CN214952099U - Intelligent piezoelectric gasket embedded with inclined fibers - Google Patents
Intelligent piezoelectric gasket embedded with inclined fibers Download PDFInfo
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- CN214952099U CN214952099U CN202022915601.9U CN202022915601U CN214952099U CN 214952099 U CN214952099 U CN 214952099U CN 202022915601 U CN202022915601 U CN 202022915601U CN 214952099 U CN214952099 U CN 214952099U
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Abstract
The utility model discloses a fibrous piezoelectricity intelligence gasket of embedded slope, piezoelectricity intelligence gasket includes casing and embedded slope fibre piezoelectric sensor, the casing is become by "positive shape" gasket and "negative shape" gasket cooperation formation circumference ring channel with one heart, embedded slope fibre piezoelectric sensor comprises piezoelectric fiber combined material, electrode layer, insulating barrier, and the structure is the annular, arranges to install in casing circumference ring channel. The piezoelectric fiber composite material is formed by solidifying a plurality of piezoelectric fiber rods which keep a certain inclination angle with the horizontal plane in an epoxy resin matrix; the piezoelectric intelligent gasket is used in bolt connection, senses information such as stress-strain change of a bolt connecting piece and the like, and realizes real-time monitoring of bolt loosening state.
Description
Technical Field
The utility model relates to an embedded fibrous piezoelectricity intelligence gasket of slope.
Background
The structural damage monitoring is a novel application field containing innovation, is a key for equipment production quality management and operation safety monitoring, and has important engineering significance and application value for ensuring the integrity and the working safety of an equipment structure. The method comprises the steps of sensing relevant information of the health state of the structure on line through a sensing network, transmitting, collecting and processing data by using methods such as data collection, signal analysis and the like to obtain a characteristic value of a sensing signal, comparing the characteristic value with the health signal, diagnosing and identifying the current state of the structure, predicting failure modes and service life of the structure, evaluating damage conditions of the structure, and reducing maintenance cost by using a means of operation and maintenance according to conditions. The special advantages of the compound are widely used and are favored by researchers at home and abroad.
Piezoelectric materials have the ability to interconvert mechanical and electrical energy, a characteristic referred to as piezoelectric effect or electromechanical coupling effect. The inherent electromechanical coupling effect is manufactured into a sensing component which is widely applied to structural health monitoring, but the traditional piezoelectric element is fragile in texture and small in strain amount and is easy to crack due to overlarge stress, so that the flexible piezoelectric sensor with excellent performance is necessary to be designed to adapt to various structural damage monitoring fields. The piezoelectric sensors are arranged on the surface of the structure or embedded in the structure in a networking mode, information such as the structure state, operation and service environment can be obtained, the sensing information diagnosis result is further used for structure health condition prejudgment and auxiliary maintenance and maintenance decision, structural damage monitoring is achieved, and structural integrity is guaranteed.
The sensor arrangement structure has the defects that the surface of the sensor arrangement structure is exposed in the external environment, is easily interfered by environmental factors, influences the service life and the like, and the sensor is embedded into the structure, so that the structure is easily damaged, the transformation process is complex, and repeated installation cannot be carried out. Most structures are connected with equipment through bolts, and the device has the important advantages of being detachable and reusable, and is widely applied to the fields of rail transit equipment, buildings, aerospace and the like. Install the sensor respectively in distributed network deployment bolt fastener, carry out the transmission of structural state information through the contact surface that exists between each by the connecting piece, can effectively detect structural state change, save sensor arrangement space, reduce environmental factor and disturb, can also in time monitor the not hard up state of bolt simultaneously.
Therefore, aiming at the field of structural damage monitoring, from the perspective of a new sensor technology, the arrangement form of the sensor is changed, and the piezoelectric intelligent gasket which is real and effective, is convenient to operate and can monitor the structural state of a connected workpiece in real time is necessary, and meanwhile, the monitoring of the bolt loosening failure state can be realized, so that the structural health state maintenance is facilitated, and the reliability of bolt connection is guaranteed.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a fibrous piezoelectricity intelligence gasket of embedded slope aims at utilizing the gasket structure with embedded slope fibre piezoelectric sensor and bolt to integrate, overcomes to paste and easily receives external environment factor to influence the degrading performance and imbed structure internal sensor at the sensor on structure surface and be difficult to change, difficult problems such as embedding technology is complicated. And respectively installing the prefabricated embedded inclined fiber piezoelectric intelligent gasket into each bolt fastener of the tested structure to form a distributed sensing network. The embedded inclined fiber piezoelectric sensor senses information such as stress-strain change of a connected workpiece structure, real-time monitoring of structural damage is achieved, meanwhile, change of bolt pretightening force can be monitored, the bolt loosening failure state is judged, the arrangement space of the sensor is saved, the sensor is easy to replace, and the service life of the sensor is prolonged.
In order to realize the purpose, the utility model discloses a technical scheme is: the utility model provides a fibrous piezoelectricity intelligence gasket of embedded slope, includes casing and embedded slope fibre piezoelectric sensor, the casing forms the circumference ring channel by "positive shape" gasket and "negative shape" gasket concentric cooperation and forms and constitutes, embedded slope fibre piezoelectric sensor structure is the annular, arranges to install in the circumference ring channel, comprises piezoelectric fiber combined material, electrode layer, insulating shielding layer, piezoelectric fiber combined material is including slope piezoelectric fiber stick, epoxy.
Furthermore, the 'male' gasket is provided with a semi-annular boss, and the center of the other semi-annular boss is provided with a cylindrical pin; the female gasket is provided with a semi-annular boss, and a round hole is formed in the center of the semi-annular boss; the cylindrical pin is in clearance fit with the round hole, and the depth of the cylindrical pin is higher than that of the round hole; the semi-annular boss of the male gasket is meshed with the semi-annular boss of the female gasket, and the cylindrical pin and the circular hole are assembled in a clearance fit mode to form a shell with a circumferential annular groove.
Furthermore, the inclined piezoelectric fiber rods are inclined at a certain angle on the horizontal plane, and are arranged in an annular array and embedded in the inclined fiber piezoelectric sensors; the epoxy resin is filled around the inclined piezoelectric fibers as a protective layer to form a piezoelectric fiber composite material with an annular structure; the electrode layer comprises an upper electrode layer and a lower electrode layer, and lead terminals are respectively arranged on the upper electrode layer and the lower electrode layer; the insulation shielding layer comprises an upper insulation shielding layer and a lower insulation shielding layer; the structure layers of the embedded inclined fiber piezoelectric sensor are an upper insulation shielding layer, an upper electrode layer, a piezoelectric fiber composite material, a lower electrode layer and a lower insulation shielding layer from top to bottom in sequence, and the embedded inclined fiber piezoelectric sensor with the central through hole is formed by concentric matching.
Further, the shell material is selected according to the matched bolt and working conditions; the height of the circumferential annular groove is 1/3-1/2 of the total height of the piezoelectric intelligent gasket; the height of the embedded inclined fiber piezoelectric sensor is equal to or slightly greater than that of the circumferential annular groove; the embedded inclined fiber piezoelectric sensor is of an annular structure, and the diameter of a central through hole of the embedded inclined fiber piezoelectric sensor is equal to or slightly larger than the diameter of a bolt hole; the inclination angle of the inclined piezoelectric fiber rod is 0-180 degrees, and can be selected according to the performance requirement of the required sensor; the epoxy resin is formed by mixing and solidifying epoxy resin glue and a curing agent, and has certain flexibility and weather resistance; the electrode layer is made of a material with excellent conductivity; the insulating shielding layer is a thin film material with good thermosetting property, and a layer of semi-conductive material is added on the surface of the thin film material.
An application method of a piezoelectric intelligent gasket with embedded inclined fibers is characterized in that:
the prefabricated embedded inclined fiber piezoelectric intelligent gasket is respectively installed in each bolt fastener of a tested structure to form a distributed sensing network, and a torque wrench is adopted to screw the threaded fastener to a pre-tightening set value, so that the contact surface between connected pieces can well transmit structural state information. A fixed excitation point is set in a measured structure for excitation, excitation information is converted into state information such as structural stress strain, the structural state information is transmitted to a piezoelectric intelligent gasket through a connecting interface of a bolt fastener, at the moment, an embedded inclined fiber piezoelectric sensor in the piezoelectric intelligent gasket converts the stress strain information into an electric signal by utilizing the electromechanical coupling characteristic of the piezoelectric intelligent gasket and outputs the electric signal to a signal acquisition end, and whether the measured structural part is damaged or not can be judged by comparing and analyzing the signal characteristic quantity acquired by the piezoelectric intelligent gasket in different bolt fasteners and the signal difference between the front and the back through related signal analysis technologies (such as a flight time method, a time reversal method, a tomography method and the like), and the damage type and the damage position can be judged, so that the structural damage monitoring is realized. The piezoelectric intelligent gasket embedded with the inclined fibers can also monitor loosening and failure of the installed bolt in real time, and when characteristic quantities such as signal amplitude received by a sensing point in a distributed sensing network are reduced or signal distortion occurs, the sensor is possibly damaged or the bolt fastener where the sensor is located is loosened or fails. The tightness of the bolt can be judged by monitoring the admittance signal value of the piezoelectric intelligent gasket according to the change of the pretightening force along with the change of the admittance signal value of the piezoelectric sensor.
Compared with the prior art, the beneficial effects of the utility model are that:
(1) the utilization is integrated with the gasket structure of embedded inclined fiber piezoelectric sensor and bolt, and the problems that the sensor adhered to the surface of the structure is easily influenced by external environmental factors to reduce performance, the sensor embedded in the structure is difficult to replace, the embedding process is complex and the like are overcome. And respectively installing the prefabricated embedded inclined fiber piezoelectric intelligent gasket into each bolt fastener of the tested structure to form a distributed sensing network. The embedded inclined fiber piezoelectric sensor senses information such as stress-strain change of a connected workpiece structure, real-time monitoring of structural damage is achieved, meanwhile, change of bolt pretightening force can be monitored, the bolt loosening failure state is judged, the arrangement space of the sensor is saved, the sensor is easy to replace, and the service life of the sensor is prolonged.
(2) This embedded slope fibre piezoelectric sensor fills through embedded slope piezoelectric fiber stick that has good performance and adoption epoxy, has certain pliability in general piezoelectric element, overcomes other flexible sensor like: PVDF, 0-3 type piezoelectric composite materials and the like have poor environmental adaptability, low piezoelectric constant and the like. The design piezoelectricity fiber rod is followed the certain angle slope of horizontal plane, can decompose into perpendicular power and tangential force with the power that bolt pretension power was used in on the slope piezoelectricity fibre, avoids causing the sensing element to become invalid because of the too big piezoelectricity fibre fracture that leads to of loading pretightning force, can bear certain impact, improves life. A plurality of inclined piezoelectric fiber rod annular arrays are connected in parallel, so that the structural state information sensing capability is improved, and the problems of uncertainty of signals and the like are effectively avoided.
(3) The semi-annular boss structure of the prefabricated 'male' gasket is meshed with the semi-annular boss structure of the 'female' gasket, so that the aim of resisting torque can be fulfilled, and the embedded fiber piezoelectric sensor is prevented from being damaged in the bolt pre-tightening process; meanwhile, the cylindrical pin in the 'male' gasket is in clearance fit with the circular hole in the 'female' gasket semi-annular boss structure, so that the 'male' gasket and the 'female' gasket are prevented from sliding relatively to influence the pre-tightening effect of the whole bolt fastener, and the 'male' gasket and the 'female' gasket are prevented from sliding relatively to damage the structure of the embedded fiber piezoelectric sensor.
Drawings
Fig. 1 is a schematic structural view of an embedded inclined fiber piezoelectric intelligent gasket of the present invention;
fig. 2 is an exploded view of the structure of the intelligent piezoelectric spacer with embedded inclined fibers of the present invention;
FIG. 3 is a schematic view of the housing structure of the present invention;
FIG. 4 is a top view of the "male" spacer structure of the present invention;
FIG. 5 is a top view of the "female" spacer structure of the present invention;
fig. 6 is a schematic structural view of the embedded inclined fiber piezoelectric sensor of the present invention.
In the figure: 1. a housing; 2. an embedded inclined fiber piezoelectric sensor; 11. a "male" pad; 12. a "female" pad; 13. a circumferential annular groove; 21. an upper insulating shield layer; 22. an upper electrode layer; 23; a piezoelectric fiber composite; 24. a lower electrode layer; 25. a lower insulating shield layer; 111. a semi-annular boss of the 'male' gasket; 112. a cylindrical pin; 121. a semi-annular boss of a 'female' gasket; 122. a circular hole; 221. a first lead wire terminal; 241. a second lead terminal; 231. tilting the piezoelectric fiber rod; 232. and (3) epoxy resin.
Detailed Description
In order to make the technical solution of the present invention better understood, the present invention is described in detail below with reference to the accompanying drawings, and the description of the present invention is only exemplary and explanatory, and should not be construed as limiting the scope of the present invention.
As shown in fig. 1-6, an embedded oblique fiber piezoelectric intelligent gasket comprises a shell 1 and an embedded oblique fiber piezoelectric sensor 2, wherein the shell 1 is formed by concentrically matching a 'male' gasket 11 and a 'female' gasket 12 to form a circumferential annular groove 13, the embedded oblique fiber piezoelectric sensor 2 is annular in structure, is arranged and installed in the circumferential annular groove 13, and is composed of a piezoelectric fiber composite material 23, electrode layers 22 and 24, and insulating shielding layers 21 and 25, and the piezoelectric fiber composite material 23 comprises an oblique piezoelectric fiber rod 231 and epoxy resin 232.
Preferably, the "male" gasket 11 is provided with a semi-annular boss 111, and a cylindrical pin 112 is arranged at the center of the other semi-annular boss; the female gasket 12 is provided with a semi-annular boss 121, and a round hole 122 is arranged at the center of the semi-annular boss 121; the cylindrical pin 112 is in clearance fit with the round hole 122, and the cylindrical pin 112 is higher than the round hole 122; the semi-annular boss 111 of the "male" gasket 11 is meshed with the semi-annular boss 121 of the "female" gasket 12, and the cylindrical pin 112 is in clearance fit with the circular hole 122 to form the shell 1 with the circumferential annular groove 13.
Preferably, the inclined piezoelectric fiber rods 231 are inclined at a certain angle in the horizontal plane, and are arranged in an annular array and embedded in the inclined fiber piezoelectric sensor 2; the epoxy resin 232 is filled around the inclined piezoelectric fiber rod 231 as a protective layer to form the piezoelectric fiber composite material 23 with an annular structure; the electrode layers comprise an upper electrode layer 22 and a lower electrode layer 24 which are respectively provided with a first lead terminal 221 and a second lead terminal 241; the insulation shielding layer comprises an upper insulation shielding layer 21 and a lower insulation shielding layer 25; the embedded inclined fiber piezoelectric sensor 2 is composed of an upper insulating shielding layer 21, an upper electrode layer 22, a piezoelectric fiber composite material 23, a lower electrode layer 24 and a lower insulating shielding layer 25 which are sequentially arranged from top to bottom in a structural hierarchy, and the annular embedded inclined fiber piezoelectric sensor 2 with a central through hole is formed in a concentric matching mode.
Preferably, the material of the shell 1 is selected according to the matched bolt and working conditions; the height of the circumferential annular groove 13 is 1/3-1/2 of the total height of the piezoelectric intelligent gasket; the height of the embedded inclined fiber piezoelectric sensor 2 is equal to or slightly greater than that of the circumferential annular groove 13; the embedded inclined fiber piezoelectric sensor 2 is of an annular structure, and the diameter of a central through hole is equal to or slightly larger than that of a bolt hole; the epoxy resin 232 is formed by mixing and solidifying epoxy resin glue and a curing agent, and has certain flexibility and weather resistance; the upper electrode layer 22 and the lower electrode layer 24 are made of materials with excellent conductivity; the upper insulation shielding layer 21 and the lower insulation shielding layer 25 are thermosetting thin film materials with a layer of semi-conductive material added on the surface.
An application method of a piezoelectric intelligent gasket with embedded inclined fibers is characterized in that:
the prefabricated embedded inclined fiber piezoelectric intelligent gasket is respectively installed in each bolt fastener of a tested structure to form a distributed sensing network, and a torque wrench is adopted to screw the threaded fastener to a pre-tightening set value, so that the contact surface between connected pieces can well transmit structural state information. A fixed excitation point is set in a measured structure for excitation, excitation information is converted into state information such as structural stress strain, the structural state information is transmitted to a piezoelectric intelligent gasket through a connecting interface of a bolt fastener, at the moment, an embedded inclined fiber piezoelectric sensor 2 in the piezoelectric intelligent gasket converts the stress strain information into an electric signal by utilizing the electromechanical coupling characteristic of the piezoelectric intelligent gasket and outputs the electric signal to a signal acquisition end, and whether a measured structural part is damaged or not can be judged by comparing and analyzing signal characteristic quantity acquired by the piezoelectric intelligent gasket in different bolt fasteners and signal difference between the front and the back through related signal analysis technologies (such as a flight time method, a time reversal method, a tomography method and the like), and the damage type and position are judged, so that the structural damage monitoring is realized. The piezoelectric intelligent gasket embedded with the inclined fibers can also monitor loosening and failure of the installed bolt in real time, and when characteristic quantities such as signal amplitude received by a sensing point in a distributed sensing network are reduced or signal distortion occurs, the sensor is possibly damaged or the bolt fastener where the sensor is located is loosened or fails. The tightness of the bolt can be judged by monitoring the admittance signal value of the piezoelectric intelligent gasket according to the change of the pretightening force along with the change of the admittance signal value of the piezoelectric sensor.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The principles and embodiments of the present invention have been explained herein using specific examples, which are presented only to assist in understanding the methods and their core concepts. The foregoing is only a preferred embodiment of the present invention, and it should be noted that there are objectively infinite specific structures due to the limited character expressions, and it will be apparent to those skilled in the art that a plurality of modifications, decorations or changes can be made without departing from the principle of the present invention, and the above technical features can be combined in a proper manner; the application of these modifications, variations or combinations, or the application of the concepts and solutions of the present invention in other contexts without modification, is not intended to be considered as a limitation of the present invention.
Claims (4)
1. The utility model provides an embedded fibrous piezoelectricity intelligence gasket that inclines which characterized in that: the piezoelectric intelligent gasket comprises a shell and an embedded inclined fiber piezoelectric sensor, wherein the shell is formed by forming a circumferential annular groove by concentrically matching a 'male' gasket and a 'female' gasket, the embedded inclined fiber piezoelectric sensor is annular, is arranged and installed in the circumferential annular groove and comprises a piezoelectric fiber composite material, an electrode layer and an insulation shielding layer, and the piezoelectric fiber composite material comprises an inclined piezoelectric fiber rod and epoxy resin.
2. The piezoelectric intelligent gasket with embedded oblique fibers as claimed in claim 1, wherein: the male gasket is provided with a semi-annular boss, and the center of the other semi-annular boss is provided with a cylindrical pin; the female gasket is provided with a semi-annular boss, and a round hole is formed in the center of the semi-annular boss; the cylindrical pin is in clearance fit with the round hole, and the height of the cylindrical pin is equal to the depth of the round hole; the semi-annular boss of the 'male' gasket is meshed with the semi-annular boss of the 'female' gasket, and the cylindrical pin and the circular hole are matched and assembled to form a shell with a circumferential annular groove.
3. The piezoelectric intelligent gasket with embedded oblique fibers as claimed in claim 1, wherein: the inclined piezoelectric fiber rods are inclined at a certain angle on the horizontal plane, and the annular array is embedded in the epoxy resin matrix; the epoxy resin is filled around the inclined piezoelectric fibers as a protective layer to form a piezoelectric fiber composite material with an annular structure; the electrode layer comprises an upper electrode layer and a lower electrode layer, and lead terminals are respectively arranged on the upper electrode layer and the lower electrode layer; the insulation shielding layer comprises an upper insulation shielding layer and a lower insulation shielding layer; the structure layers of the embedded inclined fiber piezoelectric sensor are an upper insulation shielding layer, an upper electrode layer, a piezoelectric fiber composite material, a lower electrode layer and a lower insulation shielding layer from top to bottom in sequence, and the embedded inclined fiber piezoelectric sensor with the central through hole is formed by concentric matching.
4. The piezoelectric intelligent gasket with embedded oblique fibers as claimed in claim 1, wherein: the height of the circumferential annular groove is 1/3-1/2 of the total height of the piezoelectric intelligent gasket; the height of the embedded inclined fiber piezoelectric sensor is equal to or slightly greater than that of the circumferential annular groove; the embedded inclined fiber piezoelectric sensor is of an annular structure, and the diameter of a central through hole of the embedded inclined fiber piezoelectric sensor is equal to or slightly larger than the diameter of a bolt hole; the inclination angle of the inclined piezoelectric fiber rod and the horizontal plane is within 0-180 degrees; the epoxy resin is formed by mixing and solidifying epoxy resin glue and a curing agent, and has certain flexibility and weather resistance; the electrode layer is made of a material with excellent conductivity; the insulating shielding layer is a thin film material with good thermosetting property, and a layer of semi-conductive material is added on the surface of the thin film material.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202022915601.9U CN214952099U (en) | 2020-12-08 | 2020-12-08 | Intelligent piezoelectric gasket embedded with inclined fibers |
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| CN202022915601.9U CN214952099U (en) | 2020-12-08 | 2020-12-08 | Intelligent piezoelectric gasket embedded with inclined fibers |
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| CN214952099U true CN214952099U (en) | 2021-11-30 |
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| CN202022915601.9U Active CN214952099U (en) | 2020-12-08 | 2020-12-08 | Intelligent piezoelectric gasket embedded with inclined fibers |
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