A method and system for calculating the bearing capacity of a steel tube angle steel combined tower cross arm node

Abstract

The present application belongs to the technical field of steel pipe angle steel combined tower, and provides a steel pipe angle steel combined tower cross arm node bearing capacity calculation method and system. The method comprises obtaining main pipe related parameters and calculating the main pipe axial pressure ratio; determining the steel pipe angle steel combined node failure mode based on the main pipe axial pressure ratio; determining the node plate geometric size according to the steel pipe angle steel combined node failure mode, and calculating the plate internal force distribution ratio parameter; checking the node plate bearing capacity based on the effective width method, and then calculating the ultimate bearing capacity of each combined node under the cross arm tension working condition according to the node plate bearing capacity and the node plate internal force distribution ratio parameter; and adjusting the amplitude of the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the node finite element analysis result, and obtaining the combined node bearing capacity after the amplitude adjustment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel pipe angle steel composite tower, and particularly relates to a steel pipe angle steel composite tower cross arm node bearing capacity calculation method and system. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The power transmission tower line system has the structural characteristics of high-rise, large-span and high flexibility, which puts higher requirements on the structural performance and structural design of the power transmission tower, and the structure of the node part becomes more complex. These nodes are the key parts to ensure the safety and reliability of the power transmission tower structure and have a great influence on the overall stability and load transfer performance of the structure. Among them, the narrow base tower in the crowded corridor fully utilizes the unique advantages of steel pipe and angle steel materials. The cross arm is made of angle steel, and the main material of the tower body is made of steel pipe structure. The connecting node is stressed and the value is large. To avoid local buckling of the steel pipe main material at the node, reinforcing plates, stiffening rings and other measures need to be added, and the reinforcing plates and stiffening rings need to meet their respective bearing capacity requirements.

[0004] The inventor found that the existing technology is a design and calculation method for the bearing capacity of K-type steel pipe welded nodes, and these existing methods are not applicable to the design of the bearing capacity of steel pipe angle steel composite nodes with complex structure and many plate parts. SUMMARY

[0005] To solve the technical problems in the background art, the present application provides a steel pipe angle steel composite tower cross arm node bearing capacity calculation method and system, which comprehensively considers the influence of the main pipe, horizontal node plate, vertical node plate and end ring plate to obtain the tensile bearing capacity of the composite node cross arm.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] The first aspect of the present application provides a steel pipe angle steel composite tower cross arm node bearing capacity calculation method.

[0008] A steel pipe angle steel composite tower cross arm node bearing capacity calculation method, comprising:

[0009] Obtaining the main pipe related parameters and calculating the main pipe axial pressure ratio;

[0010] Determining the steel pipe angle steel composite node failure mode based on the main pipe axial pressure ratio;

[0011] According to the steel pipe angle steel composite node failure mode, the node plate geometric size is determined, and the internal force distribution ratio parameters of each plate part are calculated;

[0012] The node plate bearing capacity is calculated based on the effective width method, and then the ultimate bearing capacity of each combined node under the cross arm tension working condition is calculated according to the node plate bearing capacity and the node plate internal force distribution ratio parameter.

[0013] The ultimate bearing capacity of each combined node under the cross arm tension working condition is adjusted based on the node finite element analysis result, and the combined node bearing capacity is obtained after the adjustment.

[0014] As an implementation form, the main pipe related parameters include the main pipe transmission axial force, the main pipe sectional area and the main pipe steel yield strength.

[0015] As an implementation form, the steel pipe angle steel combined node failure mode includes a horizontal node plate failure mode, a vertical node plate failure mode and a main pipe buckling failure mode.

[0016] As an implementation form, the calculation formula of the internal force distribution ratio parameter of each plate member is:

[0017]

[0018] Wherein, ψ (x, y) is the internal force distribution ratio parameter of each plate member, x is the thickness of the horizontal ring plate on the cross arm side of the combined node, y is the thickness of the vertical ring plate on the cross arm side of the combined node, and p1-p7 are fitting function coefficients.

[0019] As an implementation form, the expression of the node plate bearing capacity is: u =b e *t*f u ;

[0020] In the formula, N u is the ultimate tensile bearing capacity of the node plate; b e is the effective width; t is the thickness of the node plate; and f u is the tensile strength of the node plate steel.

[0021] As an implementation form, the combined node bearing capacity P obtained after the adjustment is:

[0022] P=k*min (P1, P2)

[0023] Wherein, P1 is the overall ultimate bearing capacity of the combined node calculated by the horizontal plate internal force distribution ratio and the bearing capacity; P2 is the overall ultimate bearing capacity of the combined node calculated by the vertical plate internal force distribution ratio and the bearing capacity; and k is a constant coefficient.

[0024] The second aspect of the application provides a steel pipe angle steel combined tower cross arm node bearing capacity calculation system.

[0025] A steel pipe angle steel combined tower cross arm node bearing capacity calculation system comprises:

[0026] A main pipe axial pressure ratio calculation module is configured to obtain main pipe related parameters and calculate a main pipe axial pressure ratio.

[0027] A failure mode determination module is configured to determine a steel pipe angle steel composite joint failure mode based on the main pipe axial pressure ratio.

[0028] An internal force distribution ratio parameter calculation module is configured to determine joint plate geometric dimensions according to the steel pipe angle steel composite joint failure mode and calculate internal force distribution ratio parameters of each plate.

[0029] A limit bearing capacity calculation module is configured to check joint plate bearing capacity based on an effective width method, and then calculate limit bearing capacities of each composite joint under a cross arm tension working condition according to the joint plate bearing capacity and the internal force distribution ratio parameters of the joint plate.

[0030] A composite joint bearing capacity determination module is configured to adjust amplitudes of the limit bearing capacities of each composite joint under the cross arm tension working condition based on joint finite element analysis results, and obtain composite joint bearing capacities after the adjustment.

[0031] As an implementation form, the steel pipe angle steel composite joint failure mode includes a horizontal joint plate failure mode, a vertical joint plate failure mode and a main pipe buckling failure mode.

[0032] A third aspect of the present application provides a computer readable storage medium.

[0033] A computer readable storage medium has a computer program stored thereon, and the program is executed by a processor to implement the steps of the steel pipe angle steel composite tower cross arm joint bearing capacity calculation method.

[0034] A fourth aspect of the present application provides an electronic device.

[0035] An electronic device includes a memory, a processor and a computer program stored on the memory and executable on the processor, and the processor executes the program to implement the steps of the steel pipe angle steel composite tower cross arm joint bearing capacity calculation method.

[0036] Compared with the prior art, the present application has the following advantages:

[0037] (1) The application innovatively proposes a steel pipe angle steel combined node bearing capacity calculation method considering the contribution of the middle ring plate, comprehensively considers the influence of the main pipe, horizontal node plate, vertical node plate and end ring plate to obtain the combined node cross arm tensile bearing capacity, the application also clearly defines the proportion of the external force borne by each plate of the combined node, and gives a fitting formula considering the geometric size of the node plate, thereby guiding the transmission tower structure design; Since the steel pipe angle steel combined node bearing capacity calculation needs to consider many parameters, therefore, on the basis of test and theoretical analysis, finite element numerical simulation is adopted for parameterized analysis, and based on the test and finite element analysis results, the bearing capacity calculation method is finally obtained through fitting.

[0038] (2) The steel pipe angle steel combined node obtained by the calculation method of the application has high safety performance and low engineering cost; The application can be widely applied to the design of steel pipe angle steel combined nodes of transmission lines.

[0039] (3) The calculation method of the application well makes up for the blank of the existing specification on the bearing capacity calculation of the steel pipe angle steel combined node, and based on extensive test and numerical simulation, the node bearing capacity can be accurately calculated for various failure modes.

[0040] The advantages of the additional aspects of the application will be partially given in the following description, partially will become obvious from the following description, or will be known by the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0041] The drawings accompanying the specification of the application form part of the application and serve to provide further understanding of the application, the illustrative embodiments of the application and their description serve to explain the application, and do not constitute an improper limitation of the application.

[0042] Figure 1 It is a front view of the steel pipe angle steel combined node structure of the embodiment of the application.

[0043] Figure 2 It is a top view of the steel pipe angle steel combined node of the embodiment of the application.

[0044] Figure 3 It is a force diagram of the steel pipe angle steel combined node of the embodiment of the application.

[0045] Figure 4 It is a steel pipe angle steel combined tower cross arm node bearing capacity calculation method flow chart of the embodiment of the application.

[0046] In the figure: 1 main pipe, 2 vertical plate, 3 horizontal ring plate, 4 end ring plate, 5 cross arm angle steel, 6 cross arm angle steel. DETAILED DESCRIPTION

[0047] The application will be further described below in combination with the drawings and embodiments.

[0048] It should be noted that the following detailed description is illustrative only, and is intended to provide further description in connection with the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0049] It is also important to note that the terms "example" and "exemplary" as may be used herein mean "serving as an example, instance, or illustration," and should not necessarily be construed as preferred or advantageous over other examples. While the application has been illustrated by a description of examples, it is not the intention to restrict or in any way limit the scope of the application to such examples. Any numerical values recited herein include all values from the lower value to the upper value. Any numerical value, however, can be expressed with

[0050] Example One

[0051] As shown in Figure 1 and Figure 2 , D is the diameter of the main pipe 1, T is the thickness of the main pipe 1, B is the width of the horizontal ring plate 3, X is the thickness of the horizontal ring plate 3, Y is the thickness of the vertical plate 2, and θ is the inclination angle of the cross arm angle steel 6, which are basic size parameters required for node bearing capacity analysis and calculation. In Figure 1 , 5 is a cross bar angle steel.

[0052] As shown in Figure 4 , the embodiment provides a steel pipe angle steel combined tower cross arm node bearing capacity calculation method, which comprises:

[0053] Step 1: Obtain the main pipe related parameters, and calculate the main pipe axial compression ratio.

[0054] The main pipe axial compression ratio can be calculated by formula (1);

[0055]

[0056] Where F2 is the axial force transmitted by the main pipe, A e is the cross-sectional area of the main pipe, and f y is the yield strength of the main pipe steel.

[0057] Step 2: Determine the steel pipe angle steel combined node failure mode based on the main pipe axial compression ratio.

[0058] The failure modes can be divided into horizontal node plate failure, vertical node plate failure, main pipe buckling failure and other modes; when the axial compression ratio is greater than 0.85, the existence of the axial compression of the main pipe promotes the increase of the local deformation, and the strength of the ring plate-main pipe model decreases with the increase of the main pipe pressure, at this time the failure mode is the main pipe buckling; when the axial compression ratio of the main pipe is greater than 0.6 and less than 0.85, the main pipe pressure reduces the overall bearing capacity of the node, at this time the bearing capacity formula should be multiplied by a reduction coefficient of 0.8; when the axial compression ratio of the main pipe is less than 0.6, the influence of the main pipe pressure on the bearing capacity of the node is small, and the influence can be ignored.

[0059] Step 3: According to the failure mode of the steel pipe-angle steel combined node, the geometric size of the node plate is determined, and the internal force distribution ratio parameters of each plate are calculated.

[0060] The internal force distribution ratio parameters are calculated by formula (1):

[0061]

[0062] Wherein, ψ(x, y) is the internal force distribution ratio parameter of each plate, x is the thickness of the horizontal ring plate on the side of the combined node cross arm, y is the thickness of the vertical ring plate on the side of the combined node cross arm, p1-p7 are fitting function coefficients. The thickness difference between the two plates should not be too large, and the ratio value range is (0.6-1.5).

[0063] The value range of p1-p7 is shown in Table 1:

[0064] Table 1 Value of p1-p7

[0065]

[0066]

[0067] Step 4: The bearing capacity of the node plate is calculated based on the effective width method, and then the ultimate bearing capacity of each combined node under the cross arm tension working condition is calculated according to the bearing capacity of the node plate and the internal force distribution ratio parameter of the node plate.

[0068] The bearing capacity of the node plate N u is calculated by formula (3):

[0069] N u = b e *t*f u (3)

[0070] In the formula: N u is the ultimate tensile bearing capacity of the node plate; b e is the effective width; t is the thickness of the node plate; f u is the tensile strength of the node plate steel. The effective width b eThe method is to draw a straight line from the outside of the first row of bolted connectors at an angle of 30°, and the straight line width is obtained by intersecting the straight lines passing through the last row of bolt axes.

[0071] Based on the bearing capacity N of the node plate u and the internal force distribution ratio parameter ψ in the node plate, the ultimate bearing capacity of the combined node under the tension working condition of the cross arm is calculated.

[0072] The combined node bearing capacity formula is calculated according to formulas (4) and (5):

[0073]

[0074]

[0075] Wherein, P1 is the horizontal plate internal force distribution ratio and bearing capacity calculated combined node overall ultimate bearing capacity; P2 is the vertical plate internal force distribution ratio and bearing capacity calculated combined node overall ultimate bearing capacity.

[0076] Step 5: Based on the finite element analysis results of the node, the ultimate bearing capacity of each combined node under the tension working condition of the cross arm is adjusted, and the combined node bearing capacity is obtained after adjustment, as shown in formulas (4) and (5). Figure 2 and Figure 3 In Figure 3 , F2 is the axial pressure of the main pipe, and F3 is the load of the cross arm angle steel.

[0077] P=k×min(P1,P2) (6)

[0078] Wherein, P1 is the horizontal plate internal force distribution ratio and bearing capacity calculated combined node overall ultimate bearing capacity; P2 is the vertical plate internal force distribution ratio and bearing capacity calculated combined node overall ultimate bearing capacity; k is a constant, such as 0.85.

[0079] Taking a typical steel pipe angle steel combined node as an example, the basic size parameters are as follows:

[0080] The main pipe diameter D is 325mm, the main pipe thickness T is 7mm, the vertical plate thickness Y is 12-16mm, the horizontal plate width B is 160mm, the horizontal plate thickness X is 12-16mm, and the cross arm angle steel inclination angle θ is 21°. Because the node is a typical upper cross arm node, its stress working condition is that the cross arm angle steel is in tension, the cross arm angle steel is in tension, and the main pipe is in compression.

[0081] According to the calculation method of the embodiment, the axial compression ratio of the main pipe is analyzed first. Considering that the axial resultant force borne by the main pipe is 586kN, the axial compression ratio is 0.2, and the node failure mode can be determined as horizontal plate failure or vertical plate failure. When calculating, the node plate material is Q355, the yield strength is 355N / mm 2 , and the tensile strength is 500N / mm2 Due to the limitation of the horizontal plate geometry size, the effective width is taken as 185mm, and the effective width of the vertical plate is taken as 225mm. The calculation results are shown in Table 2, which shows that the bearing capacity calculation method of the steel pipe angle steel combined node described in the embodiment can accurately and effectively calculate the bearing capacity of the node, and the results have sufficient safety margin.

[0082] Table 2 node bearing capacity results comparison

[0083]

[0084]

[0085] In the table, P is the node bearing capacity calculated by the formula, F is the node bearing capacity obtained by finite element analysis, and a is the bearing capacity ratio.

[0086] Embodiment two

[0087] The embodiment provides a steel pipe angle steel combined tower cross arm node bearing capacity calculation system, which comprises:

[0088] The main pipe axial pressure ratio calculation module is used to obtain the main pipe related parameters and calculate the main pipe axial pressure ratio;

[0089] The failure mode determination module is used to determine the steel pipe angle steel combined node failure mode based on the main pipe axial pressure ratio;

[0090] The internal force distribution ratio parameter calculation module is used to determine the node plate geometry size according to the steel pipe angle steel combined node failure mode, and calculate the internal force distribution ratio parameters of each plate;

[0091] The ultimate bearing capacity calculation module is used to check the node plate bearing capacity based on the effective width method, and then calculate the ultimate bearing capacity of each combined node under the cross arm tension working condition according to the node plate bearing capacity and the node plate internal force distribution ratio parameters;

[0092] The combined node bearing capacity determination module is used to adjust the amplitude of the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the node finite element analysis results, and obtain the combined node bearing capacity after adjustment.

[0093] The steel pipe angle steel combined node failure mode includes a horizontal node plate failure mode, a vertical node plate failure mode and a main pipe buckling failure mode.

[0094] It should be noted that the specific implementation process of each module in the embodiment is the same as that of each step in embodiment one, which will not be repeated here.

[0095] Embodiment three

[0096] The embodiment provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize steps in the steel pipe angle steel combined tower cross arm node bearing capacity calculation method.

[0097] Embodiment four

[0098] The embodiment provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor realizes steps in the steel pipe angle steel combined tower cross arm node bearing capacity calculation method when executing the program.

[0099] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a machine for realizing the functions specified in the flowcharts and / or block diagrams. Figure 1 The function of one flow or multiple flows and / or blocks Figure 1 The function of one block or multiple blocks.

[0100] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for calculating the bearing capacity of a steel tube angle steel composite tower cross arm node, characterized in that, The method comprises the following steps: obtaining main pipe related parameters to calculate a main pipe axial pressure ratio; determining a steel pipe angle steel combined node failure mode based on the main pipe axial pressure ratio; determining node plate geometric dimensions according to the steel pipe angle steel combined node failure mode to calculate node plate internal force distribution ratio parameters; a calculation formula of the node plate internal force distribution ratio parameters is: wherein, is the internal force distribution ratio parameter of each plate, x is the thickness of the horizontal ring plate on the side of the crossbeam of the composite joint, y is the thickness of the vertical ring plate on the side of the crossbeam of the composite joint, and p1-p7 are fitting function coefficients. calculating the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the effective width method and according to the node plate bearing capacity and the node plate internal force distribution ratio parameters; a combined node bearing capacity formula is: wherein, N is the combined node overall ultimate bearing capacity calculated by the horizontal plate internal force distribution ratio and bearing capacity; N is the combined node overall ultimate bearing capacity calculated by the vertical plate internal force distribution ratio and bearing capacity, u N is the node plate tensile ultimate bearing capacity; amplifying the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the node finite element analysis result to obtain the combined node bearing capacity after amplification; Combined node bearing capacity after amplitude modulation Is: wherein are constant coefficients.

2. The method of claim 1, wherein the method is characterized by: the main pipe related parameters comprise main pipe axial force transmission, main pipe cross-sectional area and main pipe steel yield strength.

3. The method of claim 1, wherein the method is characterized by: the steel pipe angle steel combined node failure mode comprises a horizontal node plate failure mode, a vertical node plate failure mode and a main pipe buckling failure mode.

4. The method of claim 1, wherein the method is characterized by: The expression of the bearing capacity of the node plate is: ; In the formula: N u is the tensile ultimate bearing capacity of the node plate; is the effective width; t is the thickness of the node plate; f u is the tensile strength of the steel material of the node plate.

5. A steel tube angle steel combined tower cross arm node bearing capacity calculation system, characterized in that, The method comprises the following steps: a main pipe axial pressure ratio calculation module is configured to obtain main pipe related parameters to calculate a main pipe axial pressure ratio; a failure mode determination module is configured to determine a steel pipe angle steel combined node failure mode based on the main pipe axial pressure ratio; an internal force distribution ratio parameter calculation module is configured to determine node plate geometric dimensions according to the steel pipe angle steel combined node failure mode to calculate node plate internal force distribution ratio parameters; a calculation formula of the node plate internal force distribution ratio parameters is: wherein, is the internal force distribution ratio parameter of each plate, x is the thickness of the horizontal ring plate on the side of the crossbeam of the composite joint, y is the thickness of the vertical ring plate on the side of the crossbeam of the composite joint, p1-p7 are fitting function coefficients; an ultimate bearing capacity calculation module is configured to calculate the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the effective width method and according to the node plate bearing capacity and the node plate internal force distribution ratio parameters; a combined node bearing capacity formula is: wherein, N is the combined node overall ultimate bearing capacity calculated by the horizontal plate internal force distribution ratio and bearing capacity; N is the combined node overall ultimate bearing capacity calculated by the vertical plate internal force distribution ratio and bearing capacity, N u N is the node plate tensile ultimate bearing capacity; a combined node bearing capacity determination module is configured to amplify the ultimate bearing capacity of each combined node under the cross arm tension working condition based on the node finite element analysis result to obtain the combined node bearing capacity after amplification; Combined node bearing capacity after amplitude modulation Is: wherein are constant coefficients.

6. The system for calculating the load bearing capacity of a steel tube angle steel combined tower cross arm node according to claim 5, characterized in that, the steel pipe angle steel combined node failure mode comprises a horizontal node plate failure mode, a vertical node plate failure mode and a main pipe buckling failure mode.

7. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the steps in the steel pipe angle steel combined tower cross arm node bearing capacity calculation method in any one of claims 1-4.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the steps in the steel pipe angle steel combined tower cross arm node bearing capacity calculation method in any one of claims 1-4.

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