CN113639912A - Method, device and system for detecting column leg stress under radial load of three-column insulator - Google Patents
Method, device and system for detecting column leg stress under radial load of three-column insulator Download PDFInfo
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Abstract
The invention discloses a method, a device and a system for detecting column leg stress under radial load of a three-column insulator, wherein the method comprises the following steps: acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as first propagation time; obtaining a vertical stress acoustoelastic equation of the material sample to be measured according to the first propagation time; acquiring the propagation time of ultrasonic longitudinal waves in the column leg under the radial load of the three-column insulator to be detected as second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected; and calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustoelastic equation. The invention has the advantages of low detection cost, high detection precision, convenient carrying, no radiation to human body and the like, and can efficiently, intuitively and nondestructively detect the column leg stress under the radial load of the three-column insulator.
Description
Technical Field
The invention relates to the field of power transmission and transformation insulating equipment, in particular to a method, a device and a system for detecting column leg stress under radial load of a three-column insulator.
Background
The three-post insulator is a key electrical component in a gas insulated metal enclosed transmission line (GIL) and plays a role in electrical insulation and mechanical support, and mechanical stress of the three-post insulator can be one of causes of insulator faults, and sources of the mechanical stress comprise residual stress in a manufacturing process and stress caused by external loads in the processes of transportation, installation and operation. The three-post insulator in the gas insulated metal closed transmission line is formed by mixing liquid epoxy resin, a curing agent and an inorganic powder filler, integrally pouring the mixture with an insert and curing the mixture at a high temperature, and residual stress exists in the manufacturing process. The insulator may have jolt vibration and mechanical friction in the transportation of the gas insulated metal enclosed transmission line, and a three-dimensional vibration impact acceleration detector is installed at present to detect the impact force applied to the gas insulated metal enclosed transmission line in the transportation process. The stress of the insulator caused by the installation of the gas insulated metal closed transmission line can be caused by the inclined installation of the conducting rod, the uneven fastening force of the fixing plate and the like, and the insulator bears the weight of the insulator and a part of the conductor when in operation, the electrodynamic force of the shell and the conductor in a current alternating electromagnetic field and the like. Therefore, the three-post insulator is confirmed to be in a stress state as soon as possible, and the method has important significance for guaranteeing safe operation of a power system.
At present, a mechanical load test can only examine whether a three-post insulator passes a certain limit value or measures a mechanical failure load, but cannot measure and evaluate the mechanical performance or stress under any load, and the stress evolution process from generation and expansion of micro defects such as cracks to mechanical failure or electrical breakdown of the insulator is not known.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a method, a device, a system and a storage medium for detecting the column leg stress under the radial load of a three-column insulator, which have the advantages of low detection cost, high detection precision, convenience in carrying, no radiation hazard to a human body and capability of efficiently, accurately and visually detecting and evaluating the column leg stress under the radial load of the three-column insulator.
The invention aims to provide a method for detecting column leg stress under radial load of a three-column insulator.
The invention also provides a device for detecting the column leg stress under the radial load of the three-column insulator.
The invention also provides a system for detecting the column leg stress under the radial load of the three-column insulator.
It is a fourth object of the present invention to provide a computer-readable storage medium.
The first purpose of the invention can be achieved by adopting the following technical scheme:
a method for detecting column leg stress under radial load of a three-column insulator comprises the following steps:
acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
obtaining a vertical stress acoustoelastic equation of the material sample to be measured according to the first propagation time;
acquiring the propagation time of ultrasonic longitudinal waves in the column leg under the radial load of the three-column insulator to be detected as second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected;
and calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustoelastic equation.
Further, the obtaining of the vertical stress acoustic-elastic equation of the material sample to be measured according to the first propagation time specifically includes:
according to the sound path d1 of the ultrasonic longitudinal wave in the material sample to be measured and the first propagation time t under the load F1Calculating the ultrasonic sound velocity V1The calculation formula is as follows:
according to the obtained ultrasonic sound velocity V1The vertical stress acoustic elastic coefficient K is calculated by the following formula:
wherein, V0Is zero stress sigma0The sound velocity of the time, measuring the sigma of the material sample to be measured0Lower ultrasonic longitudinal sound velocity V02997.02 m/s; if the external load F is uniformly distributed over the stressed area, the stress sigma1The relation with the applied load F is that F is sigma1d1d2(ii) a d1 and d2 are respectively the length and the height of the material sample to be detected;
and (3) returning the obtained vertical stress acoustic-elastic coefficient K to be substituted into the formula (2) to obtain a vertical stress acoustic-elastic equation of the material sample to be measured, wherein the equation is as follows:
wherein V is the ultrasonic sound velocity.
Furthermore, the three-post insulator comprises a solid epoxy piece, a central conductor and a grounding insert, wherein the solid epoxy piece comprises post legs, and the bottom of each post leg is combined with one grounding insert;
the detection range of the three-post insulator leg to be detected is as follows: the stress direction in the range is vertical to the ultrasonic propagation direction of the part in the set value above the interface of the three-post insulator leg to be tested and the corresponding grounding insert.
Further, the calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustic-elastic equation specifically includes:
calculating an ultrasonic sound velocity V according to a sound path D of ultrasonic longitudinal waves transmitted on a three-post insulator leg to be measured and a second transmission time t under a load F, wherein the calculation formula is as follows:
and substituting the obtained ultrasonic sound velocity V into a vertical stress acoustoelastic equation to obtain the stress of the position to be measured of the column leg under the radial load of the three-column insulator.
Furthermore, the ultrasonic detection system comprises an ultrasonic pulse generator, an oscilloscope, ultrasonic longitudinal wave straight probes, a probe adapting line and a high-impedance transmission line, wherein the two ultrasonic longitudinal wave straight probes are respectively connected with the signal output end and the signal input end of the ultrasonic pulse generator through the probe adapting line, and the signal synchronization end of the ultrasonic pulse generator is connected with the oscilloscope through the high-impedance transmission line;
when the first propagation time is obtained, adjusting an ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with an oil-based ultrasonic coupling agent at two ends of a material sample to be measured, which is installed between an upper plate and a bottom plate of a universal testing machine, so as to record the propagation time of the ultrasonic longitudinal wave in the material sample to be measured as the first propagation time;
and when the second propagation time is obtained, adjusting the ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with the oil-based ultrasonic couplant at two ends of the three-column insulator leg to be measured, which is installed on the tensile machine, so as to record the propagation time of the ultrasonic longitudinal wave in the three-column insulator leg to be measured, wherein the propagation time is used as the second propagation time.
Further, the first propagation time is: an ultrasonic primary wave is emitted by one ultrasonic longitudinal wave straight probe at one side of a material sample to be detected, the ultrasonic primary wave is vertically incident into the material sample to be detected, a penetrating wave is received by the other ultrasonic longitudinal wave straight probe at a corresponding position at the other side of the material sample to be detected, and the starting oscillation time difference of the ultrasonic primary wave and the penetrating wave is the propagation time of the ultrasonic longitudinal wave at the position to be detected.
Further, the second propagation time is: an ultrasonic longitudinal wave straight probe sends out ultrasonic initial waves at one side of a three-post insulator leg to be detected, the ultrasonic initial waves vertically enter the three-post insulator leg to be detected, penetrating waves are received by another ultrasonic longitudinal wave straight probe at a corresponding position at the other side of the three-post insulator leg to be detected, and the starting vibration time difference of the ultrasonic initial waves and the penetrating waves is the propagation time of the ultrasonic longitudinal waves at the position to be detected.
The second purpose of the invention can be achieved by adopting the following technical scheme:
a device for detecting column leg stress under radial load of a three-column insulator is characterized by comprising:
the first propagation time acquisition module is used for acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected under the radial load through the ultrasonic detection system, and the propagation time is used as the first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
the vertical stress acoustic-elastic equation acquisition module is used for acquiring a vertical stress acoustic-elastic equation of the material sample to be measured according to the first propagation time;
the second propagation time acquisition module is used for acquiring the propagation time of the ultrasonic longitudinal wave in the column leg under the radial load of the three-column insulator to be detected as second propagation time through the ultrasonic detection system in the detection range of the three-column insulator to be detected;
and the stress calculation module of the column leg under the radial load is used for calculating the stress of the column leg under the radial load of the three-column insulator to be measured according to the second propagation time and the vertical stress acoustoelastic equation.
The second purpose of the invention can be achieved by adopting the following technical scheme:
the device for detecting the column leg stress under the radial load of the three-column insulator comprises a processor and a memory for storing a program executable by the processor, and is characterized in that the detection method is realized when the processor executes the program stored in the memory.
The third purpose of the invention can be achieved by adopting the following technical scheme:
the utility model provides a detecting system of post leg stress under three post insulators radial load, the system includes the detecting device of post leg stress under three post insulators, the pulling force machine of awaiting measuring, ultrasonic testing system and three post insulators radial load, wherein:
the ultrasonic detection system comprises an ultrasonic pulse generator, an oscilloscope, two ultrasonic longitudinal straight probes, a probe adapting line and a high-impedance transmission line, wherein the two ultrasonic longitudinal straight probes are respectively connected with the signal output end and the signal input end of the ultrasonic pulse generator through the probe adapting line;
the three-post insulator leg to be tested is arranged on the tensile machine, the ultrasonic pulse generator is adjusted, and the two ultrasonic longitudinal wave straight probes coated with the oil-based ultrasonic coupling agent are symmetrically and coaxially arranged at two ends of the three-post insulator leg to be tested;
the device for detecting the stress of the column leg under the radial load of the three-column insulator is as claimed in any one of claims 8 to 9.
The fourth purpose of the invention can be achieved by adopting the following technical scheme:
a computer-readable storage medium storing a program which, when executed by a processor, implements the detection method described above.
Compared with the prior art, the invention has the following beneficial effects:
according to the method, the propagation time of the ultrasonic longitudinal wave in the material sample to be detected is obtained through the ultrasonic detection system, so that the vertical stress acoustic-elastic equation of the material sample to be detected is obtained, the propagation time of the ultrasonic longitudinal wave in the column leg under the radial load of the three-column insulator to be detected is obtained through the ultrasonic detection system, and the stress of the column leg under the radial load of the three-column insulator can be measured by combining the vertical stress acoustic-elastic equation.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a flowchart of a method for detecting column leg stress under a radial load of a three-column insulator according to embodiment 1 of the present invention.
Fig. 2 is a schematic view of an ultrasonic inspection system according to embodiment 1 of the present invention.
Fig. 3 is a schematic structural view of an ultrasonic longitudinal wave straight probe in embodiment 1 of the present invention: wherein, a) is the front view of the ultrasonic longitudinal wave straight probe, and b) is the bottom schematic view of the ultrasonic longitudinal wave straight probe.
Fig. 4 is a schematic view of a system for testing a vertical stress acoustic elastic coefficient of an epoxy composite standard sample for a three-post insulator according to embodiment 1 of the present invention.
Fig. 5 is a schematic structural diagram of a standard sample of an epoxy composite material for a post insulator according to embodiment 1 of the present invention: wherein, a) is a schematic diagram of a standard sample, b) is a front view of the standard sample, and c) is a side view of the standard sample.
Fig. 6 is a waveform diagram of ultrasonic longitudinal wave penetration detection of a standard sample of an epoxy composite material for a three-post insulator according to example 1 of the present invention.
Fig. 7 is a schematic view of a system for detecting column leg stress under a radial load of a three-column insulator according to embodiment 1 of the present invention.
Fig. 8 is a schematic structural view of a three-post insulator according to embodiment 1 of the present invention: wherein, a) is a front view of the three-post insulator, and b) is a schematic diagram of the optimal detection position of the three-post insulator leg.
Fig. 9 is a block diagram of a device for detecting column leg stress under a radial load of a three-column insulator according to embodiment 2 of the present invention.
Fig. 10 is a block diagram of a device for detecting leg stress under a radial load of a three-post insulator according to embodiment 3 of the present invention.
Fig. 11 is a block diagram of a system for detecting column leg stress under a radial load of a three-column insulator according to embodiment 4 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
as shown in fig. 1, the present embodiment provides a method for detecting a leg stress under a radial load of a three-post insulator, where the method includes the steps of:
s101, acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as a first propagation time.
In this embodiment, the material sample to be tested is a standard epoxy composite material sample for a three-post insulator, and the step S101 specifically includes:
s1011, building an ultrasonic detection system.
As shown in fig. 2, the detection system by the ultrasonic longitudinal wave reflection method includes an ultrasonic pulse generator 1, an oscilloscope 2, two ultrasonic longitudinal wave straight probes 3, two probe adaptation lines 4 and a high impedance transmission line 5.
The two ultrasonic longitudinal wave straight probes 3 are connected with a signal output end T and a signal input end R of the ultrasonic pulse generator 1 through a probe adaptive line 4, and a signal synchronization end of the ultrasonic pulse generator 1 is connected with the oscilloscope 2 through a high-impedance transmission line 5.
The ultrasonic pulse generator 1 is a pulse generator with short pulse excitation, adjustable output pulse width, high gain and low noise, and the short pulse excitation can optimize broadband response and improve the near-surface detection resolution, thereby being more beneficial to the detection and measurement application of materials with strong sound beam attenuation.
The oscilloscope 2 is a three-channel high-performance digital storage oscilloscope with the maximum sampling frequency of 2GHz and the sampling bandwidth of 500MHz, and the input channel of the oscilloscope 2 and the signal output end of the ultrasonic pulse generator 1 are connected with the electric potential through a high-impedance transmission line 5, so that the transmitted and received ultrasonic signals can be displayed on the oscilloscope in real time.
The probe adapting wire 4 is a signal wire matching the ultrasonic pulse generator 1 and the ultrasonic longitudinal wave straight probe 3, has the characteristics of high impedance, strong anti-interference capability and the like, ensures that an output electric signal of the ultrasonic pulse generator can be received by the ultrasonic longitudinal wave straight probe with high quality, and simultaneously ensures that the ultrasonic signal received by the ultrasonic longitudinal wave straight probe 3 is converted into an electric signal which returns to a receiving end of the ultrasonic pulse generator 1 with high quality.
The high-impedance transmission line is a transmission line with small stray inductance and resistance, phase delay of high-frequency signals in the transmission process is shortened, real-time identical potential and same phase of electric signals received by the oscilloscope 2 and electric signals at the signal output end of the ultrasonic pulse generator 1 are ensured, detection errors are greatly reduced, and detection precision is ensured.
As shown in fig. 3, the ultrasonic longitudinal wave straight probe 3 belongs to a cylindrical longitudinal wave straight probe, and adopts a circular composite material piezoelectric wafer 31, and the bottom surface 32 of the probe is circular, so as to increase the contact effect between the probe and the measured position of the insulator and improve the detection precision, the smaller the radius of the bottom surface of the probe is, the better, but the smaller the bottom surface of the probe requires the circular composite material piezoelectric wafer to be very small, the energy of the ultrasonic wave emitted by the probe is also very small, and the detection characteristic, the detection efficiency and the manufacturing cost are comprehensively considered.
And S1012, acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be measured as a first propagation time.
In this embodiment, as shown in fig. 4, a schematic diagram of a system for testing a vertical stress acoustic elastic coefficient of a standard sample of an epoxy composite material for a 550kV three-post insulator is shown. As shown in fig. 5, it is a schematic structural diagram of a standard sample of epoxy composite material for a 550kV three-post insulator. Adjusting an ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with an oil-based ultrasonic couplant at two ends of an epoxy composite material standard sample 7 which is installed between an upper plate 61 and a bottom plate 62 of a universal testing machine 6, and recording the propagation time t1 of the ultrasonic longitudinal wave in the standard sample as first propagation time.
Furthermore, the two ultrasonic longitudinal wave straight probes are respectively connected with a signal output end T and a signal input end R of the ultrasonic pulse generator through the probe adaptive wires.
Furthermore, the oil-based ultrasonic couplant increases the contact effect of the ultrasonic longitudinal wave straight probe and the measured surface, and ensures the stability of ultrasonic waveforms.
Further, the standard sample of the epoxy composite material is a cuboid standard sample which is the same as the three-post insulator column leg in material and process and has the size of 70mm (d1) multiplied by 60mm (d2) multiplied by 50mm (d 3).
Furthermore, the symmetrical and coaxial arrangement means that the two ultrasonic longitudinal wave straight probes are respectively arranged at the centers of two symmetrical surfaces of the standard sample, and the central lines of the two probes are coaxial.
Furthermore, the universal testing machine is a mechanical load automatic loading device controlled by a microcomputer, the testing machine model is WAW-500C, the maximum loading mechanical load is 500kN, and the control precision is 1%.
Furthermore, the universal tester upper plate is a reverse T-shaped steel plate with a flat bottom surface, the bottom plate is an I-shaped steel plate with a flat bottom surface, and the upper plate and the bottom plate are 25mm thick d0 and made of No. 50 steel.
Fig. 6 is a waveform diagram of ultrasonic longitudinal wave penetration detection of the epoxy composite material standard sample for the three-post insulator in the embodiment. The propagation time t1 of the ultrasonic longitudinal wave in the standard sample is that an ultrasonic longitudinal wave straight probe sends out an ultrasonic initial wave F at one side of the standard sample, the ultrasonic initial wave F vertically enters the epoxy part, the penetrating wave I is received by another ultrasonic longitudinal wave straight probe at the corresponding position at the other side of the epoxy part, and the oscillation starting time difference between the ultrasonic initial wave F and the ultrasonic initial wave I is the propagation time t1 of the ultrasonic longitudinal wave at the position to be detected.
And S102, obtaining a vertical stress acoustic-elastic equation of the material sample to be measured according to the first propagation time.
The step S102 specifically includes:
and S1021, calculating the vertical stress acoustic-elastic coefficient of the epoxy composite material standard sample for the three-post insulator according to the first propagation time.
The sound path of the ultrasonic wave propagating in the standard sample is set as d1, the ultrasonic propagation time t1 (unit μ s) under the load F is recorded, and the sound velocity V1 (unit m/s) is
The vertical stress acoustic elastic coefficient K is obtained from the formula (2).
Wherein, V0The sound velocity at zero stress σ 0, in m/s, is measured for a standard sample σ0Lower ultrasonic longitudinal sound velocity V0Is 2997.02 m/s. Sigma0、σ1The units are MPa and K is/MPa. If the external load F is uniformly distributed over the stressed area, the stress sigma1F is related to the applied load1d1d2And F is in the unit of N.
In this embodiment, the vertical stress σ1The test range is 0-50 MPa, and the step length is 5 MPa.
And S1022, obtaining a corresponding acoustic elastic equation according to the vertical stress acoustic elastic coefficient of the epoxy composite material standard sample for the three-post insulator.
And (3) returning the obtained vertical stress acoustic-elastic coefficient K to substitute the formula (2) to obtain an acoustic-elastic equation of the vertical stress of the epoxy composite material standard sample for the three-post insulator, wherein the acoustic-elastic equation is the formula (3). Then the stress sigma in the material can be obtained by measuring the sound velocity V in the same material:
s103, acquiring the propagation time of the ultrasonic longitudinal wave in the column leg under the radial load of the three-column insulator to be detected as a second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected.
In this embodiment, as shown in fig. 7, a schematic diagram of an ultrasonic detection system for column leg stress under a radial load of a 550kV three-column insulator in this embodiment is shown. And adjusting an ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with an oil-based ultrasonic coupling agent at two ends of a post leg 911 of a three-post insulator 9 installed on a tensile machine 8, and recording the propagation time t of the ultrasonic longitudinal wave in the standard sample as second propagation time.
Fig. 8 is a schematic structural diagram of a 550kV three-post insulator in this embodiment, where the three-post insulator 9 includes a solid epoxy member 91, a central conductor 92, and a grounding insert 93, the solid epoxy member (epoxy for short) is made of an epoxy composite material and includes three legs, and the bottom of each leg is combined with one grounding insert. In engineering, the joint of the grounding insert and the bottom of the column leg (column foot) is most prone to internal defects such as air gaps and unshelling. The central conductor is of an aluminum annular structure. The size of the three-post insulator varies with the voltage class.
Further, the installation on the tensile machine means that the central conductor of the three-post insulator is fixed, and the test column leg is fixed on the tensile machine.
Further, the determined optimal detection range of the column leg is an optimal detection range 9111 suitable for ultrasonic detection of the stress of the column leg of the three-column insulator, the stress direction in the range is perpendicular to the ultrasonic propagation direction, and the embodiment is specified to be an epoxy part within 30mm above the interface of the grounding insert and the column leg.
Further, the recording of the propagation time t of the ultrasonic longitudinal wave in the three-post insulator leg is that an ultrasonic longitudinal wave straight probe sends an ultrasonic initial wave F at one side of the three-post insulator leg, the ultrasonic initial wave F vertically enters the inside of the three-post insulator leg, a penetrating wave I is received by another ultrasonic longitudinal wave straight probe at a corresponding position at the other side of the epoxy part, and the oscillation starting time difference between the ultrasonic initial wave F and the ultrasonic initial wave I is the propagation time t of the ultrasonic longitudinal wave at the position to be measured.
And S104, calculating the stress of the column leg under the radial load of the three-column insulator to be measured according to the second propagation time and the vertical stress acoustoelastic equation.
Setting the sound path of the ultrasonic longitudinal wave transmitted by the three-post insulator leg to be detected as D (namely the thickness of the detection position of the three-post insulator leg to be detected), recording the second transmission time t (unit μ s) under the load F, and then setting the sound velocity V (unit m/s) as follows:
and substituting the calculated ultrasonic sound velocity V of the three-post insulator leg into a formula (3) to obtain the stress sigma at the moment, namely obtaining the stress of the leg under the radial load of the three-post insulator.
Example 2:
as shown in fig. 9, the present embodiment provides a device for detecting column leg stress under radial load of a three-column insulator, where the device includes a first propagation time obtaining module 901, a vertical stress acoustoelastic equation obtaining module 902, a second propagation time obtaining module 903, and a column leg stress calculating module 904 under radial load, and the details of each module are as follows:
the first propagation time acquiring module 901 is configured to acquire, by using an ultrasonic detection system, propagation time of ultrasonic longitudinal waves in a material sample to be detected under a radial load. And the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg.
And a vertical stress acoustic elastic equation obtaining module 902, configured to obtain a vertical stress acoustic elastic equation of the material sample to be measured according to the propagation time.
And a second propagation time obtaining module 903, configured to obtain, by using an ultrasonic detection system, propagation time of an ultrasonic longitudinal wave in a column leg under a radial load of the three-column insulator to be detected, within a detection range of the three-column insulator to be detected.
And the stress calculation module 904 of the column leg under the radial load is used for calculating the stress of the column leg under the radial load of the three-column insulator to be measured according to the propagation time and the vertical stress acoustoelastic equation.
For specific implementation of each module in this embodiment, reference may be made to embodiment 1, which is not described herein again. It should be noted that, the apparatus provided in this embodiment is only illustrated by dividing the functional modules, and in practical applications, the functions may be distributed by different functional modules according to needs, that is, the internal structure is divided into different functional modules to complete all or part of the functions described above.
Example 3:
as shown in fig. 10, the present embodiment provides an apparatus for detecting column leg stress under radial load of a three-column insulator, the apparatus includes a processor and a memory for storing a computer program executable by the processor, and the processor, when executing the computer program stored in the memory, implements the following operations:
acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
obtaining a vertical stress acoustoelastic equation of the material sample to be measured according to the first propagation time;
acquiring the propagation time of ultrasonic longitudinal waves in the column leg under the radial load of the three-column insulator to be detected as second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected;
and calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustoelastic equation.
Example 4:
as shown in fig. 11, this embodiment provides a system for detecting column leg stress under a radial load of a three-column insulator, where the system includes a three-column insulator 1101 to be detected, a tensile machine 1102, an ultrasonic detection system 1103, and a device 1104 for detecting column leg stress under a radial load of a three-column insulator, where:
the ultrasonic detection system comprises two ultrasonic longitudinal wave straight probes, an oscilloscope, two ultrasonic longitudinal wave straight probes, a probe adapting line and a high-impedance transmission line, wherein the two ultrasonic longitudinal wave straight probes are connected with the output end and the signal input end of the ultrasonic pulse generator through the probe adapting line, and the signal synchronization end of the ultrasonic pulse generator is connected with the oscilloscope through the high-impedance transmission line.
The three-post insulator post leg to be tested is arranged on a tensile machine, an ultrasonic pulse generator is adjusted, and two ultrasonic longitudinal wave straight probes coated with an oil-based ultrasonic coupling agent are symmetrically and coaxially arranged at two ends of the three-post insulator post leg to be tested.
The device for detecting the stress of the column leg under the radial load of the three-column insulator is the device described in the embodiment 2 or 3.
Example 5:
the present embodiment provides a storage medium, which is a computer-readable storage medium, and stores a program, which when executed by a processor, implements the following operations:
acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
obtaining a vertical stress acoustoelastic equation of the material sample to be measured according to the first propagation time;
acquiring the propagation time of ultrasonic longitudinal waves in the column leg under the radial load of the three-column insulator to be detected as second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected;
and calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustoelastic equation.
It should be noted that the computer readable storage medium of the present embodiment may be a computer readable signal medium or a computer readable storage medium or any combination of the two. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples of the computer readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
In conclusion, the invention provides a method for detecting column leg stress under radial load of a three-column insulator, and an ultrasonic detection system is built by the method. And acquiring the propagation time of the ultrasonic longitudinal wave in the epoxy composite material standard sample for the three-post insulator by using an ultrasonic detection system, and calculating the vertical stress acoustic-elastic coefficient of the epoxy composite material standard sample for the three-post insulator to obtain the acoustic-elastic equation of the vertical stress of the epoxy composite material. And then, acquiring the propagation time of the ultrasonic longitudinal wave in the column leg under the radial load of the three-column insulator to be detected by using an ultrasonic detection system for the column leg under the radial load of the three-column insulator. And calculating the sound velocity in the ultrasonic sound path at the detection position. And finally, substituting the obtained ultrasonic sound velocity into an acoustic elasticity equation, and calculating to obtain the column leg stress of the three-column insulator under the radial load. The method has the advantages of low detection cost, high detection precision, convenience in carrying, no radiation to a human body and the like, and can efficiently, visually and nondestructively detect the column leg stress under the radial load of the three-column insulator.
The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the scope of the present invention.
Claims (10)
1. A method for detecting column leg stress under radial load of a three-column insulator is characterized by comprising the following steps:
acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected through an ultrasonic detection system as first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
obtaining a vertical stress acoustoelastic equation of the material sample to be measured according to the first propagation time;
acquiring the propagation time of ultrasonic longitudinal waves in the column leg under the radial load of the three-column insulator to be detected as second propagation time through an ultrasonic detection system in the detection range of the three-column insulator to be detected;
and calculating the stress of the column leg under the radial load of the three-column insulator to be tested according to the second propagation time and the vertical stress acoustoelastic equation.
2. The detection method according to claim 1, wherein obtaining the vertical stress acoustoelastic equation of the material sample to be detected according to the first propagation time specifically comprises:
according to the sound path d1 of the ultrasonic longitudinal wave in the material sample to be measured and the first propagation time t under the load F1Calculating the ultrasonic sound velocity V1The calculation formula is as follows:
according to the obtained ultrasonic sound velocity V1The vertical stress acoustic elastic coefficient K is calculated by the following formula:
wherein, V0Is zero stress sigma0The sound velocity of the time, measuring the sigma of the material sample to be measured0Lower ultrasonic longitudinal sound velocity V02997.02 m/s; if the external load F is uniformly distributed over the stressed area, the stress sigma1The relation with the applied load F is that F is sigma1d1d2(ii) a d1 and d2 are respectively the length and the height of the material sample to be detected;
and (3) returning the obtained vertical stress acoustic-elastic coefficient K to be substituted into the formula (2) to obtain a vertical stress acoustic-elastic equation of the material sample to be measured, wherein the equation is as follows:
wherein V is the ultrasonic sound velocity.
3. The method of claim 1, wherein the three post insulator comprises a solid epoxy, a center conductor, and ground inserts, the solid epoxy comprising legs, each leg having a bottom portion coupled to one of the ground inserts;
the detection range of the three-post insulator leg to be detected is as follows: the stress direction in the range is vertical to the ultrasonic propagation direction of the part in the set value above the interface of the three-post insulator leg to be tested and the corresponding grounding insert.
4. The detection method according to claim 1, wherein the calculating the stress of the leg under the radial load of the three-post insulator to be detected according to the second propagation time and the vertical stress acoustoelastic equation specifically includes:
calculating an ultrasonic sound velocity V according to a sound path D of ultrasonic longitudinal waves transmitted on a three-post insulator leg to be measured and a second transmission time t under a load F, wherein the calculation formula is as follows:
and substituting the obtained ultrasonic sound velocity V into a vertical stress acoustoelastic equation to obtain the stress of the position to be measured of the column leg under the radial load of the three-column insulator.
5. The detection method according to claim 1, wherein the ultrasonic detection system comprises an ultrasonic pulse generator, an oscilloscope, ultrasonic longitudinal straight probes, probe adaptation wires and a high-impedance transmission line, wherein the two ultrasonic longitudinal straight probes are respectively connected with a signal output end and a signal input end of the ultrasonic pulse generator through the probe adaptation wires, and a signal synchronization end of the ultrasonic pulse generator is connected with the oscilloscope through the high-impedance transmission line;
when the first propagation time is obtained, adjusting an ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with an oil-based ultrasonic coupling agent at two ends of a material sample to be measured, which is installed between an upper plate and a bottom plate of a universal testing machine, so as to record the propagation time of the ultrasonic longitudinal wave in the material sample to be measured as the first propagation time;
and when the second propagation time is obtained, adjusting the ultrasonic pulse generator, symmetrically and coaxially placing two ultrasonic longitudinal wave straight probes coated with the oil-based ultrasonic couplant at two ends of the three-column insulator leg to be measured, which is installed on the tensile machine, so as to record the propagation time of the ultrasonic longitudinal wave in the three-column insulator leg to be measured, wherein the propagation time is used as the second propagation time.
6. The detection method according to claim 5, wherein the first propagation time is: an ultrasonic primary wave is emitted by one ultrasonic longitudinal wave straight probe at one side of a material sample to be detected, the ultrasonic primary wave is vertically incident into the material sample to be detected, a penetrating wave is received by the other ultrasonic longitudinal wave straight probe at a corresponding position at the other side of the material sample to be detected, and the starting oscillation time difference of the ultrasonic primary wave and the penetrating wave is the propagation time of the ultrasonic longitudinal wave at the position to be detected.
7. The detection method according to claim 5, wherein the second propagation time is: an ultrasonic longitudinal wave straight probe sends out ultrasonic initial waves at one side of a three-post insulator leg to be detected, the ultrasonic initial waves vertically enter the three-post insulator leg to be detected, penetrating waves are received by another ultrasonic longitudinal wave straight probe at a corresponding position at the other side of the three-post insulator leg to be detected, and the starting vibration time difference of the ultrasonic initial waves and the penetrating waves is the propagation time of the ultrasonic longitudinal waves at the position to be detected.
8. A device for detecting column leg stress under radial load of a three-column insulator is characterized by comprising:
the first propagation time acquisition module is used for acquiring the propagation time of the ultrasonic longitudinal wave in the material sample to be detected under the radial load through the ultrasonic detection system, and the propagation time is used as the first propagation time; the material and the process of the material sample to be tested are the same as those of the three-pillar insulator leg;
the vertical stress acoustic-elastic equation acquisition module is used for acquiring a vertical stress acoustic-elastic equation of the material sample to be measured according to the first propagation time;
the second propagation time acquisition module is used for acquiring the propagation time of the ultrasonic longitudinal wave in the column leg under the radial load of the three-column insulator to be detected as second propagation time through the ultrasonic detection system in the detection range of the three-column insulator to be detected;
and the stress calculation module of the column leg under the radial load is used for calculating the stress of the column leg under the radial load of the three-column insulator to be measured according to the second propagation time and the vertical stress acoustoelastic equation.
9. An apparatus for detecting leg stress under a radial load of a three-post insulator, the apparatus comprising a processor and a memory for storing a program executable by the processor, wherein the processor, when executing the program stored in the memory, implements the detection method of any one of claims 1 to 7.
10. The utility model provides a detecting system of post leg stress under three post insulators radial load which characterized in that, the system includes the detecting device of post leg stress under three post insulators, the pulling force machine that await measuring, ultrasonic testing system and three post insulators radial load, wherein:
the ultrasonic detection system comprises an ultrasonic pulse generator, an oscilloscope, two ultrasonic longitudinal straight probes, a probe adapting line and a high-impedance transmission line, wherein the two ultrasonic longitudinal straight probes are respectively connected with the signal output end and the signal input end of the ultrasonic pulse generator through the probe adapting line;
the three-post insulator leg to be tested is arranged on the tensile machine, the ultrasonic pulse generator is adjusted, and the two ultrasonic longitudinal wave straight probes coated with the oil-based ultrasonic coupling agent are symmetrically and coaxially arranged at two ends of the three-post insulator leg to be tested;
the device for detecting the stress of the column leg under the radial load of the three-column insulator is as claimed in any one of claims 8 to 9.
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