximum compressive stress; The local buckling effect contribution index is characterized by combining the geometric parameters of the steel pipe support frame to be analyzed with the material characteristic parameters of the steel pipe support frame to be analyzed, wherein the geometric parameters of the steel pipe support frame to be analyzed include the wall thickness, length and outer diameter of the steel pipe of the support frame, and the material characteristic parameters of the steel pipe support frame to be analyzed include the elastic modulus and Poisson's ratio of the steel pipe of the support frame; The environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the environmental effect contribution index is calculated based on the environmental parameters. 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, which is used as the lateral bearing capacity of the steel pipe support frame structure to be analyzed. The environmental parameters include ambient temperature and ambient wind speed.

[0009] Furthermore, the method for establishing the geometric structure model of the steel pipe support frame to be analyzed is: establishing a geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed, specifically, obtaining the connection position of the steel pipe of the support frame and the total height and width of the support frame according to the known design data, and combining the geometric parameters of the support frame including the wall thickness, length and outer diameter of the steel pipe of the support frame, as well as the number of steel pipes of the support frame and the spacing between them, to complete the establishment of the geometric model, and the specific steps include: drawing the geometric shape of each steel pipe according to the size and design requirements; modeling the connection parts between the steel pipes; adjusting the position, angle and connection method of the components; Based on the material characteristic parameters of the steel pipe support frame to be analyzed, the physical properties of the material in the geometric model are set, and a finite element analysis model of the steel pipe support frame to be analyzed is constructed. In the established finite element analysis model, a unified grid division is performed at the connection parts of the support frame steel pipe, and each grid has the same size and shape for force analysis.

[0010] Furthermore, the slip effect contribution index is calculated based on the force characteristic parameters of the connection component, wherein the slip effect contribution index is calculated based on the formula: ; In the formula, is the slip effect contribution index, is the maximum horizontal slip of all the connecting parts in the support frame, is the maximum shear stress in the contact surface of all connecting parts in the support frame, is the critical value of shear stress of the connection part, where the critical value of shear stress of the connection part is obtained by correcting the initial shear strength of the connection part by the contact area and friction coefficient between the connection part and the steel pipe, and the formula for calculating the critical value of shear stress of the connection part is: ; In the formula, is the initial shear strength of the connection, is the friction coefficient between the connecting parts and the steel pipe, is the contact area between the connecting component and the steel pipe, The contact area threshold is set.

[0011] Furthermore, the local buckling effect contribution index is characterized by combining the geometric parameters of the steel tube support frame to be analyzed with the material characteristic parameters of the steel tube support frame to be analyzed, wherein the specific formula for calculating the local buckling effect contribution index is: ; In the formula, is the contribution index of the local buckling effect, is the Poisson’s ratio of the steel pipe, is the outer diameter of the steel pipe, is the wall thickness of the steel pipe, is the elastic modulus of the steel pipe, is the local maximum compressive stress, is the critical buckling stress.

[0012] Furthermore, the critical buckling stress Based on the plate and shell theory calculation, the formula for calculating the critical buckling stress is: ; In the formula, is the buckling coefficient.

[0013] Furthermore, the environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the environmental effect contribution index is calculated based on the environmental parameters, wherein the formula for calculating the environmental effect contribution index is: ; In the formula, Contribution index for environmental effects, is the wind pressure, is the drag coefficient, is the maximum effective frontal area, is the working environment temperature of the steel pipe support frame, is the standard temperature, where the maximum effective windward area The calculation is based on the formula: ; In the formula, is the lateral area of ​​the steel pipe support frame, which is specifically represented by the product of the height and width of the steel pipe support frame. is the wind direction angle; Among them, wind pressure The calculation is based on wind speed, and the specific calculation formula is: ; In the formula, is the air density, It is the maximum wind speed in the working environment of the steel pipe support frame.

[0014] Furthermore, 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 precise value of the rated lateral load, wherein the formula for calculating the precise value of the rated lateral load is: ; In the formula, is the exact value of the rated lateral load, is the initial rated lateral load, , and are the weight coefficients of the slip effect contribution index, local buckling effect contribution index and environmental effect contribution index, respectively, where: and , and Both are greater than 0.

[0015] Compared with the prior art, the present invention has the following beneficial effects: First, the present invention simulates the mechanical properties of the node connection components in detail by establishing the geometric structure model and material property model of the steel pipe support frame with the help of finite element analysis, and quantifies the contribution of the slip effect to the lateral bearing capacity. By introducing the slip effect contribution index, the slip amount, shear stress and local maximum compressive stress of the node connection part are accurately evaluated, thereby avoiding the calculation error caused by ignoring the node slip effect in the traditional method. Secondly, the influence of the local buckling effect on the bearing capacity is accurately characterized by combining the geometric parameters and material properties of the steel pipe support frame. Through a comprehensive analysis of geometric parameters such as structural wall thickness, length and outer diameter, and material properties such as 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 of the steel pipe support frame in actual engineering 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 ignoring environmental factors in the traditional calculation method can be corrected to ensure that the calculation results are closer to the actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0018] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] Example: See also Figure 1 , the present invention provides a technical solution: A method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis, the specific steps comprising: Step 1: Collect the geometric parameters of the steel pipe support frame to be analyzed, establish the geometric structure model of the steel pipe support frame to be analyzed based on the acquired geometric parameters of the steel pipe support frame to be analyzed, collect the material characteristic parameters of the steel pipe support frame to be analyzed, and construct the finite element analysis model of the steel pipe support frame to be analyzed based on the obtained material characteristic parameters and the geometric structure model of the steel pipe support frame to be analyzed.

[0020] The method for establishing the geometric structure model of the steel pipe support frame to be analyzed is: establishing the geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed, specifically, obtaining the connection position of the support frame steel pipe and the total height and width of the support frame according to the known design data, and combining the support frame geometric parameters 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 size and design requirements; modeling the connection parts between the steel pipes; adjusting the position, angle and connection method of the components; Based on the material characteristic parameters of the steel pipe support frame to be analyzed, the physical properties of the material in the geometric model are set, and a finite element analysis model of the steel pipe support frame to be analyzed is constructed. In the established finite element analysis model, a unified grid division is performed at the connection parts of the support frame steel pipe, and each grid has the same size and shape for force analysis.

[0021] Determine the geometric dimensions of the steel pipe support frame, including the diameter, wall thickness, length of the steel pipe, and the connection method between the steel pipes (welding, bolts, buckles, etc.); clarify the components of the support frame (such as main beams, diagonal braces, cross beams, etc.) and the location of the connection points; use CAD software (such as SolidWorks, AutoCAD or CATIA) to build a three-dimensional geometric model to ensure that the dimensions are accurate and consistent with 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 whether there are duplicate faces, isolated edges or geometric defects.

[0022] The connecting parts of the steel pipe (welding area or bolt connection area) need to be finely meshed, and the size and shape of each mesh unit should be as consistent as possible. Select a suitable mesh size, usually 1 / 10 of the local minimum feature size; in stress concentration areas such as connection nodes, mesh encryption is performed to improve analysis accuracy; in areas far away 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 meshing tools 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 meshing control parameters, including unit size, unit type, and mesh growth rate.

[0023] 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.

[0024] The initial rated lateral load is the maximum lateral bearing capacity obtained by testing under ideal conditions.

[0025] 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: ; In the formula, is the slip effect contribution index, is the maximum horizontal slip of all the connecting parts in the support frame, is the maximum shear stress in the contact surface of all connecting parts in the support frame, is the critical value of shear stress of the connection component.

[0026] It should be noted that the slip effect contribution index 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. 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.

[0027] 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 contribution index of the slip effect are The larger the value, the more unstable the support frame is. It characterizes the proportional relationship and can avoid numerical anomalies when the slip is too large, while ensuring the physical rationality of the formula within the range of small slip.

[0028] The maximum shear stress in the contact surface of all connecting parts in the support frame The shear stress reflects the ability of the connection parts to resist shearing and is an important factor in determining the bearing capacity of the support frame. When the shear stress is small, the stress state of the connection parts is relatively stable, and the weakening effect on the structural bearing capacity is small. When the shear stress approaches or exceeds the critical value When the load state of the connecting parts deteriorates sharply, local failure may occur, which significantly reduces the bearing capacity of the support frame. Therefore, the maximum shear stress on the contact surface of all connecting parts in the support frame is Slip effect contribution index The larger the value, the more unstable the support frame is. Represents proportional relationship, exponential function The setting reflects the nonlinear aggravation of the shear stress on the slip effect. near , the value of the exponential function increases rapidly, indicating that the weakening effect of shear stress on bearing capacity is significantly enhanced.

[0029] Among them, the maximum horizontal slip of all connecting parts in the support frame is and are the maximum shear stresses on the contact surfaces of all connected components in the support frame The established finite element analysis model is subjected to finite element analysis, and each connecting component is analyzed according to the divided grid to obtain the maximum value.

[0030] The critical value of shear stress of the connection part is obtained by correcting the initial shear strength of the connection part by the contact area and friction coefficient between the connection part and the steel pipe. The formula for calculating the critical value of shear stress of the connection part is: ; In the formula, is the initial shear strength of the connection, is the friction coefficient between the connecting parts and the steel pipe, is the contact area between the connecting component and the steel pipe, The contact area threshold is set.

[0031] When the friction coefficient When the friction between the contact surfaces increases, the friction force can resist the slippage of the connection parts, thereby improving the shear strength. Therefore, the friction coefficient between the connection parts and the steel pipe and Proportional, through exponential form The formula emphasizes the nonlinear enhancement effect of friction coefficient on shear strength, that is, the effect of friction coefficient on shear strength is not uniform, but changes with As the speed increases, the friction effect increases through the square root form. The introduction of friction reflects that the effect of friction on shear strength is limited, rather than increasing infinitely. This treatment method makes the growth of friction enhancement effect gradually tend to be gentle, which is in line with actual engineering phenomena.

[0032] The larger the contact area, the higher the shear stress that the connection component can withstand. This is because the increase in 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 contact area has limited effect on improving the shear strength. This may be due to the uneven contact surface or the contact area is not enough to evenly distribute the load. Therefore, the contact area between the connection component and the steel pipe is and Proportional to the contact area threshold It is used to distinguish between effective contact area and ineffective contact area. Only the contact area exceeding the threshold will significantly enhance the shear strength. Indicates a proportional relationship.

[0033] The friction coefficient It is a material property between the connection part and the contact surface of the steel pipe, which reflects the friction 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 = 0.15 to 0.45 (depending on the surface finish and lubrication conditions); the friction coefficient reference data commonly used in engineering can be found in relevant design manuals, such as the Mechanical Design Manual or the Material Mechanics Standard Database. The contact area threshold set It can be set according to the actual force-bearing area and combined with expert experience.

[0034] Step 3: Characterize the local buckling effect contribution index by combining the geometric parameters of the steel tube support frame to be analyzed with the material characteristic parameters of the steel tube support frame to be analyzed, wherein the geometric parameters of the steel tube support frame to be analyzed include the wall thickness, length and outer diameter of the support frame steel tube, and the material characteristic parameters of the steel tube support frame to be analyzed include the elastic modulus and Poisson's ratio of the support frame steel tube.

[0035] The local buckling effect contribution index is characterized by combining the geometric parameters of the steel tube support frame to be analyzed with the material characteristic parameters of the steel tube support frame to be analyzed. The specific formula for calculating the local buckling effect contribution index is: ; In the formula, is the contribution index of the local buckling effect, is the Poisson’s ratio of the steel pipe, is the outer diameter of the steel pipe, is the wall thickness of the steel pipe, is the elastic modulus of the steel pipe, is the local maximum compressive stress, is the critical buckling stress.

[0036] Where, the local buckling effect contribution index is It is used 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. The local buckling effect contribution index The larger it is, the greater the possibility of local buckling effect, the more serious the local buckling effect, and the greater the weakening of bearing capacity.

[0037] The first part of the formula is of the form It is directly derived from the buckling theory of thin-walled circular tubes, especially from the critical conditions for local buckling of shell structures in elastic mechanics. Specifically, a larger outer diameter makes the shell of the steel tube more likely to buckle due to local stress concentration, so the square of the outer diameter of the steel tube It is proportional to the contribution index of the local buckling effect. The increase in wall thickness enhances the ability of the steel pipe to resist local buckling. The contribution index of the local buckling effect is proportional to the cube of the wall thickness. Inversely proportional to; elastic modulus The higher the value, the greater the stiffness of the material, and the less likely the structure is to buckle. The contribution index of the local buckling effect is Inversely proportional; Poisson's ratio It reflects the relationship between the transverse deformation and longitudinal deformation of the material, and its influence is consider.

[0038] It represents the maximum compressive stress value borne by the steel tube support frame in a specific area. Local stress concentration is the main driving factor leading to local buckling, especially when the steel tube is subjected to uneven lateral loads or has an irregular geometry.

[0039] When local compressive stress Approaching or exceeding the critical buckling stress When the local buckling possibility of the steel pipe increases significantly, the impact on the overall structural performance is also more significant. Therefore, the local buckling effect contribution index is related to the local compressive stress. The local buckling is a highly nonlinear phenomenon, and its influence is very large in the critical state (i.e. ) will increase significantly near. Through the exponential function The closer the local compressive stress is to the critical buckling stress, the more significant the influence of local buckling effect on the overall performance becomes.

[0040] The local maximum compressive stress is obtained through the above-mentioned finite element analysis.

[0041] The critical buckling stress Based on the plate and shell theory calculation, the formula for calculating the critical buckling stress is: ; In the formula, is the buckling coefficient. It is generally between 0.5 and 2.0 and can be corrected based on analysis of different materials.

[0042] 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 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 steel pipe support frame structure to be analyzed. The environmental parameters include ambient temperature and ambient wind speed.

[0043] The environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the environmental effect contribution index is calculated based on the environmental parameters. The formula for calculating the environmental effect contribution index is: ; In the formula, Contribution index for environmental effects, is the wind pressure, is the drag coefficient, is the maximum effective frontal area, is the working environment temperature of the steel pipe support frame, is the standard temperature.

[0044] Among them, the environmental effect contribution index The bearing capacity of the support frame is analyzed by comprehensive wind load and temperature, and the environmental effect contribution index The larger it is, the greater the external environmental load is, and the greater the effect of weakening the bearing capacity of the support frame is.

[0045] The greater the wind pressure and the maximum effective windward area, the greater the wind load. Therefore, the environmental effect contribution index is proportional to the wind pressure and the maximum effective windward area.

[0046] The higher the temperature, the greater the impact on the strength and stiffness of the support frame steel pipe. The higher the temperature, the smaller the strength and stiffness of the support frame steel pipe, 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.

[0047] The standard temperature Usually 25 The resistance coefficient can be set by referring to relevant materials and combining with the specific working environment, and the general range is between 0.1 and 0.5.

[0048] The maximum effective windward area The calculation is based on the formula: ; In the formula, is the lateral area of ​​the steel pipe support frame, which is specifically represented by the product of the height and width of the steel pipe support frame. is the wind direction angle; Among them, wind pressure The calculation is based on wind speed, and the specific calculation formula is: ; In the formula, is the air density, It is the maximum wind speed in the working environment of the steel pipe support frame.

[0049] 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 precise value of the rated lateral load. The formula for calculating the precise value of the rated lateral load is: ; In the formula, is the exact value of the rated lateral load, is the initial rated lateral load, , and are the weight coefficients of the slip effect contribution index, local buckling effect contribution index and environmental effect contribution index, respectively, where: and , and Both are greater than 0.

[0050] Since the above parameters are used to illustrate the exact values ​​of the rated lateral load , so they are not elaborated here.

[0051] Among them, the slip effect contribution index, local buckling effect contribution index and environmental effect contribution index are inversely proportional to the exact value of the rated lateral load. The larger the slip effect contribution index, the more likely it is to cause the support frame to become unstable, leading to safety issues. The local buckling effect contribution index indirectly represents the deformation effect of the support frame. Compared with the environmental effect contribution index, it is only an additional load of the environment, which has a greater impact on the lateral bearing capacity. Therefore, and , and Both are greater than 0.

[0052] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0053] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0054] 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, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0055] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis, characterized in that: The specific steps include: Collecting geometric parameters of the steel pipe support frame to be analyzed, establishing a geometric structure model of the steel pipe support frame to be analyzed based on the acquired geometric parameters of the steel pipe support frame to be analyzed, collecting material characteristic parameters of the steel pipe support frame to be analyzed, and constructing a finite element analysis model of the steel pipe support frame to be analyzed based on the acquired material characteristic parameters and the geometric structure model of the steel pipe support frame to be analyzed; By establishing a finite element analysis model of the steel pipe support frame to be analyzed, the force characteristic parameters of the connection components of the steel pipe support frame to be analyzed are analyzed under the condition of applying the initial rated lateral load, and the slip effect contribution index is calculated based on the force characteristic parameters of the connection components. The force characteristic parameters of the connection components include horizontal slip, shear stress on the contact surface, and local maximum compressive stress; The local buckling effect contribution index is characterized by combining the geometric parameters of the steel pipe support frame to be analyzed with the material characteristic parameters of the steel pipe support frame to be analyzed, wherein the geometric parameters of the steel pipe support frame to be analyzed include the wall thickness, length and outer diameter of the steel pipe of the support frame, and the material characteristic parameters of the steel pipe support frame to be analyzed include the elastic modulus and Poisson's ratio of the steel pipe of the support frame; The environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the environmental effect contribution index is calculated based on the environmental parameters. 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, which is used as the lateral bearing capacity of the steel pipe support frame structure to be analyzed. The environmental parameters include ambient temperature and ambient wind speed.

2. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 1 is characterized in that: The method for establishing the geometric structure model of the steel pipe support frame to be analyzed is: establishing the geometric model according to the determined geometric parameters of the steel pipe support frame to be analyzed, specifically, obtaining the connection position of the support frame steel pipe and the total height and width of the support frame according to the known design data, and combining the support frame geometric parameters 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 size and design requirements; modeling the connection parts between the steel pipes; adjusting the position, angle and connection method of the components; Based on the material characteristic parameters of the steel pipe support frame to be analyzed, the physical properties of the material in the geometric model are set, and a finite element analysis model of the steel pipe support frame to be analyzed is constructed. In the established finite element analysis model, a unified grid division is performed at the connection parts of the support frame steel pipe, and each grid has the same size and shape for force analysis.

3. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 2 is characterized in that: 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: ； In the formula, is the slip effect contribution index, is the maximum horizontal slip of all the connecting parts in the support frame, is the maximum shear stress in the contact surface of all connecting parts in the support frame, is the critical value of shear stress of the connection part, where the critical value of shear stress of the connection part is obtained by correcting the initial shear strength of the connection part by the contact area and friction coefficient between the connection part and the steel pipe, and the formula for calculating the critical value of shear stress of the connection part is: ； In the formula, is the initial shear strength of the connection component, is the friction coefficient between the connecting parts and the steel pipe, is the contact area between the connecting component and the steel pipe, The contact area threshold is set.

4. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 3 is characterized in that: The local buckling effect contribution index is characterized by combining the geometric parameters of the steel tube support frame to be analyzed with the material characteristic parameters of the steel tube support frame to be analyzed. The specific formula for calculating the local buckling effect contribution index is: ； In the formula, is the contribution index of the local buckling effect, is the Poisson’s ratio of the steel pipe, is the outer diameter of the steel pipe, is the wall thickness of the steel pipe, is the elastic modulus of the steel pipe, is the local maximum compressive stress, is the critical buckling stress.

5. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 4 is characterized in that: The critical buckling stress Based on the plate and shell theory calculation, the formula for calculating the critical buckling stress is: ； In the formula, is the buckling coefficient.

6. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 4 is characterized in that: The environmental parameters of the working environment of the steel pipe support frame to be analyzed are collected, and the environmental effect contribution index is calculated based on the environmental parameters. The formula for calculating the environmental effect contribution index is: ； In the formula, Contribution index for environmental effects, is the wind pressure, is the drag coefficient, is the maximum effective frontal area, is the working environment temperature of the steel pipe support frame, is the standard temperature, where the maximum effective windward area The calculation is based on the formula: ； In the formula, is the lateral area of ​​the steel pipe support frame, which is specifically represented by the product of the height and width of the steel pipe support frame. is the wind direction angle; Among them, wind pressure The calculation is based on wind speed, and the specific calculation formula is: ； In the formula, is the air density, It is the maximum wind speed in the working environment of the steel pipe support frame.

7. The method for calculating the lateral bearing capacity of a large steel pipe support frame structure based on finite element analysis according to claim 6 is 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 precise value of the rated lateral load. The formula for calculating the precise value of the rated lateral load is: ； In the formula, is the exact value of the rated lateral load, is the initial rated lateral load, , and are the weight coefficients of the slip effect contribution index, local buckling effect contribution index and environmental effect contribution index, respectively, where: and , and Both are greater than 0.

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