CN112115625A - Calculation method for extra-high voltage power transmission tower true test data node main pipe bearing capacity - Google Patents
Calculation method for extra-high voltage power transmission tower true test data node main pipe bearing capacity Download PDFInfo
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- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
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- E—FIXED CONSTRUCTIONS
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- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
- E04H12/02—Structures made of specified materials
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Abstract
The invention discloses a method for calculating the bearing capacity of a data node main pipe of an extra-high voltage power transmission tower true test, which comprises the following steps: carrying out a K-type node bearing capacity test on a test component of the steel pipe-inserting plate, and determining main factors influencing the K-type node bearing capacity; establishing an influence model of each factor on the bearing capacity of the K-type node; fitting finite element results in each influence model, and establishing a suggested model for calculating the bearing capacity of the K-type node; substituting various factor parameters of the K-type node connected by the steel pipe-inserting plate to be evaluated into the proposed model to obtain the ultimate main pipe bearing capacity value of the K-type node connected by the steel pipe-inserting plate. The invention obtains the bearing capacity calculation model of the K-shaped node with (or without) annular reinforcing plate steel pipe-inserting plate connection by utilizing the energy principle, reflects the mutual relation among the main pipe axial force, the main pipe wall bending moment and the shearing force, can accurately evaluate the ultimate bearing capacity of the K-shaped node, and has small deviation with the test result.
Description
Technical Field
The invention relates to the field of power transmission towers, in particular to a method for calculating the bearing capacity of a true test data node main pipe of an extra-high voltage power transmission tower.
Background
The steel pipe tower adopting the pipe-connection node has the problem of local buckling of the steel pipe, the influence of the local buckling is reduced by adding the annular reinforcing plate in the actual power transmission iron tower, and China has no corresponding design checking method. The phenomenon of local buckling of the steel pipe is observed in a prototype test of a 1000kV alternating current same-tower double-circuit transmission line tower research project SZT2 tower, which is commonly born by China institute of Electrical science and Chinese consultant group company in 2008, and the research work of the test of the local buckling of the steel pipe and the connection node of the plugboard is also preliminarily carried out in the early stage of the China institute of Electrical science and Electrical science.
For the connection node of the plug board, although scholars at home and abroad do certain research work on the limit bearing capacity, the related test data and theoretical analysis data are still scarce in general, and the specifications of various countries do not make detailed description and regulation on the limit bearing capacity of the node. The pipe node in the special structure of the power transmission tower is relatively special in form, in actual engineering, in order to improve the safety reserve of design, a plurality of construction measures are often added to the node, and no certain theoretical and experimental basis exists at present on how to consider the beneficial effects of the construction measures. Therefore, a calculation method capable of accurately analyzing the bearing capacity of the K-type node connected by the steel pipe and the plug board on the power transmission tower is needed.
Disclosure of Invention
Aiming at the problems, the invention provides a method for calculating the main pipe bearing capacity of the extra-high voltage power transmission tower true type test data node, which obtains a bearing capacity calculation model of the K type node with (or without) annular reinforcing plate steel pipe-inserting plate connection by utilizing an energy principle, reflects the mutual relation among the main pipe axial force, the main pipe wall bending moment and the shearing force, can accurately evaluate the ultimate bearing capacity of the K type node, and has small deviation with a test result.
The technical scheme of the invention is as follows:
a method for calculating the bearing capacity of a true test data node main pipe of an extra-high voltage power transmission tower comprises the following steps:
s1, carrying out a K-type node bearing capacity test on the test component of the steel pipe-inserting plate, and determining main factors influencing the K-type node bearing capacity;
s2, establishing an influence model of each factor on the bearing capacity of the K-type node;
s3, fitting finite element results in the influence models, and establishing a suggested model for calculating the bearing capacity of the K-type node;
and S4, substituting the parameters of each factor of the K-shaped node connected by the steel pipe and the inserting plate to be evaluated into the proposed model to obtain the numerical value of the ultimate main pipe bearing capacity of the K-shaped node connected by the steel pipe and the inserting plate.
In a further technical solution, in step S1, the method for performing the K-type node bearing capacity test is as follows:
s11, setting control variable parameters of the test component;
s12, placing the bottom of the test member on a base steel hinge, and connecting the end parts of the other rod pieces to a jack;
s13, strain gauges are respectively arranged at the joint of the gusset plate and the steel pipe and on the ring plate;
s14, pressing down a jack connected with the main pipe, pressing down an upper jack connected with the branch pipe, and pulling down a lower jack connected with the branch pipe to perform step-by-step synchronous loading;
s15, when the main pipe axial force N/Ny is less than 0.2, stopping loading the main pipe, and continuing loading the jack connected with the branch pipe until the node is damaged;
s16, changing the value of the control parameter, repeating the steps S12-S15 to obtain load-displacement and load-strain curves, comprehensively evaluating the obtained load-displacement and load-strain curves, and obtaining the ultimate bearing capacity of the K-type node;
and S17, analyzing and determining main factors influencing the bearing capacity of the K-type node according to the test results obtained on the load-displacement and load-strain curves.
In a further aspect, in step S11, the controlled variable parameters of the test member include: the pipe diameter D of the main pipe, the wall thickness t of the main pipe, the height B of the gusset plate, the height R of the reinforced ring plate and the thickness t of the reinforced ring platerAnd gusset thickness T.
In a further technical solution, in step S17, the determined main factors affecting the bearing capacity of the K-type node include: gusset plate height and main pipeThe diameter ratio B/D, the ratio D/t of the main pipe diameter to the main pipe wall thickness, the ratio R/D of the reinforcement ring plate height to the main pipe diameter, the reinforcement ring plate thickness to the main pipe wall thickness trT and the angle theta between the branch pipe and the main pipe.
In a further technical scheme, in step S14, the included angle between the pressure branch pipe and the main pipe is 45 °, and the included angle between the tension branch pipe and the main pipe is 50 °.
In a further technical scheme, in the step S14, in the step-by-step loading process, initial values of tension and pressure of the branch pipes are 40kN, the first 10 loading steps are carried out, the load increment of each step is 40kN, the 11 th to 20 th loading steps are carried out, the load increment of each step is 20kN, the 21 st to 30 th loading steps are carried out, the load increment of each step is 5kN, and after the 30 th loading step, tension and pressure are generated at constant load until the main pipe or the ring plate yields, and loading is stopped; the initial value of the main pipe pressure is 20kN, the first 10 loading steps are carried out, the load increment of each stage is 10kN, the 11 th to 20 th loading steps are carried out, the load increment of each stage is 5kN, and the loading is stopped in the 20 th loading step.
In a further technical scheme, in step S3, in the process of establishing a proposed model for calculating the bearing capacity of the K-type node, a least square method is adopted to fit a finite element result.
In a further technical solution, in step S3, the proposed model of the K-type node bearing capacity of the connection between the steel pipe and the insert plate without the reinforcing plate is established as follows: mw,u＝{0.26(D/t)0.6+1.15(B/D)+2.9}Bt2fy；
The suggested model of the built K-type node bearing capacity of the 1/4 reinforcing plate steel pipe-inserting plate connection is as follows: py,u＝{1.74(D/t)0.7-1.25(B/D)-2.2}t2fy；
The suggested model of the built K-type node bearing capacity of the 1/2 reinforcing plate steel pipe-inserting plate connection is as follows: py,u＝{1.30(D/t)0.8-1.0(B/D)-2.43}t2fy。
The invention provides a calculation method for local buckling bearing capacity of a pipe-plate connection node by combining a connection type of a 1000kV extra-high voltage Huainan-Shanghai (Wan power Dong) transmission line steel pipe tower, developing corresponding experimental research, clarifying the stress condition of a complex node and providing the calculation method for the local buckling bearing capacity of the pipe-plate connection node. The method provides a test basis for the design and processing of the extra-high voltage pole tower nodes, provides technical support for the construction and safe operation of extra-high voltage lines, is a key for ensuring the economical and reliable operation of the pole tower structure of the extra-high voltage transmission and transformation lines in China, and has very important significance for adopting a new design concept and design technology for the extra-high voltage lines.
The invention has the beneficial effects that: the invention obtains the bearing capacity calculation model of the K-shaped node with (or without) annular reinforcing plate steel pipe-inserting plate connection by utilizing the energy principle, reflects the mutual relation among the main pipe axial force, the main pipe wall bending moment and the shearing force, can accurately evaluate the ultimate bearing capacity of the K-shaped node, and has small deviation with the test result.
Drawings
FIG. 1 is a load-strain graph of a member U3 according to an embodiment of the present invention;
FIG. 2 is a load-displacement graph of the member U3 according to an embodiment of the present invention;
FIG. 3 is a load-strain graph of the member S4 according to an embodiment of the present invention;
FIG. 4 is a load-displacement graph of the member S4 according to an embodiment of the present invention;
FIG. 5 is a force diagram of a flexural model of a gusset plate according to an embodiment of the invention;
FIG. 6 is a stress diagram of a K-type node according to an embodiment of the present invention;
FIG. 7 is a load-strain graph of the test results and finite element calculations for the component U3 according to an embodiment of the present invention;
FIG. 8 is a load-displacement graph of the test results and finite element calculations for the component U3 according to an embodiment of the present invention;
FIG. 9 is a load-strain graph of the test results and finite element calculations of the component S4 according to an embodiment of the present invention;
FIG. 10 is a load-displacement graph of the test results and finite element calculations for the component S4 according to an embodiment of the present invention;
FIG. 11 is a graph illustrating the effect of the main tube diameter on the ultimate bearing capacity of a node according to an embodiment of the present invention;
FIG. 12 is a graph illustrating the effect of the gusset plate height on the ultimate bearing capacity of the node according to an embodiment of the present invention;
FIG. 13 is a graph of the effect of the main pipe wall thickness on the node limit bearing capacity according to an embodiment of the present invention;
FIG. 14 is a graph of the effect of host tube diameter, gusset height, and host tube wall thickness on the ultimate bearing capacity of a node according to an embodiment of the present invention;
FIG. 15 is a graph of 1/4 gusset load bearing as a function of parent pipe wall thickness and parent pipe diameter as controlled by the parent pipe in accordance with an embodiment of the present invention;
FIG. 16 is a graph of 1/4 stiffener joint bearing capacity as a function of stiffener thickness and stiffener height as controlled by a host according to embodiments of the present invention;
FIG. 17 illustrates 1/4 gusset node bearing forces as a function of t as controlled by a master pipe in accordance with an embodiment of the present inventionrA variation graph of/t;
FIG. 18 is a graph of the load bearing capacity of the 1/4 gusset as a function of D/t as controlled by the host pipe in accordance with an embodiment of the present invention;
FIG. 19 is a graph of 1/2 gusset load bearing as a function of parent pipe wall thickness and parent pipe diameter as controlled by the parent pipe in accordance with an embodiment of the present invention;
FIG. 20 illustrates 1/2 gusset node bearing forces as a function of t as controlled by a master pipe in accordance with an embodiment of the present inventionrThe variation graphs of/t and R/D;
FIG. 21 is a graph of the load bearing capacity of the 1/2 gusset as a function of D/t as controlled by the host pipe in accordance with an embodiment of the present invention;
FIG. 22 is a graph of the bearing capacity of a full-circle gusset controlled by a main pipe according to an embodiment of the present invention as a function of the wall thickness of the main pipe and the diameter of the main pipe;
FIG. 23 is a graph of the bearing capacity of a full-circle gusset with D/t under the control of a main pipe according to an embodiment of the present invention;
FIG. 24 illustrates 1/4 gusset load bearing capacity as a function of t when controlled by a loop plate in accordance with an embodiment of the present inventionrThe variation graphs of/t and D/R;
FIG. 25 is a graph of the bearing capacity of the node of 1/4 gusset as a function of D/t as controlled by the loop plate in accordance with an embodiment of the present invention;
FIG. 26 is a graph of the node load capacity of 1/4 gussets as a function of D/R as controlled by a ring plate in accordance with an embodiment of the present invention;
FIG. 27 illustrates 1/4 gusset load bearing capacity as a function of t when controlled by a loop plate in accordance with an embodiment of the present inventionrA variation graph of/t;
FIG. 28 illustrates 1/2 gusset load bearing capacity as a function of t when controlled by a loop plate according to an embodiment of the present inventionrThe variation graphs of/t and D/R;
FIG. 29 illustrates 1/2 gusset load bearing capacity as a function of t when controlled by a loop plate in accordance with an embodiment of the present inventionrA variation graph of/t;
FIG. 30 is a graph of the bearing capacity of the 1/2 gusset node as a function of D/t as controlled by the loop plate in accordance with an embodiment of the present invention;
FIG. 31 is a graph of the node load capacity of 1/2 gussets as a function of D/R as controlled by a ring plate in accordance with an embodiment of the present invention;
FIG. 32 shows the bearing capacity of a full-circle gusset with t as controlled by a ring plate according to an embodiment of the present inventionrThe variation graphs of/t and D/R;
FIG. 33 is a graph of the bearing capacity of a full-circle gusset with t as controlled by a ring plate according to an embodiment of the present inventionrA variation graph of/t;
FIG. 34 is a graph of the bearing capacity of a full-circle gusset as controlled by a ring plate according to an embodiment of the present invention as a function of D/t;
FIG. 35 is a graph of the bearing capacity of a full-circle gusset as a function of D/R as controlled by a ring plate according to an embodiment of the present invention.
Detailed Description
The embodiments of the present invention will be further described with reference to the accompanying drawings.
Example (b):
a method for calculating the main pipe bearing capacity of a K-type node connected by steel pipes and inserting plates comprises the following steps:
s1, carrying out a K-type node bearing capacity test on the test component of the steel pipe-inserting plate, and determining main factors influencing the K-type node bearing capacity;
s2, establishing an influence model of each factor on the bearing capacity of the K-type node;
s3, fitting finite element results in the influence models, and establishing a suggested model for calculating the bearing capacity of the K-type node;
and S4, substituting the parameters of each factor of the K-shaped node connected by the steel pipe and the inserting plate to be evaluated into the proposed model to obtain the numerical value of the ultimate main pipe bearing capacity of the K-shaped node connected by the steel pipe and the inserting plate.
In another embodiment, the method for testing the bearing capacity of the K-shaped node of the test component of the steel pipe-insertion plate comprises the following steps:
s11, setting control variable parameters of the test component;
s12, placing the bottom of the test member on a base steel hinge, and connecting the end parts of the other rod pieces to a jack;
s13, strain gauges are respectively arranged at the joint of the gusset plate and the steel pipe and on the ring plate;
s14, pressing down a jack connected with the main pipe, pressing down an upper jack connected with the branch pipe, and pulling down a lower jack connected with the branch pipe to perform step-by-step synchronous loading;
s15, when the main pipe axial force N/Ny is less than 0.2, stopping loading the main pipe, and continuing loading the jack connected with the branch pipe until the node is damaged;
s16, changing the value of the control parameter, repeating the steps S12-S15 to obtain load-displacement and load-strain curves, comprehensively evaluating the obtained load-displacement and load-strain curves, and obtaining the ultimate bearing capacity of the K-type node;
and S17, analyzing and determining main factors influencing the bearing capacity of the K-type node according to the test results obtained on the load-displacement and load-strain curves.
In another embodiment, the method for testing the flexural capacity of the gusset plate of the test member of the steel pipe-insert plate comprises the following steps:
a. setting control variable parameters of a test member (the test member is divided into four types of non-annular reinforcing plates, 1/4 annular reinforcing plates, 1/2 annular reinforcing plates and annular reinforcing plates);
b. the bottom of the test member is arranged on the base steel hinge, and the end parts of the other rod pieces are connected to the jack;
c. strain gauges are respectively arranged at the joint of the gusset plate and the steel pipe and on the ring plate;
d. loading the main pipe and the gusset plate at the same time, stopping loading when the axial force of the main pipe is loaded to a certain value, and continuously loading and increasing the number of the gusset plates step by step until the main pipe is obviously deformed or the gusset plate is damaged;
e. changing the value of the control parameter, repeating the steps b-d to obtain load-displacement and load-strain curves, comprehensively evaluating the obtained load-displacement and load-strain curves, and obtaining the flexural ultimate bearing capacity of the gusset plate;
f. and analyzing and determining main factors influencing the bearing capacity of the K-type node according to test results obtained on load-displacement and load-strain curves.
In another embodiment, in step S11, the controlled variable parameters of the test member include: the pipe diameter D of the main pipe, the wall thickness t of the main pipe, the height B of the gusset plate, the height R of the reinforced ring plate and the thickness t of the reinforced ring platerAnd gusset thickness T, specific test samples are as follows:
note: d-the pipe diameter of the main pipe; t-main pipe wall thickness; b-gusset plate height; r-reinforcement ring plate height; t is tr-reinforcement ring plate thickness; t-gusset plate thickness.
The test shows that the failure mode of the test piece is local failure, and the failure mode has the following phenomena: 1. the main pipe of the component C2 has a local dent on the pipe wall at the No. 1 position of the steel pipe (the key position above the gusset plate on the main pipe), and the deformation amount is small; the pipe wall is locally bulged at the No. 2 position (the key position below the gusset plate on the main pipe), and the deformation amount is small; 2. the failure mode of the steel pipe No. 1 of the components U3 and S4 is opposite to that of the steel pipe No. 2, the pipe wall is locally sunken, and the deformation is small; the pipe wall at the No. 2 position is locally bulged, the deformation is obvious, and the steel pipe at the joint of the annular reinforcing plate and the main pipe is pulled to crack; 3. the local yield of the steel pipe No. 2 of the component C1 was not significant. Therefore, this example will focus on analyzing the wall of the steel pipe near the 1,2 position. The load-strain curve and the load-displacement curve of the key point are shown in figures 1-4, and as can be seen from figures 1-4, as the load increases, the strain of the measuring point changes nonlinearly from linear change, which indicates that the vicinity of the measuring point enters the yield stage. When the load continues to increase, the measuring points all enter plasticity, the steel pipe nodes are quickly damaged, namely, the plastic domains near the steel pipe and the reinforcing ring plate are communicated, and finally the steel pipe nodes become a mechanism system, and the nodes reach a limit bearing state.
In another embodiment, in step a, the control variable parameters of the test member include: the pipe diameter D of the main pipe, the wall thickness t of the main pipe, the height B of the gusset plate, the height R of the reinforced ring plate and the thickness t of the reinforced ring platerAnd gusset thickness T, specific test samples are as follows:
the flexural test specification of the gusset plate without the reinforcing plate is as follows:
1/4 annular and semi-annular gusset plate bending test specification:
the specification of the bending test of the annular gusset plate is as follows:
in another embodimentIn the example, in the process of carrying out a K-type node bearing capacity test and a node plate bending bearing capacity test on a test component of the steel pipe-insertion plate, the determined main factors influencing the K-type node bearing capacity comprise: B/D ratio of gusset plate height to main pipe diameter, D/t ratio of main pipe diameter to main pipe wall thickness, R/D ratio of reinforcement ring plate height to main pipe diameter, and t ratio of reinforcement ring plate thickness to main pipe wall thicknessrT and the angle theta between the branch pipe and the main pipe.
Through comparison of the two test results, the main pipe at the tension end of the K-type node is easy to yield locally firstly under the action of tension and compression loads, the main pipe at the compression end of the gusset plate bending model is easy to yield locally firstly, and the equivalent stress model is shown in fig. 5-6. As can be seen from the equivalent stress model, the bending moments applied to the pipe wall of the main pipe of the two test models are consistent in direction, but the shearing directions are opposite. The bending moment and the shearing force of the pipe wall of the main pipe of the gusset plate bending model have the same effect on the pipe wall, the main pipe at the upper end is pressed, and the main pipe at the lower end is pulled, so that the main pipe is easier to generate local yield. The bending moment and the shearing force of the pipe wall of the main pipe of the K-shaped model are opposite in direction, so that the main pipe is not easy to yield locally. It can be seen that the local yield load bearing obtained from the gusset plate flexural model is smaller than the local load bearing obtained from the K-type model, which is consistent with the experimental results. Therefore, the influence of the shear force on the bearing capacity of the node is not negligible. As can be seen from the test results of the gusset plate bending model, without the annular reinforcing plate, B/D, D/t has a remarkable influence on the bending moment of the pipe wall of the main pipe. Under the condition of the annular reinforcing plate, the node generates local yielding of the main pipe and local yielding of the annular reinforcing plate; the annular stiffener type has a significant effect on the node load capacity. Because the bending moment directions borne by the pipe walls of the main pipes of the two models are the same, and the shearing directions are opposite, the areas where the nodes are firstly damaged are different. However, the failure modes are similar, and thus, the ratio B/D of the gusset height to the main pipe diameter, the ratio D/t of the main pipe diameter to the main pipe wall thickness, the ratio R/D of the reinforcement ring plate height to the main pipe diameter, and the reinforcement ring plate thickness to the main pipe wall thickness trIt is reasonable to consider the influence of the bearing capacity of the K-type node by the angle theta between the branch pipe and the main pipe.
The test results show that the parameters can influence the bearing capacity of the steel pipe-inserting plate connecting node, and the values of the parameters not only determine the structural characteristics of the node, but also influence the stress characteristics and the damage form of the node and the ultimate bearing capacity of the node. The relationship between these parameters and the ultimate bearing capacity of the node is difficult to be solved accurately by a theoretical method, so that the embodiment adopts ANSYS finite element analysis software for analysis, and inspects the stress performance of the node by observing the expansion of the plastic region of the node, the load displacement curve and the like, so as to obtain the ultimate bearing capacity of the node and the change rule of the ultimate bearing capacity of the node along with each geometric parameter. The variation range of the K-type node parameter in this embodiment is: d/t is more than or equal to 10 and less than or equal to 70, and B/D is more than or equal to 1 and less than or equal to 4.
1. Analyzing influence parameters of the bearing capacity of the K-type node without the annular reinforcing plate:
this embodiment has carried out a large amount of numerical calculations to the node of different geometric parameters, from observing the destruction form of node, under the prerequisite of guaranteeing bolted connection and welding seam quality, the destruction mode of picture peg connected node mainly has three: a failure mode (failure mode I) of excessive plastic deformation of the pipe wall of the main pipe; gusset plate local yield failure mode (failure mode II); mode I and mode II coexist.
The local yield failure of the main pipe wall is the failure caused by excessive plastic deformation of the main pipe wall at the joint of the gusset plate and the main pipe under the action of tension and compression, namely, the main pipe wall at the compression side is inwards concave, the tension side is outwards convex, when a load displacement curve at the maximum deformation position on the main pipe wall is in a descending section or the deformation amount exceeds the deformation limit (3 percent of the diameter of the main pipe), the main pipe wall is considered to reach the limit state, and the failure belongs to a mode I. In this embodiment, the failure mode is determined by observing whether the equivalent stress on the gusset plate completely reaches the yield stress when the node is failed after finite element analysis, and by determining the deformation and stress condition of the pipe wall of the main pipe at this time, if the pipe wall of the main pipe is deformed less (for example, the deformation does not exceed 3% of the diameter of the main pipe) and only enters a small range into the plastic zone, the gusset plate has been subjected to large-range yielding, and the failure mode can be considered to belong to a mode II, and this paragraph mainly discusses a first failure mode.
According to the bending theory of thin-walled cylindrical shells, the membrane force is the main component in the shell stress analysis for long cylindrical shells. However, under the action of transverse bending moment, the bending stress has a particularly important significance for the calculation of the local area of the shell. The film forces are evenly distributed along the wall thickness, while the bending stresses are linearly distributed along the thickness direction, reaching a maximum at the edges. Finite element analysis shows that the edge stress concentration part firstly yields, stress is redistributed after continuous loading, the plastic region continuously expands, and the local deformation of the pipe wall of the main pipe is accelerated until the node completely fails.
The influence curves of the parameters on the node bearing capacity through finite element analysis are shown in FIGS. 11-14.
2. Analyzing influence parameters of the bearing capacity of the K-type node of the annular reinforcing plate:
the finite element analysis discovery is passed through to this embodiment, under the prerequisite of guaranteeing bolted connection and welding seam quality and gusset plate not destroyed, the destruction mode of picture peg connected node mainly has two kinds: a failure mode (failure mode I) of excessive plastic deformation of the pipe wall of the main pipe; a node reinforcing ring plate local yield failure mode (failure mode II); mode I and mode II coexist.
The local yield failure of the main pipe wall is caused by excessive plastic deformation of the main pipe wall at the intersection of the gusset plate, the reinforcing ring plate and the main pipe under the action of tension and compression, namely, the main pipe wall at the compression side is inwards sunken, the tension side is outwards protruded, the local yield failure of the main pipe wall occurs at the tension end, mainly the tension end steel pipe is simultaneously subjected to the shearing force, and thus the tension end steel pipe is easier to yield than the compression end steel pipe. The local yield failure of the reinforcement ring plate is due to excessive plastic deformation of the reinforcement ring plate under tension and compression. The compression ring plate is easily bent under pressure, so the compression ring plate is subjected to yield failure compared with the tension ring plate. When a descending section appears on a load displacement curve at the position of the pipe wall of the main pipe with the maximum deformation, or the deformation exceeds the deformation limit (3 percent of the diameter of the main pipe), the main pipe is considered to reach a limit state, meanwhile, the failure belongs to a mode I, for a failure mode caused by local yield of the reinforcing ring plate, the bearing capacity of the node is judged as whether the equivalent stress on the reinforcing ring plate completely reaches the yield stress or not during failure is observed after finite element analysis, and the deformation and stress conditions of the pipe wall of the main pipe are judged at the moment, if the pipe wall of the main pipe deforms less (for example, the deformation does not exceed 3 percent of the diameter of the main pipe) and only enters a small range into a plastic zone, the reinforcing ring plate already yields in a large range, the failure can be considered to belong to a mode I I.
The test result analysis shows that the influence of the height B of the node plate on the bearing capacity of the node is not obvious; the influence of the pipe wall t of the main pipe on the bearing capacity is obvious and almost exponentially changes; as the height and thickness of the reinforcement ring plate increases, the change in node load capacity becomes gradual and gradual, primarily due to the transition of the failure mode of the node from ring plate yielding to parent tube yielding. When the bearing capacity of the node is controlled by the annular reinforcing plate, the influence of the height of the node plate on the bearing capacity is small. When the node bearing capacity is controlled by the master pipe, the bearing capacity is reduced along with the increase of B.
From finite element analysis, it can be seen that the bearing capacity of the K-shaped node is mainly controlled by the main pipe and the ring plate on the premise of ensuring the quality of bolt connection and welding seams and not damaging the node plate. In order to clarify the influence of the geometric parameters on the bearing capacity of the node during the control of the main pipe or the control of the ring plate, non-dimensionalized parameter analysis is respectively carried out on the two conditions. The influence curves of the parameters of the node bearing capacity controlled by the master tube are shown in fig. 15-23. When parameter analysis is carried out, the diameter D of the main pipe is 219mm, and the thickness t of the main pipe is 4 mm. It can be seen from the figure that the main pipe diameter D and the wall thickness t have a significant, almost exponential, effect on the load bearing capacity, while the other parameters have a less significant effect on the load bearing capacity. The B/D has a large influence on the bearing capacity of the K-type node under the control of the master.
The influence curve of each parameter of the node bearing capacity controlled by the ring plate is shown in fig. 24-35, the height R of the reinforced ring plate is 40mm, and the thickness t of the ring plate isrWhen the thickness is equal to 6mm,and the variation trend of the ultimate bearing capacity of the node along with each parameter. As can be seen from the graph, under the condition that other parameters are not changed, D/R and t/tr have obvious influence on the node limit bearing capacity, the node limit bearing capacity is basically linearly improved along with the increase of D/R and t/tr, and B/D has little influence on the node limit bearing capacity.
Through analysis on influence of parameters of the node in different failure modes, the geometric parameters B, D and t have significant influence on the bearing capacity of the node under the condition that the bearing capacity of the node is controlled by a main pipe when no reinforcing ring plate exists; the geometrical parameters D and t have a significant influence on the bearing capacity of the node in the presence of the stiffening ring plate. The reason for this is analyzed, and the ultimate failure mode of the node is caused by the continuous expansion of the main pipe plastic yield until the deformation is too large to damage the bearing capacity. Thus, the failure is related to the degree of plastic expansion of the main pipe, that is, to the thickness of the main pipe, and the size of the outer diameter of the steel pipe directly affects the starting point of the main pipe entering into the plastic property because the larger the pipe diameter, the lower the stress on the circumferential section of the outer diameter of the main pipe. When the bearing capacity of the node is controlled by the ring plate, the geometric parameters R and tr are main factors influencing the bearing capacity of the node, but the geometric change of the main pipe also influences the radial stress of the reinforced ring plate and the failure form of the reinforced ring plate. Therefore, the diameter and thickness of the main pipe also have certain influence on the bearing capacity of the node.
3. Analyzing the influence of the strength of the steel on the bearing capacity of the node:
the bearing capacity change rules of the nodes under different steel types are basically consistent, and the failure mechanism and the failure mode are the same. Under the condition that other conditions are not changed, the bearing capacity is correspondingly improved along with the improvement of the material strength. The nodes are partially in tension and partially in compression due to the combined action of membrane internal forces and bending internal forces within the shell. Therefore, the bearing capacity cannot be considered to increase in equal proportion to the change in material.
4. Analyzing the influence of theta on the limit bearing capacity of the node:
the larger the inclination angle theta of the branch pipe is, the larger the bearing capacity of the node is, and the reason is that under the condition that the height of the node plate is kept unchanged, the larger the included angle between the axis of the branch pipe and the axis of the main pipe is, the smaller the sum of the component forces of the axial forces of the two branch pipes along the axial direction of the main pipe is, so that the bending moment borne by the surface of the main pipe at the intersection of the node plate is smaller, and the ultimate bearing capacity of the node is increased. However, in fact, the bending action on the surface of the main pipe is caused by a couple formed by a component force of the two branch pipe axial forces in the direction perpendicular to the main pipe, so that the component force of the branch pipe perpendicular to the main pipe axial direction has a large influence on the local deformation of the main pipe wall. Although the branch pipe component perpendicular to the axial direction of the main pipe is increased due to the increase of theta, the moment arm between the branch pipe components is reduced due to the change of the angle theta, and the total result is that the bending moment value of the pipe wall of the main pipe is reduced along with the increase of theta. The change of the theta angle causes the change of the geometric dimension of the node, the smaller the theta angle is, the larger the height of the node plate is, the larger the ratio of the effective height to the effective width of the node plate is, the instability and damage of the node plate are easy to occur, the larger the axial load of the main pipe is, and the earlier buckling of the main pipe is easy to occur. The larger the angle θ, the larger the load applied to the branch pipe and the easier it breaks. Therefore, the angle theta in the engineering is 45-50 degrees.
5. And (3) analyzing the influence of the structural reinforcing ring plate on the limit bearing capacity of the node:
when only the middle reinforcing plate is arranged, although the out-of-plane support is provided for the node plate, the stress of the node area is improved, the contribution to the radial rigidity of the weak stress position of the main pipe is limited, and therefore the bearing capacity is not obviously improved. When the reinforcing ring plates are arranged at the two ends of the gusset plate, the lateral rigidity of the gusset plate is improved, the radial rigidity of the pipe wall of the main pipe is increased, the local deformation of the pipe wall of the main pipe when the gusset plate reaches a limit state is reduced, and the ultimate bearing capacity of the gusset plate is improved by about 8-15%. When the combined reinforcement is adopted, the ultimate bearing capacity of the node is improved a little compared with the condition of reinforcing the two ends, and the amplitude is about 3% -5%. Therefore, the mode of reinforcing the two ends of the gusset plate is most effective in improving the limit bearing capacity of the gusset for the construction method of the reinforced ring plate in the gusset area.
The influence of the height of the reinforcing ring plate on the ultimate bearing capacity of the node is basically ignored when the bearing capacity of the node is controlled by the main pipe bearing capacity on the premise of meeting the size requirement of the node and the common practice of actual engineering. In the case where the node load capacity is controlled by the master load capacity, the effect of the change in the height of the stiffener ring plate on the ultimate load capacity of the node is significant.
6. Analyzing the influence of the axial load of the main pipe and the shearing force of the pipe wall of the main pipe on the bearing capacity of the node:
the main failure mode of the node is excessive plastic deformation of the main pipe at the intersection of the main pipe and the node plate and yielding of the reinforcing ring plate, the influence of the self-loading condition of the main pipe on the bearing capacity of the node is large, a uniform reduction coefficient calculation method is provided for different reinforcing plate conditions in the Japanese iron tower manufacturing standard, a large amount of finite element analysis is carried out aiming at different reinforcing plate conditions, and the influence of the axial force of the main pipe on the local bearing capacity of the node is researched. When the axial load of the main pipe is considered, the ultimate bearing capacity of the node is inspected, and analysis is carried out according to bidirectional loading, namely, the axial load is applied to the main pipe to a certain specified load value, then the branch pipe is loaded, and the ultimate bearing capacity of the node under the action of the axial force of the main pipe is obtained.
The axial force ratio is the ratio of the axial load of the main pipe to the complete yield axial load of the section of the main pipe, the axial pressure of the main pipe obviously reduces the ultimate bearing capacity of the node, because the existence of the axial pressure of the main pipe can promote the local deformation of the node to be increased, and the strength of the node is obviously reduced along with the increase of the pressure stress of the main pipe. When the main pipe is pulled, the local deformation of the node is reduced by the axial tension, the strength of the node is slightly improved (about 1% -2% improvement), but if the tensile stress of the main pipe is larger to be close to the yield strength of steel, the strength of the node is reduced, and the reduction range is smaller compared with the axial pressure, so that when the main pipe has axial tension load, the improvement of the bearing capacity of the node can be not considered.
The effect of shear on the bearing capacity of the node is not negligible. When the action effect of the bending moment is the same as the action effect of the shearing force, the damage of the node is accelerated, and the bearing capacity of the node is greatly reduced; when the directions are opposite, the local yielding of the node is slowed down, but when the shearing force is large, the section of the main pipe is always yielded completely and early. The calculation result obtained according to the node plate bending model is smaller than that obtained according to the actual K type. However, in the case of the full-circle gusset master pipe control, the former calculation result is larger than the latter. The main structure is that in the K-type node, the section of the main pipe at the tension end is prone to yielding too early due to large shearing force, so that the bearing capacity of the node is greatly reduced.
In another embodiment, in step S14, the angle between the pressure branch pipe and the main pipe is 45 °, and the angle between the tension branch pipe and the main pipe is 50 °.
In another embodiment, in step S14, in the step-by-step loading process, the test loading is unidirectional step loading, in order to describe the change condition of the gusset plate stress in detail, in the test loading scheme of this embodiment, a small loading increment is considered, the loading is continued after 1 minute of pause after each step of loading until the test piece is destroyed and can not be loaded any more, specifically, the initial values of the tension and the pressure of the branch pipe are 40kN, the first 10 loading steps are performed, the load increment of each step is 40kN, the 11 th to 20 th loading steps are performed, the load increment of each step is 20kN, the 21 st to 30 th loading steps are performed, the load increment of each step is 5kN, and after the 30 th loading step, the tension and the pressure are generated with a constant load until the main pipe or the ring plate yields, and the; the initial value of the main pipe pressure is 20kN, the first 10 loading steps are carried out, the load increment of each stage is 10kN, the 11 th to 20 th loading steps are carried out, the load increment of each stage is 5kN, and the loading is stopped in the 20 th loading step.
In another embodiment, in step d, during the step-by-step loading, when the axial force is less than 0.2Ny, the initial value of the axial force is 20kN, the loading steps are from 1 to 7, the load increment of each step is 20kN, the loading steps are from 7 to 11, the load increment of each step is 10kN, and the loading is stopped by the loading step 11; the initial value of the tension of the gusset plate is 10kN, the 1 st to 7 th loading steps are carried out, the load increment of each level is 10kN, the 7 th to 11 th loading steps are carried out, the load increment of each level is 5kN, and after the 11 th loading step, the load increment of each level is 2kN until the test piece is damaged;
when the axial force is larger than 0.5Ny, the initial value of the axial force is 100kN, the 1 st to 3 rd loading steps are carried out, the load increment of each stage is 100kN, the 4 th to 15 th loading steps are carried out, the load increment of each stage is 50kN, the 16 th to 17 th loading steps are carried out, the load increment of each stage is 20kN, and the loading is stopped from the 17 th loading step; the initial value of the tension of the gusset plate is 10kN, the 1 st to 3 rd loading steps are carried out, the load increment of each stage is 10kN, the 4 th to 15 th loading steps are carried out, the load increment of each stage is 5kN, the 16 th to 17 th loading steps are carried out, the load increment of each stage is 5kN, and after the 17 th loading step, the load increment of each stage is 2kN until the test piece is damaged.
The embodiment also carries out adaptability verification on the finite element model, and utilizes a finite element program ANSYS to carry out elastoplasticity large deformation analysis on the K-shaped steel pipe-inserting plate connecting node and research the stress distribution condition and the ultimate bearing capacity of the node. In order to obtain the stress-strain distribution rule of the node conveniently, the 4-node quadrilateral shell unit shell181 is adopted to simulate the node plate, the steel pipe and the reinforcing plate in the finite element model analysis. One end of the main pipe is considered according to the fixed support, and the other end is the fixed support which only moves along the axial direction of the main pipe. The end boundaries of the two branch pipes are sliding hinged supports, only displacement is allowed along the axial direction of the pipe, radial displacement is restrained, and the loading mode is the same as that of the test. For finite element analysis, Q345 is selected. The load-deformation graphs of the test results and the finite element calculation results are shown in fig. 7 to 10.
From the comparison of load-deformation curves, the test results and the finite element calculation results have the same trend, the displacement values in the calculation curves of the test piece model are smaller than the test values in different degrees, the actual boundary conditions in the test process cannot reach the ideal state in the analysis model, the test loading adopts manual and mechanical hydraulic jack pressure application, the data calibration and the oil pressure stability of the jack are difficult to control, the static strain gauge has the sensitivity problem, the strain quantity required to be recorded by each stage of load is larger, the duration is longer, the instrument reading is easy to drift, the dial indicator cannot be completely perpendicular to the measuring point, and the like, so that the displacement measurement error is caused, but the difference value can be basically accepted. The constitutive relation of the material stress-strain curve model and the test piece steel plate of the simulation analysis has certain error, so that the calculated value of the shell model is different from the test result, but the difference between the calculated value and the test result is not large. The yield load shown by the test curve and the shell model analysis curve is basically the same. In general, the finite element model established by the embodiment can accurately reflect the stress performance and the failure characteristics of the node, and can be used for large-scale parameter analysis of the node.
In another embodiment, in step S3, in the process of creating the proposed model for calculating the load-bearing capacity of the K-type node, the least square method is used to fit the finite element results.
In another embodiment, in step S3, the proposed model of the K-node bearing capacity of the steel pipe-insert plate connection without the reinforcing plate is: mw,u＝{0.26(D/t)0.6+1.15(B/D)+2.9}Bt2fy，Mw,uBending moment of the pipe wall of the main pipe when no main pipe axial force exists;
the proposed model for the built K-type node bearing capacity of the 1/4 reinforced plate steel pipe-inserting plate connection is as follows:
and (3) controlling by a main pipe: py,u＝{1.74(D/t)0.7-1.25(B/D)-2.2}t2fy；
Controlling an annular reinforcing plate:
Py,uthe equivalent transverse force is the equivalent transverse force without main pipe axial force;
the proposed model for the built K-type node bearing capacity of the 1/2 reinforced plate steel pipe-inserting plate connection is as follows:
and (3) controlling by a main pipe: py,u＝{1.30(D/t)0.8-1.0(B/D)-2.43}t2fy；
Controlling an annular reinforcing plate:
the present embodiment has studied the node bearing capacity controlled by the main pipe bearing capacity or by the ring stiffener bearing capacity. On the basis of the test result, the influence parameters of the bearing capacity of the node are analyzed through finite elements. The solving process of the bearing capacity of the two controlled nodes is deduced by using an energy method, and an analysis model for estimating the ultimate bearing capacity of the nodes is obtained. On the basis of finite element analysis and theoretical research, a suggested calculation method for the bearing capacity of the K-type node under the action of tension and compression loads is provided. From the above analysis, the following conclusions were drawn:
1. through test results and finite element analysis, the bearing capacity of the K-type node is controlled by the bearing capacity of the main pipe or the bearing capacity of the annular reinforcing plate under the action of tensile and compressive loads. Under the condition of no annular reinforcing plate, the influence of the main pipe wall thickness t on the bearing capacity of the node is more remarkable than the influence of the main pipe diameter D and the node plate height B on the bearing capacity of the node and is increased gradually almost exponentially. Under the condition of ring plate control, D/R and t/tr have obvious influence on the node limit bearing capacity, the node limit bearing capacity is basically linearly improved along with the increase of D/R and t/tr, and B/D has small influence on the node limit bearing capacity. The main pipe axial force and the main pipe wall shearing force have obvious influence on the bearing capacity of the node.
2. The deviation of the ultimate bearing capacity of the K-type node solved by using the energy principle from the test result is about 14%, and the average deviation from the finite element result is 18.9%. This is mainly due to the fact that the influence of shearing force on the pipe wall of the main pipe and the influence of the reinforcing stage of the material on the bearing capacity are not considered. However, the method can provide theoretical basis for engineering design.
3. The proposed formula of the K-shaped node with (or without) annular reinforcing plate steel pipe-inserting plate connection provided by the equivalent model reflects the mutual relation among the main pipe axial force, the main pipe wall bending moment and the shearing force, and the upper limit value of the bearing capacity of the node can be estimated so as to be used for guiding the design.
The invention provides a calculation method for local buckling bearing capacity of a pipe-plate connection node by combining a connection type of a 1000kV extra-high voltage Huainan-Shanghai (Wan power Dong) transmission line steel pipe tower, developing corresponding experimental research, clarifying the stress condition of a complex node and providing the calculation method for the local buckling bearing capacity of the pipe-plate connection node. The method provides a test basis for the design and processing of the extra-high voltage pole tower nodes, provides technical support for the construction and safe operation of extra-high voltage lines, is a key for ensuring the economical and reliable operation of the pole tower structure of the extra-high voltage transmission and transformation lines in China, and has very important significance for adopting a new design concept and design technology for the extra-high voltage lines.
The above-mentioned embodiments only express the specific embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.
Claims (8)
1. A method for calculating the bearing capacity of a true test data node main pipe of an extra-high voltage power transmission tower is characterized by comprising the following steps:
s1, carrying out a K-type node bearing capacity test on the test component of the steel pipe-inserting plate, and determining main factors influencing the K-type node bearing capacity;
s2, establishing an influence model of each factor on the bearing capacity of the K-type node;
s3, fitting finite element results in the influence models, and establishing a suggested model for calculating the bearing capacity of the K-type node;
and S4, substituting the parameters of each factor of the K-shaped node connected by the steel pipe and the inserting plate to be evaluated into the proposed model to obtain the numerical value of the ultimate main pipe bearing capacity of the K-shaped node connected by the steel pipe and the inserting plate.
2. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true type test data node main pipe according to claim 1, wherein in step S1, the method for performing the K type node bearing capacity test is as follows:
s11, setting control variable parameters of the test component;
s12, placing the bottom of the test member on a base steel hinge, and connecting the end parts of the other rod pieces to a jack;
s13, strain gauges are respectively arranged at the joint of the gusset plate and the steel pipe and on the ring plate;
s14, pressing down a jack connected with the main pipe, pressing down an upper jack connected with the branch pipe, and pulling down a lower jack connected with the branch pipe to perform step-by-step synchronous loading;
s15, when the main pipe axial force is less than 0.2, stopping loading the main pipe, and continuing loading the jack connected with the branch pipe until the node is damaged;
s16, changing the value of the control parameter, repeating the steps S12-S15 to obtain load-displacement and load-strain curves, comprehensively evaluating the obtained load-displacement and load-strain curves, and obtaining the ultimate bearing capacity of the K-type node;
and S17, analyzing and determining main factors influencing the bearing capacity of the K-type node according to the test results obtained on the load-displacement and load-strain curves.
3. The method for calculating the extra-high voltage power transmission tower true type test data node main pipe bearing capacity according to claim 2, wherein in step S11, the control variable parameters of the test member include: the pipe diameter D of the main pipe, the wall thickness t of the main pipe, the height B of the gusset plate, the height R of the reinforced ring plate and the thickness t of the reinforced ring platerAnd gusset thickness T.
4. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true type test data node main pipe according to claim 3, wherein in the step S17, the determined main factors influencing the bearing capacity of the K type node comprise: B/D ratio of gusset plate height to main pipe diameter, D/t ratio of main pipe diameter to main pipe wall thickness, R/D ratio of reinforcement ring plate height to main pipe diameter, and t ratio of reinforcement ring plate thickness to main pipe wall thicknessr/t。
5. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true type test data node main pipe according to claim 2, wherein in step S14, the included angle between the compression branch pipe and the main pipe is 45 degrees, and the included angle between the tension branch pipe and the main pipe is 50 degrees.
6. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true test data node main pipe according to claim 2, wherein in the step S14, in the step-by-step loading process, the initial values of the tension and the pressure of the branch pipes are 40kN, the first 10 loading steps are performed, the load increment of each step is 40kN, the 11 th to 20 th loading steps are performed, the load increment of each step is 20kN, the 21 st to 30 th loading steps are performed, the load increment of each step is 5kN, and after the 30 th loading step, the tension and the pressure are generated by constant load until the main pipe or the ring plate yields, and the loading is stopped; the initial value of the main pipe pressure is 20kN, the first 10 loading steps are carried out, the load increment of each stage is 10kN, the 11 th to 20 th loading steps are carried out, the load increment of each stage is 5kN, and the loading is stopped in the 20 th loading step.
7. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true type test data node main pipe according to claim 4, wherein in the step S3, in the process of establishing the proposed model for calculating the bearing capacity of the K type node, a least square method is adopted to fit the finite element result.
8. The method for calculating the bearing capacity of the extra-high voltage power transmission tower true type test data node main pipe according to claim 5, wherein in step S3, the proposed model of the K type node bearing capacity of the built reinforcement-plate-free steel pipe-insertion plate connection is as follows: mw,u＝{0.26(D/t)0.6+1.15(B/D)+2.9}Bt2fy；
The suggested model of the built K-type node bearing capacity of the 1/4 reinforcing plate steel pipe-inserting plate connection is as follows: py,u＝{1.74(D/t)0.7-1.25(B/D)-2.2}t2fy；
The suggested model of the built K-type node bearing capacity of the 1/2 reinforcing plate steel pipe-inserting plate connection is as follows:
Py,u＝{1.30(D/t)0.8-1.0(B/D)-2.43}t2fy。
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113127997A (en) * | 2021-04-29 | 2021-07-16 | 中国电力工程顾问集团西北电力设计院有限公司 | Method for calculating acting force of five-ring-plate node ring plate for power transmission steel pipe tower |
| CN113673131A (en) * | 2021-08-27 | 2021-11-19 | 河南城建学院 | Method for calculating distributed load of stiffening plate at tube plate node of power transmission steel tube tower |
| CN114077766A (en) * | 2021-11-17 | 2022-02-22 | 绍兴大明电力设计院有限公司 | Novel full GFRP node bearing capacity calculation method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102254061A (en) * | 2011-06-09 | 2011-11-23 | 山东电力研究院 | Finite element modeling and bearing method for line-tower coupling system of power transmission tower |
| CN108875257A (en) * | 2018-07-05 | 2018-11-23 | 华北水利水电大学 | A kind of trestle Square Steel Tubes Truss N-type ultimate bearing capacity of joints regression analysis |
| CN110569530A (en) * | 2019-07-18 | 2019-12-13 | 重庆瑜煌电力设备制造有限公司 | Steel tube lattice type manifold and calculation method for beam node bearing capacity thereof |
-
2020
- 2020-08-11 CN CN202010802081.2A patent/CN112115625A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102254061A (en) * | 2011-06-09 | 2011-11-23 | 山东电力研究院 | Finite element modeling and bearing method for line-tower coupling system of power transmission tower |
| CN108875257A (en) * | 2018-07-05 | 2018-11-23 | 华北水利水电大学 | A kind of trestle Square Steel Tubes Truss N-type ultimate bearing capacity of joints regression analysis |
| CN110569530A (en) * | 2019-07-18 | 2019-12-13 | 重庆瑜煌电力设备制造有限公司 | Steel tube lattice type manifold and calculation method for beam node bearing capacity thereof |
Non-Patent Citations (1)
| Title |
|---|
| 刘红军: "特高压钢管输电塔插板连接 K 型节点的受力性能及承载力研究", 《中国优秀博硕士学位论文全文数据库(博士) 工程科技Ⅱ辑》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113127997A (en) * | 2021-04-29 | 2021-07-16 | 中国电力工程顾问集团西北电力设计院有限公司 | Method for calculating acting force of five-ring-plate node ring plate for power transmission steel pipe tower |
| CN113127997B (en) * | 2021-04-29 | 2023-06-02 | 中国电力工程顾问集团西北电力设计院有限公司 | Method for calculating acting force of five-ring plate node ring plate for power transmission steel pipe tower |
| CN113673131A (en) * | 2021-08-27 | 2021-11-19 | 河南城建学院 | Method for calculating distributed load of stiffening plate at tube plate node of power transmission steel tube tower |
| CN113673131B (en) * | 2021-08-27 | 2024-03-15 | 河南城建学院 | Distributed load calculation method for stiffening plate of tube plate node of power transmission steel tube tower |
| CN114077766A (en) * | 2021-11-17 | 2022-02-22 | 绍兴大明电力设计院有限公司 | Novel full GFRP node bearing capacity calculation method |
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Application publication date: 20201222 |