CN106568562B - The test method and device of power transmission tower crossarm bolt anti-loosening property - Google Patents
The test method and device of power transmission tower crossarm bolt anti-loosening property Download PDFInfo
- Publication number
- CN106568562B CN106568562B CN201610913012.2A CN201610913012A CN106568562B CN 106568562 B CN106568562 B CN 106568562B CN 201610913012 A CN201610913012 A CN 201610913012A CN 106568562 B CN106568562 B CN 106568562B
- Authority
- CN
- China
- Prior art keywords
- bolt
- power transmission
- cross arm
- transmission tower
- wind load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 177
- 238000010998 test method Methods 0.000 title claims abstract description 4
- 238000000034 method Methods 0.000 claims abstract description 44
- 239000004020 conductor Substances 0.000 claims description 43
- 238000012360 testing method Methods 0.000 claims description 35
- 230000002265 prevention Effects 0.000 claims description 15
- 238000004364 calculation method Methods 0.000 claims description 14
- 238000011156 evaluation Methods 0.000 claims description 10
- 239000012212 insulator Substances 0.000 claims description 4
- 238000005259 measurement Methods 0.000 abstract description 4
- 230000005611 electricity Effects 0.000 abstract 1
- 238000011835 investigation Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000005457 optimization Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
- Wind Motors (AREA)
Abstract
The present invention provides the test methods and device of a kind of power transmission tower crossarm bolt anti-loosening property.Wherein, this method comprises the following steps: calculating wind load of the power transmission tower under each default operating condition；The finite element model for establishing power transmission tower cross-arm applies corresponding wind load to power transmission tower cross-arm under each default operating condition；Stress of each rod piece under wind load in cross-arm is calculated, and chooses stress ratio and is greater than the rod piece of default stress ratio as measurement rod piece；When wind load loosens the bolt for being installed on each measurement rod piece, the pretightning force time-history curves for being installed on the bolt of selected measurement rod piece are obtained；Load number when determining that each bolt loosens according to pretightning force time-history curves；Load number when being loosened according to each bolt determines the distribution situation of each bolt disengaged position, and the bolt loosened at first is determined as to the bolt of anti-loosening property weakness.Method provided by the invention realizes the purpose of the anti-loosening property investigation to cross-arm structure entirety, and then keeps the security performance of transmission line of electricity more preferable.
Description
Technical Field
The invention relates to the technical field of bolt looseness prevention, in particular to a method and a device for testing the bolt looseness prevention performance of a cross arm of a power transmission tower.
Background
The bolt is a key component for connecting and transmitting the force of the rod piece of the power transmission tower, and the fastening state of the bolt not only influences the overall reliability of the tower, but also threatens the safe operation of the whole line. The cross arm is used for bearing continuous alternating load under the action of dynamic loads such as strong wind, galloping and the like of a wire at the hanging and supporting part of the power transmission tower, and bolts are easy to loosen. In China, large-scale conductor galloping disasters occur from the end of 2009 to the beginning of 2010, wherein tower damage caused by galloping in Henan province is serious, and the main reason of tower damage is that cross arm bolts are loosened due to galloping, so that cross arms or the whole tower are damaged.
In the existing anti-loosening performance test of the power transmission tower bolt, test objects are single bolt samples, the amplitude and the frequency are evaluated according to GB/T10431-2008 'method for testing transverse vibration of a fastener', the standard is mainly suitable for fasteners in the mechanical industry, the applied vibration load is only horizontal load, the loosening rule and the anti-loosening performance of the bolt determined by the method cannot accurately reflect the real states of the horizontal load and the vertical load of the cross arm of the power transmission tower acting simultaneously under the conditions of strong wind, galloping and the like. In addition, under the action of heavy wind or galloping load, the stress states of the upper plane, the side surface and the lower plane rod piece of the cross arm are different, so that the loosening mechanism, the sequence and the distribution position of the bolts are greatly different, the traditional single bolt loosening prevention performance test cannot meet the requirement of observing the whole loosening prevention performance of the cross arm, the whole safety of the cross arm cannot be ensured, and the safety performance of a power transmission line is threatened.
Disclosure of Invention
In view of the above, the invention provides a method and a device for testing the anti-loosening performance of a bolt of a cross arm of a power transmission tower, and aims to solve the problem that the existing bolt anti-loosening performance test method only can examine the anti-loosening performance of a single bolt, so that the safety performance of a power transmission line is poor.
In one aspect, the invention provides a method for testing the anti-loosening performance of a cross arm bolt of a power transmission tower, which comprises the following steps: a load calculation step, namely calculating wind loads of the power transmission tower under each preset working condition; a wind load applying step, wherein corresponding wind loads are applied to the cross arm of the power transmission tower under each preset working condition; a step of measuring rod piece selection, which is to calculate the stress of each rod piece in the cross arm under wind load and select the rod piece with the stress ratio larger than the preset stress ratio as a measuring rod piece; acquiring a pretightening force time-course curve, namely acquiring the pretightening force time-course curve of the bolt mounted on the selected measuring rod piece when the bolts mounted on each measuring rod piece are loosened by wind load; determining loosening and loading times, namely determining the loading times of each bolt during loosening according to a pretightening force time course curve; and (4) evaluating the anti-loosening performance, namely determining the distribution condition of loosening positions of the bolts according to the loading times when the bolts are loosened, and determining the bolt loosened firstly as the bolt with weak anti-loosening performance.
Further, in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower, the load calculation step comprises the following steps: the preset working conditions comprise: strong wind conditions and waving conditions.
Further, in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower, the preset working condition is a strong wind working condition, and the load calculation step further comprises the following steps of: a sub-step of determining horizontal wind load of the cross arm under the strong wind working condition, namely calculating the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the strong wind working condition, and determining the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the strong wind working condition as the horizontal wind load of the cross arm of the power transmission tower under the strong wind working condition; and a sub-step of determining the vertical wind load of the cross arm under the strong wind working condition, wherein the sum of the transmission conductor, the hardware fitting and the insulator is determined as the vertical wind load of the cross arm of the transmission tower under the strong wind working condition.
Further, in the method for testing the anti-loosening performance of the bolt of the cross arm of the power transmission tower, the horizontal wind load direction of the cross arm of the power transmission tower under the working condition of strong wind is vertical to the direction of the power transmission lead.
Further, in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower, the preset working condition is a galloping working condition, and the load calculation step further comprises the following steps of: and a step of determining the load of the galloping working condition, which is to determine the galloping amplitude of the transmission conductor according to the level of the galloping area of the transmission conductor and the structural parameters of the transmission conductor, and then calculate the horizontal wind load and the vertical wind load of the cross arm of the transmission tower under the galloping working condition according to the galloping amplitude of the transmission conductor and the standing wave theory.
Further, in the method for testing the anti-loosening performance of the bolt of the cross arm of the power transmission tower, the horizontal wind load direction of the cross arm of the power transmission tower under the galloping working condition is parallel to the direction of the power transmission lead.
Further, in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower, the step of determining the loosening and loading times further includes: a loading time determining substep, wherein the loading time is the time when the pretightening force of each bolt is zero; a frequency calculation substep, which is used for calculating the loading frequency of the wind load of the cross arm of the power transmission tower under each preset working condition; and a loading frequency determining sub-step, wherein the loading frequency when each bolt is loosened is determined according to the loading time and the loading frequency.
Further, in the test method for the anti-loosening performance of the cross arm bolt of the power transmission tower, in the sub-step of determining the loading frequency, the product of the loading time and the loading frequency is determined as the loading frequency.
Further, in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower, the method further comprises the following steps: repeating the steps, and respectively determining the loading times when each bolt is a single-cap bolt and a double-cap bolt; and comparing the loading times of each single-cap bolt with the loading times of each double-cap bolt, and determining the single-cap bolt and the double-cap bolt which are loosened firstly as the bolts with weak anti-loosening performance.
According to the invention, by determining the loading times of the loosening of the cross arm bolt, the mechanism, the sequence and the distribution position of the loosening of the bolt at different parts of the cross arm of the power transmission tower can be accurately determined, the aim of investigating the overall anti-loosening performance of the cross arm structure is realized, the effective evaluation of the anti-loosening performance of the cross arm of the power transmission tower is realized, the overall safety of the cross arm is ensured, and the safety performance of the power transmission line is better.
On the other hand, the invention also provides a test device for the anti-loosening performance of the cross arm bolt of the power transmission tower, which comprises the following components: the load calculation module is used for calculating wind loads of the power transmission tower under each preset working condition; the wind load applying module is used for establishing a finite element model of the power transmission tower and applying corresponding wind loads to the cross arm of the power transmission tower under each preset working condition; the measuring rod piece selecting module is used for calculating the stress of each rod piece in the cross arm under the wind load and selecting the rod piece with the stress ratio larger than the preset stress ratio as the measuring rod piece; the pre-tightening force time course curve acquisition module is used for acquiring a pre-tightening force time course curve of the bolt mounted on the selected measuring rod piece when the bolts mounted on the measuring rod pieces are loosened by wind load; the loosening and loading frequency determining module is used for determining the loading frequency of each bolt when loosening according to the pretightening force time course curve; and the anti-loosening performance evaluation module is used for determining the distribution condition of loosening positions of the bolts according to the loading times when the bolts are loosened, and determining the bolt loosened firstly as the bolt with weak anti-loosening performance.
According to the invention, by determining the loading times of the loosening of the cross arm bolt, the mechanism, the sequence and the distribution position of the loosening of the bolt at different parts of the cross arm of the power transmission tower can be accurately determined, the aim of investigating the overall anti-loosening performance of the cross arm structure is realized, the effective evaluation of the anti-loosening performance of the cross arm of the power transmission tower is further realized, the overall safety of the cross arm is ensured, and the safety performance of the power transmission line is further better.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
fig. 1 is a flowchart of a method for testing anti-loosening performance of a cross arm bolt of a power transmission tower according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a finite element model of a cross arm of a power transmission tower in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower according to the embodiment of the present invention;
fig. 3 is a schematic view illustrating an installation of a double-cap bolt pre-tightening force sensor in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower according to the embodiment of the invention;
fig. 4 is a schematic diagram illustrating arrangement of a plane bolt pre-tightening force sensor under a cross arm of a power transmission tower in the method for testing the anti-loosening performance of the cross arm bolt of the power transmission tower according to the embodiment of the present invention;
fig. 5 is a block diagram of a structure of a testing apparatus for anti-loosening performance of a cross arm bolt of a power transmission tower according to an embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
The method comprises the following steps:
referring to fig. 1, fig. 1 is a flowchart of a method for testing anti-loosening performance of a cross arm bolt of a power transmission tower according to an embodiment of the present invention. As shown, the method comprises the following steps:
and a load calculation step S1, calculating the wind load of the power transmission tower under each preset working condition.
Specifically, for accurately evaluating the anti-loosening performance of the cross arm bolt of the power transmission tower in the actual environment, wind loads of the power transmission tower in various preset working conditions of the actual environment need to be calculated, and all the working conditions are working conditions of the actual environment. It should be noted that each preset working condition may be determined according to an actual situation, and this embodiment does not limit the preset working conditions.
And a wind load applying step S1, wherein corresponding wind loads are applied to the cross arm of the power transmission tower under each preset working condition.
Specifically, referring to fig. 2, a finite element model of the transmission tower cross arm is established, and the wind load of the transmission tower under preset working conditions calculated in the above steps is applied to a hanging point 4 of a transmission conductor of the transmission tower cross arm.
And a measuring rod piece selecting step S2, calculating the stress of each rod piece in the cross arm under the wind load, and selecting the rod piece with the stress ratio peak value larger than the preset stress ratio as the measuring rod piece.
Specifically, under the wind load applied in the above steps, a finite element analysis method is adopted to calculate the stress ratio of each rod piece in the cross arm, and the rod piece with the stress ratio peak value larger than the preset stress ratio is selected as the rod piece for measuring the anti-loosening performance of the bolt, and the larger the stress ratio of the rod piece is, the stronger the vibration of the rod piece is, and the more the anti-loosening performance of the bolt connected to the rod piece needs to be evaluated. In specific implementations, the predetermined stress ratio may be 0.5. The stress ratio is the ratio of the actual stress to the designed stress of the rod. It should be noted that the finite element analysis method for calculating the stress ratio of each rod in the cross arm is well known to those skilled in the art, and therefore is not described in detail.
And a pretightening force time course curve acquiring step S3, wherein when the bolts mounted on the measuring rod pieces are loosened by wind load, the pretightening force time course curve of the bolt mounted on the selected measuring rod piece is acquired.
Specifically, a pretightening force sensor is installed between a connecting plate of the selected measuring rod piece and the bolt, the wind load calculated in the steps is applied to the cross arm under a preset working condition, and a pretightening force time-course curve of the bolt of the measuring rod piece in the period from the time when the wind load is applied to the bolt to the time when the bolt is loosened is obtained by the pretightening force sensor.
And a loosening and loading frequency determining step S4, wherein the loading frequency of each bolt during loosening is determined according to the pretightening force time course curve.
Specifically, the number of times of loading the bolt by the wind load from the beginning of applying the wind load to the loosening of the bolt is determined according to the acquired pretightening force time course curve of the bolt.
And an anti-loosening performance evaluation step S5, determining the distribution condition of loosening positions of the bolts according to the loading times when the bolts are loosened, and determining the bolt loosened firstly as a bolt with weak anti-loosening performance.
Specifically, the distribution of the loosening positions of the bolts can be obtained according to the loading times of the loosening of the bolts determined in the above steps, the bolt which is loosened first is determined to be the bolt with weak loosening prevention performance, and during specific implementation, the pretightening force can be properly added to the bolt which is loosened first to improve the loosening prevention performance of the bolt which is loosened first.
It can be seen that, in the embodiment, by determining the loading times of the loosening of the cross arm bolt, the mechanism, the sequence and the distribution positions of the loosening of the bolts at different parts of the cross arm of the power transmission iron can be accurately determined, the aim of investigating the overall anti-loosening performance of the cross arm structure is achieved, the effective evaluation of the anti-loosening performance of the cross arm of the power transmission tower is further achieved, the overall safety of the cross arm is ensured, and the safety performance of the power transmission line is further better.
In the foregoing embodiment, in the load calculating step, the preset working condition may include: strong wind conditions and waving conditions. It should be noted that the windy condition and the waving condition are well known to those skilled in the art, and therefore are not described in detail.
In this embodiment, each operating mode of transmission tower under the natural environment of simulation reality, exert wind load to the cross arm, make the locking performance of bolt more be close to actual conditions, more accurate aassessment the locking performance of bolt.
In an embodiment of the present invention, the preset condition is a strong wind condition, and the load calculating step S1 may further include:
and a horizontal load determining substep S11 of the cross arm under the strong wind condition, calculating the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the strong wind condition, and determining the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the strong wind condition as the horizontal wind load of the cross arm of the power transmission tower under the strong wind condition.
In particular, since the wind load of the cross arm itself is much smaller than the wind load of the power transmission line at the hanging point, in the test, only the wind load F of the power transmission line acting at the hanging point is consideredwc. Under the condition of strong wind, calculating the wind load F of the transmission conductor at the cross arm hanging point according to the wind speed and the length of the transmission conductor at the cross arm hanging point of the transmission towerwc. And determining the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the strong wind working condition as the horizontal wind load of the cross arm of the power transmission tower under the strong wind working condition. During specific implementation, the direction of the horizontal wind load under the working condition of strong wind can be vertical to the direction of the power transmission conductor, and the actuator can be adopted to apply sinusoidal wind load to the cross arm, and the expression of the horizontal wind load of the cross arm of the power transmission tower at different moments t is as follows:wherein f isWCF can be obtained by performing modal analysis on the cross arm of the power transmission tower for the self-oscillation frequency of the cross armWC. It should be noted that the wind load F of the transmission conductor at the cross-arm hang-up point is calculated from the wind speed and length of the transmission conductor at the cross-arm hang-up point of the transmission towerwcThe methods are well known to those skilled in the art and are not described in detail.
And a sub-step S12 of determining the vertical load of the cross arm under the strong wind condition, wherein the sum of the weights of the transmission conductor, the hardware fitting and the insulator is determined as the vertical wind load of the cross arm of the transmission tower under the strong wind condition.
Particularly, the transmission conductor, the hardware fitting and the insulator at the hanging point of the cross arm are weightedThe sum of the quantities is determined as the vertical wind load G of the cross arm under the working condition of strong windc. During specific implementation, the vertical wind load is applied in a constant load mode and is simulated and realized by adopting a counterweight method. It should be noted that the counterweight method is well known to those skilled in the art, and therefore, is not described in detail.
In the embodiment, the wind load under the working condition of strong wind in the actual environment is simulated, namely the combined action of the horizontal wind load and the vertical wind load is considered at the same time, so that the test environment of the cross arm is closer to the actual working environment, and the accuracy of the anti-loosening performance evaluation of the bolt is ensured.
In an embodiment of the present invention, the preset condition is a waving condition, and the load calculating step S1 may further include:
determining the galloping amplitude of the transmission conductor according to the level of the galloping area where the transmission conductor is located and the structural parameters of the transmission conductor, and calculating the horizontal wind load and the vertical wind load of the cross arm of the transmission tower under the galloping working condition according to the galloping amplitude of the transmission conductor and a standing wave theory.
Specifically, firstly, determining the galloping amplitude of the transmission conductor according to the strength level of the galloping area where the transmission conductor is located and the structural parameters of the transmission conductor, and then calculating the horizontal wind load F of the transmission conductor under the galloping working condition according to the galloping amplitude of the transmission conductor and the standing wave theoryGAnd vertical wind load GGFinally, the horizontal wind load F of the transmission conductor under the galloping working conditionGAnd vertical wind load GGDetermining the horizontal wind load F of the cross arm under the galloping working conditionGAnd vertical wind load GG. During specific implementation, the direction of the horizontal wind load under the galloping working condition can be parallel to the direction of the power transmission conductor, and the actuator can be adopted to apply sinusoidal wind load to the cross arm, and the expression of the horizontal wind load of the cross arm of the power transmission tower at different moments is as follows:wherein f isGThe galloping frequency of the power transmission conductor serving as the cross arm can be determined according to the structural parameters and the galloping order of the power transmission conductorF is fixedG. The vertical wind load is applied in a constant load mode and is simulated and realized by adopting a counterweight method. It should be noted that the calculation method of the transmission conductor galloping amplitude and the method of calculating the horizontal wind load and the vertical wind load by using the standing wave theory are well known to those skilled in the art, and therefore are not described in detail.
In this embodiment, simulate the wind load under the working condition of waving in the actual environment, consider simultaneously promptly horizontal wind load and vertical wind load's combined action, make the experimental environment of cross arm more close actual operational environment, ensured the accuracy of bolt locking performance aassessment.
In one embodiment of the present invention, the loose load number determining step S4 may further include:
and a loading time determining substep S41, wherein the loading time is the time when the pretension force of each bolt is zero.
Specifically, the pretightening force time-course curve of each bolt obtained in the above steps is observed, and when the pretightening force of each bolt is zero, the time is recorded and taken as the loading time.
And a frequency calculation substep S42, calculating the loading frequency of the wind load of the cross arm of the transmission tower under each preset working condition.
Specifically, under the condition of strong wind, the natural vibration frequency f of the cross armWCDetermining the loading frequency of the wind load, and carrying out modal analysis on the cross arm of the power transmission tower to obtain fWC. Under the condition of galloping, the galloping frequency f of the transmission conductorGDetermining the loading frequency of wind load, and determining f according to the structural parameters and the waving order of the transmission conductorG。
And a loading frequency determining substep S43 of determining the number of times of loading when each bolt is loosened, based on the loading time and the loading frequency.
Specifically, the number of times of loading when each bolt is loosened is determined according to the product of the loading time and the loading frequency of each bolt obtained in the above step.
In the embodiment, the loading times of each bolt in loosening are determined according to the loading time and the loading frequency of each bolt, and the method is simple and easy to implement.
In order to compare different schemes, the single-cap bolt and the double-cap bolt can be respectively tested by adopting the method, so that bolt loosening distribution conditions in single-cap bolt connection and the double-cap bolt can be determined, the loading times of the single-cap bolt and the double-cap bolt are compared, and the single-cap bolt and the double-cap bolt which are loosened firstly are determined as bolts with weak loosening prevention performance.
Specifically, the bolts all select single-cap bolts, the load calculation step S1, the wind load application step S2, the measurement rod piece selection step S3, the pretightening force time course curve acquisition step S4 and the loosening loading frequency determination step S5 are repeated, and the loading frequency of each single-cap bolt is determined respectively. And then, selecting all the bolts as double-cap bolts, repeating the load calculation step S1, the wind load applying step S2, the measuring rod piece selecting step S3, the pretightening force time course curve acquiring step S4 and the loosening loading frequency determining step S5, and determining the loading frequency of each double-cap bolt. And finally, comparing the loading times of each single-cap bolt with each double-cap bolt, and determining the single-cap bolt and the double-cap bolt which are loosened firstly as the bolts with weak anti-loosening performance. For the bolt which is loosened firstly, the bolt is a single-cap bolt, and the looseness prevention performance of the single-cap bolt can be improved by properly increasing pretightening force or replacing the single-cap bolt with a double-cap bolt. For the bolt which is loosened firstly is the double-cap bolt, the anti-loosening performance of the double-cap bolt can be improved by properly increasing the pretightening force.
In the embodiment, the anti-loosening performance of the single-cap bolt and the double-cap bolt is effectively evaluated by comparing the loading times of each single-cap bolt and each double-cap bolt, and an anti-loosening optimization scheme of the bolts can be better provided.
The method in this embodiment will be described in more detail below by taking the waving condition as an example:
500kV dry wave zoneFor example, a rectangular tower is provided with 1-base tension towers at the front and the rear, and the lead span at the front and the rear is 275m and 310m respectively. The transmission conductor is 4 XLGJ 630/45, the initial tension of a single transmission conductor is 47.02kN, and the galloping frequency f of the transmission conductorGIs 0.05 Hz. The cross arm of the power transmission tower adopts 6.8-grade bolts of M16 and M20, and the standard values of the bolt installation torque are respectively 80N M and 100N M.
Firstly, determining the galloping amplitude values of front and rear two-gear transmission conductors of the tension tower to be 7.17m and 8.08m respectively, and calculating to obtain the horizontal load F of the transmission conductor based on the standing wave theoryGAnd vertical load GG240kN and 30kN, respectively.
Then, a finite element model of the power transmission tower cross arm shown in fig. 2 is established, the wind load under the determined galloping condition is applied to a hanging point 4 ○ of a power transmission conductor of the power transmission tower cross arm, a finite element analysis method is adopted to calculate the stress ratio of each rod piece of the cross arm under the galloping condition, the preset stress ratio is 0.5, the distribution of the rod pieces with the peak value of the stress ratio exceeding 0.5 is shown in fig. 2, the rod piece distribution is respectively a main plane material 1 under the cross arm, a diagonal plane material 2 under the first cross arm and a diagonal plane material 3 under the second cross arm, and the calculated value of the stress ratio of the rod piece with the peak value exceeding 0.5 can be referred to table 1:
TABLE 1
| Rod numbering | Lower plane main material 1 | First lower plane inclined material 2 | Second lower plane inclined material 3 |
| Stress ratio | 0.62 | 0.83 | 0.93 |
And taking the rod piece with the stress ratio peak value exceeding the preset stress ratio as a rod piece for measuring the anti-loosening performance of the bolt, and installing a pre-tightening force sensor between the connecting bolt and the connecting plate of each rod piece. The connecting bolt of each measuring rod can be a single-cap bolt or a double-cap bolt, and when each bolt is a double-cap bolt, referring to fig. 3, the nut 5 and the nut 6 are arranged on the connecting plate 7, the nut 9 is arranged below the connecting plate 7, and the pretightening force sensor 8 is arranged between the connecting plate 7 and the bolt 9. The arrangement of the cross-arm lower-plane bolt pretension sensor 8 can be seen in fig. 4.
And respectively applying horizontal wind load and vertical load at the hanging point of the transmission conductor of the cross arm of the transmission tower. And adjusting the relative position of the loading direction of the actuator and the cross arm structure to realize the application of the horizontal wind load under the galloping working condition. The characteristic curve of the horizontal wind load of the vibration test of the cross arm of the power transmission tower under the galloping working condition is a sine curve. According to horizontal wind load FGThe expression formula for obtaining the horizontal wind load in the vibration test of the cross arm of the power transmission tower at different moments is FG(t) ═ 120+120sin (2 π × 0.05 t). Vertical wind load G of hanging point of power transmission towerGIs 30kN and the vertical wind load is applied in a constant load mode, and is simulated by a counterweight method.
When the bolts are respectively single-cap bolts and double-cap bolts, a vibration test of the cross arm bolt of the power transmission tower under the galloping working condition is carried out, and a pretightening force time course curve F (t) of the bolt is measured by using the pretightening force sensor 8.
And finally, determining the loading times N of the bolt loosening according to the pretightening force time course curve F (t), wherein the loading times N of the single-cap bolt and the double-cap bolt can be shown in a table 2:
TABLE 2
| Bolt form | Bolt A | Bolt B | Bolt C | Bolt D |
| Single nut | 45 | 60 | 90 | 105 |
| Double nut | 180 | 150 | 210 | ＞300 |
It can be seen from table 2 that bolt a and bolt B are loosened first under the action of wind load under the working condition of galloping, and when the cross arm bolt of the power transmission tower is anti-loose, the anti-loose performance of the cross arm bolt can be improved by properly increasing the pretightening force of the two bolts or replacing the single-cap bolt with a double-cap bolt for the single-cap bolt, and the anti-loose performance of the cross arm bolt can be improved by properly increasing the pretightening force of the two bolts for the double-cap bolt.
In the embodiment, by determining the loading times of the loosening of the cross arm bolt, the mechanism, the sequence and the distribution positions of the loosening of the bolts at different parts of the cross arm of the power transmission tower can be accurately determined, the aim of investigating the overall anti-loosening performance of the cross arm structure is fulfilled, the effective evaluation of the anti-loosening performance of the cross arm of the power transmission tower is further realized, the overall safety of the cross arm is ensured, and the safety performance of the power transmission line is further better.
The embodiment of the device is as follows:
referring to fig. 5, fig. 5 is a structural block diagram of a testing apparatus for anti-loosening performance of a cross arm bolt of a power transmission tower according to an embodiment of the present invention. As shown, the apparatus comprises: the device comprises a load calculation module 100, a wind load applying module 200, a measuring rod piece selecting module 300, a pretightening force time course curve acquiring module 400, a loosening and loading frequency determining module 500 and a loosening prevention performance evaluating module 600. Wherein,
the load calculation module 100 is configured to calculate a wind load of the power transmission tower under each preset working condition. The wind load applying module 200 is configured to establish a finite element model of the power transmission tower, and apply a corresponding wind load to the cross arm of the power transmission tower under each preset working condition. The measuring rod piece selecting module 300 is used for calculating the stress of each rod piece in the cross arm under the wind load, and selecting the rod piece with the stress ratio larger than the preset stress ratio as the measuring rod piece. The pretightening force time course curve acquiring module 400 is configured to acquire a pretightening force time course curve of the bolt installed on the selected measuring rod when the bolts installed on the measuring rod are loosened by the wind load. The loosening and loading frequency determining module 500 is used for determining the loading frequency of each bolt when loosening according to the pretightening force time course curve. The anti-loosening performance evaluation module 600 is configured to determine distribution of loosening positions of bolts according to the number of times of loading when the bolts are loosened, and determine a bolt that is loosened first as a bolt with weak anti-loosening performance. The specific implementation process of the apparatus may refer to the description in the above method embodiments, and the description of the embodiment is omitted here for brevity.
In the embodiment, by determining the loading times of the loosening of the cross arm bolt, the mechanism, the sequence and the distribution positions of the loosening of the bolts at different parts of the cross arm of the power transmission iron can be accurately determined, the aim of investigating the overall anti-loosening performance of the cross arm structure is fulfilled, the effective evaluation of the anti-loosening performance of the cross arm of the power transmission tower is further realized, the overall safety of the cross arm is ensured, and the safety performance of the power transmission line is further better.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A test method for anti-loosening performance of a cross arm bolt of a power transmission tower is characterized by comprising the following steps:
calculating wind load of the power transmission tower under each preset working condition;
applying corresponding wind load to the cross arm of the power transmission tower under each preset working condition;
calculating the stress of each rod piece in the cross arm under the wind load, and selecting the rod piece with the stress ratio larger than a preset stress ratio as a measuring rod piece;
when the wind load enables the bolts mounted on the measuring rod pieces to be loosened, acquiring a pretightening force time course curve of the bolt mounted on the selected measuring rod piece, and determining the loading times when the bolts are loosened according to the pretightening force time course curve;
and determining the distribution condition of the loosening positions of the bolts according to the loading times when the bolts are loosened, and determining the bolt loosened firstly as a bolt with weak loosening prevention performance.
2. The method for testing the anti-loosening performance of the cross arm bolt of the transmission tower according to claim 1, wherein the method is used for calculating the wind load of the transmission tower under each preset working condition: the preset working condition comprises: strong wind conditions and waving conditions.
3. The method for testing looseness-proof performance of the cross arm bolt of the power transmission tower according to claim 2, wherein the preset working conditions are high wind working conditions, and the calculating the wind load of the power transmission tower under each preset working condition further comprises:
calculating the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the working condition of strong wind, and determining the wind load of the power transmission line at the hanging point of the cross arm of the power transmission tower under the working condition of strong wind as the horizontal wind load of the cross arm of the power transmission tower under the working condition of strong wind;
and determining the sum of the weight of the transmission conductor, the hardware fitting and the insulator as the vertical wind load of the cross arm of the transmission tower under the working condition of strong wind.
4. The method for testing looseness prevention performance of a cross arm bolt of a transmission tower according to claim 3,
and the horizontal wind load direction of the cross arm of the power transmission tower under the strong wind working condition is vertical to the direction of the power transmission conductor.
5. The method for testing looseness prevention performance of the cross arm bolt of the power transmission tower according to claim 2, wherein the preset working conditions are galloping working conditions, and the calculating the wind load of the power transmission tower under each preset working condition further comprises:
determining the galloping amplitude of the transmission conductor according to the level of the galloping area of the transmission conductor at the hanging point of the transmission tower cross arm and the structural parameters of the transmission conductor, and calculating the horizontal wind load and the vertical wind load of the transmission tower cross arm under the galloping working condition according to the galloping amplitude of the transmission conductor and a standing wave theory.
6. The method for testing looseness prevention performance of a cross arm bolt of a transmission tower according to claim 5,
and the horizontal wind load direction of the cross arm of the power transmission tower under the galloping working condition is parallel to the direction of the power transmission conductor.
7. The method for testing looseness-proof performance of the cross arm bolt of the power transmission tower according to claim 1, wherein the determining the loading times when each bolt loosens according to the pretightening force time course curve further comprises:
the loading time is the time when the pretightening force of each bolt is zero;
calculating the loading frequency of the wind load of the cross arm of the power transmission tower under each preset working condition;
and determining the loading times when the bolts are loosened according to the loading time and the loading frequency.
8. The method for testing looseness prevention performance of a cross arm bolt of a transmission tower according to claim 7, wherein in the determining of the number of times of loading when each of the bolts is loosened based on the loading time and the loading frequency,
and determining the product of the loading time and the loading frequency as the loading times.
9. The method for testing the looseness prevention performance of the cross arm bolt of the power transmission tower according to claim 1, further comprising:
repeating the steps, and respectively determining the loading times when each bolt is a single-cap bolt and a double-cap bolt;
and comparing the loading times of each single-cap bolt with the loading times of each double-cap bolt, and determining the single-cap bolt and the double-cap bolt which are loosened firstly as bolts with weak anti-loosening performance.
10. The utility model provides a test device of locking performance of transmission tower cross arm bolt, characterized in that includes:
the load calculation module is used for calculating wind loads of the power transmission tower under each preset working condition;
the wind load applying module is used for establishing a finite element model of the power transmission tower and applying corresponding wind loads to the cross arm of the power transmission tower under each preset working condition;
the measuring rod piece selecting module is used for calculating the stress of each rod piece in the cross arm under the wind load and selecting the rod piece with the stress ratio larger than the preset stress ratio as the measuring rod piece;
the pre-tightening force time-course curve acquisition module is used for acquiring a pre-tightening force time-course curve of the bolt installed on the selected measuring rod piece when the bolts installed on the measuring rod pieces are loosened by the wind load;
the loosening and loading frequency determining module is used for determining the loading frequency of each bolt when the bolt is loosened according to the pretightening force time course curve;
and the anti-loosening performance evaluation module is used for determining the distribution condition of the loosening positions of the bolts according to the loading times when the bolts are loosened, and determining the bolt loosened firstly as a bolt with weak anti-loosening performance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610913012.2A CN106568562B (en) | 2016-10-19 | 2016-10-19 | The test method and device of power transmission tower crossarm bolt anti-loosening property |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610913012.2A CN106568562B (en) | 2016-10-19 | 2016-10-19 | The test method and device of power transmission tower crossarm bolt anti-loosening property |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106568562A CN106568562A (en) | 2017-04-19 |
| CN106568562B true CN106568562B (en) | 2019-08-27 |
Family
ID=58534063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610913012.2A Active CN106568562B (en) | 2016-10-19 | 2016-10-19 | The test method and device of power transmission tower crossarm bolt anti-loosening property |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106568562B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109000873B (en) * | 2018-06-07 | 2020-02-04 | 西南交通大学 | Bolt loosening life prediction method |
| CN109918854B (en) * | 2019-04-09 | 2022-08-19 | 国网江苏省电力有限公司电力科学研究院 | Composite insulation cross arm durability evaluation method and device |
| CN111122140B (en) * | 2020-01-08 | 2021-07-16 | 国网湖北省电力有限公司电力科学研究院 | Device and method for diagnosing looseness of bolt of connecting node of pole material of power transmission tower |
| CN113358313A (en) * | 2021-06-08 | 2021-09-07 | 国网河南省电力公司电力科学研究院 | Method for testing looseness of bolts of power transmission iron tower |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0198705A (en) * | 1987-10-08 | 1989-04-17 | Mitsui Eng & Shipbuild Co Ltd | Looseness detecting method of bolt |
| CN101866395A (en) * | 2010-05-27 | 2010-10-20 | 中国电力科学研究院 | Method for calculating load of hanging point of power transmission line tower during conductor galloping |
| CN102879161A (en) * | 2012-09-29 | 2013-01-16 | 河南省电力公司电力科学研究院 | Method for evaluating and detecting looseness prevention performance of fasteners of transmission towers |
| CN103218499A (en) * | 2013-05-03 | 2013-07-24 | 国家电网公司 | Method of line waving load risk modeling |
| CN105181315A (en) * | 2015-09-07 | 2015-12-23 | 江苏欧讯能源科技有限公司 | High-strength wind power tower cylinder bolt state early warning method in wind power generation |
| CN105719071A (en) * | 2016-01-18 | 2016-06-29 | 中国电力科学研究院 | Evaluation method of safety performance of power transmission circuit under effects of strong wind |
-
2016
- 2016-10-19 CN CN201610913012.2A patent/CN106568562B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0198705A (en) * | 1987-10-08 | 1989-04-17 | Mitsui Eng & Shipbuild Co Ltd | Looseness detecting method of bolt |
| CN101866395A (en) * | 2010-05-27 | 2010-10-20 | 中国电力科学研究院 | Method for calculating load of hanging point of power transmission line tower during conductor galloping |
| CN102879161A (en) * | 2012-09-29 | 2013-01-16 | 河南省电力公司电力科学研究院 | Method for evaluating and detecting looseness prevention performance of fasteners of transmission towers |
| CN103218499A (en) * | 2013-05-03 | 2013-07-24 | 国家电网公司 | Method of line waving load risk modeling |
| CN105181315A (en) * | 2015-09-07 | 2015-12-23 | 江苏欧讯能源科技有限公司 | High-strength wind power tower cylinder bolt state early warning method in wind power generation |
| CN105719071A (en) * | 2016-01-18 | 2016-06-29 | 中国电力科学研究院 | Evaluation method of safety performance of power transmission circuit under effects of strong wind |
Non-Patent Citations (2)
| Title |
|---|
| 大功率碟式太阳能发电系统关键螺栓连接强度分析;刘繁茂 等;《湖南科技大学学报（自然科学版）》;20160930;第31卷(第3期);第25-31页 * |
| 导线舞动时输电铁塔承载性能及破坏模式分析;杨风利 等;《中国电机工程学报》;20130805;第33卷(第22期);第135-141页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106568562A (en) | 2017-04-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106568562B (en) | The test method and device of power transmission tower crossarm bolt anti-loosening property | |
| CN106841577B (en) | Concrete loading device and method applicable to load-environment coupling effect | |
| CN102879161B (en) | The anti-loosening property assessment detection method of electric power pylon securing member | |
| CN109388865A (en) | The shaft tower emergency early warning method for failure under operating condition is settled a kind ofly | |
| CN102507123A (en) | Test method used for transmission line ice coating disconnection | |
| CN106679916A (en) | Anti-seismic experimental method and test system of GIS device | |
| RU2570231C1 (en) | Bench for testing of reinforced concrete elements for joint short-term dynamic impact of twisting and running torque | |
| CN106525368B (en) | A kind of cathead electric power pylon damping ratio recognition methods | |
| CN106528902A (en) | Method for evaluating anti-loosening property of double-nut bolt of power transmission iron tower | |
| WO2022001703A1 (en) | Marine climate environment-bending load coordinated acceleration test method for metal material | |
| CN108152130A (en) | Three side method wind electricity blade static test methods | |
| US8714032B2 (en) | Universal force measurement apparatus and method | |
| KR20130021960A (en) | Measurement system and method of variation rate within rotor bolt | |
| CN113504038A (en) | Method for evaluating damage of engineering equipment arm support structure | |
| CN109520922A (en) | A kind of test device and test method of bolt coefficient of friction and torque coefficient | |
| Weidinger et al. | Investigations towards extrapolation approaches for torque transducer characteristics | |
| CN106021776B (en) | A kind of aircraft structure test part is anti-bending and measuring device and its measurement method | |
| CN114814664A (en) | Fretting wear experiment device and method for wire system of connecting wire clamp | |
| CN107609293A (en) | The determination methods of product loosened fastener in random vibration | |
| CN207396254U (en) | A kind of auxiliary device based on the calibrating of bolt torsion tester torque | |
| CN103364277B (en) | A kind of system and method thereof of monitoring mechanical resistance | |
| CN104614162A (en) | Bolt connecting piece deformation and friction simulation test device | |
| CN107063611B (en) | Anti-seismic evaluation method for electrical equipment made of pillar composite material | |
| CN205749146U (en) | The device of easy detection structural steel intensity | |
| CN114492012A (en) | Multi-axis random vibration life prediction method considering bandwidth influence |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |